Signaling but not trafficking function of HIV-1 protein Nef is essential for Nef-induced defects in human intrathymic T-cell development.
The HIV-1 gene nef is important for progression toward AIDS and cellular depletion of the infected thymus. Expression of the Nef protein alone impairs human thymopoiesis. Here, we performed a structure-function analysis of the Nef protein by comparing the effect on T-cell development of different nef alleles, either wild type or defective for selected functions, expressed by human thymocytes. We show that Nef-mediated impaired thymopoiesis is not due to altered surface marker trafficking, nor dependent on oligomerization of Nef. By contrast, mutations in the myristoylation site and in signaling sites of Nef, ie, sites important for interaction with phosphofurin acidic cluster sorting protein-1 (PACS-1), Src homology domain 3 (SH3) domains, and p21-activated kinase 2 (PAK2), were found to be critical for its effect on T-cell development. These results point to sites in Nef to target therapeutically for restoration of thymopoiesis in HIV infection.
Stove
Veronique
V
Department of Clinical Chemistry, Microbiology, and Immunology, Ghent University, Ghent University Hospital, Belgium.
Naessens
Evelien
E
Stove
Christophe
C
Swigut
Tomek
T
Plum
Jean
J
Verhasselt
Bruno
B
D000483:Alleles; D000911:Antibodies, Monoclonal / Q000378:metabolism; D018952:Antigens, CD34 / Q000096:biosynthesis; D002352:Carrier Proteins / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D002469:Cell Separation; D019281:Dimerization; D015536:Down-Regulation; D005434:Flow Cytometry; D015693:Gene Products, nef / Q000378:metabolism*; D018014:Gene Transfer Techniques; D006801:Humans; D009154:Mutation; D019814:Myristic Acid / Q000378:metabolism; D010957:Plasmids / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D017434:Protein Structure, Tertiary; D012190:Retroviridae / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D013234:Stem Cells / Q000378:metabolism; D013601:T-Lymphocytes / Q000378:metabolism*; D013950:Thymus Gland / Q000166:cytology* / Q000378:metabolism; D033921:Vesicular Transport Proteins; D054462:p21-Activated Kinases; D018909:src Homology Domains
D000911:Antibodies, Monoclonal; D018952:Antigens, CD34; D002352:Carrier Proteins; D015693:Gene Products, nef; C491914:PACS1 protein, human; D033921:Vesicular Transport Proteins; D019814:Myristic Acid; C515907:PAK2 protein, human; D017346:Protein Serine-Threonine Kinases; D054462:p21-Activated Kinases