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Nuclear cap-binding protein subunit 2

 
Known also as: 20 kDa nuclear cap-binding protein,Cell proliferation-inducing gene 55 protein,NCBP 20 kDa subunit, NCBP-interacting protein 1

Known abbreviations: NCBP2, CBP20, PIG55, NIP1

 

FUNCTION:
 
Component of the cap-binding complex (CBC), which binds co-transcriptionally to the 5' cap of pre-mRNAs and is involved in various processes such as pre-mRNA splicing, translation regulation, nonsense-mediated mRNA decay, RNA-mediated gene silencing (RNAi) by microRNAs (miRNAs) and mRNA export. The CBC complex is involved in mRNA export from the nucleus via its interaction with ALYREF/THOC4/ALY, leading to the recruitment of the mRNA export machinery to the 5' end of mRNA and to mRNA export in a 5' to 3' direction through the nuclear pore. The CBC complex is also involved in mediating U snRNA and intronless mRNAs export from the nucleus. The CBC complex is essential for a pioneer round of mRNA translation, before steady state translation when the CBC complex is replaced by cytoplasmic cap-binding protein eIF4E. The pioneer round of mRNA translation mediated by the CBC complex plays a central role in nonsense-mediated mRNA decay (NMD), NMD only taking place in mRNAs bound to the CBC complex, but not on eIF4E-bound mRNAs. The CBC complex enhances NMD in mRNAs containing at least one exon-junction complex (EJC) via its interaction with UPF1, promoting the interaction between UPF1 and UPF2. The CBC complex is also involved in 'failsafe' NMD, which is independent of the EJC complex, while it does not participate in Staufen-mediated mRNA decay (SMD). During cell proliferation, the CBC complex is also involved in microRNAs (miRNAs) biogenesis via its interaction with SRRT/ARS2, thereby being required for miRNA-mediated RNA interference. The CBC complex also acts as a negative regulator of PARN, thereby acting as an inhibitor of mRNA deadenylation. In the CBC complex, NCBP2/CBP20 recognizes and binds capped RNAs (m7GpppG-capped RNA) but requires NCBP1/CBP80 to stabilize the movement of its N-terminal loop and lock the CBC into a high affinity cap-binding state with the cap structure.
 
SUBUNIT STRUCTURE:
 
Component of the nuclear cap-binding complex (CBC), a heterodimer composed of NCBP1/CBP80 and NCBP2/CBP20 that interacts with m7GpppG-capped RNA. Found in a U snRNA export complex with RNUXA/PHAX, NCBP1/CBP80, NCBP2/CBP20, RAN, XPO1 and m7G-capped RNA. Interaction with RNUXA/PHAX. Is part of the exon junction complex (EJC) containing NCBP1, NCBP2, RNPS1, RBM8A, SRRM1, NXF1, UPF3B, UPF2, ALYREF/THOC4 and/or REFBP2. Interacts with EIF4G1, HNRNPF, HNRNPH1 and ALYREF/THOC4/ALY.
 
CELLULAR LOCALIZATION:
 
Nucleus. Cytoplasm 
 
POST-TRANSLATIONAL MODIFICATION:
 
Phosphorylated upon DNA damage, probably by ATM or ATR.



This protein can be a part of a given complexes: Activities in which Nuclear cap-binding protein subunit 2 is involved: Pathways in which Nuclear cap-binding protein subunit 2 is involved:

NCBI GI number(s): 110349727
110349726
110349728
19923387
Species: Homo sapiens

Links to other databases:

Database ID Link
Uniprot P52298 P52298
BRENDA - -
KEGG hsa:22916 hsa:22916
PFAM: PF00076
PF00076
InterPro: IPR012677
IPR000504
IPR012677
IPR000504
CATH: - -
SCOP: - -
Solved crystal structures: 3FEY
3FEX
1N54
1N52
1H6K
1H2V
1H2U
1H2T
[PDB] [details]
[PDB] [details]
[PDB] [details]
[PDB] [details]
[PDB] [details]
[PDB] [details]
[PDB] [details]
[PDB] [details]


Protein sequence:
MSGGLLKALRSDSYVELSQYRDQHFRGDNEEQEKLLKKSCTLYVGNLSFY
TTEEQIYELFSKSGDIKKIIMGLDKMKKTACGFCFVEYYSRADAENAMRY
INGTRLDDRIIRTDWDAGFKEGRQYGRGRSGGQVRDEYRQDYDAGRGGYG
KLAQNQ

Nuclear cap-binding protein subunit 2 (Homo sapiens) is product of expression of NCBP2 gene.

