NCBP2_XENLA
ID NCBP2_XENLA Reviewed; 153 AA.
AC P52299; Q6GQ46;
DT 01-OCT-1996, integrated into UniProtKB/Swiss-Prot.
DT 22-SEP-2009, sequence version 2.
DT 03-AUG-2022, entry version 105.
DE RecName: Full=Nuclear cap-binding protein subunit 2;
DE AltName: Full=20 kDa nuclear cap-binding protein;
DE AltName: Full=NCBP 20 kDa subunit;
DE Short=CBP20;
GN Name=ncbp2; Synonyms=cbp20;
OS Xenopus laevis (African clawed frog).
OC Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Amphibia;
OC Batrachia; Anura; Pipoidea; Pipidae; Xenopodinae; Xenopus; Xenopus.
OX NCBI_TaxID=8355;
RN [1]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA].
RC TISSUE=Ovary;
RG NIH - Xenopus Gene Collection (XGC) project;
RL Submitted (JUN-2004) to the EMBL/GenBank/DDBJ databases.
RN [2]
RP NUCLEOTIDE SEQUENCE [MRNA] OF 6-153, AND FUNCTION.
RC TISSUE=Kidney epithelium;
RX PubMed=7651522; DOI=10.1038/376709a0;
RA Izaurralde E., Lewis J., Gamberi C., Jarmolowski A., McGuigan C.,
RA Mattaj A.W.;
RT "A cap-binding protein complex mediating U snRNA export.";
RL Nature 376:709-712(1995).
CC -!- FUNCTION: Component of the cap-binding complex (CBC), which binds co-
CC transcriptionally to the 5' cap of pre-mRNAs and is involved in various
CC processes such as pre-mRNA splicing, translation regulation, nonsense-
CC mediated mRNA decay, RNA-mediated gene silencing (RNAi) by microRNAs
CC (miRNAs) and mRNA export. The CBC complex is involved in mRNA export
CC from the nucleus, leading to the recruitment of the mRNA export
CC machinery to the 5' end of mRNA and to mRNA export in a 5' to 3'
CC direction through the nuclear pore. The CBC complex is also involved in
CC mediating U snRNA and intronless mRNAs export from the nucleus. The CBC
CC complex is essential for a pioneer round of mRNA translation, before
CC steady state translation when the CBC complex is replaced by
CC cytoplasmic cap-binding protein eIF4E. The pioneer round of mRNA
CC translation mediated by the CBC complex plays a central role in
CC nonsense-mediated mRNA decay (NMD), NMD only taking place in mRNAs
CC bound to the CBC complex, but not on eIF4E-bound mRNAs. The CBC complex
CC enhances NMD in mRNAs containing at least one exon-junction complex
CC (EJC), promoting the interaction between upf1 and upf2. The CBC complex
CC is also involved in 'failsafe' NMD, which is independent of the EJC
CC complex, while it does not participate in Staufen-mediated mRNA decay
CC (SMD). During cell proliferation, the CBC complex is also involved in
CC microRNAs (miRNAs) biogenesis via its interaction with srrt/ars2,
CC thereby being required for miRNA-mediated RNA interference. The CBC
CC complex also acts as a negative regulator of parn, thereby acting as an
CC inhibitor of mRNA deadenylation. In the CBC complex, ncbp2/cbp20
CC recognizes and binds capped RNAs (m7GpppG-capped RNA) but requires
CC ncbp1/cbp80 to stabilize the movement of its N-terminal loop and lock
CC the CBC into a high affinity cap-binding state with the cap structure.
CC The conventional cap-binding complex with NCBP2 binds both small
CC nuclear RNA (snRNA) and messenger (mRNA) and is involved in their
CC export from the nucleus (By similarity).
CC {ECO:0000250|UniProtKB:P52298}.
CC -!- SUBUNIT: Component of the nuclear cap-binding complex (CBC), a
CC heterodimer composed of ncbp1/cbp80 and ncbp2/cbp20 that interacts with
CC m7GpppG-capped RNA. {ECO:0000250|UniProtKB:P52298}.
CC -!- SUBCELLULAR LOCATION: Nucleus {ECO:0000250|UniProtKB:P52298}. Cytoplasm
CC {ECO:0000250|UniProtKB:P52298}.
CC -!- SIMILARITY: Belongs to the RRM NCBP2 family. {ECO:0000305}.
CC ---------------------------------------------------------------------------
CC Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms
CC Distributed under the Creative Commons Attribution (CC BY 4.0) License
CC ---------------------------------------------------------------------------
DR EMBL; BC072902; AAH72902.1; -; mRNA.
DR EMBL; X84788; CAA59259.1; -; mRNA.
DR PIR; I51602; I51602.
DR RefSeq; NP_001167476.1; NM_001174005.1.
DR AlphaFoldDB; P52299; -.
DR SMR; P52299; -.
DR BioGRID; 1079029; 1.
DR IntAct; P52299; 1.
DR MaxQB; P52299; -.
