5lmy

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== Publication Abstract from PubMed ==
== Publication Abstract from PubMed ==
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We determined the solution structure of myristoylated Mason-Pfizer monkey virus matrix protein by NMR spectroscopy. The myristoyl group is buried inside the protein and causes a slight reorientation of the helices. This reorientation leads to the creation of a binding site for phosphatidylinositols. The interaction between the matrix protein and phosphatidylinositols carrying C(8) fatty acid chains was monitored by observation of concentration-dependent chemical shift changes of the affected amino acid residues, a saturation transfer difference experiment and changes in (31)P chemical shifts. No differences in the binding mode or affinity were observed with differently phosphorylated phosphatidylinositols. The structure of the matrix protein-phosphatidylinositol-(4,5)-bisphosphate [PI(4,5)P(2)] complex was then calculated with HADDOCK software based on the intermolecular nuclear Overhauser enhancement contacts between the ligand and the matrix protein obtained from a (13)C-filtered/(13)C-edited nuclear Overhauser enhancement spectroscopy experiment. PI(4,5)P(2) binding was not strong enough for triggering of the myristoyl-switch. The structural changes of the myristoylated matrix protein were also found to result in a drop in the oligomerization capacity of the protein.
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Matrix proteins play a key role in the transport of retroviral proteins inside infected cells and in the interaction with cellular membranes. In most retroviruses, retroviral matrix proteins are N-terminally myristoylated. This modification serves as a membrane targeting signal and also as an anchor for the membrane interaction. The aim of this work was to characterize interactions anchoring retroviral matrix protein at the plasma membrane of infected cell. To address this issue, we compared the structures and membrane affinity of the Mason-Pfizer monkey virus (M-PMV) wild-type matrix protein with its two budding deficient double mutants, i.e. T41I/T78I and Y28F/Y67F. The structures of the mutants were determined using solution NMR spectroscopy and their interactions with water-soluble phospholipids were studied. Water-soluble phospholipids are widely used models for studying membrane interactions by solution NMR spectroscopy. However, this approach might lead to artificial results due to unnatural hydrophobic interactions. Therefore, we used a new approach based on the measurement of the loss of the 1H NMR signal intensity of the protein sample induced by the addition of the liposomes containing phospholipids with naturally long fatty acids. HIV-1 matrix protein was used as a positive control because its ability to interact with liposomes has already been described. We found that in contrast to HIV-1, the M-PMV matrix protein interacted with the liposomes differently and much weaker. In our in-vivo experiments, the M-PMV matrix protein did not co-localize with lipid rafts. Therefore, we concluded that M-PMV might adopt different membrane binding mechanism than HIV-1.
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The Structure of Myristoylated Mason-Pfizer Monkey Virus Matrix Protein and the Role of Phosphatidylinositol-(4,5)-Bisphosphate in Its Membrane Binding.,Prchal J, Srb P, Hunter E, Ruml T, Hrabal R J Mol Biol. 2012 Aug 2. PMID:22863803<ref>PMID:22863803</ref>
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Membrane interactions of the Mason-Pfizer monkey virus matrix protein and its budding deficient mutants.,Kroupa T, Langerova H, Dolezal M, Prchal J, Spiwok V, Hunter E, Rumlova M, Hrabal R, Ruml T J Mol Biol. 2016 Oct 7. pii: S0022-2836(16)30425-9. doi:, 10.1016/j.jmb.2016.10.010. PMID:27725181<ref>PMID:27725181</ref>
From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>

Revision as of 09:25, 19 October 2016

Solution structure of the m-pmv myristoylated matrix protein

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