1. |
- Andrews, B. J., et al.
(author)
-
Quantitative human cell encyclopedia
- 2016
-
In: Science Signaling. - : American Association for the Advancement of Science (AAAS). - 1945-0877 .- 1937-9145. ; 9:443
-
Journal article (peer-reviewed)abstract
- Scientists gathered to discuss the necessity, feasibility, and challenges of generating a quantitative catalog of the components in human cells that is essential for our understanding of human physiology in health and disease and to support future breakthroughs in treating diseases. This report summarizes the discussion that emerged at the Human Quantitative Dynamics Workshop held in Bethesda, MD, USA, in December 2015.
|
|
2. |
|
|
3. |
|
|
4. |
- Baltanas, R., et al.
(author)
-
Pheromone-Induced Morphogenesis Improves Osmoadaptation Capacity by Activating the HOG MAPK Pathway
- 2013
-
In: Science Signaling. - : American Association for the Advancement of Science (AAAS). - 1937-9145 .- 1945-0877. ; 6:272
-
Journal article (peer-reviewed)abstract
- Environmental and internal conditions expose cells to a multiplicity of stimuli whose consequences are difficult to predict. We investigate the response to mating pheromone of yeast cells adapted to high osmolarity. Events downstream of pheromone binding involve two mitogen-activated protein kinase (MAPK) cascades: the pheromone response (PR) and the cell wall integrity (CWI) response. Although the PR MAPK pathway shares components with a third MAPK pathway, the high osmolarity (HOG) response, each one is normally only activated by its cognate stimulus, a phenomenon called insulation. We found that in cells adapted to high osmolarity, PR activated the HOG pathway in a pheromone- and osmolarity-dependent manner. Activation of HOG by the PR was not due to loss of insulation, but rather a response to a reduction in internal osmolarity, which resulted from an increase in glycerol release caused by the PR. By analyzing single-cell time courses, we found that stimulation of HOG occurred in discrete bursts that coincided with the "shmooing" morphogenetic process. Activation required the polarisome, the CWI MAPK Slt2, and the aquaglyceroporin Fps1. HOG activation resulted in high glycerol turnover, which improved adaptability to rapid changes in osmolarity. Our work shows how a differentiation signal can recruit a second, unrelated sensory pathway to fine-tune yeast response in a complex environment.
|
|
5. |
- Bozhkov, Peter, et al.
(author)
-
Aspasing Out Metacaspases and Caspases: Proteases of Many Trades
- 2010
-
In: Science Signaling. - : American Association for the Advancement of Science (AAAS). - 1945-0877 .- 1937-9145. ; 3
-
Journal article (peer-reviewed)abstract
- Execution of programmed cell death (PCD) in nonmetazoan organisms is morphologically different from apoptotic PCD in animals and lacks a number of key molecular components of apoptotic machinery, including caspases. Yet protozoan, fungal, and plant cells exhibit caspase-like proteolytic activities, which increase in a PCD-dependent manner. This poses a question whether nonmetazoan organisms contain structurally dissimilar proteases that functionally substitute for caspases. Putative ancestors of caspases, metacaspases, are candidates for this role; however, their distinct substrate specificity raises doubts. The identification of a common biological target of caspases and metacaspases and previously unknown functions unrelated to cell death of metacaspases provide new food for thought.
|
|
6. |
- Breasson, Ludovic, et al.
(author)
-
PI3Kγ activity in leukocytes promotes adipose tissue inflammation and early-onset insulin resistance during obesity.
- 2017
-
In: Science signaling. - : American Association for the Advancement of Science (AAAS). - 1937-9145 .- 1945-0877. ; 10:488
-
Journal article (peer-reviewed)abstract
- The phosphoinositide 3-kinase γ (PI3Kγ) plays a major role in leukocyte recruitment during acute inflammation and has been proposed to inhibit classical macrophage activation by driving immunosuppressive gene expression. PI3Kγ plays an important role in diet-induced obesity and insulin resistance. In seeking to determine the underlying molecular mechanisms, we showed that PI3Kγ action in high-fat diet-induced inflammation and insulin resistance depended largely on its role in the control of adiposity, which was due to PI3Kγ activity in a nonhematopoietic cell type. However, PI3Kγ activity in leukocytes was required for efficient neutrophil recruitment to adipose tissue. Neutrophil recruitment was correlated with proinflammatory gene expression in macrophages in adipose tissue, which triggered insulin resistance early during the development of obesity. Our data challenge the concept that PI3Kγ is a general suppressor of classical macrophage activation and indicate that PI3Kγ controls macrophage gene expression by non-cell-autonomous mechanisms, the outcome of which is context-dependent.
|
|
7. |
- Brownlie, Rebecca J., et al.
(author)
-
Lack of the Phosphatase PTPN22 Increases Adhesion of Murine Regulatory T Cells to Improve Their Immunosuppressive Function
- 2012
-
In: Science Signaling. - : American Association for the Advancement of Science (AAAS). - 1937-9145 .- 1945-0877. ; 5:252, s. 87-87
-
Journal article (peer-reviewed)abstract
- The cytoplasmic phosphatase PTPN22 (protein tyrosine phosphatase nonreceptor type 22) plays a key role in regulating lymphocyte homeostasis, which ensures that the total number of lymphocytes in the periphery remains relatively constant. Mutations in PTPN22 confer an increased risk of developing autoimmune diseases; however, the precise function of PTPN22 and how mutations contribute to auto-immunity remain controversial. Loss-of-function mutations in PTPN22 are associated with increased numbers of effector T cells and autoreactive B cells in humans and mice; however, the complete absence of PTPN22 in mice does not result in spontaneous autoimmunity. We found that PTPN22 was a key regulator of regulatory T cell (T-reg) function that fine-tuned the signaling of the T cell receptor and integrins. PTPN22(-/-) T-regs were more effective at immunosuppression than were wild-type T-regs, and they suppressed the activity of PTPN22(-/-) effector T cells, preventing autoimmunity. Compared to wildtype T-regs, PTPN22(-/-) T-regs produced increased amounts of the immunosuppressive cytokine interleukin-10 and had enhanced adhesive properties mediated by the integrin lymphocyte function-associated antigen-1, processes that are critical for T-reg function. This previously undiscovered role of PTPN22 in regulating integrin signaling and T-reg function suggests that PTPN22 may be a useful therapeutic target for manipulating T-reg function in human disease.
|
|
8. |
- Burn, Garth L., et al.
