Author/Editor		Peterlin, Matija B; Brogie, John E; Price, David H
Title		7SK snRNA: a noncoding RNA that plays a major role in regulating eukaryotic transcription
Type		članek
Source		Wiley Interdiscip Rev RNA
Vol. and No.		Letnik 3, št. 1
Publication year		2012
Volume		str. 92-103
Language		eng
Abstract		The human 7SK small nuclear RNA (snRNA) is an abundant noncoding RNA whose function has been conserved in evolution from invertebrates to humans. It is transcribed by RNA polymerase III (RNAPIII) and is located in the nucleus. Together with associated cellular proteins, 7SK snRNA regulates the activity of the positive transcription elongation factor b (P-TEFb). In humans, this regulation is accomplished by the recruitment of P-TEFb by the 7SK snRNA-binding proteins, hexamethylene bisacetamide (HMBA)-induced mRNA 1/2 (HEXIM1 or HEXIM2), which inhibit the kinase activity of P-TEFb. P-TEFb regulates the transition of promoter proximally paused RNA polymerase II (RNAPII) into productive elongation, thereby, allowing efficient mRNA production. The protein composition of the 7SK small nuclear ribonucleoprotein (snRNP) is regulated dynamically. While the Lupus antigen (La)-related protein 7 (LARP7) is a constitutive component, the methylphosphate capping enzyme (MePCE) associates secondarily to phosphorylate the 5' end of 7SK snRNA. The release of active P-TEFb is closely followed by release of HEXIM proteins and both are replaced by heterogeneous nuclear ribonucleoproteins (hnRNPs). The released P-TEFb activates the expression of most cellular and viral genes. Regulated release of P-TEFb determines the expression pattern of many of the genes that respond to environmental stimuli and regulate growth, proliferation, and differentiation of cells. WIREs RNA 2011 DOI: 10.1002/wrna.106 For further resources related to this article, please visit the WIREs website.
Descriptors		TRANSCRIPTION, GENETIC RNA, SMALL NUCLEAR RNA POLYMERASE III TRANSCRIPTION FACTORS RNA-BINDING PROTEINS RIBONUCLEOPROTEINS, SMALL NUCLEAR LUPUS AUTOANTIGENS GENES, VIRAL EUKARYOTIC CELLS