HIV-1 Nef binds with human GCC185 protein and regulates mannose 6 phosphate receptor recycling.
HIV-1 Nef modulates cellular function that enhances viral replication in vivo which culminate into AIDS pathogenesis. With no enzymatic activity, Nef regulates cellular function through host protein interaction. Interestingly, trans-cellular introduction of recombinant Nef protein in Caenorhabditis elegans results in AIDS like pathogenesis which might share common pathophysiology because the gene sequence of C. elegans and humans share considerable homology. Therefore employing C. elegans based initial screen complemented with sequence based homology search we identified GCC185 as novel host protein interacting with HIV-1 Nef. The detailed molecular characterization revealed N-terminal EEEE65 acidic domain of Nef as key region for interaction. GCC185 is a tethering protein that binds with Rab9 transport vesicles. Our results show that Nef-GCC185 interaction disrupts Rab9 interaction resulting in delocalization of CI-MPR (cation independent Mannose 6 phosphate receptor) resulting in elevated secretion of hexosaminidase. In agreement with this, our studies identified novel host GCC185 protein that interacts with Nef EEEE65 acidic domain interfering GCC185-Rab9 vesicle membrane fusion responsible for retrograde vesicular transport of CI-MPR from late endosomes to TGN. In light of existing report suggesting critical role of Nef-GCC185 interaction reveals valuable mechanistic insights affecting specific protein transport pathway in docking of late endosome derived Rab9 bearing transport vesicle at TGN elucidating role of Nef during viral pathogenesis.
Toxicology Division, CSIR-Central Drug Research Institute, Lucknow, UP, 226031, India.
Manjeet
M
Kumar
Toxicology Division, CSIR-Central Drug Research Institute, Lucknow, UP, 226031, India.
Supinder
S
Kaur
Toxicology Division, CSIR-Central Drug Research Institute, Lucknow, UP, 226031, India.
Aamir
A
Nazir
Toxicology Division, CSIR-Central Drug Research Institute, Lucknow, UP, 226031, India. Electronic address: rajkamalcdri@gmail.com.
Raj Kamal
RK
Tripathi
D001665:Binding Sites; D005786:Gene Expression Regulation / Q000502:physiology*; D000077614:Golgi Matrix Proteins; D006801:Humans; D008565:Membrane Proteins / Q000378:metabolism*; D011485:Protein Binding; D025941:Protein Interaction Mapping / Q000379:methods; D017527:Receptor, IGF Type 2 / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*; D054311:nef Gene Products, Human Immunodeficiency Virus / Q000378:metabolism*
C472299:GCC2 protein, human; D000077614:Golgi Matrix Proteins; D008565:Membrane Proteins; D017527:Receptor, IGF Type 2; D054311:nef Gene Products, Human Immunodeficiency Virus; C514837:nef protein, Human immunodeficiency virus 1
Caenorhadbitis elegans; Human homolog; In situ proximity ligation assay; Late endosome trafficking; Lysosome; Mammalian two hybrid assay; Protein–protein interaction; Regulation of MPRs cycle; trans-Golgi network