P83953 · IMA5_RAT
- ProteinImportin subunit alpha-5
- GeneKpna1
- StatusUniProtKB reviewed (Swiss-Prot)
- Organism
- Amino acids538 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score5/5
Function
function
Functions in nuclear protein import as an adapter protein for nuclear receptor KPNB1 (PubMed:18303947).
Binds specifically and directly to substrates containing either a simple or bipartite NLS motif (PubMed:18303947).
Docking of the importin/substrate complex to the nuclear pore complex (NPC) is mediated by KPNB1 through binding to nucleoporin FxFG repeats and the complex is subsequently translocated through the pore by an energy requiring, Ran-dependent mechanism (PubMed:18303947).
At the nucleoplasmic side of the NPC, Ran binds to importin-beta and the three components separate and importin-alpha and -beta are re-exported from the nucleus to the cytoplasm where GTP hydrolysis releases Ran from importin (PubMed:18303947).
The directionality of nuclear import is thought to be conferred by an asymmetric distribution of the GTP- and GDP-bound forms of Ran between the cytoplasm and nucleus (PubMed:18303947).
Mediator of PR-DUB complex component BAP1 nuclear import; acts redundantly with KPNA2 and Transportin-1/TNPO1 (By similarity).
Binds specifically and directly to substrates containing either a simple or bipartite NLS motif (PubMed:18303947).
Docking of the importin/substrate complex to the nuclear pore complex (NPC) is mediated by KPNB1 through binding to nucleoporin FxFG repeats and the complex is subsequently translocated through the pore by an energy requiring, Ran-dependent mechanism (PubMed:18303947).
At the nucleoplasmic side of the NPC, Ran binds to importin-beta and the three components separate and importin-alpha and -beta are re-exported from the nucleus to the cytoplasm where GTP hydrolysis releases Ran from importin (PubMed:18303947).
The directionality of nuclear import is thought to be conferred by an asymmetric distribution of the GTP- and GDP-bound forms of Ran between the cytoplasm and nucleus (PubMed:18303947).
Mediator of PR-DUB complex component BAP1 nuclear import; acts redundantly with KPNA2 and Transportin-1/TNPO1 (By similarity).
GO annotations
all annotations | all molecular function | virus receptor activity | dna binding | rna binding | cytoskeletal motor activity | catalytic activity | gtpase activity | structural molecule activity | transporter activity | cytoskeletal protein binding | lipid binding | cyclase activity | antioxidant activity | oxidoreductase activity | transferase activity | hydrolase activity | lyase activity | isomerase activity | ligase activity | protein tag activity | cargo receptor activity | histone binding | protein folding chaperone | translation regulator activity | nutrient reservoir activity | receptor ligand activity | molecular transducer activity | molecular adaptor activity | toxin activity | cell adhesion mediator activity | molecular function regulator activity | virus coreceptor activity | catalytic activity, acting on a protein | catalytic activity, acting on dna | catalytic activity, acting on rna | molecular carrier activity | transcription regulator activity | general transcription initiation factor activity | molecular sensor activity | molecular sequestering activity | atp-dependent activity | other molecular function | all biological process | mitotic cell cycle | cytokinesis | cytoplasmic translation | immune system process | muscle system process | circulatory system process | renal system process | respiratory system process | carbohydrate metabolic process | generation of precursor metabolites and energy | dna replication | dna repair | dna recombination | chromatin organization | dna-templated transcription | regulation of dna-templated transcription | trna metabolic process | protein folding | protein glycosylation | amino acid metabolic process | modified amino acid metabolic process | lipid metabolic process | vitamin metabolic process | sulfur compound metabolic process | intracellular protein transport | nucleocytoplasmic transport | autophagy | inflammatory response | mitochondrion organization | cytoskeleton organization | microtubule-based movement | peroxisome organization | lysosome organization | chromosome segregation | cell adhesion | establishment or maintenance of cell polarity | programmed cell death | photosynthesis | mrna metabolic process | snrna metabolic process | vesicle-mediated transport | reproductive process | digestive system process | signaling | cell differentiation | protein catabolic process | extracellular matrix organization | regulatory ncrna-mediated gene silencing | telomere organization | cell junction organization | wound healing | ribosome biogenesis | cilium organization | anatomical structure development | cell motility | nervous system process | endocrine process | protein maturation | transmembrane transport | nucleobase-containing small molecule metabolic process | hepaticobiliary system process | membrane organization | protein-containing complex assembly | cell wall organization or biogenesis | nitrogen cycle metabolic process | protein localization to plasma membrane | defense response to other organism | detoxification | meiotic nuclear division | mitotic nuclear division | mitochondrial gene expression | carbohydrate derivative metabolic process | other biological process | all cellular component | nuclear chromosome | extracellular region | extracellular space | cell wall | nucleus | nuclear envelope | nucleoplasm | chromosome | nucleolus | mitochondrion | lysosome | endosome | vacuole | peroxisome | endoplasmic reticulum | golgi apparatus | lipid droplet | microtubule organizing center | cytosol | ribosome | cytoskeleton | plasma membrane | cilium | plastid | thylakoid | external encapsulating structure | extracellular matrix | cytoplasmic vesicle | organelle | other cellular component | |||
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Aspect | Term | |
---|---|---|
Cellular Component | cytosol | |
Cellular Component | dendrite | |
Cellular Component | glutamatergic synapse | |
Cellular Component | NLS-dependent protein nuclear import complex | |
Cellular Component | nucleoplasm | |
Cellular Component | nucleus | |
Cellular Component | postsynaptic density | |
Molecular Function | nuclear import signal receptor activity | |
Molecular Function | nuclear localization sequence binding | |
Biological Process | NLS-bearing protein import into nucleus | |
Biological Process | postsynapse to nucleus signaling pathway | |
Biological Process | regulation of apoptotic process | |
Biological Process | regulation of canonical Wnt signaling pathway | |
Biological Process | satellite cell activation involved in skeletal muscle regeneration | |
Biological Process | skeletal muscle satellite cell proliferation | |
Biological Process | skeletal muscle tissue regeneration |
Keywords
- Biological process
Enzyme and pathway databases
Names & Taxonomy
Protein names
- Recommended nameImportin subunit alpha-5
- Alternative names
Gene names
Organism names
- Organism
- Strain
- Taxonomic lineageEukaryota > Metazoa > Chordata > Craniata > Vertebrata > Euteleostomi > Mammalia > Eutheria > Euarchontoglires > Glires > Rodentia > Myomorpha > Muroidea > Muridae > Murinae > Rattus
Accessions
- Primary accessionP83953
Proteomes
Organism-specific databases
PTM/Processing
Features
Showing features for modified residue, chain.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Modified residue | 1 | N-acetylmethionine | ||||
Sequence: M | ||||||
Chain | PRO_0000120721 | 1-538 | Importin subunit alpha-5 | |||
Sequence: MSTPGKENFRLKSYKNKSLNPDEMRRRREEEGLQLRKQKREEQLFKRRNVATAEEETEEEVMSDGGFHEAQINNMEMAPGGVITSDMTEMIFSNSPEQQLSATQKFRKLLSKEPNPPIDEVINTPGVVARFVEFLKRKENCTLQFESAWVLTNIASGNSLQTRIVIQAGAVPIFIELLSSEFEDVQEQAVWALGNIAGDSTMCRDYVLDCNILPPLLQLFSKQNRLTMTRNAVWALSNLCRGKSPPPEFAKVSPCLNVLSWLLFVSDTDVLADACWALSYLSDGPNDKIQAVIDAGVCRRLVELLMHNDYKVVSPALRAVGNIVTGDDIQTQVILNCSALQSLLHLLSSPKESIKKEACWTISNITAGNRAQIQTVIDANMFPALISILQTAEFRTRKEAAWAITNATSGGSAEQIKYLVELGCIKPLCDLLTVMDAKIVQVALNGLENILRLGEQEAKRNGSGINPYCALIEEAYGLDKIEFLQSHENQEIYQKAFDLIEHYFGTEDEDSSIAPQVDLSQQQYIFQQCEAPMEGSQL | ||||||
Modified residue | 3 | Phosphothreonine | ||||
Sequence: T | ||||||
Modified residue | 63 | Phosphoserine | ||||
Sequence: S |
Post-translational modification
Polyubiquitinated in the presence of RAG1 (in vitro).
