Previous Article | Next Article ![]()
J. Virol., 11 1995, 6852-6858, Vol 69, No. 11
AC Black, J Luo, C Watanabe, S Chun, A Bakker, JK Fraser, JP Morgan and JD Rosenblatt
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.
Copyright © 1995, American Society for Microbiology
Polypyrimidine tract-binding protein and heterogeneous nuclear ribonucleoprotein A1 bind to human T-cell leukemia virus type 2 RNA regulatory elements
Division of Hematology/Oncology, University of California, Los Angeles 90095-1678, USA.
This article has been cited by other articles:
| J. Bacteriol. | Mol. Cell. Biol. | Microbiol. Mol. Biol. Rev. |
|---|
| Clin. Vaccine Immunol. | ALL ASM JOURNALS |
|---|