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 PETERLINZákladní 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.