Overview
| Uniprot ID | Q56A27 |
|---|
| Protein Name | Nuclear cap-binding protein subunit 1 |
|---|
| Gene Name | Ncbp1 |
|---|
| Organism | Rattus norvegicus |
|---|
Kla Sites from experimental identification
| Position |
Flanking peptide |
| 17 |
NDGGQPHKRRKTSDA |
| 20 |
GQPHKRRKTSDANET |
Function
Component of the cap-binding complex (CBC), which binds cotranscriptionally 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 and is 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, NCBP1/CBP80 does not bind directly capped RNAs (m7GpppG-capped RNA) but is required to stabilize the movement of the N-terminal loop of NCBP2/CBP20 and lock the CBC into a high affinity cap-binding state with the cap structure. Associates with NCBP3 to form an alternative cap-binding complex (CBC) which plays a key role in mRNA export and is particularly important in cellular stress situations such as virus infections. The conventional CBC with NCBP2 binds both small nuclear RNA (snRNA) and messenger (mRNA) and is involved in their export from the nucleus whereas the alternative CBC with NCBP3 does not bind snRNA and associates only with mRNA thereby playing a role only in mRNA export. NCBP1/CBP80 is required for cell growth and viability (By similarity)
Protein Sequence
10
MSRRRHSYEN
20
DGGQPHKRRK
30
TSDANETEDH
40
LESLICKVGE
50
KSACSLESNL
60
EGLAGVLEAD
70
LPNYKSKILR
80
LLCTVARLLP
90
EKLTIYTTLV
100
GLLNARNYNF
110
GGEFVEAMIR
120
QLKESLKANN
130
YNEAVYLVRF
140
LSDLVNCHVI
150
AAPSMVAMFE
160
NFVSVTQEED
170
VPQVRRDWYV
180
YAFLSSLPWV
190
GKELYEKKDA
200
EMDRIFSSTE
210
SYLKRRQKTH
220
VPMLQVWTAD
230
KPHPQEEYLD
240
CLWAQIQKLK
250
KDRWQERHIL
260
RPYLAFDSIL
270
CEALQHNLPP
280
FTPPPHTEDS
290
VYPMPRVIFR
300
MFDYTDDPEG
310
PVMPGSHSVE
320
RFVIEENLHC
330
IIKSYWKERK
340
TCAAQLVSYP
350
GKNKIPLNYH
360
IVEVIFAELF
370
QLPAPPHIDV
380
MYTTLLIELC
390
KLQPGSLPQV
400
LAQATEMLYM
410
RLDTMSTTCV
420
DRFINWFSHH
430
LSNFQFRWSW
440
EDWSDCLTQD
450
LESPKPKFVR
460
EVLEKCMRLS
470
YHQHILDIVP
480
PTFSALCPAN
490
PTCIYKYGDE
500
SSNSLPGHSV
510
ALCLSVAFKS
520
KATNDEIFSI
530
LKDVPNPNQV
540
DDDDEGFRFN
550
PLKIEVFVQT
560
LLHLAAKSFS
570
HSFSALAKFH
580
EVFKTLAESD
590
KGKLHVLRVM
600
FEVWRNHPQM
610
IAVLVDKMIR
620
TQIVDCAAVA
630
NWIFSSELSR
640
DFTRLFVWEI
650
LHSTIRKMNK
660
HVLKIQKELE
670
EAKEKLARQH
680
KRRSDDDDRG
690
SDRKDGALEE
700
QIERLQEKVE
710
SAQSEQKNLF
720
LVIFQRFIMI
730
LTEHLVRCET
740
DGTSILTPWY
750
KNCIERLQQI
760
FLQHHQIIQQ
770
YMVTLENLLF
780
TAELDPHILA
790
VFQQFCALQA
Gene Ontology
| Classification |
GO ID |
Description |
| Cellular Component |
GO:0005737 |
cytoplasm |
| Cellular Component |
GO:0005829 |
cytosol |
| Cellular Component |
GO:0005846 |
nuclear cap binding complex |
| Cellular Component |
GO:0005654 |
nucleoplasm |
| Cellular Component |
GO:0005634 |
nucleus |
| Cellular Component |
GO:1990904 |
ribonucleoprotein complex |
| Cellular Component |
GO:0034518 |
RNA cap binding complex |
| Molecular Function |
GO:0060090 |
molecular adaptor activity |
| Molecular Function |
GO:0003729 |
mRNA binding |
| Molecular Function |
GO:0000340 |
RNA 7-methylguanosine cap binding |
| Molecular Function |
GO:0000339 |
RNA cap binding |
| Biological Process |
GO:0006370 |
7-methylguanosine mRNA capping |
| Biological Process |
GO:0051607 |
defense response to virus |
| Biological Process |
GO:0008334 |
histone mRNA metabolic process |
| Biological Process |
GO:0006406 |
mRNA export from nucleus |
| Biological Process |
GO:0016071 |
mRNA metabolic process |
| 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:0030307 |
positive regulation of cell growth |
| Biological Process |
GO:0031442 |
positive regulation of mRNA 3'-end processing |
| Biological Process |
GO:0048026 |
positive regulation of mRNA splicing, via spliceosome |
| Biological Process |
GO:0050684 |
regulation of mRNA processing |
| Biological Process |
GO:0006446 |
regulation of translational initiation |
| Biological Process |
GO:0031047 |
regulatory ncRNA-mediated gene silencing |
| Biological Process |
GO:0006401 |
RNA catabolic process |
| Biological Process |
GO:0006408 |
snRNA export from nucleus |
| Biological Process |
GO:0000245 |
spliceosomal complex assembly |
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.