HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 73/1/94    most recent biolreprod.104.038794v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by O'Flaherty, C. Articles by Gagnon, C. Search for Related Content PubMed PubMed Citation Articles by O'Flaherty, C. Articles by Gagnon, C. Agricola Articles by O'Flaherty, C. Articles by Gagnon, C.

Reactive Oxygen Species and Protein Kinases Modulate the Level of Phospho-MEK-Like Proteins During Human Sperm Capacitation¹

Urology Research Laboratory, Royal Victoria Hospital and Faculty of Medicine, McGill University, Montréal, Québec, Canada H3A 1A1

Capacitation is an essential process by which spermatozoa acquire fertilizing ability. Reactive oxygen species (ROS), protein kinase A (PKA), protein kinase C (PKC), protein tyrosine kinases (PTKs), and the extracellular signal-regulated protein kinase (ERK or mitogen-activated protein kinase [MAPK]) pathway regulate sperm capacitation. Our aim was to evaluate the phosphorylation of MEK (MAPK kinase or MAP2K) or MEK-like proteins in human sperm capacitation and its modulation by ROS and kinases. Immunoblotting using an anti-phospho-MEK antibody indicated that the phosphorylation of three protein bands (55, 94, and 115 kDa) increased in spermatozoa treated with fetal cord serum ultrafiltrate (FCSu), BSA, or isobutylmethylxanthine plus dibutyryl cAMP as capacitating agents. These phospho-MEK-like proteins are localized along the sperm flagellum. The MEK-inhibitors PD98059 and U126 prevented this phosphorylation, suggesting that these proteins are MEK-like proteins. The ROS scavengers prevented, and the addition of H₂O₂ or spermine-NONOate (nitric oxide donor) triggered, the increase of phospho-MEK-like proteins. The capacitation-related increases in phospho-MEK-like proteins induced by FCSu, H₂O₂, and spermine-NONOate were similarly modulated by PKA, PKC, and PTK, suggesting ROS as mediators in this phenomenon. These results indicate that phospho-MEK-like proteins are modulated by ROS and kinases and probably represent an intermediary step between the early events and the late tyrosine phosphorylation associated with capacitation.

gamete biology, kinases, nitric oxide, signal transduction, sperm capacitation

² Correspondence: Cristian O'Flaherty, Urology Research Laboratory, H6.47, Royal Victoria Hospital, 687 avenue des Pins ouest, Montréal, Québec H3A 1A1, Canada. FAX: 514 843 1457; coflaher{at}yahoo.com

This article has been cited by other articles:

				Y.-F. Li, W. He, K. N. Jha, K. Klotz, Y.-H. Kim, A. Mandal, S. Pulido, L. Digilio, C. J. Flickinger, and J. C. Herr FSCB, a Novel Protein Kinase A-phosphorylated Calcium-binding Protein, Is a CABYR-binding Partner Involved in Late Steps of Fibrous Sheath Biogenesis J. Biol. Chem., November 23, 2007; 282(47): 34104 - 34119. [Abstract] [Full Text] [PDF]

				K.N. Jha, A.M. Salicioni, E. Arcelay, O. Chertihin, S. Kumari, J.C. Herr, and P.E. Visconti Evidence for the involvement of proline-directed serine/threonine phosphorylation in sperm capacitation Mol. Hum. Reprod., December 1, 2006; 12(12): 781 - 789. [Abstract] [Full Text] [PDF]

				L. Cotton, G. M. Gibbs, L. G. Sanchez-Partida, J. R. Morrison, D. M. de Kretser, and M. K. O'Bryan FGFR-1 signaling is involved in spermiogenesis and sperm capacitation J. Cell Sci., January 1, 2006; 119(1): 75 - 84. [Abstract] [Full Text] [PDF]