Structural highlights
Function
[F10A1_RAT] One HIP oligomer binds the ATPase domains of at least two HSC70 molecules dependent on activation of the HSC70 ATPase by HSP40. Stabilizes the ADP state of HSC70 that has a high affinity for substrate protein. Through its own chaperone activity, it may contribute to the interaction of HSC70 with various target proteins.
Publication Abstract from PubMed
The Hsp70-interacting protein, Hip, cooperates with the chaperone Hsp70 in protein folding and prevention of aggregation. Hsp70 interacts with non-native protein substrates in an ATP-dependent reaction cycle regulated by J-domain proteins and nucleotide exchange factors (NEFs). Hip is thought to delay substrate release by slowing ADP dissociation from Hsp70. Here we present crystal structures of the dimerization domain and the tetratricopeptide repeat (TPR) domain of rat Hip. As shown in a cocrystal structure, the TPR core of Hip interacts with the Hsp70 ATPase domain through an extensive interface, to form a bracket that locks ADP in the binding cleft. Hip and NEF binding to Hsp70 are mutually exclusive, and thus Hip attenuates active cycling of Hsp70-substrate complexes. This mechanism explains how Hip enhances aggregation prevention by Hsp70 and facilitates transfer of specific proteins to downstream chaperones or the proteasome.
Structure and function of Hip, an attenuator of the Hsp70 chaperone cycle.,Li Z, Hartl FU, Bracher A Nat Struct Mol Biol. 2013 Aug;20(8):929-35. doi: 10.1038/nsmb.2608. Epub 2013 Jun, 30. PMID:23812373[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Li Z, Hartl FU, Bracher A. Structure and function of Hip, an attenuator of the Hsp70 chaperone cycle. Nat Struct Mol Biol. 2013 Aug;20(8):929-35. doi: 10.1038/nsmb.2608. Epub 2013 Jun, 30. PMID:23812373 doi:10.1038/nsmb.2608
