Fig 9. Serine phosphorylation of GSK3α/β.

(A) Western blot analysis with anti-phospho GSK3α/β (pSer 21/9) antibody of freshly prepared sperm extract (4X10⁶ sperm/lane) from sperm of proximal caput, distal caput and caudal regions of epididymis. (B) Sperm incubated at 37°C in 1 mM L-homocysteine and adenosine or 5 nM okadaic acid in HEPES buffer supplemented with glucose and BSA show increased immunoreactivity at 55Kd and 47Kd corresponding to phosphorylated GSK3α and GSK3β respectively (2X10⁶ sperm/lane). The same blot was re-probed with Anti-PP2A antibody showing equal protein loading.