Role and regulation of Glycogen synthase kinase‐3 beta in bovine spermatozoa. Issue 1 (30th November 2016)

• Record Type: Journal Article
• Authors: Belenky, Michael; Breitbart, Haim
• Is Part Of: Molecular reproduction and development. Volume 84:Issue 1(2017)
• Page Start: 8
• Page End: 18
• Publication Date: 2016-11-30
• Subjects: Reproduction -- Periodicals; Molecular biology -- Periodicals; Molecular genetics -- Periodicals; Embryology -- Periodicals; 571.8
• DOI: 10.1002/mrd.22759
• Languages: English
• ISSNs: 1040-452X

Abstract

SUMMARY: The serine/threonine kinase Glycogen synthase kinase 3 (GSK‐3) is a master switch that regulates a multitude of cellular pathways, including the acrosome reaction in sperm. In epididymal sperm cells, for example, GSK‐3 activity correlates with inhibition of motility—yet no direct pathways connecting GSK‐3 activation with loss of motility have been described. Indeed, the details of how GSK‐3 is regulated during sperm capacitation and the acrosome reaction remains obscure. To this end, we addressed the involvement of the GSK‐3 beta isoform in several known pathways that contribute to motility and the acrosome reaction. We established that Protein kinase A (PKA) is the main regulator of GSK‐3β in sperm, as pre‐treatment of cells with a GSK‐3 inhibitor prior to addition of H89, an inhibitor of PKA, attenuated the motility loss induced by blocking PKA activity. Both induced and spontaneous acrosome reactions also occurred less frequently in sperm treated with GSK‐3 inhibitors. Finally, we observed a slow decline in phosphorylation of GSK‐3β on Ser 9, which represents an inhibited state, during sperm capacitation; this phenotype is reversed during the induced acrosome reaction, in parallel to activation of Protein phosphatase 1. These results suggest that maintenance of sperm motility and acrosome reaction timing are mediated by PKA through the regulation of GSK‐3 beta activity. Mol. Reprod. Dev. 84: 8–18, 2017. © 2016 Wiley Periodicals, Inc .