9h0c

Structural highlights

Disease

BIP_HUMAN Autoantigen in rheumatoid arthritis.^[1]

Function

BIP_HUMAN Endoplasmic reticulum chaperone that plays a key role in protein folding and quality control in the endoplasmic reticulum lumen (PubMed:2294010, PubMed:23769672, PubMed:23990668, PubMed:28332555). Involved in the correct folding of proteins and degradation of misfolded proteins via its interaction with DNAJC10/ERdj5, probably to facilitate the release of DNAJC10/ERdj5 from its substrate (By similarity). Acts as a key repressor of the ERN1/IRE1-mediated unfolded protein response (UPR) (PubMed:1550958, PubMed:19538957). In the unstressed endoplasmic reticulum, recruited by DNAJB9/ERdj4 to the luminal region of ERN1/IRE1, leading to disrupt the dimerization of ERN1/IRE1, thereby inactivating ERN1/IRE1 (By similarity). Accumulation of misfolded protein in the endoplasmic reticulum causes release of HSPA5/BiP from ERN1/IRE1, allowing homodimerization and subsequent activation of ERN1/IRE1 (By similarity). Plays an auxiliary role in post-translational transport of small presecretory proteins across endoplasmic reticulum (ER). May function as an allosteric modulator for SEC61 channel-forming translocon complex, likely cooperating with SEC62 to enable the productive insertion of these precursors into SEC61 channel. Appears to specifically regulate translocation of precursors having inhibitory residues in their mature region that weaken channel gating.[UniProtKB:G3I8R9][UniProtKB:P20029]^{[2] [3] [4] [5] [6] [7] [8]}

References

1. ↑ Corrigall VM, Bodman-Smith MD, Fife MS, Canas B, Myers LK, Wooley P, Soh C, Staines NA, Pappin DJ, Berlo SE, van Eden W, van Der Zee R, Lanchbury JS, Panayi GS. The human endoplasmic reticulum molecular chaperone BiP is an autoantigen for rheumatoid arthritis and prevents the induction of experimental arthritis. J Immunol. 2001 Feb 1;166(3):1492-8. PMID:11160188
2. ↑ Ng DT, Watowich SS, Lamb RA. Analysis in vivo of GRP78-BiP/substrate interactions and their role in induction of the GRP78-BiP gene. Mol Biol Cell. 1992 Feb;3(2):143-55. doi: 10.1091/mbc.3.2.143. PMID:1550958 doi:http://dx.doi.org/10.1091/mbc.3.2.143
3. ↑ Oikawa D, Kimata Y, Kohno K, Iwawaki T. Activation of mammalian IRE1alpha upon ER stress depends on dissociation of BiP rather than on direct interaction with unfolded proteins. Exp Cell Res. 2009 Sep 10;315(15):2496-504. doi: 10.1016/j.yexcr.2009.06.009., Epub 2009 Jun 16. PMID:19538957 doi:http://dx.doi.org/10.1016/j.yexcr.2009.06.009
4. ↑ Dana RC, Welch WJ, Deftos LJ. Heat shock proteins bind calcitonin. Endocrinology. 1990 Jan;126(1):672-4. PMID:2294010
5. ↑ Oka OB, Pringle MA, Schopp IM, Braakman I, Bulleid NJ. ERdj5 is the ER reductase that catalyzes the removal of non-native disulfides and correct folding of the LDL receptor. Mol Cell. 2013 Jun 27;50(6):793-804. doi: 10.1016/j.molcel.2013.05.014. Epub 2013, Jun 13. PMID:23769672 doi:http://dx.doi.org/10.1016/j.molcel.2013.05.014
6. ↑ Evensen NA, Kuscu C, Nguyen HL, Zarrabi K, Dufour A, Kadam P, Hu YJ, Pulkoski-Gross A, Bahou WF, Zucker S, Cao J. Unraveling the role of KIAA1199, a novel endoplasmic reticulum protein, in cancer cell migration. J Natl Cancer Inst. 2013 Sep 18;105(18):1402-16. doi: 10.1093/jnci/djt224. Epub, 2013 Aug 29. PMID:23990668 doi:http://dx.doi.org/10.1093/jnci/djt224
7. ↑ Cuevas EP, Eraso P, Mazon MJ, Santos V, Moreno-Bueno G, Cano A, Portillo F. LOXL2 drives epithelial-mesenchymal transition via activation of IRE1-XBP1 signalling pathway. Sci Rep. 2017 Mar 23;7:44988. doi: 10.1038/srep44988. PMID:28332555 doi:http://dx.doi.org/10.1038/srep44988
8. ↑ Hassdenteufel S, Johnson N, Paton AW, Paton JC, High S, Zimmermann R. Chaperone-Mediated Sec61 Channel Gating during ER Import of Small Precursor Proteins Overcomes Sec61 Inhibitor-Reinforced Energy Barrier. Cell Rep. 2018 May 1;23(5):1373-1386. doi: 10.1016/j.celrep.2018.03.122. PMID:29719251 doi:http://dx.doi.org/10.1016/j.celrep.2018.03.122