The Arf GAP SMAP2 is necessary for organized vesicle budding from the trans-Golgi network and subsequent acrosome formation in spermiogenesis

• DOI: 10.1091/mbc.e13-05-0234
• Publication Date: 2013-07-18T02:18:51Z
• Authors: Tomo Funaki; Shunsuke Kon; Kenji Tanabe; Waka Natsume; Sayaka Sato; Tadafumi Shimizu; Naomi Yoshida; Won Fen Wong; Atsuo Ogura; Takehiko Ogawa; Kimiko Inoue; Narumi Ogonuki; Hiromi Miki; Keiji Mochida; Keisuke Endoh; Kentarou Yomogida; Manabu Fukumoto; Reiko Horai; Yoichiro Iwakura; Chizuru Ito; Kiyotaka Toshimori; Toshio Watanabe; Masanobu Satake
• Keywords: Spermiogenesis; Spermatid

The trans-Golgi network (TGN) functions as a hub organelle in the exocytosis of clathrin-coated membrane vesicles, and SMAP2 is an Arf GTPase-activating protein that binds to both clathrin assembly (CALM). In present study, detected on TGN pachytene spermatocyte round spermatid stages spermatogenesis. Gene targeting reveals SMAP2-deficient male mice are healthy survive adulthood but infertile exhibit globozoospermia. spermatids, diameter proacrosomal vesicles budding from increases, structures distorted, acrosome formation severely impaired, reorganization nucleus does not proceed properly. CALM regulate vesicle sizes, this study shows recruited absence SMAP2. Furthermore, syntaxin2, component soluble N-ethylmaleimide-sensitive factor attachment receptor (SNARE) complex, properly concentrated at site formation. Thus link between CALM/syntaxin2 subsequent provide model for globozoospermia humans.