Overview
| Uniprot ID | B1WC40 |
|---|
| Protein Name | Nuclear cap-binding protein subunit 2 |
|---|
| Gene Name | Ncbp2 |
|---|
| Organism | Rattus norvegicus |
|---|
Kla Sites from experimental identification
| Position |
Flanking peptide |
| 151 |
AGRGGYGKLAQKQ** |
| 78 |
MGLDKMKKTACGFCF |
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. The conventional cap-binding complex with NCBP2 binds both small nuclear RNA (snRNA) and messenger (mRNA) and is involved in their export from the nucleus (By similarity)
Protein Sequence
10
MSGGLLKALR
20
SDSYVELSEY
30
RDQHFRGDNE
40
EQEKLLKKSC
50
TLYVGNLSFY
60
TTEEQIYELF
70
SKSGDIKKII
80
MGLDKMKKTA
90
CGFCFVEYYS
100
RADAENAMRY
110
INGTRLDDRI
120
IRTDWDAGFK
130
EGRQYGRGRS
140
GGQVRDEYRE
150
DYDAGRGGYG
KLAQKQ
Gene Ontology
| Classification |
GO ID |
Description |
| Cellular Component |
GO:0005846 |
nuclear cap binding complex |
| Cellular Component |
GO:0005737 |
cytoplasm |
| Cellular Component |
GO:0005829 |
cytosol |
| Cellular Component |
GO:0005654 |
nucleoplasm |
| Cellular Component |
GO:0005634 |
nucleus |
| Cellular Component |
GO:0034518 |
RNA cap binding complex |
| Molecular Function |
GO:0003677 |
DNA binding |
| Molecular Function |
GO:0003729 |
mRNA binding |
| Molecular Function |
GO:0000340 |
RNA 7-methylguanosine cap binding |
| Molecular Function |
GO:0000339 |
RNA cap binding |
| Molecular Function |
GO:0017069 |
snRNA binding |
| Biological Process |
GO:0008334 |
histone mRNA metabolic process |
| Biological Process |
GO:0045292 |
mRNA cis splicing, via spliceosome |
| Biological Process |
GO:0006406 |
mRNA export from nucleus |
| Biological Process |
GO:0016071 |
mRNA metabolic process |
| Biological Process |
GO:0000398 |
mRNA splicing, via spliceosome |
| Biological Process |
GO:0042789 |
mRNA transcription by RNA polymerase II |
| Biological Process |
GO:0000184 |
nuclear-transcribed mRNA catabolic process, nonsense-mediated decay |
| Biological Process |
GO:0031442 |
positive regulation of mRNA 3'-end processing |
| Biological Process |
GO:0046833 |
positive regulation of RNA export from nucleus |
| Biological Process |
GO:0006446 |
regulation of translational initiation |
| Biological Process |
GO:0031047 |
regulatory ncRNA-mediated gene silencing |
| Biological Process |
GO:0008380 |
RNA splicing |
| Biological Process |
GO:0006408 |
snRNA export from nucleus |
Reference
[1] Sheng L, Xu H, Wang Y, Ni J, Xiang T et al.. Systematic analysis of lysine lactylation in nucleus pulposus cells.. iScience 27(11):111157. 2024 Nov 15. PMID: 39524337.