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PACT, a protein activator of the interferon‐induced protein kinase, PKR
Author(s) -
Patel Rekha C.,
Sen Ganes C.
Publication year - 1998
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1093/emboj/17.15.4379
Subject(s) - protein kinase r , pact , activator (genetics) , biology , interferon , eif 2 kinase , protein kinase a , microbiology and biotechnology , rna silencing , antiviral protein , signal transduction , kinase , rna , virology , rna interference , mitogen activated protein kinase kinase , cyclin dependent kinase 2 , biochemistry , gene , history , archaeology
PKR, a latent protein kinase, mediates the antiviral actions of interferon. It is also involved in cellular signal transduction, apoptosis, growth regulation and differentiation. Although in virus‐infected cells, viral double‐stranded (ds) RNA can serve as a PKR activator, cellular activators have remained obscure. Here, we report the cloning of PACT, a cellular protein activator of PKR. PACT heterodimerized with PKR and activated it in vitro in the absence of dsRNA. In mammalian cells, overexpression of PACT caused PKR activation and, in yeast, co‐expression of PACT enhanced the anti‐growth effect of PKR. Thus, PACT has the hallmarks of a direct activator of PKR.