Evaluation of the effect of triple mutations of phosphorylatable residues of HSP27-S3D and HSP27- S3A and the HSP27-C137S mutant in suppression of human HSP27 protein-mediated cell death

• Grant number: 21/13331-1
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: March 01, 2022
• End date: December 31, 2023
• Field of knowledge: Biological Sciences - Biochemistry
• Principal Investigator: José Ribamar dos Santos Ferreira Júnior
• Grantee: Gabriela Cristina Janeiro
• Host Institution: Escola de Artes, Ciências e Humanidades (EACH). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Apoptosis is a highly organized active cell death process that aids organogenesis and tissue remodeling during embryonic development. In the immune system, apoptosis participates in the negative selection of cells of the lymphoid lineage, and eliminates neoplastic and virus-infected cells, after the action of cytotoxic T lymphocytes and natural killer cells. Changes in apoptosis inducing or inhibiting mechanisms are causes of diseases that lead to neurodegeneration, autoimmunity and cancer. In mammals, HSP27 is a molecular chaperone involved in protein aggregate remodeling and increased cell survival. Its cytoprotective function is related to the suppression of apoptosis pathways by interaction with pro-apoptotic proteins such as Bax, Smac/DIABLO and tBid, in addition to apoptogenic factors such as cytochrome c and with initiating caspases. In some neoplasms, HSP27 becomes overexpressed and inhibits tumor cell apoptosis, supporting oncogenesis and resistance to chemotherapy. This project aims to evaluate the effect of triple mutations of phosphorylatable residues of HSP27-S3D (S15D, S78D and S82D) and HSP27-S3A (S15A, S78A and S82A) and the mutant HSP27-C137S in the suppression of protein-mediated cell death Human HSP27 through a system built in Saccharomyces cerevisiae, as well as using the CellROX fluorescent probe to detect oxidizing species during cell death.(AU)