X-box binding protein 1 (XBP1)

Target Class
Transcription factor
Official Symbol
Accession Number
Alias Names
TREB5; X-box binding protein 1; X-box-binding protein 1; XBP-1; XBP2; tax-responsive element-binding protein 5
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]
+ Show More

Solution Portfolio

Related Group Members:

Transcription factor

DiscoveRx offers cell-based assays that target other members of this gene family or functional group. Click on the family name to browse all available assays for that target family

Assay Measures Background Species Cell Line
XBP1 translocation U2OS Human 93-0857C3
Assay Measures Background Species Assay Kit
XBP1 Translocation U2OS Human 93-0857E3CP5M
XBP1 Translocation U2OS Human 93-0857E3CP5L

KINOMEscan TKscan BROMOscan NHRscan GPCRscan PATHscan