DR DNASU; 100380998; -.
DR GeneID; 100380998; -.
DR KEGG; xla:100380998; -.
DR CTD; 100380998; -.
DR Xenbase; XB-GENE-1005792; ncbp2.L.
DR OMA; AENCMRY; -.
DR OrthoDB; 1421503at2759; -.
DR Proteomes; UP000186698; Chromosome 5L.
DR Bgee; 100380998; Expressed in egg cell and 19 other tissues.
DR GO; GO:0005737; C:cytoplasm; ISS:UniProtKB.
DR GO; GO:0005845; C:mRNA cap binding complex; ISS:UniProtKB.
DR GO; GO:0005846; C:nuclear cap binding complex; IEA:InterPro.
DR GO; GO:0005654; C:nucleoplasm; ISS:UniProtKB.
DR GO; GO:0005634; C:nucleus; ISS:UniProtKB.
DR GO; GO:0003729; F:mRNA binding; ISS:UniProtKB.
DR GO; GO:0000340; F:RNA 7-methylguanosine cap binding; ISS:UniProtKB.
DR GO; GO:0017069; F:snRNA binding; ISS:UniProtKB.
DR GO; GO:0031047; P:gene silencing by RNA; IEA:UniProtKB-KW.
DR GO; GO:0045292; P:mRNA cis splicing, via spliceosome; ISS:UniProtKB.
DR GO; GO:0051028; P:mRNA transport; IEA:UniProtKB-KW.
DR GO; GO:0000184; P:nuclear-transcribed mRNA catabolic process, nonsense-mediated decay; ISS:UniProtKB.
DR GO; GO:0046833; P:positive regulation of RNA export from nucleus; IDA:UniProtKB.
DR GO; GO:0006446; P:regulation of translational initiation; ISS:UniProtKB.
DR GO; GO:0008380; P:RNA splicing; IDA:UniProtKB.
DR GO; GO:0006408; P:snRNA export from nucleus; IDA:UniProtKB.
DR CDD; cd12240; RRM_NCBP2; 1.
DR Gene3D; 3.30.70.330; -; 1.
DR InterPro; IPR027157; NCBP2.
DR InterPro; IPR034148; NCBP2_RRM.
DR InterPro; IPR012677; Nucleotide-bd_a/b_plait_sf.
DR InterPro; IPR035979; RBD_domain_sf.
DR InterPro; IPR000504; RRM_dom.
DR PANTHER; PTHR18847; PTHR18847; 1.
DR Pfam; PF00076; RRM_1; 1.
DR SMART; SM00360; RRM; 1.
DR SUPFAM; SSF54928; SSF54928; 1.
DR PROSITE; PS50102; RRM; 1.
PE 2: Evidence at transcript level;
KW Cytoplasm; mRNA processing; mRNA splicing; mRNA transport;
KW Nonsense-mediated mRNA decay; Nucleus; Reference proteome; RNA-binding;
KW RNA-mediated gene silencing; Translation regulation; Transport.
FT CHAIN 1..153
FT /note="Nuclear cap-binding protein subunit 2"
FT /id="PRO_0000081501"
FT DOMAIN 37..115
FT /note="RRM"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00176"
FT BINDING 17
FT /ligand="mRNA"
FT /ligand_id="ChEBI:CHEBI:33699"
FT /ligand_part="mRNA cap"
FT /evidence="ECO:0000250"
FT BINDING 40
FT /ligand="mRNA"
FT /ligand_id="ChEBI:CHEBI:33699"
FT /ligand_part="mRNA cap"
FT /evidence="ECO:0000250"
FT BINDING 109..113
FT /ligand="mRNA"
FT /ligand_id="ChEBI:CHEBI:33699"
FT /ligand_part="mRNA cap"
FT /evidence="ECO:0000250"
FT BINDING 120..124
FT /ligand="mRNA"
FT /ligand_id="ChEBI:CHEBI:33699"
FT /ligand_part="mRNA cap"
FT /evidence="ECO:0000250"
FT BINDING 130..131
FT /ligand="mRNA"
FT /ligand_id="ChEBI:CHEBI:33699"
FT /ligand_part="mRNA cap"
FT /evidence="ECO:0000250"
FT CONFLICT 6..8
FT /note="LRS -> ARG (in Ref. 2; CAA59259)"
FT /evidence="ECO:0000305"
FT CONFLICT 92..93
FT /note="EQ -> GT (in Ref. 2; CAA59259)"
FT /evidence="ECO:0000305"
SQ SEQUENCE 153 AA; 17565 MW; EFC141AB5C247627 CRC64;
MALSALRSDS YVDLSQYRDQ HFRGNRSDQE SLLKQSCTLY VGNLSFYTTE EQIHELFSKS
GDVKRIVMGL DKVKKTACGF CFVEYYTRAD AEQAMRFING TRLDDRIVRT DWDAGFKEGR
QYGRGKSGGQ VRDEYRQDYD AGRGGYGKVV QSF