(author)
-
Superresolution imaging of the cytoplasmic phosphatase PTPN22 links integrin-mediated T cell adhesion with autoimmunity
- 2016
-
In: Science Signaling. - : American Association for the Advancement of Science (AAAS). - 1945-0877 .- 1937-9145. ; 9:448
-
Journal article (peer-reviewed)abstract
- Integrins are heterodimeric transmembrane proteins that play a fundamental role in the migration of leukocytes to sites of infection or injury. We found that protein tyrosine phosphatase nonreceptor type 22 (PTPN22) inhibits signaling by the integrin lymphocyte function-associated antigen-1 (LFA-1) in effector T cells. PTPN22 colocalized with its substrates at the leading edge of cells migrating on surfaces coated with the LFA-1 ligand intercellular adhesion molecule-1 (ICAM-1). Knockout or knockdown of PTPN22 or expression of the autoimmune disease-associated PTPN22-R620W variant resulted in the enhanced phosphorylation of signaling molecules downstream of integrins. Superresolution imaging revealed that PTPN22-R620 (wild-type PTPN22) was present as large clusters in unstimulated T cells and that these disaggregated upon stimulation of LFA-1, enabling increased association of PTPN22 with its binding partners at the leading edge. The failure of PTPN22-R620W molecules to be retained at the leading edge led to increased LFA-1 clustering and integrin-mediated cell adhesion. Our data define a previously uncharacterized mechanism for fine-tuning integrin signaling in T cells, as well as a paradigm of auto-immunity in humans in which disease susceptibility is underpinned by inherited phosphatase mutations that perturb integrin function. 2016
|
|
9. |
- Cantù, Claudio, et al.
(author)
-
A cytoplasmic role of Wnt/β-catenin transcriptional cofactors Bcl9, Bcl9l, and Pygopus in tooth enamel formation.
- 2017
-
In: Science Signaling. - : American Association for the Advancement of Science (AAAS). - 1945-0877 .- 1937-9145. ; 10:465
-
Journal article (peer-reviewed)abstract
- Wnt-stimulated β-catenin transcriptional regulation is necessary for the development of most organs, including teeth. Bcl9 and Bcl9l are tissue-specific transcriptional cofactors that cooperate with β-catenin. In the nucleus, Bcl9 and Bcl9l simultaneously bind β-catenin and the transcriptional activator Pygo2 to promote the transcription of a subset of Wnt target genes. We showed that Bcl9 and Bcl9l function in the cytoplasm during tooth enamel formation in a manner that is independent of Wnt-stimulated β-catenin-dependent transcription. Bcl9, Bcl9l, and Pygo2 localized mainly to the cytoplasm of the epithelial-derived ameloblasts, the cells responsible for enamel production. In ameloblasts, Bcl9 interacted with proteins involved in enamel formation and proteins involved in exocytosis and vesicular trafficking. Conditional deletion of both Bcl9 and Bcl9l or both Pygo1 and Pygo2 in mice produced teeth with defective enamel that was bright white and deficient in iron, which is reminiscent of human tooth enamel pathologies. Overall, our data revealed that these proteins, originally defined through their function as β-catenin transcriptional cofactors, function in odontogenesis through a previously uncharacterized cytoplasmic mechanism, revealing that they have roles beyond that of transcriptional cofactors.
|
|
10. |
|
|
11. |
|
|
12. |
- Charmandari, E, et al.
(author)
-
Stress response and child health
- 2012
-
In: Science signaling. - : American Association for the Advancement of Science (AAAS). - 1937-9145 .- 1945-0877. ; 5:248, s. mr1-
-
Journal article (peer-reviewed)abstract
- Endocrine and inflammatory responses to stress affect many aspects of development, physiology, and cognition.
|
|
13. |
- Dolan, Brendan, et al.
(author)
-
Clearance of small intestinal crypts involves goblet cell mucus secretion by intracellular granule rupture and enterocyte ion transport
- 2022
-
In: Science Signaling. - : American Association for the Advancement of Science (AAAS). - 1945-0877 .- 1937-9145. ; 15:752
-
Journal article (peer-reviewed)abstract
- Goblet cells in the small intestinal crypts contain large numbers of mucin granules that are rapidly discharged to clean bacteria from the crypt. Because acetylcholine released by neuronal and nonneuronal cells controls many aspects of intestinal epithelial function, we used tissue explants and organoids to investigate the response of the small intestinal crypt to cholinergic stimulation. The activation of muscarinic acetylcholine receptors initiated a coordinated and rapid emptying of crypt goblet cells that flushed the crypt contents into the intestinal lumen. Cholinergic stimulation induced an expansion of the granule contents followed by intracellular rupture of the mucin granules. The mucus expanded intracellularly before the rupture of the goblet cell apical membrane and continued to expand after its release into the crypt lumen. The goblet cells recovered from membrane rupture and replenished their stores of mucin granules. Mucus secretion from the goblet cells depended on Ca2+ signaling and the expansion of the mucus in the crypt depended on gap junctions and on ion and water transport by enterocytes adjacent to the goblet cells. This distinctive mode of mucus secretion, which we refer to as “expanding secretion,” efficiently cleans the small intestine crypt through coordinated mucus, ion, and fluid secretion by goblet cells and enterocytes.
|
|
14. |
- Donner, Lili, et al.
