SPAG11C and GLRX3 in the rat male reproductive tract: protein/protein interaction, cellular expression and physiological role

• Grant number: 11/16290-2
• Support Opportunities: Scholarships in Brazil - Master
• Start date: March 01, 2012
• End date: October 31, 2013
• Field of knowledge: Biological Sciences - Pharmacology - General Pharmacology
• Principal Investigator: Maria Christina Werneck de Avellar
• Grantee: Pamella Aparecida Jacon Pelosi
• Host Institution: Instituto Nacional de Farmacologia (INFAR). Universidade Federal de São Paulo (UNIFESP). Campus São Paulo. São Paulo , SP, Brazil

Abstract

SPAG11 (sperm associated antigen 11) is a family of proteins that have a specific domain designated "Sperm antigen HE2" and some isoforms also have a domain of ²-defensin. These proteins are abundantly expressed in the male reproductive tract, particularly in the epididymis. SPAG11 proteins have antimicrobial activity, as well as being involved in sperm maturation, capacitation, sperm survival and sperm-oocyte interaction. Besides all these functions, little is known about its mechanism of action and biological function. Through double-hybrid assays, we detected the interaction between SPAG11 isoform C (SPAG11C) with glutaredoxin 3 (GLRX3). GLRX3 is expressed in various tissues, as well as in the reproductive tract. Additionally, GLRX3 has been shown to interact with other targets, including MLP (muscle LIM protein), a protein abundantly expressed in muscle, where it plays a role in cardiac hypertrophy. GLRX3 exerts an indirect effect on the activation of calcineurin via its interaction with MLP, which results in regression of hypertrophic process of the heart muscle. Although, we have no information about the possible role of SPAG11C in muscle tissues. Thus, this project aims to study the interaction between SPAG11C and GLRX3 in vitro, evaluate the expression in the male reproductive tract and reproductive tissues of rats and investigate the possible cellular function of the complex SPAG11C/GLRX3 in cultured neonatal cardiomyocytes, which in a second step can be assessed in cells of the reproductive tract. (AU)