| Structural highlights
Function
[RPAP3_HUMAN] Forms an interface between the RNA polymerase II enzyme and chaperone/scaffolding protein, suggesting that it is required to connect RNA polymerase II to regulators of protein complex formation.[1] [HS90A_HUMAN] Molecular chaperone that promotes the maturation, structural maintenance and proper regulation of specific target proteins involved for instance in cell cycle control and signal transduction. Undergoes a functional cycle that is linked to its ATPase activity. This cycle probably induces conformational changes in the client proteins, thereby causing their activation. Interacts dynamically with various co-chaperones that modulate its substrate recognition, ATPase cycle and chaperone function.[2] [3]
Publication Abstract from PubMed
RPAP3 and PIH1D1 are part of the HSP90 co-chaperone R2TP complex involved in the assembly process of many molecular machines. In this study, we performed a deep structural investigation of the HSP binding abilities of the two TPR domains of RPAP3. We combined 3D NMR, non-denaturing MS, and ITC techniques with Y2H, IP-LUMIER, FRET, and ATPase activity assays and explain the fundamental role played by the second TPR domain of RPAP3 in the specific recruitment of HSP90. We also established the 3D structure of an RPAP3:PIH1D1 sub-complex demonstrating the need for a 34-residue insertion, specific of RPAP3 isoform 1, for the tight binding of PIH1D1. We also confirm the existence of a complex lacking PIH1D1 in human cells (R2T), which shows differential binding to certain clients. These results highlight similarities and differences between the yeast and human R2TP complexes, and document the diversification of this family of co-chaperone complexes in human.
Deep Structural Analysis of RPAP3 and PIH1D1, Two Components of the HSP90 Co-chaperone R2TP Complex.,Henri J, Chagot ME, Bourguet M, Abel Y, Terral G, Maurizy C, Aigueperse C, Georgescauld F, Vandermoere F, Saint-Fort R, Behm-Ansmant I, Charpentier B, Pradet-Balade B, Verheggen C, Bertrand E, Meyer P, Cianferani S, Manival X, Quinternet M Structure. 2018 Jul 18. pii: S0969-2126(18)30208-9. doi:, 10.1016/j.str.2018.06.002. PMID:30033218[4]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Jeronimo C, Forget D, Bouchard A, Li Q, Chua G, Poitras C, Therien C, Bergeron D, Bourassa S, Greenblatt J, Chabot B, Poirier GG, Hughes TR, Blanchette M, Price DH, Coulombe B. Systematic analysis of the protein interaction network for the human transcription machinery reveals the identity of the 7SK capping enzyme. Mol Cell. 2007 Jul 20;27(2):262-74. PMID:17643375 doi:http://dx.doi.org/10.1016/j.molcel.2007.06.027
- ↑ Martinez-Ruiz A, Villanueva L, Gonzalez de Orduna C, Lopez-Ferrer D, Higueras MA, Tarin C, Rodriguez-Crespo I, Vazquez J, Lamas S. S-nitrosylation of Hsp90 promotes the inhibition of its ATPase and endothelial nitric oxide synthase regulatory activities. Proc Natl Acad Sci U S A. 2005 Jun 14;102(24):8525-30. Epub 2005 Jun 3. PMID:15937123 doi:10.1073/pnas.0407294102
- ↑ Forsythe HL, Jarvis JL, Turner JW, Elmore LW, Holt SE. Stable association of hsp90 and p23, but Not hsp70, with active human telomerase. J Biol Chem. 2001 May 11;276(19):15571-4. Epub 2001 Mar 23. PMID:11274138 doi:10.1074/jbc.C100055200
- ↑ Henri J, Chagot ME, Bourguet M, Abel Y, Terral G, Maurizy C, Aigueperse C, Georgescauld F, Vandermoere F, Saint-Fort R, Behm-Ansmant I, Charpentier B, Pradet-Balade B, Verheggen C, Bertrand E, Meyer P, Cianferani S, Manival X, Quinternet M. Deep Structural Analysis of RPAP3 and PIH1D1, Two Components of the HSP90 Co-chaperone R2TP Complex. Structure. 2018 Jul 18. pii: S0969-2126(18)30208-9. doi:, 10.1016/j.str.2018.06.002. PMID:30033218 doi:http://dx.doi.org/10.1016/j.str.2018.06.002
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