title: Interactions of HIV-1 nef with the mu subunits of adaptor protein complexes 1, 2, and 3: role of the dileucine-based sorting motif.
abstract: HIV-1 Nef interacts with cellular adaptor protein (AP) complexes and their medium (mu) subunits. However, the role of the dileucine-based sorting motif within Nef in these interactions has been incompletely characterized. Here, yeast two-hybrid assays indicated that HIV-1 Nef interacted not only with the mu subunits of AP-1 and AP-2, but also with that of AP-3. The interactions with mu1 and mu3 were markedly stronger than the interaction with mu2. Leucine residues of the sorting motif were required for the interactions with mu3 and mu2 and contributed to the interaction with mu1. Confocal immunofluorescence microscopy indicated that Nef, AP-1, and AP-3 (but not AP-2) were concentrated in a juxtanuclear region near the cell center, potentially facilitating interaction between Nef and the mu1 and mu3 subunits. However, leucine residues of the sorting motif were not required for this subcellular localization of Nef. These data suggest that the dileucine motif, required for optimal viral replication, functions through interactions with a variety of AP complexes, including AP-3, potentially by recruiting adaptor complexes to subcellular locations specified by additional determinants in the Nef protein.
authors.affiliation: Department of Pathology and, Department of Medicine, San Diego Veterans Affairs Medical Center, University of California at San Diego, 9500 Gilman Drive, La Jolla, California, 92093-0679, USA.
authors.forename: H M
authors.initials: HM
authors.lastname: Craig
authors.forename: T R
authors.initials: TR
authors.lastname: Reddy
authors.forename: N L
authors.initials: NL
authors.lastname: Riggs
authors.forename: P P
authors.initials: PP
authors.lastname: Dao
authors.forename: J C
authors.initials: JC
authors.lastname: Guatelli
mesh_terms: D033961:Adaptor Protein Complex 1; D033962:Adaptor Protein Complex 2; D033963:Adaptor Protein Complex 3; D033965:Adaptor Protein Complex alpha Subunits; D033983:Adaptor Protein Complex mu Subunits; D033942:Adaptor Proteins, Vesicular Transport; D015153:Blotting, Western; D004591:Electrophoresis, Polyacrylamide Gel; D015693:Gene Products, nef / Q000378:metabolism*; D015497:HIV-1; D007930:Leucine; D008565:Membrane Proteins / Q000378:metabolism*; D008856:Microscopy, Fluorescence; D034041:Monomeric Clathrin Assembly Proteins; D011487:Protein Conformation; D013329:Structure-Activity Relationship; D054311:nef Gene Products, Human Immunodeficiency Virus
chemical_list: D033961:Adaptor Protein Complex 1; D033962:Adaptor Protein Complex 2; D033963:Adaptor Protein Complex 3; D033965:Adaptor Protein Complex alpha Subunits; D033983:Adaptor Protein Complex mu Subunits; D033942:Adaptor Proteins, Vesicular Transport; D015693:Gene Products, nef; D008565:Membrane Proteins; D034041:Monomeric Clathrin Assembly Proteins; C499066:adaptor protein complex 1, mu 1 subunit; C499065:adaptor protein complex 1, mu 2 subunit; C438885:adaptor protein complex 2, mu 1 subunit; C438886:adaptor protein complex 2, mu 2 subunit; C439023:clathrin assembly protein AP180; D054311:nef Gene Products, Human Immunodeficiency Virus; D007930:Leucine