The HIV-1 matrix protein does not interact directly with the protein interactive domain of AP-3δ.
During the late phase of the Human Immunodeficiency Virus Type-1 (HIV-1) replication cycle, viral Gag proteins and the intact RNA genome are trafficked to specific sub-cellular membranes where virus assembly and budding occurs. Targeting to the plasma membranes of T cells and macrophages is mediated by interactions between the N-terminal matrix (MA) domain of Gag and cellular phosphatidylinositol-4,5-bisphosphate [PI(4,5)P(2)] molecules. However, in macrophages and dendritic cells, a subset of Gag proteins appears to be targeted to tetraspanin enriched viral compartments, a process that appears to be mediated by MA interactions with the Delta subunit of the cellular Adaptor Protein AP-3 (AP-3δ). We cloned, overexpressed and purified the protein interactive domain of AP-3δ and probed for MA binding by NMR. Unexpectedly, no evidence of binding was observed in these in vitro experiments, even at relatively high protein concentrations (200μM), suggesting that AP-3δ plays an alternative role in HIV-1 assembly.
Howard Hughes Medical Institute, Department of Chemistry and Biochemistry, University of Maryland, Baltimore County, Baltimore, MD 21250, USA.
Sampson K
SK
Kyere
Peter Y
PY
Mercredi
Xinhong
X
Dong
Paul
P
Spearman
Michael F
MF
Summers
D033963:Adaptor Protein Complex 3 / Q000235:genetics / Q000378:metabolism*; D033981:Adaptor Protein Complex delta Subunits / Q000235:genetics / Q000378:metabolism*; D003001:Cloning, Molecular; D015870:Gene Expression; D015488:HIV Antigens / Q000378:metabolism*; D015497:HIV-1 / Q000502:physiology*; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D011485:Protein Binding; D025941:Protein Interaction Mapping; D019065:Virus Assembly; D054301:gag Gene Products, Human Immunodeficiency Virus / Q000378:metabolism*
C491904:AP3D1 protein, human; D033963:Adaptor Protein Complex 3; D033981:Adaptor Protein Complex delta Subunits; D015488:HIV Antigens; D054301:gag Gene Products, Human Immunodeficiency Virus; C054858:p17 protein, Human Immunodeficiency Virus Type 1