Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P11021 (BiP)
 2,049 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The FKB2 gene of Saccharomyces cerevisiae encodes a homolog of mammalian FKBP-13, an FK506/rapamycin-binding protein that localizes to the lumen of the endoplasmic reticulum (ER). We have found that FKB2 mRNA levels increase in response to the accumulation of unfolded precursor proteins in the ER. FKB2 mRNA levels are elevated in cells blocked in N-glycosylation--i.e., in wild-type cells treated with tunicamycin and in the sec53-6 mutant grown at the nonpermissive temperature. Mutations that block other steps in secretion have no effect on FKB2 mRNA levels, indicating that increases in FKB2 mRNA are not the consequence of a general block in secretion. The increase in FKB2 mRNA in response to unfolded proteins in the ER is mediated through a 21-bp unfolded-protein response (UPR) element located in the 5' noncoding region of FKB2. UPR elements present in other ER chaperone genes, such as yeast KAR2 (BiP), mammalian GRP78 (BiP), and GRP94, function in an analogous manner to that in FKB2. As with KAR2, FKB2 mRNA levels are also elevated by heat shock. The similarities in the regulation of FKB2 and other ER chaperone genes suggest that FKBP-13 may play a role in protein trafficking in the ER.
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PMID:The FKB2 gene of Saccharomyces cerevisiae, encoding the immunosuppressant-binding protein FKBP-13, is regulated in response to accumulation of unfolded proteins in the endoplasmic reticulum. 768 4

FK506 binding proteins (FKBPs) belong to the family of peptidyl prolyl cis-trans isomerases (PPIases) catalyzing the cis/trans isomerisation of Xaa-Pro bonds in oligopeptides and proteins. FKBPs are involved in folding, assembly and trafficking of proteins. However, only limited knowledge is available about the roles of FKBPs in the endoplasmic reticulum (ER) and their interaction with other proteins. Here we show the ER located Neurospora crassa FKBP22 to be a dimeric protein with PPIase and a novel chaperone activity. While the homodimerization of FKBP22 is mediated by its carboxy-terminal domain, the amino-terminal domain is a functional FKBP domain. The chaperone activity is mediated by the FKBP domain but is exhibited only by the full-length protein. We further demonstrate a direct interaction between FKBP22 and BiP, the major Hsp70 chaperone in the ER. The binding to BiP is mediated by the FKBP domain of FKBP22. Interestingly BiP enhances the chaperone activity of FKBP22. Both proteins form a stable complex with an unfolded substrate protein and thereby prevent its aggregation. These results suggest that BiP and FKBP22 form a folding helper complex with a high chaperoning capacity in the ER of Neurospora crassa.
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PMID:Neurospora crassa FKBP22 is a novel ER chaperone and functionally cooperates with BiP. 1742 99

FKBP22 is a dimeric protein in the lumen of the endoplasmic reticulum, which exhibits a chaperone as well as a PPIase activity. It binds via its FK506 binding protein (FKBP) domain directly to the Hsp70 chaperone BiP that stimulates the chaperone activity of FKBP22. Here we demonstrate additionally the association of FKBP22 with the molecular chaperones and folding catalysts Grp170, alpha-subunit of glucosidase II, PDI, ERp38, and CyP23. These proteins are associated with FKBP22 in at least two protein complexes. Furthermore, we report an essential role for FKBP22 in the development of microconidiophores in Neurospora crassa.
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PMID:FKBP22 is part of chaperone/folding catalyst complexes in the endoplasmic reticulum of Neurospora crassa. 1747 Mar 67

FK506 binding proteins (FKBPs) in cells are known as immunophilins. We have identified and characterized a cDNA encoding an endoplasmic reticulum (ER) immunophilin, FKBP23, from pig liver by nested PCR. The predicted amino acid sequence of pig FKBP23 shows high identity to those of human FKBP23 and mouse FKBP23. It possesses a conserved FKBP-type peptidylprolyl cis-trans isomerase (PPIase) domain and EF-hand domain. We constructed a plasmid to express pFKBP23. Furthermore, we proved that the recombinant pFKBP23 can specifically bind to natural BiP, the main protein of the molecular chaperone Hsp70 in ER lumen; the binding is interrelated with the Ca2+ concentration just as the FKBP23 from mice.
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PMID:De-novo cloning of FKBP23 cDNA from pig ER using nested PCR. 1952 27