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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Studies on the effect of the J-domain on the substrate binding domain (SBD) of Hsp70 using a chimeric human J-SBD polypeptide

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Tiroli-Cepeda, Ana O. [1] ; Seraphim, Thiago V. [1] ; Pinheiro, Glaucia M. S. [1] ; Souto, Denio E. P. [1] ; Kubota, Lauro T. [1, 2] ; Borges, Julio C. [3] ; Barbosa, Leandro R. S. [4] ; Ramos, Carlos H. I. [1, 5]
Total Authors: 8
[1] Univ Estadual Campinas, BR-13083970 Campinas, SP - Brazil
[2] INCTBioanalitica, Campinas, SP - Brazil
[3] Univ Sao Paulo, Sao Carlos Inst Chem, BR-13560970 Sao Carlos, SP - Brazil
[4] Univ Sao Paulo, Inst Phys, Sao Paulo, SP - Brazil
[5] INBEB, Londrina - Brazil
Total Affiliations: 5
Document type: Journal article
Source: International Journal of Biological Macromolecules; v. 124, p. 111-120, MAR 1 2019.
Web of Science Citations: 0

DnaJ/Hsp40 chaperones deliver unfolded proteins and stimulate the ATPase activity of DnaK/Hsp70 via their J-domain. However, the interaction is transient, creating a challenge for detailed analysis. We investigated whether it would be possible to gain further understanding of this interaction by engineering a chimeric polypeptide where the J-domain of Hsp40 was covalently attached to the substrate binding domain (SBD) of Hsp70 by a flexible linker. The rationale is to increase the proximity between the interacting partners to promote their natural interaction and facilitate the characterization of the interaction. The resulting chimera, termed J-SBD, was properly folded and had properties not present in the full-length Hsp70 or in the SBD alone, for instance a higher protective effect against aggregation and being a monomer. Substrate binding also appear to exceed that of SBD alone as revealed by a decreased binding to bis-ANS, a probe for hydrophobic patches. This hypothesis is supported by the structural model created by small angle X-ray scattering, suggesting that the lid subdomain (SBD alpha) is partially opened in the J-SBD. Collectively, our results suggest a model in which J-domain binding may shift the Hsp70 equilibrium towards the monomer state, exposing hydrophobic sites prone to substrate accommodation. (C) 2018 Elsevier B.V. All rights reserved. (AU)

FAPESP's process: 14/07206-6 - Studies of the mitochondrial HSP70 of human and protozoa: structural and functional approaches
Grantee:Julio Cesar Borges
Support type: Regular Research Grants
FAPESP's process: 17/07335-9 - Studies of human HSP70 isoforms residing in the cytoplasm and mitochondria and their high molecular weight oligomers: interaction with co-chaperones and client proteins
Grantee:Julio Cesar Borges
Support type: Regular Research Grants
FAPESP's process: 15/15822-1 - Physicochemical and structural properties of Ionic Liquids and drugs interacting with biologicaly relevant systems.
Grantee:Leandro Ramos Souza Barbosa
Support type: Regular Research Grants
FAPESP's process: 12/50161-8 - Study of the structure and function of the Hsp90 chaperone with emphasis on its role in cellular homeostasis
Grantee:Carlos Henrique Inacio Ramos
Support type: Research Projects - Thematic Grants