(author)
-
Platelets contribute to amyloid-β aggregation in cerebral vessels through integrin αIIbβ3-induced outside-in signaling and clusterin release
- 2016
-
In: Science Signaling. - Washington, USA : American Association for the Advancement of Science (A A A S). - 1945-0877 .- 1937-9145. ; 9:429
-
Journal article (peer-reviewed)abstract
- Cerebral amyloid angiopathy (CAA) is a vascular dysfunction disorder characterized by deposits of amyloid-β (Aβ) in the walls of cerebral vessels. CAA and Aβ deposition in the brain parenchyma contribute to dementia and Alzheimer's disease (AD). We investigated the contribution of platelets, which accumulate at vascular Aβ deposits, to CAA. We found that synthetic monomeric Aβ40 bound through its RHDS (Arg-His-Asp-Ser) sequence to integrin αIIbβ3, which is the receptor for the extracellular matrix protein fibrinogen, and stimulated the secretion of adenosine diphosphate (ADP) and the chaperone protein clusterin from platelets. Clusterin promoted the formation of fibrillar Aβ aggregates, and ADP acted through its receptors P2Y1 and P2Y12 on platelets to enhance integrin αIIbβ3 activation, further increasing the secretion of clusterin and Aβ40 binding to platelets. Platelets from patients with Glanzmann's thrombasthenia, a bleeding disorder in which platelets have little or dysfunctional αIIbβ3, indicated that the abundance of this integrin dictated Aβ-induced clusterin release and platelet-induced Aβ aggregation. The antiplatelet agent clopidogrel, which irreversibly inhibits P2Y12, inhibited Aβ aggregation in platelet cultures; in transgenic AD model mice, this drug reduced the amount of clusterin in the circulation and the incidence of CAA. Our findings indicate that activated platelets directly contribute to CAA by promoting the formation of Aβ aggregates and that Aβ, in turn, activates platelets, creating a feed-forward loop. Thus, antiplatelet therapy may alleviate fibril formation in cerebral vessels of AD patients.
|
|
15. |
- Engelsdorf, Timo, et al.
(author)
-
The plant cell wall integrity maintenance and immune signaling systems cooperate to control stress responses in Arabidopsis thaliana
- 2018
-
In: Science Signaling. - : American Association for the Advancement of Science (AAAS). - 1945-0877 .- 1937-9145. ; 11:536
-
Journal article (peer-reviewed)abstract
- Cell walls surround all plant cells, and their composition and structure are modified in a tightly controlled, adaptive manner to meet sometimes opposing functional requirements during growth and development. The plant cell wall integrity (CWI) maintenance mechanism controls these functional modifications, as well as responses to cell wall damage (CWD). We investigated how the CWI system mediates responses to CWD in Arabidopsis thaliana. CWD induced by cell wall-degrading enzymes or an inhibitor of cellulose biosynthesis elicited similar, turgor-sensitive stress responses. Phenotypic clustering with 27 genotypes identified a core group of receptor-like kinases (RLKs) and ion channels required for the activation of CWD responses. A genetic analysis showed that the RLK FEI2 and the plasma membrane-localized mechanosensitive Ca2+ channel MCA1 functioned downstream of the RLK THE1 in CWD perception. In contrast, pattern-triggered immunity (PTI) signaling components, including the receptors for plant elicitor peptides (AtPeps) PEPR1 and PEPR2, repressed responses to CWD. CWD induced the expression of PROPEP1 and PROPEP3, which encode the precursors of AtPep1 and AtPep3, and the release of PROPEP3 into the growth medium. Application of AtPep1 and AtPep3 repressed CWD-induced phytohormone accumulation in a concentration-dependent manner. These results suggest that AtPep-mediated signaling suppresses CWD-induced defense responses controlled by the CWI mechanism. This suppression was alleviated when PTI signaling downstream of PEPR1 and PEPR2 was impaired. Defense responses controlled by the CWI maintenance mechanism might thus compensate to some extent for the loss of PTI signaling elements.
|
|
16. |
- Galvani, Sylvain, et al.
(author)
-
HDL-bound sphingosine 1-phosphate acts as a biased agonist for the endothelial cell receptor S1P1 to limit vascular inflammation.
- 2015
-
In: Science Signaling. - : American Association for the Advancement of Science (AAAS). - 1937-9145 .- 1945-0877. ; 8:389, s. 79-79
-
Journal article (peer-reviewed)abstract
- The sphingosine 1-phosphate receptor 1 (S1P1) is abundant in endothelial cells, where it regulates vascular development and microvascular barrier function. In investigating the role of endothelial cell S1P1 in adult mice, we found that the endothelial S1P1 signal was enhanced in regions of the arterial vasculature experiencing inflammation. The abundance of proinflammatory adhesion proteins, such as ICAM-1, was enhanced in mice with endothelial cell-specific deletion of S1pr1 and suppressed in mice with endothelial cell-specific overexpression of S1pr1, suggesting a protective function of S1P1 in vascular disease. The chaperones ApoM(+)HDL (HDL) or albumin bind to sphingosine 1-phosphate (S1P) in the circulation; therefore, we tested the effects of S1P bound to each chaperone on S1P1 signaling in cultured human umbilical vein endothelial cells (HUVECs). Exposure of HUVECs to ApoM(+)HDL-S1P, but not to albumin-S1P, promoted the formation of a cell surface S1P1-β-arrestin 2 complex and attenuated the ability of the proinflammatory cytokine TNFα to activate NF-κB and increase ICAM-1 abundance. Although S1P bound to either chaperone induced MAPK activation, albumin-S1P triggered greater Gi activation and receptor endocytosis. Endothelial cell-specific deletion of S1pr1 in the hypercholesterolemic Apoe(-/-) mouse model of atherosclerosis enhanced atherosclerotic lesion formation in the descending aorta. We propose that the ability of ApoM(+)HDL to act as a biased agonist on S1P1 inhibits vascular inflammation, which may partially explain the cardiovascular protective functions of HDL.
|
|
17. |
|
|
18. |
- Gekara, Nelson O., et al.
