On the structure and function of Sorghum bicolor CHIP (carboxyl terminus of Hsc70-interacting protein): A link between chaperone and proteasome systems

Author(s)

Goncalves, Conrado de C. ^[1] ; Pinheiro, Glaucia M. S. ^{[1, 2]} ; Dahlstrom, Kathe M. ^{[1, 2]} ; Souto, Denio E. P. ^{[1, 2, 3]} ; Kubota, Lauro T. ^{[1, 2]} ; Barbosa, Leandro R. S. ^[4] ; Ramos, I, Carlos H.

Affiliation

^[1] I, Univ Estadual Campinas, Inst Chem, UNICAMP, BR-13083970 Campinas, SP - Brazil

^[2] Souto, Denio E. P., Fed Univ Parana UFPR, Dept Chem, BR-81530900 Curitiba, Parana, Brazil.Goncalves, Conrado de C., I, Univ Estadual Campinas, Inst Chem, UNICAMP, BR-13083970 Campinas, SP - Brazil

^[3] Fed Univ Parana UFPR, Dept Chem, BR-81530900 Curitiba, Parana - Brazil

^[4] Univ Sao Paulo, Inst Phys, BR-05508090 Sao Paulo, SP - Brazil

• Document type: Journal article
• Source: Plant Science; v. 296, JUL 2020.
• Web of Science Citations: 1

Abstract

The co-chaperone CHIP (carboxy terminus of Hsc70 interacting protein) is very important for many cell activities since it regulates the ubiquitination of substrates targeted for proteasomal degradation. However, information on the structure-function relationship of CHIP from plants and how it interacts and ubiquitinates other plant chaperones is still needed. For that, the CHIP ortholog from Sorghum bicolor (SbCHIP) was identified and studied in detail. SbCHIP was purified and produced folded and pure, being capable of keeping its structural conformation up to 42 degrees C, indicating that cellular function is maintained even in a hot environment. Also, SbCHIP was able to bind plant Hsp70 and Hsp90 with high affinity and interact with E2 enzymes, performing E3 ligase activity. The data allowed to reveal the pattern of plant Hsp70 and Hsp90 ubiquitination and described which plant E2 enzymes are likely involved in SbCHIP-mediated ubiquitination. Aditionally, we obtained information on the SbCHIP conformation, showing that it is a non-globular symmetric dimer and allowing to put forward a model for the interaction of SbCHIP with chaperones and E2 enzymes that suggests a mechanism of ubiquitination. Altogether, the results presented here are useful additions to the study of protein folding and degradation in plants. (AU)

• FAPESP's process: 17/26158-0 - Prion protein as stem regulator in glioblastoma stem cells: its role in the formation and function of multiprotein signaling platforms
• Grantee: Mariana Brandão Prado
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• FAPESP's process: 18/11948-9 - Interaction mechanism between the co-chaperone J-domain protein with their substrates and the chaperone Hsp70
• Grantee: Glaucia Melina Squizato Pinheiro de Castro
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 17/26058-6 - Characterization of interactions in the protein quality system for the understanding of its role in the proteostasis maintenance
• Grantee: Dênio Emanuel Pires Souto
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 14/00076-0 - Study of important chaperone-interaction from the celular protein quality control system in higher eukaryotes.
• Grantee: Conrado de Campos Gonçalves
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 16/14228-1 - Hsp90 interaction with other proteins
• Grantee: Käthe Margareta Dahlström
• 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
• 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 Opportunities: Regular Research Grants