InnateDB: Systems Biology of the Innate Immune Response

Mus musculus Protein: Ncbp1

Summary

InnateDB Protein

IDBP-144838.6

Last Modified

2014-10-13 [Report errors or provide feedback]

Gene Symbol

Ncbp1

Protein Name

nuclear cap binding protein subunit 1

Synonyms

Species

Mus musculus

Ensembl Protein

ENSMUSP00000030014

InnateDB Gene

IDBG-144836 (Ncbp1)

Protein Structure

UniProt Annotation

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. {ECO:0000269PubMed:19632182}.

Subcellular Localization

Nucleus {ECO:0000269PubMed:22767893}. Cytoplasm {ECO:0000250}. Note=Localized in cytoplasmic mRNP granules containing untranslated mRNAs. {ECO:0000250}.

Disease Associations

Tissue Specificity

Comments

Interactions

Number of Interactions

This gene and/or its encoded proteins are associated with 1 experimentally validated interaction(s) in this database.
They are also associated with 54 interaction(s) predicted by orthology.

Experimentally validated
Total	1 [view]
Protein-Protein	1 [view]
Protein-DNA	0
Protein-RNA	0
DNA-DNA	0
RNA-RNA	0
DNA-RNA	0

Predicted by orthology
Total	54 [view]

Gene Ontology

Molecular Function

Accession	GO Term
GO:0000339	RNA cap binding
GO:0003723	RNA binding
GO:0005488	binding
GO:0005515	protein binding
GO:0044822	poly(A) RNA binding

Biological Process

GO:0000184	nuclear-transcribed mRNA catabolic process, nonsense-mediated decay
GO:0006370	7-methylguanosine mRNA capping
GO:0006379	mRNA cleavage
GO:0006406	mRNA export from nucleus
GO:0006446	regulation of translational initiation
GO:0016070	RNA metabolic process
GO:0031047	gene silencing by RNA
GO:0031442	positive regulation of mRNA 3'-end processing
GO:0045292	mRNA cis splicing, via spliceosome

Cellular Component

GO:0005634	nucleus
GO:0005737	cytoplasm
GO:0005739	mitochondrion
GO:0005845	mRNA cap binding complex
GO:0005846	nuclear cap binding complex
GO:0005886	plasma membrane
GO:0030529	ribonucleoprotein complex