(author)
-
The innate immune DNA sensor cGAS : A membrane, cytosolic, or nuclear protein?
- 2019
-
In: Science Signaling. - Washington : American Association for the Advancement of Science. - 1945-0877 .- 1937-9145. ; 12:581
-
Journal article (other academic/artistic)abstract
- Cyclic cGMP-AMP synthase (cGAS) alerts the innate immune system to the presence of foreign or damaged self-DNA inside the cell and is critical for the outcome of infections, inflammatory diseases, and cancer. Two studies now demonstrate that cGAS activation is regulated by differential subcellular localization through its non-enzymatic, N-terminal domain.
|
|
19. |
- Gordon, Emma J., et al.
(author)
-
The endothelial adaptor molecule TSAd is required for VEGF-induced angiogenic sprouting through junctional c-Src activation
- 2016
-
In: Science Signaling. - : American Association for the Advancement of Science (AAAS). - 1945-0877 .- 1937-9145. ; 9:437
-
Journal article (peer-reviewed)abstract
- Activation of vascular endothelial growth factor (VEGF) receptor 2 (VEGFR2) by VEGF binding is critical for vascular morphogenesis. In addition, VEGF disrupts the endothelial barrier by triggering the phosphorylation and turnover of the junctional molecule VE-cadherin, a process mediated by the VEGFR2 downstream effectors T cell-specific adaptor (TSAd) and the tyrosine kinase c-Src. We investigated whether the VEGFR2-TSAd-c-Src pathway was required for angiogenic sprouting. Indeed, Tsad-deficient embryoid bodies failed to sprout in response to VEGF. Tsad-deficient mice displayed impaired angiogenesis specifically during tracheal vessel development, but not during retinal vasculogenesis, and in VEGF-loaded Matrigel plugs, but not in those loaded with FGF. The SH2 and proline-rich domains of TSAd bridged VEGFR2 and c-Src, and this bridging was critical for the localization of activated c-Src to endothelial junctions and elongation of the growing sprout, but not for selection of the tip cell. These results revealed that vascular sprouting and permeability are both controlled through the VEGFR2-TSAd-c-Src signaling pathway in a subset of tissues, which may be useful in developing strategies to control tissue-specific pathological angiogenesis.
|
|
20. |
- Gudey, Shyam Kumar, et al.
(author)
-
TRAF6 stimulates the tumor-promoting effects of TGF beta type I receptor through polyubiquitination and activation of Presenilin 1
- 2014
-
In: Science Signaling. - : American Association for the Advancement of Science. - 1945-0877 .- 1937-9145. ; 7:307
-
Journal article (peer-reviewed)abstract
- Transforming growth factor-beta (TGF beta) can be both a tumor promoter and suppressor, although the mechanisms behind the protumorigenic switch remain to be fully elucidated. The TGF beta type I receptor (T beta RI) is proteolytically cleaved in the ectodomain region. Cleavage requires the combined activities of tumor necrosis factor (TNF) receptor-associated factor 6 (TRAF6) and TNF-alpha-converting enzyme (TACE). The cleavage event occurs selectively in cancer cells and generates an intracellular domain (ICD) of T beta RI, which enters the nucleus to mediate gene transcription. Presenilin 1 (PS1), a gamma-secretase catalytic core component, mediates intramembrane proteolysis of transmembrane receptors, such as Notch. We showed that TGF beta increased both the abundance and activity of PS1. TRAF6 recruited PS1 to the T beta RI complex and promoted lysine-63-linked polyubiquitination of PS1, which activated PS1. Furthermore, PS1 cleaved T beta RI in the transmembrane domain between valine-129 and isoleucine-130, and ICD generation was inhibited when these residues were mutated to alanine. We also showed that, after entering the nucleus, T beta RI-ICD bound to the promoter and increased the transcription of the gene encoding T beta RI. The TRAF6- and PS1-induced intramembrane proteolysis of T beta RI promoted TGF beta-induced invasion of various cancer cells in vitro. Furthermore, when a mouse xenograft model of prostate cancer was treated with the gamma-secretase inhibitor DBZ {(2S)-2-[2-(3,5-difluorophenyl)-acetylamino]-N-(5-methyl-6-oxo-6,7-dihydro-5H-dibenzo[b, d]azepin-7-yl)-propionamide}, generation of T beta RI-ICD was prevented, transcription of the gene encoding the proinvasive transcription factor Snail1 was reduced, and tumor growth was inhibited. These results suggest that gamma-secretase inhibitors may be useful for treating aggressive prostate cancer.
|
|
21. |
- Gudey, Shyam Kumar, et al.
