1. |
- Sasaki, Takaaki, et al.
(author)
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Elevated Intraocular Pressure, Optic Nerve Atrophy, and Impaired Retinal Development in ODAG Transgenic Mice
- 2009
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In: Investigative Ophthalmology and Visual Science. - : Association for Research in Vision and Ophthalmology (ARVO). - 0146-0404 .- 1552-5783. ; 50:1, s. 242-248
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Journal article (peer-reviewed)abstract
- PURPOSE. In an earlier study, a cDNA was cloned that showed abundant expression in the eye at postnatal day (P) 2 but was downregulated at P10; it was named ODAG (ocular development-associated gene). Its biological function was examined by generating and analyzing transgenic mice overexpressing ODAG (ODAG Tg) in the eye and by identifying ODAG-binding proteins. METHODS. Transgenic mice were generated by using the mouse Crx promoter. EGFP was designed to be coexpressed with transgenic ODAG, to identify transgene-expressing cells. Overexpression of ODAG was confirmed by Northern and Western blot analysis. IOP was measured with a microneedle technique. The eyes were macroscopically examined and histologically analyzed. EGFP expression was detected by confocal microscope. Proteins associated with ODAG were isolated by pull-down assay in conjugation with mass spectrometry. RESULTS. Macroscopically, ODAG Tg exhibited gradual protrusion of the eyeballs. The mean IOP of ODAG Tg was significantly higher than that of wild-type (WT) littermates. Histologic analysis exhibited optic nerve atrophy and impaired retinal development in the ODAG Tg eye. EGFP was expressed highly in the presumptive outer nuclear layer and weakly in the presumptive inner nuclear layer in the ODAG Tg retina. Rab6-GTPase-activating protein (Rab6-GAP) and its substrate, Rab6, were identified as ODAG-binding proteins. CONCLUSIONS. Deregulated expression of ODAG in the eye induces elevated intraocular pressure and optic nerve atrophy and impairs retinal development, possibly by interfering with the Rab6/Rab6-GAP-mediated signaling pathway. These results provide new insights into the mechanisms regulating ocular development, and ODAG Tg would be a novel animal model for human diseases caused by ocular hypertension.
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2. |
- Bhaskaran, Nimesh, et al.
(author)
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Comparative proteome profiling of MCF10A and 184A1 human breast epithelial cells emphasized involvement of CDK4 and cyclin D3 in cell proliferation
- 2009
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In: Proteomics Clinical Applications. - : Wiley. - 1862-8354 .- 1862-8346. ; 3:1, s. 68-77
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Journal article (peer-reviewed)abstract
- Acquiring high proliferation rate is crucial for carcinogenic transformation of cells. We reporthere proteome profiling of human breast epithelial cells with low (184A1) and high (MCF10A)proliferation rates.We identified 183 proteins in 184A1 and 318 proteins in MCF10A cells. Thesedatasets provide the most comprehensive proteome annotations of 184A1 and MCF10A cells.Proteins were taken for identification from 2-D gels in a systematic and unbiased way. Functionalclustering of the identified proteins showed similarities in distribution of proteins to the samefunctional domains, indicating similarities in proteomes of 184A1 and MCF10A cells. Amongobserved differences in protein expression, we validated correlation of expression of endogenouscyclin-dependent kinase 4 (CDK4), cyclin D3, cdc25B, and p38g with cell proliferation. Furthermore,down-regulation of CDK4 and cyclin D3 with specific siRNA inhibited cell proliferation,which emphasized the role of CDK4 and cyclin D3 in enhancement of cell proliferation rate ofhuman breast epithelial cells.
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3. |
- Bhaskaran, Nimesh, et al.
(author)
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Novel post-translational modifications of Smad2 identified by mass spectrometry
- 2008
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In: Central European Journal of Biology. - : Walter de Gruyter GmbH. - 1895-104X .- 1644-3632. ; 3:4, s. 359-370
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Journal article (peer-reviewed)abstract
- Smad2 is a crucial component of transforming growth factor-b (TGFb) signaling, and is involved in the regulation of cell proliferation,death and differentiation. Phosphorylation, ubiquitylation and acetylation of Smad2 have been found to regulate its activity. We usedmass spectrometry to search for novel post-translational modifications (PTMs) of Smad2. Peptide mass fingerprinting (PMF) indicatedthat Smad2 can be acetylated, methylated, citrullinated, phosphorylated and palmitoylated. Sequencing of selected peptides validatedmethylation at Gly122 and hydroxylation at Trp18 of Smad2. We also observed a novel, so far unidentified modification at Tyr128 andTyr151. Our observations open for further exploration of biological importance of the detected PTMs.
