Endoplasmic reticulum chaperone BiP - P11021 (BIP_HUMAN)

 

Protein Feature View of PDB entries mapped to a UniProtKB sequence  

  • Number of PDB entries for P11021: 16
 
Function
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. UniProt
Catalytic Activity
ATP + H2O = ADP + phosphate. UniProt
Pathway Maps
Maps:       
Reactions:
      ESCHER  BiGG
Subunit Structure
Monomer and homooligomer; homooligomerization via the interdomain linker inactivates the chaperone activity and acts as a storage of HSPA5/BiP molecules (By similarity). Interacts with DNAJC1 (via J domain) (By similarity). Component of an EIF2 complex at least composed of CELF1/CUGBP1, CALR, CALR3, EIF2S1, EIF2S2, HSP90B1 and HSPA5 (By similarity). Part of a large chaperone multiprotein complex comprising DNAJB11, HSP90B1, HSPA5, HYOU, PDIA2, PDIA4, PDIA6, PPIB, SDF2L1, UGT1A1 and very small amounts of ERP29, but not, or at very low levels, CALR nor CANX (By similarity). Interacts with TMEM132A and TRIM21 (PubMed:12699405). May form a complex with ERLEC1, OS9, SEL1L and SYVN1 (PubMed:18264092,PubMed:18502753). Interacts with DNAJC10 (PubMed:12411443, PubMed:23769672). Interacts with DNAJB9/ERdj4; leading to recruit HSPA5/BiP to ERN1/IRE1 (By similarity). Interacts with ERN1/IRE1; interaction takes place following interaction with DNAJB9/ERdj4 and leads to inactivate ERN1/IRE1 (By similarity). Interacts with MX1 (By similarity). Interacts with METTL23 (PubMed:23349634). Interacts with CEMIP; the interaction induces calcium leakage from the endoplasmic reticulum and cell migration (PubMed:23990668). Interacts with PCSK4 form; the interaction takes place in the endoplasmic reticulum (PubMed:21080038). Interacts with CIPC (PubMed:26657846). Interacts with CCDC88B (via C-terminus); the interaction opposes ERN1-mediated JNK activation, protecting against apoptosis (PubMed:21289099). Interacts with INPP5K; necessary for INPP5K localization at the endoplasmic reticulum (PubMed:26940976). Interacts with MANF; the interaction is direct (PubMed:22637475). Interacts with LOXL2; leading to activate the ERN1/IRE1-XBP1 pathway of the unfolded protein response (PubMed:28332555). UniProt
Domain
The interdomain linker regulates the chaperone activity by mediating the formation of homooligomers. Homooligomers are formed by engagement of the interdomain linker of one HSPA5/BiP molecule as a typical substrate of an adjacent HSPA5/BiP molecule. HSPA5/BiP oligomerization inactivates participating HSPA5/BiP protomers. HSPA5/BiP oligomers probably act as reservoirs to store HSPA5/BiP molecules when they are not needed by the cell. When the levels of unfolded proteins rise, cells can rapidly break up these oligomers to make active monomers. UniProt
Legend
The Protein Feature View requires a browser that supports SVG (Scalable Vector Graphics). Mouse over tracks and labels for more information.
Data origin/color codes
The vertical color bar on the left side indicates data provenance.
Data in green originates from UniProtKB  
Variation data (sourced from UniProt) shows non-genetic variation from the ExPASy   and dbSNP   websites.
Data in yellow originates from Pfam  , by interacting with the HMMER3 web site  
Data in purple originates from Phosphosite  .
Data in orange originates from the SCOP   (version 1.75) and SCOPe   (version 2.04) classifications.
Data in grey has been calculated using BioJava  . Protein disorder predictions are based on JRONN (Troshin, P. and Barton, G. J. unpublished), a Java implementation of RONN  
  • Red: potentially disorderd region
  • Blue: probably ordered region.
Hydropathy has been calculated using a sliding window of 15 residues and summing up scores from standard hydrophobicity tables.
  • Red: hydrophobic
  • Blue: hydrophilic.
Data in lilac represent the genomic exon structure projected onto the UniProt sequence.
Data in blue originates from PDB
  • Secstruc: Secondary structure projected from representative PDB entries onto the UniProt sequence.
Sequence Mismatches It is now possible to see information about expression tags, cloning artifacts, and many other details related to sequence mismatches.
Icons represent a number of different sequence modifications that can be observed in PDB files. For example the 'T' icon T represents expression tags that have been added to the sequence. The 'E' icon E represents an engineered mutation. However, besides these two, there are many other icons. For more information about the meaning and exact position of a sequence modification, move the cursor over the icon.
Validation Track

For more details on the Validation Track (Structure Summary Page only) see the dedicated help page.

Data in red indicates combined ranges of Homology Models from SBKB   and the Protein Model Portal  
The PDB to UniProt mapping is based on the data provided by the EBI SIFTS project. See also Velankar et al., Nucleic Acids Research 33, D262-265 (2005).
Organism icons generated by flaticon.com under CC BY. The authors are: Freepik, Icons8, OCHA, Scott de Jonge.

For more details on the Protein Feature view see the dedicated help page.