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dc.contributor.authorYik, JHN
dc.contributor.authorChen, RC
dc.contributor.author陈瑞川
dc.contributor.authorPezda, AC
dc.contributor.authorZhou, Q
dc.contributor.author周强
dc.date.accessioned2011-10-02T13:21:01Z
dc.date.available2011-10-02T13:21:01Z
dc.date.issued2005
dc.identifier.citationJOURNAL OF BIOLOGICAL CHEMISTRY,v280, issue16,pp368-16376.zh_CN
dc.identifier.issn0021-9258
dc.identifier.urihttp://dx.doi.org/doi:10.1074/jbc.M500912200
dc.identifier.urihttps://dspace.xmu.edu.cn/handle/2288/10819
dc.description.abstractHuman positive transcriptional elongation factor b (P-TEFb), consisting of a cyclin-dependent kinase 9-cyclin T heterodimer, stimulates general and disease-specific transcriptional elongation by phosphorylating RNA polymerase II. The HEXIM1 protein, aided by the 7SK snRNA, sequesters P-TEFb into an inactive 7SK center dot HEXIM1 center dot P-TEFb small nuclear ribonucleic acid particle for inhibition of transcription and, consequently, cell proliferation. Here we show that, like HEXIM1, a highly homologous protein named HEXIM2 also possesses the ability to inactivate P-TEFb to suppress transcription through a 7SK-mediated interaction with P-TEFb. Furthermore, HEXIM1 and HEXIM2 can form stable homo- and hetero-oligomers ( most likely dimers), which may nucleate the formation of the 7SK small nuclear ribonucleic acid particle. Despite their similar functions, HEXIM1 and HEXIM2 exhibit distinct expression patterns in various human tissues and established cell lines. In HEXIM1-knocked down cells, HEXIM2 can functionally and quantitatively compensate for the loss of HEXIM1 to maintain a constant level of the 7SK/ HEXIM-bound P-TEFb. Our results demonstrate that there is a tightly regulated cellular process to maintain the balance between active and inactive P-TEFb complexes, which controls global transcription as well as cell growth and differentiation.zh_CN
dc.language.isoenzh_CN
dc.publisherAMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INCzh_CN
dc.titleCompensatory contributions of HEXIM1 and HEXIM2 in maintaining the balance of active and inactive positive transcription elongation factor b complexes for control of transcriptionzh_CN
dc.typeArticlezh_CN


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