(author)
-
TRAF6 Stimulates the Tumor-Promoting Effects of TGFβ Type I Receptor Through Polyubiquitination and Activation of Presenilin 1
- 2014
-
In: Science signaling. - : American Association for the Advancement of Science (AAAS). - 1937-9145 .- 1945-0877. ; 7:307, s. ra2-
-
Journal article (peer-reviewed)abstract
- Transforming growth factor-β (TGFβ) can be both a tumor promoter and suppressor, although the mechanisms behind the protumorigenic switch remain to be fully elucidated. The TGFβ type I receptor (TβRI) is proteolytically cleaved in the ectodomain region. Cleavage requires the combined activities of tumor necrosis factor (TNF) receptor-associated factor 6 (TRAF6) and TNF-α-converting enzyme (TACE). The cleavage event occurs selectively in cancer cells and generates an intracellular domain (ICD) of TβRI, which enters the nucleus to mediate gene transcription. Presenilin 1 (PS1), a γ-secretase catalytic core component, mediates intramembrane proteolysis of transmembrane receptors, such as Notch. We showed that TGFβ increased both the abundance and activity of PS1. TRAF6 recruited PS1 to the TβRI complex and promoted lysine-63-linked polyubiquitination of PS1, which activated PS1. Furthermore, PS1 cleaved TβRI in the transmembrane domain between valine-129 and isoleucine-130, and ICD generation was inhibited when these residues were mutated to alanine. We also showed that, after entering the nucleus, TβRI-ICD bound to the promoter and increased the transcription of the gene encoding TβRI. The TRAF6- and PS1-induced intramembrane proteolysis of TβRI promoted TGFβ-induced invasion of various cancer cells in vitro. Furthermore, when a mouse xenograft model of prostate cancer was treated with the γ-secretase inhibitor DBZ {(2S)-2-[2-(3,5-difluorophenyl)-acetylamino]-N-(5-methyl-6-oxo-6,7-dihydro-5H-dibenzo[b,d]azepin-7-yl)-propionamide}, generation of TβRI-ICD was prevented, transcription of the gene encoding the proinvasive transcription factor Snail1 was reduced, and tumor growth was inhibited. These results suggest that γ-secretase inhibitors may be useful for treating aggressive prostate cancer.
|
|
22. |
- Hamidi, Anahita, et al.
(author)
-
TGF-β promotes PI3K-AKT signaling and prostate cancer cell migration through the TRAF6-mediated ubiquitylation of p85α
- 2017
-
In: Science Signaling. - : American Association for the Advancement of Science. - 1945-0877 .- 1937-9145. ; 10:486
-
Journal article (other academic/artistic)abstract
- TGF-β signaling stimulates various intracellular pathways that can promote migration in tumor cells. These pathways are generally thought to be either dependent or independent of transcription factors called SMADs. One of the SMAD-independent pathways (PI3K-AKT) is mediated by a direct interaction between PI3K and the TGF-β type I receptor. However, Hamidi et al. found that the TGF-β–induced activation of PI3K depends on another ubiquitin ligase–mediated mechanism and a SMAD protein but is independent of the kinase function of TβRI. The binding of TGF-β to its receptor triggered the recruitment of PI3K and the ubiquitin ligase TRAF6, which polyubiquitylated the regulatory PI3K subunit p85α, thus enabling phosphorylation of the catalytic PI3K subunit p110, but only in the presence of SMAD7. The abundance of ubiquitylated p85α correlated with migration in cultured cells and prostate tumor grade in patient samples. TRAF6 mediates activation of the other “SMAD-independent” (JNK) pathway. These data suggest that, although distinct, the TGF-β signaling pathways are not as insulated from each other as was once thought.
|
|
23. |
|
|
24. |
- Healy, JA, et al.
(author)
-
Cholinergic augmentation of insulin release requires ankyrin-B
- 2010
-
In: Science signaling. - : American Association for the Advancement of Science (AAAS). - 1937-9145 .- 1945-0877. ; 3:113, s. ra19-
-
Journal article (peer-reviewed)abstract
- The scaffolding protein ankyrin-B is needed for maximal insulin release, and loss of function is a risk factor for diabetes.
|
|
25. |
|
|
26. |
- Idevall-Hagren, Olof, et al.
(author)
-
Spatial Control of Epac2 Activity by cAMP and Ca2+-Mediated Activation of Ras in Pancreatic beta Cells
- 2013
-
In: Science Signaling. - : American Association for the Advancement of Science (AAAS). - 1945-0877 .- 1937-9145. ; 6:273, s. ra29-
-
Journal article (peer-reviewed)abstract
- The cAMP (adenosine 3',5'-monophosphate)-activated guanine nucleotide exchange factor (GEF) Epac2 is an important mediator of cAMP-dependent processes in multiple cell types. We used real-time confocal and total internal reflection fluorescence microscopy to examine the spatiotemporal regulation of Epac2, which is a GEF for the guanosine triphosphatase (GTPase) Rap. We demonstrated that increases in the concentration of cAMP triggered the translocation of Epac2 from the cytoplasm to the plasma membrane in insulin-secreting beta cells. Glucose-induced oscillations of the submembrane concentration of cAMP were associated with cyclic translocation of Epac2, and this translocation could be amplified by increases in the cytoplasmic Ca2+ concentration. Analyses of Epac2 mutants identified the high-affinity cAMP-binding and the Ras association domains as crucial for the translocation. Expression of a dominant-negative Ras mutant reduced Epac2 translocation, and Ca2+-dependent oscillations in Ras activity synchronized with Epac2 translocation in single beta cells. The cyclic translocation of Epac2 was accompanied by oscillations of Rap GTPase activity at the plasma membrane, and expression of an inactive Rap1B mutant decreased insulin secretion. Thus, Epac2 localization is dynamically controlled by cAMP as well as by Ca2+-mediated activation of Ras. These results help to explain how oscillating signals can produce pulses of insulin release from pancreatic b cells.
|
|
27. |
- Kliche, Johanna, et al.
