Structural and functional studies of the Leishmania braziliensis mitochondrial Hsp70: Similarities and dissimilarities to human orthologues

Author(s)

Dores-Silva, Paulo R. ; Nishimura, Leticia S. ; Kiraly, Vanessa T. R. ; Borges, Julio C.

• Document type: Journal article
• Source: Archives of Biochemistry and Biophysics; v. 613, p. 43-52, JAN 1 2017.
• Web of Science Citations: 2

Abstract

Heat shock protein 70 kDa (Hsp70) is a conserved molecular chaperone family involved in several functions related to protein homeostasis. In eukaryotes, Hsp70 homologues are found in all cell compartments. The mitochondrial Hsp70 isoform (mtHsp70) is involved in import of mitochondrial matrix proteins as well as their folding and maturation. Moreover, mtHsp70 has the propensity to self-aggregate, and it depends on the action of the co-chaperone Hsp70-escort protein 1 (Hep1) to be produced functional. Here, we analyze the solution structure and function of mtHsp70 of Leishmania braziliensis (LbmtHsp70). This recombinant protein was obtained folded, in the monomeric state and it has an elongated shape. We observed that LbmtHsp70 suffers thermal aggregation that depends on the protein concentration and is composed of domains with different thermal stabilities. LbmtHsp70 interacted with adenosine nucleotides with a thermodynamic signature different from those reported for human orthologues and interacted, driven by both enthalpy and entropy, with L. braziliensis Hep1 (LbHep1) with a nanomolar dissociation constant. Moreover, LbHep1 stimulated the LbmtHsp70 ATPase activity. Since little is known about mitochondrial Hsp70, particularly in protozoa, we believe that our data are of interest for understanding protozoan Hsp70 machinery. (C) 2016 Elsevier Inc. All rights reserved. (AU)

• FAPESP's process: 11/23110-0 - Using isothermal titration calorimetry for the determination of thermodynamic properties of protein-ligand and protein-protein interactions
• Grantee: Julio Cesar Borges
• Support Opportunities: Regular Research Grants
• FAPESP's process: 14/07206-6 - Studies of the mitochondrial HSP70 of human and protozoa: structural and functional approaches
• Grantee: Julio Cesar Borges
• Support Opportunities: Regular Research Grants
• FAPESP's process: 14/16646-0 - Human mortalin: interaction with co-chaperones, p53 and mutants, aggregation kinectics, regulation/modulation and vesicle secretion
• Grantee: Paulo Roberto das Dores da Silva
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• 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 Opportunities: Research Projects - Thematic Grants