Pre-snRNA is elongated and capped with 7-methylguanosine

Stable Identifier
R-HSA-6814559
Type
Reaction [omitted]
Species
Homo sapiens
Compartment
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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
2944599 Cap trimethylation of U snRNA is cytoplasmic and dependent on U snRNP protein binding

Mattaj, IW

Cell 1986
9407024 5'-Capping enzymes are targeted to pre-mRNA by binding to the phosphorylated carboxy-terminal domain of RNA polymerase II

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

Genes Dev. 1997
22137580 Ser7 phosphorylation of the CTD recruits the RPAP2 Ser5 phosphatase to snRNA genes

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

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

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

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

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

Transcription 2011
Participants
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Catalyst Activity
Catalyst Activity
Title
protein serine/threonine kinase activity of RNA polymerase II (phosphoserine-5,7):RPRD1A,B:RPRD2:RPAP2:Integrator:LEC:pre-snRNA:Initiation factors:snRNA gene [nucleoplasm]
Physical Entity
Activity
Title
protein serine/threonine phosphatase activity of RNA polymerase II (phosphoserine-5,7):RPRD1A,B:RPRD2:RPAP2:Integrator:LEC:pre-snRNA:Initiation factors:snRNA gene [nucleoplasm]
Physical Entity
Activity
Title
RNA polymerase II activity of RNA polymerase II (phosphoserine-5,7):RPRD1A,B:RPRD2:RPAP2:Integrator:LEC:pre-snRNA:Initiation factors:snRNA gene [nucleoplasm]
Physical Entity
Activity
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