Tyrphostin-A47 inhibitable tyrosine phosphorylation of flagellar proteins is associated with distinct alteration of motility pattern in hamster spermatozoa
Article first published online: 11 OCT 2005
Copyright © 2005 Wiley-Liss, Inc.
Molecular Reproduction and Development
Volume 73, Issue 2, pages 215–225, February 2006
How to Cite
Mariappa, D., Siva, A. B., Shivaji, S. and Seshagiri, P. B. (2006), Tyrphostin-A47 inhibitable tyrosine phosphorylation of flagellar proteins is associated with distinct alteration of motility pattern in hamster spermatozoa. Mol. Reprod. Dev., 73: 215–225. doi: 10.1002/mrd.20384
- Issue published online: 24 NOV 2005
- Article first published online: 11 OCT 2005
- Manuscript Accepted: 13 AUG 2005
- Manuscript Received: 20 APR 2005
- Council of Scientific and Industrial Research, New Delhi
- Indian Council of Medical Research, New Delhi
- spermatozoa (hamster);
- tyrosine phosphorylation;
To acquire fertilizing potential, mammalian spermatozoa must undergo capacitation and acrosome reaction. Our earlier work showed that pentoxifylline (0.45 mM), a sperm motility stimulant, induced an early onset of hamster sperm capacitation associated with tyrosine phosphorylation of 45–80 kDa proteins, localized to the mid-piece of the sperm tail. To assess the role of protein tyrosine phosphorylation in sperm capacitation, we used tyrphostin-A47 (TP-47), a specific protein tyrosine kinase inhibitor. The dose-dependent (0.1–0.5 mM) inhibition of tyrosine phosphorylation by TP-47 was associated with inhibition of hyperactivated motility and 0.5 mM TP-47-treated spermatozoa exhibited a distinct circular motility pattern. This was accompanied by hypo-tyrosine phosphorylation of 45–60 kDa proteins, localized to the principal piece of the intact-sperm and the outer dense fiber-like structures in detergent treated-sperm. Sperm kinematic analysis (by CASA) of spermatozoa, exhibiting circular motility (at 1st hr), showed lower values of straight line velocity, curvilinear velocity and average path velocity, compared to untreated controls. Other TP-47 analogues, tyrphostin-AG1478 and -AG1296, had no effect either on kinematic parameters or sperm protein tyrosine phosphorylation. These studies indicate that TP-47-induced circular motility of spermatozoa is compound-specific and that the tyrosine phosphorylation status of 45–60 kDa flagellum-localized proteins could be key regulators of sperm flagellar bending pattern, associated with the hyperactivation of hamster spermatozoa. Mol. Reprod. Dev. © 2005 Wiley-Liss, Inc.