References:

Title Authors Journal Publication date (Issue) PubMed ID
The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC). Gerhard DS, Wagner L, Feingold EA, Shenmen CM, Grouse LH, Schuler G, Klein SL, Old S, Rasooly R, Good P, Guyer M, Peck AM, Derge JG, Lipman D, Collins FS, Jang W, Sherry S, Feolo M, Misquitta L, Lee E, Rotmistrovsky K, Greenhut SF, Schaefer CF, Buetow K, Bonner TI, Haussler D, Kent J, Kiekhaus M, Furey T, Brent M, Prange C, Schreiber K, Shapiro N, Bhat NK, Hopkins RF, Hsie F, Driscoll T, Soares MB, Casavant TL, Scheetz TE, Brown-stein MJ, Usdin TB, Toshiyuki S, Carninci P, Piao Y, Dudekula DB, K Genome Res 2004-10-01 (14) 15489334
Complete sequencing and characterization of 21,243 full-length human cDNAs. Ota T, Suzuki Y, Nishikawa T, Otsuki T, Sugiyama T, Irie R, Wakamatsu A, Hayashi K, Sato H, Nagai K Nat Genet 2004-02-01 (36) 14702039
NMD resulting from encephalomyocarditis virus IRES-directed translation initiation seems to be restricted to CBP80/20-bound mRNA. Woeller CF, Gaspari M, Isken O, Maquat LE EMBO Rep 2008-05-01 (9) 18369367
Structural basis of m7GpppG binding to the nuclear cap-binding protein complex. Calero G, Wilson KF, Ly T, Rios-Steiner JL, Clardy JC, Cerione RA Nat Struct Biol 2002-12-01 (9) 12434151
Identification of the factors that interact with NCBP, an 80 kDa nuclear cap binding protein. Kataoka N, Ohno M, Moda I, Shimura Y Nucleic Acids Res 1995-09-25 (23) 7478990
A cap-binding protein complex mediating U snRNA export. Izaurralde E, Lewis J, Gamberi C, Jarmolowski A, McGuigan C, Mattaj IW Nature 1995-08-24 (376) 7651522
Large-scale induced fit recognition of an m(7)GpppG cap analogue by the human nuclear cap-binding complex. Mazza C, Segref A, Mattaj IW, Cusack S EMBO J 2002-10-15 (21) 12374755
Human mRNA export machinery recruited to the 5' end of mRNA. Cheng H, Dufu K, Lee CS, Hsu JL, Dias A, Reed R Cell 2006-12-01 (127) 17190602
Initial characterization of the human central proteome. Burkard TR, Planyavsky M, Kaupe I, Breitwieser FP, Burckstummer T, Bennett KL, Superti-Furga G, Colinge J BMC Syst Biol 2011-01-01 (5) 21269460
ATM and ATR substrate analysis reveals extensive protein networks responsive to DNA damage. Matsuoka S, Ballif BA, Smogorzewska A, McDonald ER 3rd, Hurov KE, Luo J, Bakalarski CE, Zhao Z, Solimini N, Lerenthal Y, Shiloh Y, Gygi SP, Elledge SJ Science 2007-05-25 (316) 17525332
Lysine acetylation targets protein complexes and co-regulates major cellular functions. Choudhary C, Kumar C, Gnad F, Nielsen ML, Rehman M, Walther TC, Olsen JV, Mann M Science 2009-08-14 (325) 19608861
A nuclear cap-binding complex binds Balbiani ring pre-mRNA cotranscriptionally and accompanies the ribonucleoprotein particle during nuclear export. Visa N, Izaurralde E, Ferreira J, Daneholt B, Mattaj IW J Cell Biol 1996-04-01 (133) 8601613
Interaction between the human nuclear cap-binding protein complex and hnRNP F. Gamberi C, Izaurralde E, Beisel C, Mattaj IW Mol Cell Biol 1997-05-01 (17) 9111328
Evidence for a pioneer round of mRNA translation: mRNAs subject to nonsense-mediated decay in mammalian cells are bound by CBP80 and CBP20. Ishigaki Y, Li X, Serin G, Maquat LE Cell 2001-09-07 (106) 11551508
The exon junction complex is detected on CBP80-bound but not eIF4E-bound mRNA in mammalian cells: dynamics of mRNP remodeling. Lejeune F, Ishigaki Y, Li X, Maquat LE EMBO J 2002-07-01 (21) 12093754
eIF4G is required for the pioneer round of translation in mammalian cells. Lejeune F, Ranganathan AC, Maquat LE Nat Struct Mol Biol 2004-10-01 (11) 15361857
The interaction between cap-binding complex and RNA export factor is required for intronless mRNA export. Nojima T, Hirose T, Kimura H, Hagiwara M J Biol Chem 2007-05-25 (282) 17363367
Failsafe nonsense-mediated mRNA decay does not detectably target eIF4E-bound mRNA. Matsuda D, Hosoda N, Kim YK, Maquat LE Nat Struct Mol Biol 2007-10-01 (14) 17873884
Ars2 links the nuclear cap-binding complex to RNA interference and cell proliferation. Gruber JJ, Zatechka DS, Sabin LR, Yong J, Lum JJ, Kong M, Zong WX, Zhang Z, Lau CK, Rawlings J, Cherry S, Ihle JN, Dreyfuss G, Thompson CB Cell 2009-07-23 (138) 19632182
Crystal structure of the human nuclear cap binding complex. Mazza C, Ohno M, Segref A, Mattaj IW, Cusack S Mol Cell 2001-08-01 (8) 11545740



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Last modification of this entry: Sept. 25, 2012.

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