Keywords
- PTM
Proteomic databases
PTM databases
Expression
Tissue specificity
Expressed significantly in the heart, kidney, placenta, pancreas and spleen with lower levels detected in the brain, liver and skeletal muscle.
Induction
Injection of 6-hydroxydopamine into the ascending medial forebrain bundle causes the formation of lesions and leads to up-regulation of KPNA1 in the denervated striatum in a time-dependent manner, reaching a maximum two weeks post-lesion.
Interaction
Subunit
Heterodimer; with KPNB1 (By similarity).
Interacts with APEX1 (via its N-terminus) (By similarity).
Interacts with CTNNBL1 (via its N-terminal) (By similarity).
Interacts with AICDA (via its NLS) (By similarity).
Interacts with ANP32E and ZIC3 (By similarity).
Interacts with SNAI1 (via zinc fingers) (By similarity).
Interacts with NSMF; the interaction occurs in a calcium-independent manner after synaptic NMDA receptor stimulation and is required for nuclear import of NSMF but is competed by CABP1 (PubMed:18303947).
Interacts with DCAF8 (By similarity).
Interacts with ITSN1 isoform 2 (By similarity).
Interacts with TALDO1 (By similarity).
Interacts with the AMPK-mediated 'Ser-659' phosphorylated form of ACSS2; this interaction results in nuclear translocation of ACSS2 (By similarity).
Interacts with BAP1 (via C-terminus); the interaction contributes to BAP1 nuclear localization (By similarity).
Interacts with APEX1 (via its N-terminus) (By similarity).
Interacts with CTNNBL1 (via its N-terminal) (By similarity).
Interacts with AICDA (via its NLS) (By similarity).
Interacts with ANP32E and ZIC3 (By similarity).
Interacts with SNAI1 (via zinc fingers) (By similarity).
Interacts with NSMF; the interaction occurs in a calcium-independent manner after synaptic NMDA receptor stimulation and is required for nuclear import of NSMF but is competed by CABP1 (PubMed:18303947).
Interacts with DCAF8 (By similarity).
Interacts with ITSN1 isoform 2 (By similarity).
Interacts with TALDO1 (By similarity).
Interacts with the AMPK-mediated 'Ser-659' phosphorylated form of ACSS2; this interaction results in nuclear translocation of ACSS2 (By similarity).
Interacts with BAP1 (via C-terminus); the interaction contributes to BAP1 nuclear localization (By similarity).
Protein-protein interaction databases
Structure
Family & Domains
Features
Showing features for region, domain, compositional bias, motif, repeat.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Region | 1-41 | Disordered | ||||
Sequence: MSTPGKENFRLKSYKNKSLNPDEMRRRREEEGLQLRKQKRE | ||||||
Domain | 1-57 | IBB | ||||
Sequence: MSTPGKENFRLKSYKNKSLNPDEMRRRREEEGLQLRKQKREEQLFKRRNVATAEEET | ||||||
Compositional bias | 10-41 | Basic and acidic residues | ||||
Sequence: RLKSYKNKSLNPDEMRRRREEEGLQLRKQKRE | ||||||
Motif | 42-51 | Nuclear localization signal | ||||
Sequence: EQLFKRRNVA | ||||||
Repeat | 77-117 | ARM 1; truncated | ||||
Sequence: MAPGGVITSDMTEMIFSNSPEQQLSATQKFRKLLSKEPNPP | ||||||
Repeat | 118-161 | ARM 2 | ||||
Sequence: IDEVINTPGVVARFVEFLKRKENCTLQFESAWVLTNIASGNSLQ | ||||||
Region | 149-241 | NLS binding site (major) | ||||
Sequence: WVLTNIASGNSLQTRIVIQAGAVPIFIELLSSEFEDVQEQAVWALGNIAGDSTMCRDYVLDCNILPPLLQLFSKQNRLTMTRNAVWALSNLCR | ||||||
