IHEM   20887
INSTITUTO DE HISTOLOGIA Y EMBRIOLOGIA DE MENDOZA DR. MARIO H. BURGOS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
CSP drives trans SNARE assembly during acrosomal exocytosis
Autor/es:
BERBERIAN MV; RUETE MC; FLORES MONTERO K
Reunión:
Congreso; SAIB-SAMIGE2020; 2020
Resumen:
The cysteine string protein (CSP) is a chaperone that belongs to the DnaJ/Hsp40 family proteins, initially described in neuronal synaptic vesicles. Subsequent studies demonstrated its presence in various secretory organelles and vertebrate tissues (e.g., testis), which led us to assume human sperm presence. Functionally, CSP interacts with the Hsc70 and SGT proteins, forming a ternary complex that collaborates with the SNAREs proteins? assembly, and facilitates the exocytosis of neurotransmitters in synaptic vesicles.One of the main events for the fertilization of oocytes is the acrosomal reaction in sperm. Acrosomal reaction is the regulated exocytosis of a single large flat granule, the acrosome. The acrosome release implies the fusion of the outer acrosomal and the plasma membranes, thanks to the assembly of the SNAREs proteins in a trans configuration, which causes the irreversible coupling of these membranes.Since CSP?s role in human sperm is still unknown, this work aims to determine the presence, location, and function of this protein in the assembly of trans-SNAREs complexes in acrosomal exocytosis.Using western blot and immunofluorescence, we demonstrated the presence of CSP in human sperm. Furthermore, by subcellular fractionation, we showed that CSP is predominantly membrane-bound and by cell partitions, we found that CSP separates into the detergent fraction, demonstrating its hydrophobic characteristics. Through functional assays, using anti-CSP antibodies, we demonstrated that it is necessary in acrosome secretion as it inhibits acrosomal reaction in a concentration-dependent manner (p