Molecular Human Reproduction, Vol. 9, No. 3, 125-131,
March 2003
© 2003 European Society of Human Reproduction and Embryology
Article |
Role of protein tyrosine phosphorylation in the thapsigargin-induced intracellular Ca2+ store depletion during human sperm acrosome reaction
Submitted on August 15, 2002; resubmitted on November 1, 2002. accepted on November 26, 2002
1 Département dObstétrique/Gynécologie and Centre de recherche en Biologie de la Reproduction, Université Laval, and Centre de recherche du CHUQ, Québec, G1L 3L5 and 2 Centre de recherche du CHUL, Québec, Canada G1V 4G2
3 To whom correspondence should be addressed at: Endocrinologie de la Reproduction, Pav. St-François dAssise, 10 de LEspinay, Québec, PQ, Canada, G1L 3L5. e-mail: pierre.leclerc{at}crsfa.ulaval.ca
During human sperm capacitation, an increase in phosphotyrosine content of specific proteins results partially from an increase in the intracellular free Ca2+ concentrations. In the present study, the inter-regulation between protein phosphotyrosine content and the intracellular Ca2+ concentration during the thapsigargin treatment of capacitated human sperm was investigated. The involvement of a tyrosine kinase pathway in the thapsigargin-induced acrosome reaction was also investigated. In response to thapsigargin, two sperm subpopulations, called LR (low responsive) and HR (high responsive), according to their increase in intracellular Ca2+, were observed. In addition to their high increase in intracellular Ca2+, sperm from the HR population expressed a higher protein phosphotyrosine content, and a higher proportion (P < 0.05) of them underwent the acrosome reaction in response to thapsigargin, as compared with LR sperm. Although the tyrosine kinase inhibitor PP2 abolished the thapsigargin-induced increase in protein phosphotyrosine content, it did not affect the intracellular Ca 2+ concentration or the percentage of acrosome-reacted sperm. The inability of an src-related tyrosine kinase inhibitor to block the thapsigargin-mediated Ca2+ increase and acrosomal exocytosis suggests that, during the acrosome reaction, the signalling pathway mediated by src-related tyrosine kinases is involved upstream of the capacitative Ca2+ entry.
Key words: acrosome/calcium store/Ca 2+-ATPase/capacitation/phosphotyrosine
![]()
CiteULike
Connotea
Del.icio.us What's this?
This article has been cited by other articles:
![]() |
C. Lawson, V. Dorval, S. Goupil, and P. Leclerc Identification and localisation of SERCA 2 isoforms in mammalian sperm Mol. Hum. Reprod., May 1, 2007; 13(5): 307 - 316. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. Liguori, E. de Lamirande, A. Minelli, and C. Gagnon Various protein kinases regulate human sperm acrosome reaction and the associated phosphorylation of Tyr residues and of the Thr-Glu-Tyr motif Mol. Hum. Reprod., March 1, 2005; 11(3): 211 - 221. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Kurokawa, K.-i. Sato, J. Smyth, H. Wu, K. Fukami, T. Takenawa, and R. A Fissore Evidence that activation of Src family kinase is not required for fertilization-associated [Ca2+]i oscillations in mouse eggs Reproduction, April 1, 2004; 127(4): 441 - 454. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. C. Kirkman-Brown Editorial Commentary J Androl, September 1, 2003; 24(5): 734 - 735. [Full Text] [PDF] |
||||