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4. |
- Conrotto, Paolo, et al.
(author)
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Interactome of transforming growth factor-beta type I receptor (T beta RI) : Inhibition of TGF beta signaling by Epac1
- 2007
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In: Journal of Proteome Research. - : American Chemical Society (ACS). - 1535-3893 .- 1535-3907. ; 6:1, s. 287-297
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Journal article (peer-reviewed)abstract
- Transforming growth factor-beta (TGF beta) is a potent regulator of cell growth, differentiation, and apoptosis. Type I TGF beta receptor (T beta RI) is the key receptor for initiation of intracellular signaling by TGF beta. Here we report proteomics-based identification of proteins that form a complex with T beta RI. Using 2D-GE and MALDI TOF mass spectrometry, we identified 16 proteins that specifically interacted with a GST-fused T beta RI Thr204Asp construct with constitutively active serine/threonine kinase. We confirmed interactions of the receptor with cAMP regulated guanine nucleotide exchange factor 1 (Epac1), alpha-spectrin, PIASy, and alpha-catenin proteins using immunoblotting. Interaction of the receptor with Epac1 required intact kinase activity of T beta RI but was not affected by deletion of cAMP-binding domain of Epac1. TGF beta 1-induced C-terminal phosphorylation of Smad2 was inhibited in vivo and in vitro in the presence of Epac1. Epac1 inhibited also TGF beta 1/T beta RI-dependent transcriptional activation, as evaluated by luciferase reporter assays. We observed that expression of Epac1 counteracted TGF beta/T beta RI-dependent decrease of cell adhesion and TGF beta/T beta RI-induced stimulation of cell migration. Thus, we have reported novel T beta RI-interacting proteins and have shown that Epac1 inhibited TGF beta-dependent regulation of cell migration and adhesion.
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5. |
- Dubrovska, Anna, et al.
(author)
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Efficient enrichment of intact phosphorylated proteins by modified immobilized metal-affinity chromatography
- 2005
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In: Proteomics. - : Wiley. - 1615-9853 .- 1615-9861. ; 5:18, s. 4678-4683
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Journal article (peer-reviewed)abstract
- Phosphoproteome studies are hampered by the lack of methods which allow a comprehensive and fast analysis of intact phosphoproteins. Here we describe an immobilized metal-affinity chromatography (IMAC)-based technique for the enrichment of phosphorylated proteins, which allows recovery of up to 90% of phosphoproteins. This technique is compatible with 2-DE and can be applied to cultured cells and tissues.
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6. |
- Dubrovska, Anna, et al.
(author)
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TGFbeta1/Smad3 counteracts BRCA1-dependent repair of DNA damage
- 2005
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In: Oncogene. - : Springer Science and Business Media LLC. - 0950-9232 .- 1476-5594. ; 24:14, s. 2289-2297
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Journal article (peer-reviewed)abstract
- Inactivation of the BRCA1 gene has been found to confer susceptibility to early-onset familial breast and ovarian cancers. BRCA1 regulates DNA repair, chromatin remodeling and affects gene transcription. Transforming growth factor-beta (TGFbeta) is a potent regulator of growth, apoptosis and invasiveness of tumor cells, including breast cancer cells. Here we show that Smad3 which is a component of the TGFbeta signaling pathway, forms a complex with BRCA1 in vitro and in vivo. The interaction is mediated by the MH1 domain of Smad3 and the C-terminal part of BRCA1. We observed a co-localization of Smad3 and BRCA1 in nuclear complexes. We also found that TGFbeta1/Smad3 counteracted BRCA1-dependent repair of DNA double-strand breaks in human breast epithelial cells, as evaluated by BRCA1 nuclear foci formation, single-cell gel electrophoresis and cell survival assays. Thus, TGFbeta1/Smad3 suppresses BRCA1-dependent DNA repair in response to a DNA damaging agent.
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7. |
- Hassel, Sylke, et al.
