       Document 0201
 DOCN  M9610201
 TI    Double-stranded-RNA-dependent protein kinase and TAR RNA-binding protein
       form homo- and heterodimers in vivo.
 DT    9601
 AU    Cosentino GP; Venkatesan S; Serluca FC; Green SR; Mathews MB; Sonenberg
       N; Department of Biochemistry, McGill University, Montreal, QC; Canada.
 SO    Proc Natl Acad Sci U S A. 1995 Oct 10;92(21):9445-9. Unique Identifier :
       AIDSLINE MED/96003795
 AB    The yeast two-hybrid system and far-Western protein blot analysis were
       used to demonstrate dimerization of human double-stranded RNA
       (dsRNA)-dependent protein kinase (PKR) in vivo and in vitro. A
       catalytically inactive mutant of PKR with a single amino acid
       substitution (K296R) was found to dimerize in vivo, and a mutant with a
       deletion of the catalytic domain of PKR retained the ability to
       dimerize. In contrast, deletion of the two dsRNA-binding motifs in the
       N-terminal regulatory domain of PKR abolished dimerization. In vitro
       dimerization of the dsRNA-binding domain required the presence of dsRNA.
       These results suggest that the binding of dsRNA by PKR is necessary for
       dimerization. The mammalian dsRNA-binding protein TRBP, originally
       identified on the basis of its ability to bind the transactivation
       region (TAR) of human immunodeficiency virus RNA, also dimerized with
       itself and with PKR in the yeast assay. Taken together, these results
       suggest that complexes consisting of different combinations of
       dsRNA-binding proteins may exist in vivo. Such complexes could mediate
       differential effects on gene expression and control of cell growth.
 DE    Amino Acid Sequence  Human  Molecular Sequence Data  Protein Binding
       Protein Conformation  Protein-Serine-Threonine
       Kinases/GENETICS/*METABOLISM  Recombinant Fusion Proteins/METABOLISM
       RNA-Binding Proteins/GENETICS/*METABOLISM  Sequence Deletion
       Structure-Activity Relationship  Support, Non-U.S. Gov't  Support, U.S.
       Gov't, P.H.S.  Trans-Activation (Genetics)  JOURNAL ARTICLE

       SOURCE: National Library of Medicine.  NOTICE: This material may be
       protected by Copyright Law (Title 17, U.S.Code).

