Author/Editor		Zhang, Fan; Barborič, Matjaž; Blackwell, T Keith; Peterlin, Matjaž
Title		A model of repression: CTD analogs and PIE-1 inhibit transcriptional elongation by P-TEFb
Type		članek
Source		Genes Dev
Vol. and No.		Letnik 17, št. 6
Publication year		2003
Volume		str. 748-58
Language		eng
Abstract		The positive transcription elongation factor b (P-TEFb) contains cyclin T1 (CycT1) and cyclin-dependent kinase 9 (Cdk9). For activating the expression of eukaryotic genes, the histidine-rich sequence in CycT1 binds the heptapeptide repeats in the C-terminal domain (CTD) of RNA polymerase II (RNAPII), whereupon Cdk9 phosphorylates the CTD. We found that alanine-substituted heptapeptide repeats that cannot be phosphorylated also bind CycT1. When placed near transcription units, these CTD analogs block effects of P-TEFb. Remarkably, the transcriptional repressor PIE-1 from Caenorhabditis elegans behaves analogously. It binds CycT1 via an alanine-containing heptapeptide repeat and inhibits transcriptional elongation. Thus, our findings reveal a new mechanism by which repressors inhibit eukaryotic transcription.
Descriptors		NUCLEAR PROTEINS PROTEIN-SERINE-THREONINE KINASES RNA POLYMERASE II PROTEIN STRUCTURE, TERTIARY ALANINE BINDING SITES BINDING, COMPETITIVE BLOTTING, WESTERN COS CELLS CAENORHABDITIS ELEGANS CYCLIN-DEPENDENT KINASES GLUTAMIC ACID HELA CELLS HISTIDINE MODELS, GENETIC MUTATION PEPTIDES PHOSPHORYLATION PLASMIDS PROTEIN BINDING RIBONUCLEASES SERINE TRANS-ACTIVATION (GENETICS) TRANSCRIPTION, GENETIC TRANSFECTION