Characterization of RNA-binding proteins in presynaptic terminals of squid (Loligo) neurons

• Grant number: 10/19108-8
• Support Opportunities: Regular Research Grants
• Start date: March 01, 2011
• End date: February 28, 2013
• Field of knowledge: Biological Sciences - Biochemistry - Molecular Biology
• Principal Investigator: Roy Edward Larson
• Grantee: Roy Edward Larson
• Host Institution: Faculdade de Medicina de Ribeirão Preto (FMRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
• Associated researchers: Jorge Eduardo Moreira ; José César Rosa ; Joseph Alan DeGiorgis ; Munira Muhammad Abdel Baqui

Abstract

The giant synapse and axons of squid (Loligo) represent an important classical model that has contributed to the elucidation of mechanisms of axoplasmic flux and neuronal transmission. This neuronal system has also played a critical role in the demonstration of transport, processing and translation of mRNA locally at the pre-synaptic terminal. The questions that now arise are 1) what are the components and mechanisms involved in RNA processing and translation; 2) how are they regulated; 3) what are their roles in synaptic function. Preliminary to this project, we have purified and partially characterized an RNA-binding protein of 65 kDa (p65) from optic lobes of squid (Loligo plei and Loligo pealei) (Lico et al. 2010). We also have obtained electrophysiological data that implicates p65 in neurotransmission (Larson, Moreira & Llinás, manuscript in preparation). The localization of p65 in pre-synaptic terminals led to the hypothesis that p65 participates in mechanisms of site-specific processing and/or translation of RNA. Sequences of p65 obtained by mass spectrometry allowed for the production of specific antibodies. The analyses in silico using a data bank of Loligo pealei has led to the realization that we were dealing with a family of RNA-binding proteins, about which not much is known. We will apply biochemical methods, molecular cloning and immunological techniques to characterize p65, and related proteins, in order to elucidate its synaptic function. (AU)