Levels of cAMP-dependent protein kinase activity in sea urchin gametes and embryos during the first cell division

Abstract

Summary The levels of protein kinase activity in the gametes of the sea urchin Lytechinus variegatus were determined on a per sperm and per egg basis. The levels of protein kinase were also determined in sea urchin embryos through the first cell cycle following fertilization. The enzyme activity, which decreased the first 5 min, increased rapidly during the S phase of the cell cycle but decreased during metaphase and cell division. The timing of the fluctuation was constant with different substrates, although the magnitude of the activity varied. The periodic change in protein kinase levels may be correlated with histone phosphorylation or tubulin polymerization.