1742-4690-6-S2-O15 1742-4690 Oral presentation <p>Targeting of MuLV Gag to the plasma membrane is mediated by PI(4,5)P<sub>2 </sub>and PhosphatidylSerine</p> Hamard-Peron E Juilliard F Saad JS Roy C Roingeard P Summers F Michael Darlix JL Picart C Muriaux D

LaboRetro, InsermU758, ENS de Lyon, IFR128, 69364 Lyon, France

Howard Hughes Medical Institute and Department of Chemistry and Biochemistry, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, Maryland 21250, USA

Department of Microbiology, University of Alabama at Birmingham, 845 19th street south, Birmingham, AL 35294, USA

CNRS-UMR 5235, Université de Montpellier 2, Montpellier, France

Inserm U966, Université François Rabelais, Tours, France

CNRS-UMR 5628, LMGP, 3 parvis L. Neel, 38016 Grenoble, France

 Retrovirology <p>Frontiers of Retrovirology: Complex retroviruses, retroelements and their hosts</p> Meeting abstracts - A single PDF containing all abstracts in this Supplement is available here. http://www.biomedcentral.com/content/pdf/1742-4690-6-S2-info.pdf <p>Frontiers of Retrovirology: Complex retroviruses, retroelements and their hosts</p> Montpellier, France 21-23 September 2009 http://www.frontiersofretrovirology.com 1742-4690 2009 6 Suppl 2 O15 http://www.retrovirology.com/content/6/S2/O15 10.1186/1742-4690-6-S2-O15 24 9 2009 2009 Hamard-Peron et al; licensee BioMed Central Ltd.

Membrane targeting by the modern human immunodeficiency viruses is dependent on the plasma membrane-located phospholipid PI(4,5)P2. In order to determine if evolutionarily distant retroviruses are targeted by a similar mechanism, we generated mutant Gag constructs in the matrix (MA) domain of the Murine Leukemia Virus (MuLV) and examined their binding to membrane models and phenotypes in cell culture. Mutations in the MA polybasic region altered Gag localization, membrane binding and virion production. In addition, we show that MA binds with good affinity to all the phosphatidylinositol phosphates but displays a strong specificity for PI(4,5)P2 only if enhanced by phophatidylserine. Virus production was strongly impaired by PI(4,5)P2 depletion under 5ptaseIV overexpression. Our results suggest that the N-terminal polybasic region of MA is essential for Gag targeting to the plasma membrane and Gag cellular trafficking. The binding of the MA domain to PI(4,5)P2 appears to be a conserved feature among retroviruses, despite the fact that the MuLV-MA domain is structurally different from that of HIV-1 and -2 and lacks a readily identifiable PI(4,5)P2 binding cleft.