TY - JOUR
T1 - HIV-1 Tat Directly Interacts with the Interferon-Induced, Double-Stranded RNA-Dependent Kinase, PKR
AU - McMillan, Nigel A.J.
AU - Chun, Rene F.
AU - Siderovski, David P.
AU - Galabru, Julien
AU - Toone, W. Mark
AU - Samuel, Charles E.
AU - Mak, Tak W.
AU - Hovanessian, Ara G.
AU - Jeang, Kuan Teh
AU - Williams, Bryan R.G.
N1 - Funding Information:
This investigation was supported by NIAID grants, RO1 AI-34039 and AI-20611, a grant from the Human Frontier Science program to B.R.G.W and A.G.H, and the AIDS Targeted Anti-Viral program from the Office of the Director, NIH. D.P.S. was supported by a Ph.D. studentship from the MRC (Canada). We thank Drs. Robert Silverman and M. Berkirane for invaluable advice, Dr. Ian Clark-Lewis (Vancouver) for synthetic Tat protein, Drs. Michael Katze and Glen Barber for PKR polyclonal antibody, and Dr. William Merrick for mammalian eIF2. Thanks also go to Juliet Sheldon and Lorenz Truemper for technical support. Antiserum to Tat from Dr. Bryan Cullen (Hauber et al., 1987) was obtained through the AIDS Research and Reference Reagent Program, Division of AIDS, NIAID, NIH.
PY - 1995/11
Y1 - 1995/11
N2 - We present evidence that the HIV-1 Tat protein and the RNA-dependent cellular protein kinase, PKR, interact with each other bothin vitroandin vivo.Using GST fusion chromatography, we demonstrate that PKR, interacts directly with the HIV-1 Tat protein. The region in Tat sufficient for binding PKR maps within amino acids 20 to 72. Inin vitroassays, the two-exon form of Tat (Tat 86) was phosphorylated by PKR, while the one exon form of Tat (Tat 72) inhibited PKR autophosphorylation and substrate phosphorylation. The ability of Tat to interact with PKR was demonstrated in both yeast and mammalian cells. Expression of PKR in yeast results in a growth suppressor phenotype which was reversed by coexpression of a one exon form of Tat. Expression of Tat 72 in HeLa cells resulted in direct interaction with PKR as detected by coimmunprecipitation with a Tat antibody. Tat and PKR also form a coimmunoprecipitable complex in cell-free extracts prepared from productively infected T lymphocytes. The interaction of Tat with PKR provides a potential mechanism by which HIV could suppress the interferon system.
AB - We present evidence that the HIV-1 Tat protein and the RNA-dependent cellular protein kinase, PKR, interact with each other bothin vitroandin vivo.Using GST fusion chromatography, we demonstrate that PKR, interacts directly with the HIV-1 Tat protein. The region in Tat sufficient for binding PKR maps within amino acids 20 to 72. Inin vitroassays, the two-exon form of Tat (Tat 86) was phosphorylated by PKR, while the one exon form of Tat (Tat 72) inhibited PKR autophosphorylation and substrate phosphorylation. The ability of Tat to interact with PKR was demonstrated in both yeast and mammalian cells. Expression of PKR in yeast results in a growth suppressor phenotype which was reversed by coexpression of a one exon form of Tat. Expression of Tat 72 in HeLa cells resulted in direct interaction with PKR as detected by coimmunprecipitation with a Tat antibody. Tat and PKR also form a coimmunoprecipitable complex in cell-free extracts prepared from productively infected T lymphocytes. The interaction of Tat with PKR provides a potential mechanism by which HIV could suppress the interferon system.
UR - http://www.scopus.com/inward/record.url?scp=0028840839&partnerID=8YFLogxK
U2 - 10.1006/viro.1995.0014
DO - 10.1006/viro.1995.0014
M3 - Article
C2 - 7491766
AN - SCOPUS:0028840839
SN - 0042-6822
VL - 213
SP - 413
EP - 424
JO - Virology
JF - Virology
IS - 2
M1 - 70014
ER -