Pre-snRNA is elongated and capped with 7-methylguanosine

Stable Identifier
Reaction [omitted]
Homo sapiens
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A 7-methylguanosine triphosphate group is added to the 5' end of the pre-snRNA during transcription elongation (Mattaj 1986). The capping enzyme and cap methyltransferase involved in mRNA capping may also be responsible for this reaction. In the case of mRNA capping, the capping enzyme is targeted to the pre-mRNA by interaction with the phosphorylated C-terminal domain (CTD) of RNA polymerase II (McCracken et al. 1997). During elongation, the phosphorylation pattern of the CTD also changes: serine-5 is dephosphorylated by RPAP2 (Egloff et al. 2012) interacting with RPRD1A and RPRD1B (Ni et al. 2011, Ni et al. 2014) and serine-2 is phosphoryated by P-TEFb. Serine-7 is also phosphorylated, possibly, however the responsible kinase is not certain. The order of the capping and phosphorylation events is unknown.

Literature References
PubMed ID Title Journal Year
9407024 5'-Capping enzymes are targeted to pre-mRNA by binding to the phosphorylated carboxy-terminal domain of RNA polymerase II

Siderovski, D, Hessel, A, Fong, N, Bentley, DL, Foster, S, Yankulov, K, McCracken, S, Shuman, S, Rosonina, E, Brothers, G

Genes Dev. 1997
2944599 Cap trimethylation of U snRNA is cytoplasmic and dependent on U snRNP protein binding

Mattaj, IW

Cell 1986
22137580 Ser7 phosphorylation of the CTD recruits the RPAP2 Ser5 phosphatase to snRNA genes

Laitem, C, Murphy, S, Kiss, T, Zaborowska, J, Egloff, S

Mol. Cell 2012
24997600 RPRD1A and RPRD1B are human RNA polymerase II C-terminal domain scaffolds for Ser5 dephosphorylation

Mosley, AL, Young, P, Li, J, Murphy, S, Olsen, JB, Zhong, G, He, H, Hunter, GO, Emili, A, Huang, H, Xu, C, Senisterra, GA, Min, J, Ni, Z, Kuo, WH, Guo, X, Greenblatt, JF, Loppnau, P, Arrowsmith, CH, Guo, H, Marcon, E, Tempel, W, Wan, C, El Bakkouri, M, Kuznetsova, OV, Sidhu, SS

Nat. Struct. Mol. Biol. 2014
22231121 Control of the RNA polymerase II phosphorylation state in promoter regions by CTD interaction domain-containing proteins RPRD1A and RPRD1B

Guo, H, Marcon, E, Young, P, Li, J, Ruan, ED, Olsen, JB, Emili, A, Zhong, G, Ni, Z, Moffat, J, Guo, X, Greenblatt, JF

Transcription 2011
Catalyst Activity

RNA polymerase II activity of RNA polymerase II (phosphoserine-5,7):RPRD1A,B:RPRD2:RPAP2:Integrator:LEC:pre-snRNA:Initiation factors:snRNA gene [nucleoplasm]

This event is regulated
Orthologous Events
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