Anti-X-box Binding Protein-1, CT (XBP1)

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) (1). 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 (3,4). Applications: Suitable for use in Western Blot and Immunocytochemistry. Other applications not tested. Recommended Dilution: Western Blot: 0.5-1ug/ml, Immunocytochemistry: 2ug/ml., Optimal dilutions to be determined by the researcher. Positive Control: P3113-99: PC-3 cell lysate, Storage and Stability: May be stored at 4°C for short-term only. For long-term storage, aliquot and store at -20°C. Aliquots are stable for at least 12 months at -20°C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.