| 1. |
- Isaksson, Linnéa, et al.
(författare)
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Highly Efficient NMR Assignment of Intrinsically Disordered Proteins: Application to B- and T Cell Receptor Domains
- 2013
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 8:5
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Tidskriftsartikel (refereegranskat)abstract
- We present an integrated approach for efficient characterization of intrinsically disordered proteins. Batch cell-free expression, fast data acquisition, automated analysis, and statistical validation with data resampling have been combined for achieving cost-effective protein expression, and rapid automated backbone assignment. The new methodology is applied for characterization of five cytosolic domains from T- and B-cell receptors in solution.
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| 2. |
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| 3. |
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| 4. |
- Rödström, Karin, 1986, et al.
(författare)
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Structural studies of staphylococcal enterotoxin H in complex with T cell receptor and major histocompatibility complex class II
- 2010
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Ingår i: FEBS JOURNAL. - 1742-464X. ; 2010, 277, s. 53-54
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Superantigens (SAgs) are bacterial toxins capable of cross-linking the immune receptors of the host, the T cell receptor (TCR) and major histocompatibility complex (MHC) class II, and thereby trigger a massive release of cytokines. This could lead to toxic shock syndrome, which can have a fatal outcome. Here, we present the crystal structure of the ternary complex between the superantigen, staphylococcal enterotoxin H (SEH), TCR and MHC, as well as the dimer complex, including only TCR and SEH. It is evident that SEH interacts with the variable α domain (Vα) of TCR, in sharp contrast to previously studied SAgs that interact with the Vβ domain. Due to the high structural conservation of amino acids in SEH that are crucial for the interaction, we propose that in addition to Vβ activation of T cells, there are SAgs, in addition to SEH, which are able to activate T cells through Vα as well. In addition to providing crucial information regarding the nature of TCR-mediated recognition of superantigens, the finding have central implications for future strategies aimed at preventing or modulating the often pathogenic response to superantigens.
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| 6. |
- Saline, Maria, 1979, et al.
(författare)
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A large ‘discovery’ experiment: Gender Initiative for Excellence (Genie) at Chalmers University of Technology
- 2021
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Ingår i: QRB Discovery. - : Cambridge University Press (CUP). - 2633-2892. ; 2
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Forskningsöversikt (refereegranskat)abstract
- Sweden tops gender equality rankings, but Swedish academia is still lacking women in top positions. To address gender inequality in its faculty, Chalmers University of Technology has invested 300 million SEK (30 million Euros) over 10 years in Gender initiative for Excellence (Genie). Genie aims to increase the university’s success and excellence via gender equality efforts. In this editorial, we want to share insights on explicit efforts during Genie’s first 2.5 years with the goal to inspire and advise other universities and researchers.
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| 7. |
- Saline, Maria, et al.
(författare)
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AMPK and AKT protein kinases hierarchically phosphorylate the N-terminus of the FOXO1 transcription factor, modulating interactions with 14-3-3 proteins
- 2019
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Ingår i: Journal of Biological Chemistry. - 0021-9258 .- 1083-351X. ; 294:35, s. 13106-13116
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Tidskriftsartikel (refereegranskat)abstract
- Forkhead box protein O1 (FOXO1) is a transcription factor involved in various cellular processes such as glucose metabolism, development, stress resistance, and tumor suppression. FOXO1's transcriptional activity is controlled by different environmental cues through a myriad of posttranslational modifications. In response to growth factors, the serine/threonine kinase AKT phosphorylates Thr24 and Ser256 in FOXO1 to stimulate binding of 14-3-3 proteins, causingFOXO1inactivation. In contrast, low nutrient and energy levels induce FOXO1 activity. AMP-activated protein kinase (AMPK), a master regulator of cellular energy homeostasis, partly mediates this effect through phosphorylation of Ser383 and Thr649 in FOXO1. In this study, we identified Ser22 as an additional AMPK phosphorylation site in FOXO1's N terminus, with Ser22 phosphorylation preventing binding of 14-3-3 proteins. The crystal structure of a FOXO1 peptide in complex with 14-3-3 σ at 2.3 Å resolution revealed that this is a consequence of both steric hindrance and electrostatic repulsion. Furthermore, we found that AMPK-mediated Ser22 phosphorylation impairs Thr24 phosphorylation by AKT in a hierarchical manner. Thus, numerous mechanisms maintain FOXO1 activity via AMPK signaling. AMPK-mediated Ser22 phosphorylation directly and indirectly averts binding of 14-3-3 proteins, whereas phosphorylation of Ser383 and Thr649 complementarily stimulates FOXO1 activity. Our results shed light on a mechanism that integrates inputs from both AMPK and AKT signaling pathways in a small motif to fine-tune FOXO1 transcriptional activity.
