Participación de proteínas de la familia CRISP en el proceso de interacción de gametas

COHEN, DJ, BUSSO, D, DA ROS, V, MALDERA, JA, GOLDWEIC, N Y CUASNICÚ, PS

Tafi del Valle, Tucuman

Simposio; XXIV Jornadas Científicas de la Asociación de Biología de Tucumán; 2007

Asociación de Biología de Tucuman

Rat epididymal protein DE is a member of the CRISP family, and it is localized on the equatorial segment of acrosome-reacted sperm. DE participates in gamete fusion through its binding to egg-complementary sites. Recent results revealed that the egg binding ability of DE resides in a 12 aa region corresponding to a highly conserved motif of the CRISP family, the Signature 2 (S2). Further experiments analyzing the egg binding ability of other CRISPs (Tpx-1, ARP and helothermine) in correlation with the aa sequence of their S2 regions, suggested that the aa sequence would be relevant for the ability of these proteins to interact with the egg. The binding of Tpx-1 to the egg opened the possibility for a role of this protein in gamete fusion. Subsequent experiments confirmed the participation of Tpx-1 in this step of fertilization through its binding to the egg. Competition studies indicated that DE and Tpx-1 bind to in-common egg binding sites. The participation of both epididymal DE and testicular Tpx-1 in gamete fusion provides important information on the molecular mechanisms involved in this process and supports the idea of a functional cooperation between homologue molecules as a mechanism to ensure the success of fertilization.