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Suppression of HIV‐1 transcriptional elongation by a DING phosphatase
Author(s) -
Darbinian Nune,
Gomberg Rebeccah,
Mullen Loriann,
Garcia Samantha,
White Martyn K.,
Khalili Kamel,
Amini Shohreh
Publication year - 2011
Publication title -
journal of cellular biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.028
H-Index - 165
eISSN - 1097-4644
pISSN - 0730-2312
DOI - 10.1002/jcb.22915
Subject(s) - long terminal repeat , transcription (linguistics) , rna polymerase ii , microbiology and biotechnology , phosphatase , biology , phosphorylation , gene , promoter , gene expression , chemistry , genetics , linguistics , philosophy
HIV‐1 gene transcription is controlled by the cooperation of viral and host factors which bind to specific DNA sequences within the viral promoter spanning the long terminal repeat (LTR). Previously we showed that the St. John's Wort DING phosphatase, p27SJ, suppresses HIV‐1 gene transcription by binding to the viral protein Tat and preventing its nuclear import. Here, we describe the inhibitory effect of p27SJ on the phosphorylation of the C‐terminal domain (CTD) of RNA polymerase II (RNAPII). This inhibition leads to the suppression of the association of RNAPII with the LTR. Inhibition of binding of RNAPII to LTR by p27SJ resulted in the suppression of LTR transcription elongation and a decrease in LTR transcriptional activity. Another form of the St. John's Wort DING phosphatase, p38SJ, also suppressed binding of RNAPII to the LTR, reduced transcription elongation and was even more powerful than p27SJ in inhibiting the transcriptional activity of the LTR. Our data suggest a possible mechanism by which the p27SJ/p38SJ DING phosphatase can regulate HIV‐1 LTR expression by inhibiting phosphorylation of the CTD of RNAPII and suppressing LTR transcription elongation. J. Cell. Biochem. 112: 225–232, 2011. © 2010 Wiley‐Liss, Inc.