J 2006

Hexim1 sequesters positive transcription elongation factor b from the class II transactivator on MHC class II promoters

KOHOUTEK, Jiří, Dalibor BLAŽEK a B Matija PETERLIN

Základní údaje

Originální název

Hexim1 sequesters positive transcription elongation factor b from the class II transactivator on MHC class II promoters

Autoři

KOHOUTEK, Jiří, Dalibor BLAŽEK a B Matija PETERLIN

Vydání

Proceedings of the National Academy of Sciences of the United States of America, WASHINGTON, NATL ACAD SCIENCES, 2006, 0027-8424

Další údaje

Jazyk

angličtina

Typ výsledku

Článek v odborném periodiku

Obor

10600 1.6 Biological sciences

Stát vydavatele

Spojené státy

Utajení

není předmětem státního či obchodního tajemství

Odkazy

Impakt faktor

Impact factor: 9.643

UT WoS

000242249400052

Klíčová slova anglicky

RNA-POLYMERASE-II; MELANOMA CELL-LINES; P-TEFB; 7SK SNRNA; EXPRESSION; CIITA; COMPLEX; GENES; DIFFERENTIATION; ACTIVATION

Štítky

Příznaky

Mezinárodní význam, Recenzováno
Změněno: 24. 7. 2012 05:54, Olga Křížová

Anotace

V originále

The class II transactivator (CIITA) is the master integrator of expression of MHC class II genes. It interacts with variety of basal transcription factors to initiate and elongate transcription of these genes. Among others, it recruits positive transcription elongation factor b (P-TEFb) to MHC class II promoters. In cells, P-TEFb is found in small active or large inactive complexes. The large complex is composed of P-TEFb, 7SK small nuclear RNA, and hexamethylene bisacetamide-inducible protein 1 (Hexim1). The present study identifies Hexim1 as a potent inhibitor of CIITA-mediated transcription. Not only the exogenously expressed but also IFN-gamma-induced CIITA was inhibited by Hexim1. This inhibition did riot result from an association between Hexim1 and CIITA but depended on the intact Cyclin T1-binding domain in Hexim1. importantly, Hexim1 sequestered P-TEFb from CIITA, as documented by binding competition and ChIP assays. Conversely, the depletion of Hexim1 from cells by siRNA increased CIITA-mediated transcription. Thus, modulating ratios between active and inactive P-TEFb complexes is an additional mechanism of regulating transcriptional activators such as CIITA.