       Document 0400
 DOCN  M9620400
 TI    Polypyrimidine tract-binding protein and heterogeneous nuclear
       ribonucleoprotein A1 bind to human T-cell leukemia virus type 2 RNA
       regulatory elements.
 DT    9602
 AU    Black AC; Luo J; Watanabe C; Chun S; Bakker A; Fraser JK; Morgan JP;
       Rosenblatt JD; Division of Hematology/Oncology, University of
       California, Los; Angeles 90095-1678, USA.
 SO    J Virol. 1995 Nov;69(11):6852-8. Unique Identifier : AIDSLINE
       MED/96013782
 AB    Efficient expression of human T-cell leukemia virus (HTLV) and human
       immunodeficiency virus structural proteins requires Rx and Rev proteins,
       respectively. Decreased expression of Gag and Env appears to be due, in
       part, to intragenic RNA sequences, termed cis-acting repressive
       sequences (CRS), and may be mediated by binding of specific cellular
       factors. We demonstrated previously that two cellular proteins, p60CRS
       and p40CRS, interact with HTLV type 2.5' long terminal repeat CRS RNA
       and that the interaction of both proteins with CRS RNA correlates with
       function (A. C. Black, C. T. Ruland, J. Luo, A. Bakker, J. K. Fraser,
       and J. D. Rosenblatt, Virology 200:29-41, 1994). By
       radioimmunoprecipitation of HeLa nuclear proteins UV cross-linked to CRS
       RNAs with murine monoclonal antibodies, we now show that p40CRS is
       heterogeneous nuclear ribonucleoprotein (hnRNP) A1 and p60CRS is
       polypyrimidine tract-binding protein or hnRNP I. These
       immunoprecipitation results were confirmed by an immunobinding assay
       with hnRNP I and hnRNP AI antibodies and by cross-competition
       electrophoretic mobility shift experiments. In addition, we mapped a
       putative hnRNP A1 binding site in U5 RNA and demonstrated that p40CRS
       (hnRNP A1) binding to that site correlates with CRS function. Since both
       hnRNP I and hnRNP A1 have been shown to influence splicing and
       potentially other steps in RNA processing, the binding of both hnRNP I
       and hnRNP A1 to HTLV RNA regulatory elements may alter retrovirus RNA
       processing and may be involved in regulation by Rex.
 DE    Base Sequence  Binding Sites  Chloramphenicol
       Acetyltransferase/BIOSYNTHESIS  Gene Expression  Gene Expression
       Regulation, Viral  Gene Products, env/BIOSYNTHESIS  Gene Products,
       gag/BIOSYNTHESIS  Human  HTLV-II/GENETICS/*PHYSIOLOGY  Molecular
       Sequence Data  Mutagenesis, Site-Directed  Oligodeoxyribonucleotides
       Oligonucleotides, Antisense  *Regulatory Sequences, Nucleic Acid
       Ribonucleoproteins/*METABOLISM  RNA-Binding Proteins/*METABOLISM
       Support, Non-U.S. Gov't  Support, U.S. Gov't, P.H.S.  Transfection
       JOURNAL ARTICLE

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

