Shoeb Mohammed, Laloraya Malini, Kumar Pradeep G
Molecular Reproduction Unit, School of Life Sciences, Devi Ahilya University, Vigyan Bhawan, Khandwa Road, Indore 452 017, MP, India.
Biochem Biophys Res Commun. 2004 Mar 12;315(3):763-70. doi: 10.1016/j.bbrc.2004.01.119.
Capacitated mammalian spermatozoa undergo a fusion response of their head plasma membrane and the outer acrosomal membrane leading to vesiculation classically known as acrosome reaction. Acrosome reaction occurs in response to various acrosome reaction inducers including zona pellucida proteins, calcium ionophore, dibutyryl cAMP, progesterone, etc. All the acrosome reaction inducers cause a transient of calcium influx into the sperm through voltage-dependent cation channels. Efflux of chloride, stimulation of activity of phospholipases, and phosphorylation of proteins are other known changes introduced by acrosome reaction inducers. Macromolecular organization and dynamics of sperm membranes during the progression of this vesiculation are largely unexplored. In this study, we report that progesterone induced the formation of horizontal microdomains within the exofacial surfaces of sperm membranes, which showed progressive and independent alterations in molecular dynamics. In the light of this observation, we propose that sperm membrane rafts may contain both horizontal and vertical microdomains.
获能的哺乳动物精子会经历其头部质膜与顶体外膜的融合反应，从而导致经典的囊泡化，即顶体反应。顶体反应是对包括透明带蛋白、钙离子载体、二丁酰环磷腺苷、孕酮等各种顶体反应诱导剂的反应。所有的顶体反应诱导剂都会通过电压依赖性阳离子通道使钙离子短暂流入精子。氯离子外流、磷脂酶活性的刺激以及蛋白质的磷酸化是顶体反应诱导剂引起的其他已知变化。在这种囊泡化过程中，精子膜的大分子组织和动力学在很大程度上尚未得到探索。在本研究中，我们报告孕酮诱导精子膜外表面形成水平微结构域，其分子动力学表现出渐进性和独立性变化。鉴于这一观察结果，我们提出精子膜筏可能同时包含水平和垂直微结构域。