(author)
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Interaction and functional cooperation between the serine/threonine kinase bone morphogenetic protein type II receptor with the tyrosine kinase stem cell factor receptor
- 2006
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In: Journal of Cellular Physiology. - : Wiley. - 0021-9541 .- 1097-4652. ; 206:2, s. 457-467
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Journal article (peer-reviewed)abstract
- Transmembrane receptors with intrinsic serine/threonine or tyrosine kinase domains regulate vital functions of cells in multicellular eukaryotes, e.g., differentiation, apoptosis, and proliferation. Here, we show that bone morphogenetic protein type II receptor (BMPR-II) which has a serine/threonine kinase domain, and stem cell factor receptor (c-kit) which contains a tyrosine kinase domain form a complex in vitro and in vivo; the interaction is induced upon treatment of cells with BMP2 and SCF. Stem cell factor (SCF) modulated BMP2-dependent activation of Smad1/5/8 and phosphorylation of Erk kinase. SCF also enhanced BMP2-dependent differentiation of C2C12 cells. We found that BMPR-II was phosphorylated at Ser757 upon co-expression with and activation of c-kit. BMPR-II phosphorylation required intact kinase activity of BMPR-II. Abrogation of the c-kit/SCF-dependent phosphorylation of BMPR-II at the Ser757 interfered with the cooperative effect of BMP2 and SCF. Our data suggest that the complex formation between c-kit and BMPR-II leads to phosphorylation of BMPR-II at Ser757, which modulates BMPR-II-dependent signaling.
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8. |
- Iwahana, Hiroyuki, et al.
(author)
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Glycoproteome profiling of transforming growth factor-beta (TGF beta) signaling : Nonglycosylated cell death-inducing DFF-like effector A inhibits TGF beta 1-dependent apoptosis
- 2006
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In: Proteomics. - : Wiley. - 1615-9853 .- 1615-9861. ; 6:23, s. 6168-6180
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Journal article (peer-reviewed)abstract
- Transforming growth factor-beta (TGFbeta) is a potent regulator of cell growth, differentiation, and apoptosis. TGFbeta binds to specific serine/threonine kinase receptors, which leads to activation of Smad-dependent and Smad-independent signaling pathways. O-Glycosylation is a dynamic PTM which has been observed in many regulatory proteins, but has not been studied in the context of TGFbeta signaling. To explore the effect of TGFbeta1 on protein O-glycosylation in human breast epithelial cells, we performed analyses of proteins which were affinity purified with Helix pomatia agglutinin (HPA). HPA lectin allowed enrichment of proteins containing GalNAc and GlcNAc linked to serine and threonine residues. Using 2-DE and MALDI-TOF-MS, we identified 21 HPA-precipitated proteins, which were affected by treatment of cells with TGFbeta1. Among these proteins, regulators of cell survival, apoptosis, trafficking, and RNA processing were identified. We found that TGFbeta1 inhibited the appearance of cell death-inducing DFF-like effector A (CIDE-A) in 2-D gels with HPA-precipitated proteins. CIDE-A is a cell death activator which promotes DNA fragmentation. We observed that TGFbeta1 did not affect expression of CIDE-A, but inhibited its glycosylation. We found that deglycosylation of CIDE-A correlated with enhanced nuclear export of the protein, and that high level of nonglycosylated CIDE-A inhibited TGFbeta1-dependent cell death. Thus, inhibition of the glycosylation of CIDE-A may be a mechanism to protect cells from apoptosis.
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9. |
- Lomnytska, Marta, et al.
(author)
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Increased expression of cSHMT, Tbx3 and utrophin in plasma of ovarian and breast cancer patients
- 2006
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In: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 118:2, s. 412-421
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Journal article (peer-reviewed)abstract
- Plasma samples of ovarian and breast cancer patients were used to search for markers of cancer using 2-dimensional gel electrophoresis and matrix-assisted laser desorption/ionization time of flight mass spectrometry. Truncated forms of cytosolic serine hydroxymethyl transferase (cSHMT), T-box transcription factor 3 (Tbx3) and utrophin were aberrantly expressed in samples from cancer patients as compared to samples from noncancerous cases. Aberrant expression of proteins was validated by immunoblotting of plasma samples with specific antibodies to cSHMT, Tbx3 and utrophin. A cohort of 79 breast and 39 ovarian cancer patients and 31 individuals with noncancerous conditions was studied. We observed increased expression of truncated cSHMT, Tbx3 and utrophin in plasma samples obtained from patients at early stages of disease. Our data suggest that cSHMT, Tbx3 and utrophin can be used as components of multiparameter monitoring of ovarian and breast cancer (supplementary material for this article can be found on the International Journal of Cancer website at http://www.interscience.wiley.com/jpages/0020-7136/suppmat/index.html).
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10. |
- Moustakas, Aristidis, et al.
(author)
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Receptor Serine/Threonine Kinases
- 2006
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In: Encyclopedic Reference of Genomics and Proteomics in Molecular Medicine. - : Springer Verlag. ; , s. 1603-1608
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Book chapter (other academic/artistic)
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