Gene: XBP1

Alternate names for this Gene: TREB-5|TREB5|XBP-1|XBP2

Gene 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.

Gene is located in Chromosome: 22

Location in Chromosome : 22q12.1|22q12

Description of this Gene: X-box binding protein 1

Type of Gene: protein-coding

rs2239815 in XBP1 gene and Esophageal Neoplasms PMID 22960999 2012 Genome-wide association analyses of esophageal squamous cell carcinoma in Chinese identify multiple susceptibility loci and gene-environment interactions.

rs2239815 in XBP1 gene and Squamous cell carcinoma PMID 22960999 2012 Genome-wide association analyses of esophageal squamous cell carcinoma in Chinese identify multiple susceptibility loci and gene-environment interactions.

rs2239815 in XBP1 gene and Squamous cell carcinoma of esophagus PMID 25129146 2014 Joint analysis of three genome-wide association studies of esophageal squamous cell carcinoma in Chinese populations.