title: Refined study of the interaction between HIV-1 p6 late domain and ALIX.
abstract: The interaction between the HIV-1 p6 late budding domain and ALIX, a class E vacuolar protein sorting factor, was explored by using the yeast two-hybrid approach. We refined the ALIX binding site of p6 as being the leucine triplet repeat sequence (Lxx)4 (LYPLTSLRSLFG). Intriguingly, the deletion of the C-terminal proline-rich region of ALIX prevented detectable binding to p6. In contrast, a four-amino acid deletion in the central hinge region of p6 increased its association with ALIX as shown by its ability to bind to ALIX lacking the proline rich domain. Finally, by using a random screening approach, the minimal ALIX391-510 fragment was found to specifically interact with this p6 deletion mutant. A parallel analysis of ALIX binding to the late domain p9 from EIAV revealed that p6 and p9, which exhibit distinct ALIX binding motives, likely bind differently to ALIX. Altogether, our data support a model where the C-terminal proline-rich domain of ALIX allows the access of its binding site to p6 by alleviating a conformational constraint resulting from the presence of the central p6 hinge.
authors.affiliation: Université Lyon 1, Centre National de Recherche Scientifique (CNRS), VirPatH FRE 3011, Faculté de Médecine RTH Laennec, Lyon, France. carine.lazert@recherche.univ-lyon1.fr
authors.forename: Carine
authors.initials: C
authors.lastname: Lazert
authors.forename: Nathalie
authors.initials: N
authors.lastname: Chazal
authors.forename: Laurence
authors.initials: L
authors.lastname: Briant
authors.forename: Denis
authors.initials: D
authors.lastname: Gerlier
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Cortay
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D002135:Calcium-Binding Proteins / Q000737:chemistry / Q000378:metabolism*; D018797:Cell Cycle Proteins / Q000737:chemistry / Q000378:metabolism*; D056827:Endosomal Sorting Complexes Required for Transport; D015497:HIV-1 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D009154:Mutation; D011485:Protein Binding; D020798:Two-Hybrid System Techniques; D054301:gag Gene Products, Human Immunodeficiency Virus / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
chemical_list: D002135:Calcium-Binding Proteins; D018797:Cell Cycle Proteins; D056827:Endosomal Sorting Complexes Required for Transport; C117020:PDCD6IP protein, human; D054301:gag Gene Products, Human Immunodeficiency Virus; C083002:p6 gag protein, Human immunodeficiency virus 1