Interaction of human immunodeficiency virus type 1 Vif with APOBEC3G is not dependent on serine/threonine phosphorylation status.
The human immunodeficiency virus type 1 accessory protein Vif is important for viral infectivity because it counteracts the antiviral protein APOBEC3G (A3G). ³²P metabolic labelling of stimulated cells revealed in vivo phosphorylation of the control protein, whereas no serine/threonine phosphorylation was detected for Vif or the A3G protein. These data were confirmed by in vitro kinase assays using active recombinant kinase. Mitogen-activated protein kinase/extracellular signal-regulated kinase 2 efficiently phosphorylated its target ELK, but failed to phosphorylate Vif. Putative serine/threonine phosphorylation point mutations in Vif (T96, S144, S165, T188) using single-round infection assays demonstrated that these mutations did not alter Vif activity, with the exception of Vif.T96E. Interestingly, T96E and not T96A was functionally impaired, indicating that this residue is critical for Vif-A3G physical interaction and activity. Our data suggest that Vif and A3G are not serine/threonine phosphorylated in human cells and phosphorylation is not linked to their functional activities.
Division of Medical Biotechnology, Paul-Ehrlich-Institut, Langen, Germany.
Ferdinand
F
Kopietz
Clinic for Gastroenterology, Hepatology and Infectiology, Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany.
Ananda Ayyappan
AA
Jaguva Vasudevan
Clinic for Gastroenterology, Hepatology and Infectiology, Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany.
Melanie
M
Krämer
Division of Medical Biotechnology, Paul-Ehrlich-Institut, Langen, Germany.
Heide
H
Muckenfuss
Division of Medical Biotechnology, Paul-Ehrlich-Institut, Langen, Germany.
Ralf
R
Sanzenbacher
Division of Medical Biotechnology, Paul-Ehrlich-Institut, Langen, Germany.
Klaus
K
Cichutek
Division of Medical Biotechnology, Paul-Ehrlich-Institut, Langen, Germany.
Egbert
E
Flory
Clinic for Gastroenterology, Hepatology and Infectiology, Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany.
Carsten
C
Münk
D000071480:APOBEC-3G Deaminase; D000595:Amino Acid Sequence; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2 / Q000235:genetics / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases; D003564:Cytidine Deaminase / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation; D057809:HEK293 Cells; D015497:HIV-1 / Q000145:classification* / Q000235:genetics; D006801:Humans; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D020929:Mitogen-Activated Protein Kinase Kinases; D010766:Phosphorylation; D017354:Point Mutation; D012694:Serine / Q000378:metabolism; D013912:Threonine / Q000378:metabolism; D054320:vif Gene Products, Human Immunodeficiency Virus / Q000235:genetics / Q000378:metabolism*
D054320:vif Gene Products, Human Immunodeficiency Virus; C514847:vif protein, Human immunodeficiency virus 1; D013912:Threonine; D012694:Serine; D017868:Cyclic AMP-Dependent Protein Kinases; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D019950:Mitogen-Activated Protein Kinase 1; D020929:Mitogen-Activated Protein Kinase Kinases; D000071480:APOBEC-3G Deaminase; C464924:APOBEC3G protein, human; D003564:Cytidine Deaminase