Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.3.1.28 (chloramphenicol acetyltransferase)
 5,100 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Phosphorylation of HeLa SII (or TFIIS)-related nuclear protein p21/SIIR was demonstrated in transfected COS-1 cells. To test for a possible functional link between phosphorylation and the previously described Rous sarcoma virus (RSV) long terminal repeat (LTR) repression (Yeh, C.H., and Shatkin, A.J. (1994) Proc. Natl. Acad. Sci. U.S.A. 91, 11002-11006), p21/SIIR mutants were constructed and assayed for phosphorylation level and effect on RSV LTR-driven chloramphenicol acetyltransferase (CAT) reporter expression. A major phosphorylation target in p21/SIIR was localized to the Arg/Ser-rich region between amino acids 12 and 49. Deletion of this region impaired the ability of p21/SIIR to down-regulate RSV LTR promoter function. Four serine pairs, all displaying the Arg/Lys-Ser-Ser motif typical of phosphorylation sites, are present in p21/SIIR between positions 31 and 48. Conversion of these individual serine pairs to alanine resulted in decreased phosphorylation in each case. Mutation of the Ser36-Ser37 pair also diminished by severalfold the repression activity of p21/SIIR. The single tyrosine (Tyr155) in p21/SIIR was not detectably phosphorylated in transfected COS-1 cells, suggesting that the Ser36-Ser37 pair mediates Ser/Thr phosphorylation of p21/SIIR and is critical for LTR repression function.
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PMID:The Ser36-Ser37 pair in HeLa nuclear protein p21/SIIR mediates Ser/Thr phosphorylation and is essential for Rous sarcoma virus long terminal repeat repression. 759 88