Tag Content
SG ID
SG00002568 
UniProt Accession
Theoretical PI
4.92  
Molecular Weight
119275 Da  
Genbank Nucleotide ID
Genbank Protein ID
Gene Name
Ipo4 
Gene Synonyms/Alias
Imp4a, Ranbp4 
Protein Name
Importin-4 
Protein Synonyms/Alias
Imp4 Importin-4a;Imp4a Ran-binding protein 4;RanBP4 
Organism
Mus musculus (Mouse) 
NCBI Taxonomy ID
10090 
Chromosome Location
chr:14;56244237-56256732;-1
View in Ensembl genome browser  
Function in Stage
Uncertain 
Function in Cell Type
Uncertain 
Probability (GAS) of Function in Spermatogenesis
0.595328855 
The probability was calculated by GAS algorithm, ranging from 0 to 1. The closer it is to 1, the more possibly it functions in spermatogenesis.
Description
Temporarily unavailable 
Abstract of related literatures
1. Many nuclear transport pathways are mediated by importin beta-related transport receptors. Here, we identify human importin (Imp) 4b as well as mouse Imp4a, Imp9a and Imp9b as novel family members. Imp4a mediates import of the ribosomal protein (rp) S3a, while Imp9a and Imp9b import rpS7, rpL18a and apparently numerous other substrates. Ribosomal proteins, histones and many other nuclear import substrates are very basic proteins that aggregate easily with cytoplasmic polyanions such as RNA. Imp9 effectively prevents such precipitation of, for example, rpS7 and rpL18a by covering their basic domains. The same applies to Imp4, Imp5, Imp7 and Impbeta and their respective basic import substrates. The Impbeta-Imp7 heterodimer appears specialized for the most basic proteins, such as rpL4, rpL6 and histone H1, and is necessary and sufficient to keep them soluble in a cytoplasmic environment prior to rRNA or DNA binding, respectively. Thus, just as heat shock proteins function as chaperones for exposed hydrophobic patches, importins act as chaperones for exposed basic domains, and we suggest that this represents a major and general cellular function of importins. PMID: [11823430] 

2. This study describes comprehensive polling of transcription start and termination sites and analysis of previously unidentified full-length complementary DNAs derived from the mouse genome. We identify the 5' and 3' boundaries of 181,047 transcripts with extensive variation in transcripts arising from alternative promoter usage, splicing, and polyadenylation. There are 16,247 new mouse protein-coding transcripts, including 5154 encoding previously unidentified proteins. Genomic mapping of the transcriptome reveals transcriptional forests, with overlapping transcription on both strands, separated by deserts in which few transcripts are observed. The data provide a comprehensive platform for the comparative analysis of mammalian transcriptional regulation in differentiation and development. PMID: [16141072] 

3. The National Institutes of Health's Mammalian Gene Collection (MGC) project was designed to generate and sequence a publicly accessible cDNA resource containing a complete open reading frame (ORF) for every human and mouse gene. The project initially used a random strategy to select clones from a large number of cDNA libraries from diverse tissues. Candidate clones were chosen based on 5'-EST sequences, and then fully sequenced to high accuracy and analyzed by algorithms developed for this project. Currently, more than 11,000 human and 10,000 mouse genes are represented in MGC by at least one clone with a full ORF. The random selection approach is now reaching a saturation point, and a transition to protocols targeted at the missing transcripts is now required to complete the mouse and human collections. Comparison of the sequence of the MGC clones to reference genome sequences reveals that most cDNA clones are of very high sequence quality, although it is likely that some cDNAs may carry missense variants as a consequence of experimental artifact, such as PCR, cloning, or reverse transcriptase errors. Recently, a rat cDNA component was added to the project, and ongoing frog (Xenopus) and zebrafish (Danio) cDNA projects were expanded to take advantage of the high-throughput MGC pipeline. PMID: [15489334] 

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Function
Functions in nuclear protein import as nuclear transportreceptor. Serves as receptor for nuclear localization signals(NLS) in cargo substrates. Is thought to mediate docking of theimportin/substrate complex to the nuclear pore complex (NPC)through binding to nucleoporin and the complex is subsequentlytranslocated through the pore by an energy requiring, Ran-dependent mechanism. At the nucleoplasmic side of the NPC, Ranbinds to the importin, the importin/substrate complex dissociatesand importin is re-exported from the nucleus to the cytoplasmwhere GTP hydrolysis releases Ran. The directionality of nuclearimport is thought to be conferred by an asymmetric distribution ofthe GTP- and GDP-bound forms of Ran between the cytoplasm andnucleus (By similarity). Mediates the nuclear import of RPS3A.Acts as chaperone for exposed basic domains. 
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Subcellular Location
Cytoplasm (By similarity). Nucleus (Bysimilarity). 
Tissue Specificity
 
Gene Ontology
GO IDGO termEvidence
GO:0005737 C:cytoplasm IEA:UniProtKB-SubCell.
GO:0005634 C:nucleus IEA:UniProtKB-SubCell.
GO:0008565 F:protein transporter activity IEA:InterPro.
GO:0006610 P:ribosomal protein import into nucleus ISA:MGI.
GO:0042254 P:ribosome biogenesis ISA:MGI.
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Interpro
IPR011989;    ARM-like.
IPR016024;    ARM-type_fold.
IPR000357;    HEAT.
IPR001494;    Importin-beta_N.
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Pfam
PF02985;    HEAT;    1.
PF03810;    IBN_N;    1.
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SMART
SM00913;    IBN_N;    1.
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PROSITE
PS50077;    HEAT_REPEAT;    FALSE_NEG.
PS50166;    IMPORTIN_B_NT;    1.
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PRINTS
Created Date
18-Oct-2012 
Record Type
GAS predicted 
Sequence Annotation
CHAIN         1   1082       Importin-4.
                             /FTId=PRO_0000120749.
DOMAIN       24     90       Importin N-terminal.
REPEAT      348    385       HEAT 1.
REPEAT      390    427       HEAT 2.
REPEAT      431    471       HEAT 3.
REPEAT      475    513       HEAT 4.
REPEAT      896    933       HEAT 5.
REPEAT      937    975       HEAT 6.
MOD_RES       1      1       N-acetylmethionine (By similarity).
MOD_RES      86     86       Phosphothreonine (By similarity).
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Nucleotide Sequence
Length: 3249 bp   Go to nucleotide: FASTA
Protein Sequence
Length: 1082 bp   Go to amino acid: FASTA
The verified Protein-Protein interaction information
UniProt
Gene Symbol Ref Databases
Poldip2String 
Poldip2String 
Other Protein-Protein interaction resources
String database  
View Microarray data
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