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| 8. |
- Saline, Maria, et al.
(författare)
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Backbone resonance assignment of Staphylococcal Enterotoxin H.
- 2009
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Ingår i: Biomolecular NMR assignments. - : Springer Science and Business Media LLC. - 1874-270X .- 1874-2718.
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Tidskriftsartikel (refereegranskat)abstract
- The staphylococcal enterotoxin H (SEH; 217 aa, 25 kD) belongs to a family of superantigens that cause a massive immune response upon simultaneous binding to the T cell receptor (TCR) and the major histocompatibility complex class II. The SEH-TCR interaction is weak and amenable to studies using NMR methodology. Essentially, 2 mg of U{(2)H, (13)C,(15)N}-labeled SEH was used for the complete sequential backbone assignment of SEH at 900 MHz. The protein secondary structure inferred from the chemical shift index (C(alpha) and C(beta)) is in very good agreement with the secondary structure elements of the X-ray structure.
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| 9. |
- Saline, Maria
(författare)
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Structural analyses of immune cell receptor signalling and activation
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Structural biology is a scientific field where the aim is to observe macromolecules on a atomic level to understand their functions. Often these macromolecules are proteins that make, almost, everything happen within the cells; from hormones and enzymes to building blocks and controlling gene expression. With structural biology tools, scientists can visualize structures, interactions and mobility within the proteins to get an insight in the chain of events in a cell. In this thesis, the function of signalling has been in focus. Both signalling within the immune system through a membrane bound receptor that finds an invading pathogen and signals into the cells “alert, we have an invader” where the immune system reacts. How the signalling passes from the outside of the cell to the inside is still not revealed. One part of this thesis investigates the outside of an immune cell and the other, the inside, past the membrane. Proteins are chains of amino acids that are predestined to either fold into a stable structure or stay loose and flexible. Superantigens are very stable proteins; they are toxins, made to last and conquer. The opposite are the intracellular flexible domains of the immune receptors which belong to a class of proteins, so-called intrinsically disordered proteins, IDPs, which are less investigated but omnipresent. In this thesis some flexible domains of the immune receptors have efficiently been produced in a cell free protein synthesis and examined by NMR, using a new setup of acquisition and analysis. All domains are lacking secondary structure and a well-defined three-dimensional structure. The proteins investigated more in depth within the work of this thesis, show tendency for α-helical regions, most likely of functional significance. Viruses are evolved to use its host and get a free ride. Here we explore the interaction of one SIV (orthologous to HIV) protein with one of the intracellular flexible domains of the T-cell receptor, which leads to down regulation of the receptor resulting in immune deficiency. This interaction is unique in that no changes in the very sensitive NMR spectra are seen; yet other techniques indicate specific interaction. As the SIV protein is abusing the immune system, superantigens hijack the immune system by crosslinking the T-cell receptor to an antigen-presenting cell displaying pieces of an invading pathogen on it´s surface, and by this start an extreme immune response, sometimes lethal. This superantigen can circumvent the intricate, specific and effective immune system and they are up to date thought to interact with the β-chain of the T-cell receptor. We show in this thesis by structural biology techniques such as x-ray and NMR that a superantigen interacts with the α-chain of the TCR. This is the first structure structurally determined ternary complex of an antigen-MHC-superantigen-TCR, a paradigm shift in superantigen biology.
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| 10. |
- Saline, Maria, et al.
(författare)
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The structure of superantigen complexed with TCR and MHC reveals novel insights into superantigenic T cell activation.
- 2010
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Ingår i: Nature communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 1:8
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Tidskriftsartikel (refereegranskat)abstract
- Superantigens (SAgs) are bacterial toxins that interact with immunoreceptors, T cell receptor (TCR) and major histocompatibility complex (MHC) class II, conventionally through the variable β-domain of TCR (TCRVβ). They induce a massive release of cytokines, which can lead to diseases such as food poisoning and toxic shock syndrome. In this study, we report the X-ray structure of the ternary complex between staphylococcal enterotoxin H (SEH) and its human receptors, MHC class II and TCR. The structure demonstrates that SEH predominantly interacts with the variable α-domain of TCR (TCRVα), which is supported by nuclear magnetic resonance (NMR) analyses. Furthermore, there is no contact between MHC and TCR upon complex formation. Structural analyses suggest that the major contact points to TCRVα are conserved among other bacterial SAgs. Consequently, a new dimension of SAg biology emerges, suggesting that in addition to the conventional interactions with the TCRVβ domain, SAgs can also activate T cells through the TCRVα domain.
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