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

J 2006

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

KOHOUTEK, Jiří, Dalibor BLAŽEK and B Matija PETERLIN

Basic information

Original name

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

Authors

KOHOUTEK, Jiří, Dalibor BLAŽEK and B Matija PETERLIN

Edition

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

Other information

Language

English

Type of outcome

Článek v odborném periodiku

Field of Study

10600 1.6 Biological sciences

Country of publisher

United States of America

Confidentiality degree

není předmětem státního či obchodního tajemství

References:

URL

Impact factor

Impact factor: 9.643

DOI

http://dx.doi.org/10.1073/pnas.0603079103

UT WoS

000242249400052

Keywords in English

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

Abstract

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.

Citovat

KOHOUTEK, Jiří, Dalibor BLAŽEK and B Matija PETERLIN. Hexim1 sequesters positive transcription elongation factor b from the class II transactivator on MHC class II promoters. Proceedings of the National Academy of Sciences of the United States of America. WASHINGTON: NATL ACAD SCIENCES, 2006, vol. 103, No 46, p. 17349-17354. ISSN 0027-8424. Available from: https://dx.doi.org/10.1073/pnas.0603079103.

@article{987839,
   author = {Kohoutek, Jiří and Blažek, Dalibor and Peterlin, B Matija},
   article_location = {WASHINGTON},
   article_number = {46},
   doi = {http://dx.doi.org/10.1073/pnas.0603079103},
   keywords = {RNA-POLYMERASE-II; MELANOMA CELL-LINES; P-TEFB; 7SK SNRNA; EXPRESSION; CIITA; COMPLEX; GENES; DIFFERENTIATION; ACTIVATION},
   language = {eng},
   issn = {0027-8424},
   journal = {Proceedings of the National Academy of Sciences of the United States of America},
   title = {Hexim1 sequesters positive transcription elongation factor b from the class II transactivator on MHC class II promoters},
   url = {http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1859933/},
   volume = {103},
   year = {2006}
}

TY  - JOUR
ID  - 987839
AU  - Kohoutek, Jiří - Blažek, Dalibor - Peterlin, B Matija
PY  - 2006
TI  - Hexim1 sequesters positive transcription elongation factor b from the class II transactivator on MHC class II promoters
JF  - Proceedings of the National Academy of Sciences of the United States of America
VL  - 103
IS  - 46
SP  - 17349-17354
EP  - 17349-17354
PB  - NATL ACAD SCIENCES
SN  - 00278424
KW  - RNA-POLYMERASE-II
KW  - MELANOMA CELL-LINES
KW  - P-TEFB
KW  - 7SK SNRNA
KW  - EXPRESSION
KW  - CIITA
KW  - COMPLEX
KW  - GENES
KW  - DIFFERENTIATION
KW  - ACTIVATION
UR  - http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1859933/
N2  - 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.
ER  -

KOHOUTEK, Jiří, Dalibor BLAŽEK and B Matija PETERLIN. Hexim1 sequesters positive transcription elongation factor b from the class II transactivator on MHC class II promoters. \textit{Proceedings of the National Academy of Sciences of the United States of America}. WASHINGTON: NATL ACAD SCIENCES, 2006, vol.~103, No~46, p.~17349-17354. ISSN~0027-8424. Available from: https://dx.doi.org/10.1073/pnas.0603079103.

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