Autophosphorylation of boar sperm membranes

Boar sperm plasma membranes and the membranes released during an in vitro acrosome-like reaction were capable of autophosphorylation. The purified membranes were incubated in Tyrode's buffer containing [32P]ATP with or without Ca2+ and/or diacylglycerol. In both membrane fractions, Ca2+ plus diacylglycerol stimulated the autophosphorylation of several sperm membrane proteins. These results suggest a protein kinase C activity is present in sperm membranes and could play a role in the acrosome reaction.