(author)
-
Cytoplasmic short linear motifs in ACE2 and integrin beta(3) link SARS-CoV-2 host cell receptors to mediators of endocytosis and autophagy
- 2021
-
In: Science Signaling. - : American Association for the Advancement of Science (AAAS). - 1945-0877 .- 1937-9145. ; 14:665
-
Journal article (peer-reviewed)abstract
- The spike protein of SARS-CoV-2 binds the angiotensin-converting enzyme 2 (ACE2) on the host cell surface and subsequently enters host cells through receptor-mediated endocytosis. Additional cell receptors may be directly or indirectly involved, including integrins. The cytoplasmic tails of ACE2 and integrins contain several predicted short linear motifs (SLiMs) that may facilitate internalization of the virus as well as its subsequent propagation through processes such as autophagy. Here, we measured the binding affinity of predicted interactions between SLiMs in the cytoplasmic tails of ACE2 and integrin beta(3) with proteins that mediate endocytic trafficking and autophagy. We validated that a class I PDZ-binding motif mediated binding of ACE2 to the scaffolding proteins SNX27, NHERF3, and SHANK, and that a binding site for the clathrin adaptor AP2 mu 2 in ACE2 overlaps with a phospho-dependent binding site for the SH2 domains of Src family tyrosine kinases. Furthermore, we validated that an LC3-interacting region (LIR) in integrin beta(3) bound to the ATG8 domains of the autophagy receptors MAP1LC3 and GABARAP in a manner enhanced by LIR-adjacent phosphorylation. Our results provide molecular links between cell receptors and mediators of endocytosis and autophagy that may facilitate viral entry and propagation.
|
|
28. |
|
|
29. |
|
|
30. |
|
|
31. |
|
|
32. |
- Malmerberg, Erik, 1980, et al.
(author)
-
Conformational activation of visual rhodopsin in native disc membranes
- 2015
-
In: Science Signaling. - : American Association for the Advancement of Science (AAAS). - 1945-0877 .- 1937-9145. ; 8:367
-
Journal article (peer-reviewed)abstract
- Rhodopsin is the G protein-coupled receptor (GPCR) that serves as a dim-light receptor for vision in vertebrates. We probed light-induced conformational changes in rhodopsin in its native membrane environment at room temperature using time-resolved wide-angle x-ray scattering. We observed a rapid conformational transition that is consistent with an outward tilt of the cytoplasmic portion of transmembrane helix 6 concomitant with an inward movement of the cytoplasmic portion of transmembrane helix 5. These movements were considerably larger than those reported from the basis of crystal structures of activated rhodopsin, implying that light activation of rhodopsin involves a more extended conformational change than was previously suggested.
|
|
33. |
|
|
34. |
|
|
35. |
- Morikawa, Masato, et al.
(author)
-
The ALK-1/SMAD/ATOH8 axis attenuates hypoxic responses and protects against the development of pulmonary arterial hypertension
- 2019
-
In: Science Signaling. - : American Association for the Advancement of Science. - 1945-0877 .- 1937-9145. ; 12:607
-
Journal article (peer-reviewed)abstract
- Dysregulated bone morphogenetic protein (BMP) signaling in endothelial cells (ECs) is implicated in vascular diseases such as pulmonary arterial hypertension (PAH). Here, we showed that the transcription factor ATOH8 was a direct target of SMAD1/5 and was induced in a manner dependent on BMP but independent of Notch, another critical signaling pathway in ECs. In zebrafish and mice, inactivation of Atoh8 did not cause an arteriovenous malformation-like phenotype, which may arise because of dysregulated Notch signaling. In contrast, Atoh8-deficient mice exhibited a phenotype mimicking PAH, which included increased pulmonary arterial pressure and right ventricular hypertrophy. Moreover, ATOH8 expression was decreased in PAH patient lungs. We showed that in cells, ATOH8 interacted with hypoxia-inducible factor 2 alpha (HIF-2 alpha) and decreased its abundance, leading to reduced induction of HIF-2 alpha target genes in response to hypoxia. Together, these findings suggest that the BMP receptor type II/ALK-1/SMAD/ATOH8 axis may attenuate hypoxic responses in ECs in the pulmonary circulation and may help prevent the development of PAH.
|
|
36. |
- Moustakas, Aristidis
(author)
-
The mitotic checkpoint protein kinase BUB1 is an engine in the TGF-beta signaling apparatus
- 2015
-
In: Science Signaling. - : American Association for the Advancement of Science (AAAS). - 1945-0877 .- 1937-9145. ; 8:359
-
Journal article (other academic/artistic)abstract
- The transforming growth factor-beta (TGF-beta) pathway mediates critical events in cell behavior that contribute to development and disease. The mitotic checkpoint guarantees faithful chromosomal segregation during cell division. In the 6 January 2015 issue of Science Signaling, Nyati et al. reported that the mitotic checkpoint kinase BUB1 promotes the activity of TGF-beta receptors, which adds new molecular links between these fundamental biological processes.
|
|
37. |
- Munir, Muhammad
(author)
-
TRIM Proteins: Another Class of Viral Victims
- 2010
-
In: Science Signaling. - : American Association for the Advancement of Science (AAAS). - 1945-0877 .- 1937-9145. ; 3, s. 1-4
-
Research review (peer-reviewed)abstract
- TRIM (tripartite motif) proteins are a family of RING (really interesting new gene) domain-containing proteins comprising more than 70 human members, with new members still being described. In addition to their involvement in cell proliferation, differentiation, development, morphogenesis, and apoptosis, roles in immune signaling and antiviral functions are emerging. In response to viral infection, TRIM25 ubiquitinates the N terminus of the viral RNA receptor retinoic acid-inducible gene-I (RIG-I), and this modification is essential for RIG- I to interact with its downstream partner mitochondrial antiviral signaling (MAVS). TRIM25 activity thus leads to activation of the RIG- I signaling pathway, which results in type I interferon production to limit viral replication. Recently, it has been demonstrated that influenza A viruses target TRIM25 and disable its antiviral function, thereby suppressing the host interferon response. This Journal Club article highlights the emerging roles of TRIM proteins in antiviral defense mechanisms and an immune evasion strategy in which influenza viruses target a member of the TRIM family.
|
|
38. |
- Okita, Yukari, et al.
