X box binding protein 1 (XBP-1) is a key protein in the mammalian unfolded protein response (UPR) that protects the cell against the stress of malfolded proteins in the endoplasmic reticulum (ER). Upon sensing unfolded proteins, an ER transmembrane endonuclease and kinase termed IRE1p is activated and excises an intron from XBP-1 mRNA. The spliced XBP-1 mRNA results in a 371 amino acid protein (XBP-1s) which is then translocated to the nucleus where it binds to the regulatory elements of downstream genes. Together with other UPR transcription factors such as ATF6, XBP-1 stimulates the production of ER stress proteins including the ER resident protein chaperones glucose regulated protein (GRP) 78 and GRP94.
SDS-PAGE analysis of recombinant XBP1 on Coomassie Blue-stained 4-15% gradient gel.
Protein Accession Number
BAB82982
Application
This recombinant protein can be used for WB, ELISA, MS and neutralization assays.
Buffer
1X PBS containing 0.1% SDS
Fusion Partner
N-terminal His-tag
Molecular Weight
25 kDa (calculated)
Protein GI Number
18148382
Source
E. coli
Tested Application
E, WB, MS
Storage
Store at -70ËšC. As with any protein, exposing XBP1 recombinant protein to repeated freeze/thaw cycles is not recommended. When working with proteins care should be taken to keep recombinant protein at a cool and stable temperature.
Species Reactivity
n/a
Purity
~95%
Reference
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Yoshida H, Matsui T, Yamamoto T, et al. XBP1 mRNA is induced by ATF6 and spliced by IRE1p in response to ER stress to produce a highly active transcription factor. Cell 2001; 107:881-91.
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Calfon M, Zeng H, Urano F, et al. IRE1 couples endoplasmic reticulum load to secretory capacity by processing the XBP-1 mRNA. Nature 2002; 415:92-6.
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Haze K, Yoshida H, Yanagi H, et al. Mammalian transcription factor ATF6 is synthesized as a transmembrane protein and activated by proteolysis in response to endoplasmic stress.Mol. Cell. Biol. 1999; 10:3787-99.
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Little E, Ramakrishnan M, Roy B, et al. The glucose-regulated proteins (GRP78 and GRP94): functions, gene regulation, and applications. Crit. Rev. Eukaryot. Gene Expr.1994; 4:1-18. ]