Breitbart H, Lax J, Rotem R, Naor Z
Department of Life Sciences, Bar Ilan University, Ramat Gran, Israel.
Biochem J. 1992 Jan 15;281 ( Pt 2)(Pt 2):473-6. doi: 10.1042/bj2810473.
Mammalian spermatozoa undergo a Ca(2+)-dependent exocytotic event before fertilization which is known as the acrosome reaction. The process of exocytosis in several cell systems is mediated by a protein kinase C (PKC)-catalysed phosphorylation. Addition of phorbol 12-myristate-13-acetate or the membrane-permeant diacylglycerol analogue 1-oleoyl-2-acetylglycerol, which are potent activators of PKC, to bovine spermatozoa resulted in stimulation of the acrosome reaction. This stimulation was inhibited by low concentrations (50% inhibition at 0.7 nM) of the PKC inhibitor staurosporine. PKC specific activity in bovine spermatozoa is extremely low in comparison with other cells; however, it is comparable with the activity found in human spermatozoa. Immunohistochemical analysis using anti-PKC antibodies revealed staining in the equatorial segment, the post-acrosomal region and the upper region of the head. We propose that PKC is involved in the mammalian sperm acrosome reaction.
哺乳动物精子在受精前会经历一种依赖钙离子的胞吐事件，即顶体反应。在几个细胞系统中，胞吐过程是由蛋白激酶C（PKC）催化的磷酸化介导的。向牛精子中添加佛波醇12-肉豆蔻酸酯-13-乙酸酯或膜渗透性二酰甘油类似物1-油酰基-2-乙酰甘油（它们是PKC的有效激活剂）会刺激顶体反应。这种刺激被低浓度（0.7 nM时50%抑制）的PKC抑制剂星形孢菌素所抑制。与其他细胞相比，牛精子中的PKC比活性极低；然而，它与人类精子中的活性相当。使用抗PKC抗体的免疫组织化学分析显示，在赤道段、顶体后区域和头部上部区域有染色。我们认为PKC参与了哺乳动物精子顶体反应。