(author)
-
The transcription factor MAFK induces EMT and malignant progression of triple-negative breast cancer cells through its target GPNMB
- 2017
-
In: Science Signaling. - : AMER ASSOC ADVANCEMENT SCIENCE. - 1945-0877 .- 1937-9145. ; 10:474
-
Journal article (peer-reviewed)abstract
- Triple-negative breast cancer (TNBC) is particularly aggressive and difficult to treat. For example, the transforming growth factor-beta (TGF-beta) pathway is implicated in TNBC progression and metastasis, but its opposing role in tumor suppression in healthy tissues and early-stage lesions makes it a challenging target. Therefore, additional molecular characterization of TNBC may lead to improved patient prognosis by informing the development and optimum use of targeted therapies. We found that musculoaponeurotic fibrosarcoma (MAF) oncogene family protein K (MAFK), a member of the small MAF family of transcription factors that are induced by the TGF-beta pathway, was abundant in human TNBC and aggressive mouse mammary tumor cell lines. MAFK promoted tumorigenic growth and metastasis by 4T1 cells when implanted subcutaneously in mice. Overexpression of MAFK in mouse breast epithelial NMuMG cells induced epithelial-mesenchymal transition (EMT) phenotypes and promoted tumor formation and invasion in mice. MAFK induced the expression of the gene encoding the transmembrane glycoprotein nmb(GPNMB). Similar to MAFK, GPNMB overexpression in NMuMG cells induced EMT, tumor formation, and invasion, in mice, whereas knockdown of MAFK in tumor cells before implantation suppressed tumor growth and progression. MAFK and GPNMB expression correlated with poor prognosis in TNBC patients. These findings suggest that MAFK and its target gene GPNMB play important roles in the malignant progression of TNBC cells, offering potentially new therapeutic targets for TNBC patients.
|
|
39. |
- Rizk, John, et al.
(author)
-
SMAC mimetics promote NIK-dependent inhibition of CD4+ TH17 cell differentiation
- 2019
-
In: Science Signaling. - : American Association for the Advancement of Science (AAAS). - 1945-0877 .- 1937-9145. ; 12:596
-
Journal article (peer-reviewed)abstract
- Second mitochondria-derived activator of caspase (SMAC) mimetics (SMs) are selective antagonists of the inhibitor of apoptosis proteins (IAPs), which activate noncanonical NF-B signaling and promote tumor cell death. Through gene expression analysis, we found that treatment of CD4+ T cells with SMs during T helper 17 (TH17) cell differentiation disrupted the balance between two antagonistic transcription factor modules. Moreover, proteomics analysis revealed that SMs altered the abundance of proteins associated with cell cycle, mitochondrial activity, and the balance between canonical and noncanonical NF-B signaling. Whereas SMs inhibited interleukin-17 (IL-17) production and ameliorated TH17 cell-driven inflammation, they stimulated IL-22 secretion. Mechanistically, SM-mediated activation of NF-B-inducing kinase (NIK) and the transcription factors RelB and p52 directly suppressed Il17a expression and IL-17A protein production, as well as the expression of a number of other immune genes. Induction of IL-22 production correlated with the NIK-dependent reduction in cMAF protein abundance and the enhanced activity of the aryl hydrocarbon receptor. Last, SMs also increased IL-9 and IL-13 production and, under competing conditions, favored the differentiation of naïve CD4+ T cells into TH2 cells rather than TH17 cells. These results demonstrate that SMs shape the gene expression and protein profiles of TH17 cells and inhibit TH17 cell-driven autoimmunity.
|
|
40. |
- Robinson, Jonathan, 1986, et al.
(author)
-
An atlas of human metabolism
- 2020
-
In: Science Signaling. - : American Association for the Advancement of Science (AAAS). - 1945-0877 .- 1937-9145. ; 13:624
-
Journal article (peer-reviewed)abstract
- Genome-scale metabolic models (GEMs) are valuable tools to study metabolism and provide a scaffold for the integrative analysis of omics data. Researchers have developed increasingly comprehensive human GEMs, but the disconnect among different model sources and versions impedes further progress. We therefore integrated and extensively curated the most recent human metabolic models to construct a consensus GEM, Human1. We demonstrated the versatility of Human1 through the generation and analysis of cell- and tissue-specific models using transcriptomic, proteomic, and kinetic data. We also present an accompanying web portal, Metabolic Atlas (https://www.metabolicatlas.org/), which facilitates further exploration and visualization of Human1 content. Human1 was created using a version-controlled, open-source model development framework to enable community-driven curation and refinement. This framework allows Human1 to be an evolving shared resource for future studies of human health and disease.
|
|
41. |
|
|
42. |
|
|
43. |
- Roth, Lise, et al.
(author)
-
Neuropilin-1 mediates vascular permeability independently of vascular endothelial growth factor receptor-2 activation
- 2016
-
In: Science Signaling. - : American Association for the Advancement of Science (AAAS). - 1945-0877 .- 1937-9145. ; 9:425
-
Journal article (peer-reviewed)abstract
- Neuropilin-1 (NRP1) regulates developmental and pathological angiogenesis, arteriogenesis, and vascular permeability, acting as a coreceptor for semaphorin 3A (Sema3A) and the 165-amino acid isoform of vascular endothelial growth factor A (VEGF-A(165)). NRP1 is also the receptor for the CendR peptides, a class of cell-and tissue-penetrating peptides with a specific R-x-x-R carboxyl-terminal motif. Because the cytoplasmic domain of NRP1 lacks catalytic activity, NRP1 is mainly thought to act through the recruitment and binding to other receptors. We report here that the NRP1 intracellular domain mediates vascular permeability. Stimulation with VEGF-A(165), a ligand-blocking antibody, and a CendR peptide led to NRP1 accumulation at cell-cell contacts in endothelial cell monolayers, increased cellular permeability in vitro and vascular leakage in vivo. Biochemical analyses, VEGF receptor-2 (VEGFR-2) silencing, and the use of a specific VEGFR blocker established that the effects induced by the CendR peptide and the antibody were independent of VEGFR-2. Moreover, leakage assays in mice expressing a mutant NRP1 lacking the cytoplasmic domain revealed that this domain was required for NRP1-induced vascular permeability in vivo. Hence, these data define a vascular permeability pathway mediated by NRP1 but independent of VEGFR-2 activation.
|
|
44. |
- Samuelsson, Malin, et al.
