World J Mens Health.  2024 Apr;42(2):373-383. 10.5534/wjmh.230004.

Regulation of Phosphorylation of Glycogen Synthase Kinase 3α and the Correlation with Sperm Motility in Human

• Park SH
• Kim YP
• Lee JM
• Park DW
• Seo JT
• Gye MC

• KMID: 2554403
• DOI: http://doi.org/10.5534/wjmh.230004

Abstract

Purpose
To unravel the mechanism regulating the phosphorylation of glycogen synthase kinase 3 (GSK3) and the correlation between the inhibitory phosphorylation of GSK3α and sperm motility in human.
Materials and Methods
The phosphorylation and priming phosphorylated substrate-specific kinase activity of GSK3 were examined in human spermatozoa with various motility conditions.
Results
In human spermatozoa, GSK3α/β was localized in the head, midpiece, and principal piece of tail and p-GSK3α(Ser21) was enriched in the midpiece. The ratio of p-GSK3α(Ser21)/GSK3α was positively coupled with normal sperm motility criteria of World Health Organization. In high-motility spermatozoa, p-GSK3α(Ser21) phosphotyrosine (p-Tyr) proteins but p-GSK3α(Tyr279) markedly increased together with decreased kinase activity of GSK3 after incubation in Ca2+ containing medium. In high-motility spermatozoa, p-GSK3α(Ser21) levels were negatively coupled with kinase activity of GSK3, and which was deregulated in low-motility spermatozoa. In high-motility spermatozoa, 6-bromo-indirubin-3′-oxime, an inhibitor of kinase activity of GSK3 increased p-GSK3α(Ser21) and p-Tyr proteins. p-GSK3α(Ser21) and p-Tyr protein levels were decreased by inhibition of PKA and Akt. Calyculin A, a protein phosphatase-1/2A inhibitor, markedly increased the p-GSK3α(Ser21) and p-Tyr proteins, and significantly increased the motility of low-motility human spermatozoa.
Conclusions
Down regulation of kinase activity of GSK3α by inhibitory phosphorylation was positively coupled with human sperm motility, and which was regulated by Ca2+, PKA, Akt, and PP1. Small-molecule inhibitors of GSK3 and PP1 can be considered to potentiate human sperm motility.

Keyword

Glycogen synthase kinase 3; Humans; Phosphorylation; Sperm motility