TF Info Page for XBP1 (bZIP)
Conclusion
| Assessment | Binding Mode | Motif Status | Notes | Comments |
|---|---|---|---|---|
| Known motif | 1 Monomer or homomultimer | High-throughput in vitro |
Description
| Description: | X-box binding protein 1 [Source:HGNC Symbol;Acc:HGNC:12801] | |||||||||
| Entrez Summary | This gene encodes a transcription factor that regulates MHC class II genes by binding to a promoter element referred to as an X box. This gene product is a bZIP protein, which was also identified as a cellular transcription factor that binds to an enhancer in the promoter of the T cell leukemia virus type 1 promoter. It may increase expression of viral proteins by acting as the DNA binding partner of a viral transactivator. It has been found that upon accumulation of unfolded proteins in the endoplasmic reticulum (ER), the mRNA of this gene is processed to an active form by an unconventional splicing mechanism that is mediated by the endonuclease inositol-requiring enzyme 1 (IRE1). The resulting loss of 26 nt from the spliced mRNA causes a frame-shift and an isoform XBP1(S), which is the functionally active transcription factor. The isoform encoded by the unspliced mRNA, XBP1(U), is constitutively expressed, and thought to function as a negative feedback regulator of XBP1(S), which shuts off transcription of target genes during the recovery phase of ER stress. A pseudogene of XBP1 has been identified and localized to chromosome 5. [provided by RefSeq, Jul 2008] | |||||||||
| Ensembl ID: | ENSG00000100219 | |||||||||
| External Link: | CisBP | |||||||||
| Interpro | IPR004827; ; | |||||||||
| Protein Domain: | ENSP00000216037 | |||||||||
| Protein Domain: | ENSP00000384295 | |||||||||
| Protein Domain: | ENSP00000385162 | |||||||||
| Domain: |
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Previous Annotations
| Source | Annotation |
| TF-CAT classification |
TF Gene_DNA-Binding sequence-specific_DNA Binding Transactivation_ PMIDS:2321018 |
| Vaquerizas 2009 TF classification "a" Has direct evidence of TF function; "b" Has evidence for an orthologous TF; "c" contains likely DBDs, but has no functional evidence; "x" is an unlikely TF such as predicted gene, genes with likely non-specific DBDs or that have function outside transcription; "other" category contains proteins without clear DBDs they curated from external sources. |
a |
| CisBP considers it as a TF? | Yes |
| TFclass considers it as a TF? | Yes |
| Has GO:0003700 "transcription factor activity, sequence-specific DNA binding" | Yes |
| GO-Info |
GO:0000981 sequence-specific DNA binding RNA polymerase II transcription factor activity IEA - GO_REF:0000019 GO:0003700 sequence-specific DNA binding transcription factor activity IDA - PMID:1903538, PMID:8657566 |
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Initial Assessment
1a1 Protein has a high confidence PWM (HT-SELEX, PBM or B1H model) or there is a crystal structure that supports sequence specific DNA binding; 1a2 There is high confidence data for a close ortholog (as defined in CisBP); 2a1 There is lower confidence direct evidence, such as a Jaspar, Hocomoco or Transfac model; 2a2 There is lower confidence evidence for an close ortholog; 3a There is decent circumstantial evidence for its role as a TF or not; 4a Two or more datasets predict it as a TF; 5a One of the source datasets predicts is as a TF |
1a1, Direct HQ evidence |
| TF has conditional DNA-binding requirements |