FAM71F1 binds to RAB2A and RAB2B and is essential for acrosome formation and male fertility in mice

• DOI: 10.1242/dev.199644
• Publication Date: 2021-10-29T15:00:24Z
• Authors: Akane Morohoshi; Haruhiko Miyata; Yuki Oyama; Seiya Oura; Taichi Noda; Masahito Ikawa
• Keywords: Acrosome reaction; Male fertility

The acrosome is a cap-shaped, Golgi-derived membranous organelle that located over the anterior of sperm nucleus and highly conserved throughout evolution. Although morphological changes during biogenesis in spermatogenesis have been well described, molecular mechanism underlying this process still largely unknown. Family with sequence similarity 71, member F1 F2 (FAM71F1 FAM71F2) are testis-enriched proteins contain RAB2B-binding domain, small GTPase involved vesicle transport membrane trafficking. Here, by generating mutant mice for each gene, we found Fam71f1 essential male fertility. In Fam71f1-mutant mice, was abnormally expanded at round spermatid stage, likely because enhanced Mass spectrometry analysis after immunoprecipitation indicated that, testes, FAM71F1 binds not only RAB2B, but also RAB2A. Further study suggested to GTP-bound active form RAB2A/B, inactive form. These results indicate complex RAB2A/B suppresses excessive trafficking formation.