Lipidations and their effects on the Golgi Reassembly and Stacking Proteins (GRASPs)

• Grant number: 21/10795-7
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: April 01, 2022
• Status: Discontinued
• Field of knowledge: Biological Sciences - Biophysics - Molecular Biophysics
• Principal Investigator: Antonio José da Costa Filho
• Grantee: Emanuel Kava
• Host Institution: Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto (FFCLRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
• Associated scholarship(s): 24/05793-3 - Exploring the liquid-liquid phase separation and membrane interaction of human Golgi Reassembly and Stacking proteins, BE.EP.DR

Abstract

The Golgi Reassembly And Stacking Proteins (GRASPs) are involved in a series of functions, both in unconventional secretion mechanisms and in the structuration and organization of the Golgi apparatus. However, understanding their exact role in each situation still needs more structural and functional results at the molecular level. In performing such functions, GRASPs always seem to be somehow interacting with membranes. The presence of post-translational modifications, such as myristoylation and palmitoylation, is a fundamental issue when thinking about a strategy to obtain detailed information about the interaction processes between GRASPs and membranes. It is noteworthy that such post-translational modifications have been routinely little investigated in the studies reported to date, which compromises the models previously proposed for GRASP-membrane interactions. Thus, we have the possibility of contributing to the generation of knowledge in two problems: (1) reconstitution and characterization of GRASPs in their myristoylated and palmitoylated versions, with the potential to produce data to understand the role of GRASPs in Golgi structuration and in secretion vesicles; (2) evaluation of the synergy between the presence of the membrane and the formation of supramolecular structures of GRASPs (eg, amyloid-like fibers). For this, we will use GRASPs myristoylation protocol recently established in our group. We will use the combination of a series of Biophysics and Molecular Biology techniques, ranging from structural characterization by Nuclear Magnetic Resonance (NMR), to the study of lipidated GRASPs and their interaction with natural ligands, such as golgins GM130 and Golgin45, and with biological membrane models through spectroscopy such as Electron Paramagnetic Resonance (EPR). The data will fill a large and little explored gap, namely, the adequate evaluation of the presence of membranes on the structure-function dyad of GRASPs. (AU)