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Distinct regions of cyclinT1 are required for binding to CDK9 and for recruitment to the HIV‐1 Tat/TAR complex
Author(s) -
Fraldi Alessandro,
Licciardo Paolo,
Majello Barbara,
Giordano Antonio,
Lania Luigi
Publication year - 2001
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.1149
Subject(s) - p tefb , cyclin dependent kinase 9 , transcription (linguistics) , yeast , rna polymerase ii , two hybrid screening , microbiology and biotechnology , biology , human immunodeficiency virus (hiv) , ctd , in vivo , elongation factor , tar (computing) , chemistry , rna , promoter , virology , genetics , gene expression , gene , ribosome , protein kinase a , kinase , mitogen activated protein kinase kinase , philosophy , linguistics , oceanography , computer science , programming language , geology
Abstract Tat‐mediated activation of the HIV‐1 promoter activity requires Tat‐dependent recruitment of the cyclinT1/CDK9 complex (P‐TEFb) to the transacting element (TAR) RNA. Tat interaction with the cyclinT1, the regulatory partner of CDK9, results in a specific recruitment of the heterodimer CycT1/CDK9 complex to TAR, whereby it promotes transcription elongation of the HIV‐1 LTR‐mediated transcription. Using the yeast two‐hybrid protein interaction assay we analyzed the binding between cyclinT1 and CDK9. Moreover, using a modified three‐hybrid yeast interaction system, we analyzed the recruitment of CycT1 to the Tat/TAR complex. The data presented here demonstrated that distinct domains of cyclinT1 interact with CDK9 and Tat/TAR in vivo. These findings will be instrumental for the designing of proper dominant‐negative P‐TEFb components capable to interfere with Tat function. J. Cell. Biochem. Suppl. 36: 247–253, 2001. © 2001 Wiley‐Liss, Inc.