6ha7

From Proteopedia

Crystal structure of the BiP NBD and MANF complex

Structural highlights

6ha7 is a 4 chain structure with sequence from Cricetulus griseus and Mus musculus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	X-ray diffraction, Resolution 2.49Å
Ligands:
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

BIP_CRIGR Endoplasmic reticulum chaperone that plays a key role in protein folding and quality control in the endoplasmic reticulum lumen (By similarity). 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:29198525). 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 (PubMed:29198525). Accumulation of misfolded protein in the endoplasmic reticulum causes release of HSPA5/BiP from ERN1/IRE1, allowing homodimerization and subsequent activation of ERN1/IRE1 (PubMed:29198525). 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:P11021][UniProtKB:P20029]^[1]

Publication Abstract from PubMed

Despite its known role as a secreted neuroprotectant, much of the mesencephalic astrocyte-derived neurotrophic factor (MANF) is retained in the endoplasmic reticulum (ER) of producer cells. There, by unknown mechanisms, MANF plays a role in protein folding homeostasis in complex with the ER-localized Hsp70 chaperone BiP. Here we report that the SAF-A/B, Acinus, and PIAS (SAP) domain of MANF selectively associates with the nucleotide binding domain (NBD) of ADP-bound BiP. In crystal structures the SAP domain engages the cleft between NBD subdomains Ia and IIa, stabilizing the ADP-bound conformation and clashing with the interdomain linker that occupies this site in ATP-bound BiP. MANF inhibits both ADP release from BiP and ATP binding to BiP, and thereby client release. Cells lacking MANF have fewer ER stress-induced BiP-containing high molecular weight complexes. These findings suggest that MANF contributes to protein folding homeostasis as a nucleotide exchange inhibitor that stabilizes certain BiP-client complexes.

MANF antagonizes nucleotide exchange by the endoplasmic reticulum chaperone BiP.,Yan Y, Rato C, Rohland L, Preissler S, Ron D Nat Commun. 2019 Feb 1;10(1):541. doi: 10.1038/s41467-019-08450-4. PMID:30710085^[2]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Amin-Wetzel N, Saunders RA, Kamphuis MJ, Rato C, Preissler S, Harding HP, Ron D. A J-Protein Co-chaperone Recruits BiP to Monomerize IRE1 and Repress the Unfolded Protein Response. Cell. 2017 Dec 14;171(7):1625-1637.e13. doi: 10.1016/j.cell.2017.10.040. Epub, 2017 Nov 30. PMID:29198525 doi:http://dx.doi.org/10.1016/j.cell.2017.10.040
↑ Yan Y, Rato C, Rohland L, Preissler S, Ron D. MANF antagonizes nucleotide exchange by the endoplasmic reticulum chaperone BiP. Nat Commun. 2019 Feb 1;10(1):541. doi: 10.1038/s41467-019-08450-4. PMID:30710085 doi:http://dx.doi.org/10.1038/s41467-019-08450-4