Enhancement of mouse sperm motility by trophinin-binding peptide
1 Tumor Microenvironment Program, Cancer Center, Sanford-Burnham Medical Research Institute, 10901 North Torrey Pines Rd, La Jolla, CA 92037, USA
2 Department of Prescriptionology, College of Oriental Medicine, Kyung Hee University, Seoul, 130-701, Republic of Korea
3 Department of Gynecology and Obstetrics, Hamamatsu University School of Medicine, Hamamatsu City, Shizuoka, 431-3192, Japan
4 Department of Urology, Hirosaki University School of Medicine, Hirosaki, Aomori, 036-8562, Japan
5 Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya, 464-8601, Japan
Reproductive Biology and Endocrinology 2012, 10:101 doi:10.1186/1477-7827-10-101Published: 29 November 2012
Trophinin is an intrinsic membrane protein that forms a complex in the cytoplasm with bystin and tastin, linking it microtubule-associated motor dynein (ATPase) in some cell types. Previously, we found that human sperm tails contain trophinin, bystin and tastin proteins, and that trophinin-binding GWRQ (glycine, tryptophan, arginine, glutamine) peptide enhanced motility of human sperm.
Immunohistochemistry was employed to determine trophinin protein in mouse spermatozoa from wild type mouse, by using spermatozoa from trophinin null mutant mice as a negative control. Multivalent 8-branched GWRQ (glycine, tryptophan, arginine, glutamine) peptide or GWRQ-MAPS, was chemically synthesized, purified by HPLC and its structure was confirmed by MALDI-TOF mass spectrometry. Effect of GWRQ-MAPS on mouse spermatozoa from wild type and trophinin null mutant was assessed by a computer-assisted semen analyzer (CASA).
Anti-trophinin antibody stained the principal (central) piece of the tail of wild type mouse sperm, whereas the antibody showed no staining on trophinin null sperm. Phage particles displaying GWRQ bound to the principal piece of sperm tail from wild type but not trophinin null mice. GWRQ-MAPS enhanced motility of spermatozoa from wild type but not trophinin null mice. CASA showed that GWRQ-MAPS enhanced both progressive motility and rapid motility in wild type mouse sperm.
Present study established the expression of trophinin in the mouse sperm tail and trophinin-dependent effect of GWRQ-MAPS on sperm motility. GWRQ causes a significant increase in sperm motility.