Repeat | 162-206 | ARM 3 | ||||
Sequence: TRIVIQAGAVPIFIELLSSEFEDVQEQAVWALGNIAGDSTMCRDY | ||||||
Repeat | 207-245 | ARM 4 | ||||
Sequence: VLDCNILPPLLQLFSKQNRLTMTRNAVWALSNLCRGKSP | ||||||
Region | 245-437 | Binding to RAG1 | ||||
Sequence: PPPEFAKVSPCLNVLSWLLFVSDTDVLADACWALSYLSDGPNDKIQAVIDAGVCRRLVELLMHNDYKVVSPALRAVGNIVTGDDIQTQVILNCSALQSLLHLLSSPKESIKKEACWTISNITAGNRAQIQTVIDANMFPALISILQTAEFRTRKEAAWAITNATSGGSAEQIKYLVELGCIKPLCDLLTVMDA | ||||||
Repeat | 246-290 | ARM 5 | ||||
Sequence: PPEFAKVSPCLNVLSWLLFVSDTDVLADACWALSYLSDGPNDKIQ | ||||||
Repeat | 291-330 | ARM 6 | ||||
Sequence: AVIDAGVCRRLVELLMHNDYKVVSPALRAVGNIVTGDDIQ | ||||||
Region | 318-406 | NLS binding site (minor) | ||||
Sequence: RAVGNIVTGDDIQTQVILNCSALQSLLHLLSSPKESIKKEACWTISNITAGNRAQIQTVIDANMFPALISILQTAEFRTRKEAAWAITN | ||||||
Repeat | 331-372 | ARM 7 | ||||
Sequence: TQVILNCSALQSLLHLLSSPKESIKKEACWTISNITAGNRAQ | ||||||
Repeat | 373-412 | ARM 8 | ||||
Sequence: IQTVIDANMFPALISILQTAEFRTRKEAAWAITNATSGGS | ||||||
Repeat | 413-457 | ARM 9 | ||||
Sequence: AEQIKYLVELGCIKPLCDLLTVMDAKIVQVALNGLENILRLGEQE | ||||||
Repeat | 460-504 | ARM 10; atypical | ||||
Sequence: RNGSGINPYCALIEEAYGLDKIEFLQSHENQEIYQKAFDLIEHYF |
Domain
Consists of an N-terminal hydrophilic region, a hydrophobic central region composed of 10 repeats, and a short hydrophilic C-terminus. The N-terminal hydrophilic region contains the importin beta binding domain (IBB domain), which is sufficient for binding importin beta and essential for nuclear protein import.
The IBB domain is thought to act as an intrasteric autoregulatory sequence by interacting with the internal autoinhibitory NLS. Binding of KPNB1 probably overlaps the internal NLS and contributes to a high affinity for cytoplasmic NLS-containing cargo substrates. After dissociation of the importin/substrate complex in the nucleus the internal autohibitory NLS contributes to a low affinity for nuclear NLS-containing proteins (By similarity).
The major and minor NLS binding sites are mainly involved in recognition of simple or bipartite NLS motifs. Structurally located within in a helical surface groove they contain several conserved Trp and Asn residues of the corresponding third helices (H3) of ARM repeats which mainly contribute to binding (By similarity).
Sequence similarities
Belongs to the importin alpha family.
Keywords
- Domain
Phylogenomic databases
Family and domain databases
Sequence
- Sequence statusComplete
- Length538
- Mass (Da)60,137
- Last updated2004-06-07 v1
- ChecksumB5B66B860D96EC5B
Computationally mapped potential isoform sequences
There are 4 potential isoforms mapped to this entry
Entry | Entry name | Gene name | Length | ||
---|---|---|---|---|---|
A0A8I6AKK8 | A0A8I6AKK8_RAT | Kpna1 | 547 | ||
A0A0G2K0T0 | A0A0G2K0T0_RAT | Kpna1 | 544 | ||
A0A8I6A8S8 | A0A8I6A8S8_RAT | Kpna1 | 145 | ||
Q56R20 | Q56R20_RAT | Kpna1 | 538 |
Features
Showing features for compositional bias.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Compositional bias | 10-41 | Basic and acidic residues | ||||
Sequence: RLKSYKNKSLNPDEMRRRREEEGLQLRKQKRE |
Keywords
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
AY351984 EMBL· GenBank· DDBJ | AAQ56727.1 EMBL· GenBank· DDBJ | mRNA |