(author)
-
RhoB controls the Rab11-mediated recycling and surface reappearance of LFA-1 in migrating T lymphocytes
- 2017
-
In: Science Signaling. - Washington, DC, USA : American Association for the Advancement of Science (A A A S). - 1945-0877 .- 1937-9145. ; 10:509
-
Journal article (peer-reviewed)abstract
- The regulation of cell adhesion and motility is complex and requires the intracellular trafficking of integrins to and from sites of cell adhesion, especially in fast-moving cells such as leukocytes. The Rab family of guanosine triphosphatases (GTPases) is essential for vesicle transport, and vesicles mediate intracellular integrin trafficking. We showed that RhoB regulates the vesicular transport of the integrin LFA-1 along the microtubule network in migrating T lymphocytes. Impairment in RhoB function resulted in the accumulation of both LFA-1 and the recycling endosomal marker Rab11 at the rear of migrating T lymphocytes and decreased the association between these molecules. T lymphocytes lacking functional RhoB exhibited impaired recycling and subsequently decreased surface amounts of LFA-1, leading to reduced T cell adhesion and migration mediated by the cell adhesion molecule ICAM-1 (intercellular adhesion molecule-1). We propose that vesicle-associated RhoB is a regulator of the Rab11-mediated recycling of LFA-1 to the cell surface, an event that is necessary for T lymphocyte motility.
|
|
45. |
|
|
46. |
- Savendahl, L
(author)
-
The effect of acute and chronic stress on growth
- 2012
-
In: Science signaling. - : American Association for the Advancement of Science (AAAS). - 1937-9145 .- 1945-0877. ; 5:247, s. pt9-
-
Journal article (peer-reviewed)abstract
- The glucocorticoids and inflammatory cytokines induced by stress can impair bone growth.
|
|
47. |
|
|
48. |
- Schmied, Laurent, et al.
(author)
-
SHP-1 localization to the activating immune synapse promotes NK cell tolerance in MHC class I deficiency.
- 2023
-
In: Science Signaling. - : American Association for the Advancement of Science (AAAS). - 1945-0877 .- 1937-9145. ; 16:780, s. eabq0752-
-
Journal article (peer-reviewed)abstract
- Natural killer (NK) cells recognize virally infected cells and tumors. NK cell function depends on balanced signaling from activating receptors, recognizing products from tumors or viruses, and inhibitory receptors (such as KIR/Ly49), which recognize major histocompatibility complex class I (MHC-I) molecules. KIR/Ly49 signaling preserves tolerance to self but also conveys reactivity toward MHC-I-low target cells in a process known as NK cell education. Here, we found that NK cell tolerance and education were determined by the subcellular localization of the tyrosine phosphatase SHP-1. In mice lacking MHC-I molecules, uneducated, self-tolerant Ly49A+ NK cells showed accumulation of SHP-1 in the activating immune synapse, where it colocalized with F-actin and the signaling adaptor protein SLP-76. Education of Ly49A+ NK cells by the MHC-I molecule H2Dd led to reduced synaptic accumulation of SHP-1, accompanied by augmented signaling from activating receptors. Education was also linked to reduced transcription of Ptpn6, which encodes SHP-1. Moreover, synaptic SHP-1 accumulation was reduced in NK cells carrying the H2Dd-educated receptor Ly49G2 but not in those carrying the noneducating receptor Ly49I. Colocalization of Ly49A and SHP-1 outside of the synapse was more frequent in educated compared with uneducated NK cells, suggesting a role for Ly49A in preventing synaptic SHP-1 accumulation in NK cell education. Thus, distinct patterning of SHP-1 in the activating NK cell synapse may determine NK cell tolerance.
|
|
49. |
- Sehat, Bita, et al.
(author)
-
SUMOylation Mediates the Nuclear Translocation and Signaling of the IGF-1 Receptor
- 2010
-
In: Science Signaling. - : American Association for the Advancement of Science (AAAS). - 1945-0877 .- 1937-9145. ; 3:108
-
Journal article (peer-reviewed)abstract
- The insulin-like growth factor 1 receptor (IGF-1R) plays crucial roles in developmental and cancer biology. Most of its biological effects have been ascribed to its tyrosine kinase activity, which propagates signaling through the phosphatidylinositol 3-kinase and mitogen-activated protein kinase pathways. Here, we report that IGF-1 promotes the modification of IGF-1R by small ubiquitin-like modifier protein-1 (SUMO-1) and its translocation to the nucleus. Nuclear IGF-1R associated with enhancer-like elements and increased transcription in reporter assays. The SUMOylation sites of IGF-1R were identified as three evolutionarily conserved lysine residues-Lys(1025), Lys(1100), and Lys(1120)-in the beta subunit of the receptor. Mutation of these SUMO-1 sites abolished the ability of IGF-1R to translocate to the nucleus and activate transcription, but did not alter its kinase-dependent signaling. Thus, we demonstrate a SUMOylation-mediated mechanism of IGF-1R signaling that has potential implications for gene regulation.
|
|
50. |
|
|