Characterization of rtSH3p13 gene encoding a development protein involved in vesicular traffic in spermiogenesis

Abstract

A cDNA, designated as rtSH3p13, was isolated from a rat testis cDNA library. It consists of 1463 bp nuclear acids, which encodes a protein of 312 amino acids and was assigned the GenBank accession number AF227439. The deduced rtSH3p13 protein is a truncated isoform of SH3p13 as a result of mRNA alternative splicing. It is mainly expressed in the rat testis, detected in spermatid at the steps 8-19 of spermiogenesis, and found around the acrosome. During postnatal development, rtSH3p13 appears on day 18 and reaches maximum on day 60. Further experimental results suggested that rtSH3p13 forms a complex with activated epidermal growth factor receptor (EGFR) and interacts with synaptojanin I. Surprisingly, similar to SH3 domain, the V region of rtSH3p13 also inhibits endocytosis in CHO cells. Our results reveal a link between an rtSH3p13-synaptojanin-clathrin complex-mediated formation of pits and the process of spermiogenesis.

The Structure and Function of Endophilin Proteins

“…This effect might be due to a dominant negative effect on the pro-endocytotic endophilin A1, as the SH3 domains of A1 and A3 are similar in structure [41]. In any case, these results demonstrate that both the SH3 domain and the variable region are key players in endophilin's regulation of receptor-coupled endocytosis, and that the variable region determines the direction of this influence (see also [31]). …”

“…Subcellular fractionation studies indicate that endophilins A associate with the light membrane fraction (enriched in ER/Golgi, endosomes and lysosomes) and mitochondria, and also appears in solution in the cytosol [21,27,29,30]. In germ cells from testis, endophilin A3 is found in the acrosome region [31].…”

Sperm associated antigen 8 (SPAG8), a novel regulator of activator of CREM in testis during spermatogenesis

“…Germ cells were isolated from the testes of adult Balb/c mice as described [19]. Briefly, the tunica albuginea of the mouse testis was removed.…”

Small Kinetochore Associated Protein (SKAP) Promotes UV-Induced Cell Apoptosis through Negatively Regulating Pre-mRNA Processing Factor 19 (Prp19)

“…SKAP immunostaining was performed as described previously [17]. Briefly, HeLa cells were plated on coverslips in DMEM medium and cultured for 24 hours.…”