Structural characterization of the human DjC20/HscB cochaperone in solution.

Autor: Coto ALS; São Carlos Institute of Chemistry, University of São Paulo - USP, 13560-970 São Carlos, SP, Brazil., Pereira AA; São Carlos Institute of Chemistry, University of São Paulo - USP, 13560-970 São Carlos, SP, Brazil., Oliveira SD; São Carlos Institute of Chemistry, University of São Paulo - USP, 13560-970 São Carlos, SP, Brazil., Moritz MNO; São Carlos Institute of Chemistry, University of São Paulo - USP, 13560-970 São Carlos, SP, Brazil., Franco da Rocha AM; São Carlos Institute of Chemistry, University of São Paulo - USP, 13560-970 São Carlos, SP, Brazil., Dores-Silva PR; São Carlos Institute of Chemistry, University of São Paulo - USP, 13560-970 São Carlos, SP, Brazil., da Silva NSM; São Carlos Institute of Chemistry, University of São Paulo - USP, 13560-970 São Carlos, SP, Brazil., de Araújo Nogueira AR; Embrapa Pecuária Sudeste, São Carlos, SP, Brazil., Gava LM; Department of Genetics and Evolution, Federal University of São Carlos, SP, Brazil., Seraphim TV; São Carlos Institute of Chemistry, University of São Paulo - USP, 13560-970 São Carlos, SP, Brazil., Borges JC; São Carlos Institute of Chemistry, University of São Paulo - USP, 13560-970 São Carlos, SP, Brazil. Electronic address: borgesjc@iqsc.usp.br.
Jazyk: angličtina
Zdroj: Biochimica et biophysica acta. Proteins and proteomics [Biochim Biophys Acta Proteins Proteom] 2024 Jan 01; Vol. 1872 (1), pp. 140970. Date of Electronic Publication: 2023 Oct 21.
DOI: 10.1016/j.bbapap.2023.140970
Abstrakt: J-domain proteins (JDPs) form a very large molecular chaperone family involved in proteostasis processes, such as protein folding, trafficking through membranes and degradation/disaggregation. JDPs are Hsp70 co-chaperones capable of stimulating ATPase activity as well as selecting and presenting client proteins to Hsp70. In mitochondria, human DjC20/HscB (a type III JDP that possesses only the conserved J-domain in some region of the protein) is involved in [FeS] protein biogenesis and assists human mitochondrial Hsp70 (HSPA9). Human DjC20 possesses a zinc-finger domain in its N-terminus, which closely contacts the J-domain and appears to be essential for its function. Here, we investigated the hDjC20 structure in solution as well as the importance of Zn +2 for its stability. The recombinant hDjC20 was pure, folded and capable of stimulating HSPA9 ATPase activity. It behaved as a slightly elongated monomer, as attested by small-angle X-ray scattering and SEC-MALS. The presence of Zn 2+ in the hDjC20 samples was verified, a stoichiometry of 1:1 was observed, and its removal by high concentrations of EDTA and DTPA was unfeasible. However, thermal and chemical denaturation in the presence of EDTA led to a reduction in protein stability, suggesting a synergistic action between the chelating agent and denaturators that facilitate protein unfolding depending on metal removal. These data suggest that the affinity of Zn +2 for the protein is very high, evidencing its importance for the hDjC20 structure.
Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2023 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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