Soluble adenylyl cyclase isoforms essential for male fertility

描述（由申请人提供）：普遍存在的第二信使cAMP在雄性生殖细胞中发挥多种作用，对哺乳动物受精至关重要。精子中cAMP的主要来源是碳酸氢盐和钙调节的可溶性腺苷酸环化酶（sAC）。在睾丸中，选择性剪接产生两种异构体，sACt和sACfl，它们的缺失（在Sacytm1Lex敲除小鼠中）或抑制（通过小分子，sac特异性抑制剂）阻断精子的运动，获能和体外受精。由于sACt和sACfl在Sacytm1Lex敲除过程中被去除，并被小分子抑制剂抑制，因此它们在精子中多种sac衍生的camp依赖过程中的单独作用尚不清楚。在这项应用中，我们提出了免疫学、生化和遗传学实验，以确定是否存在多个sAC剪接变体的功能必要性，并区分它们在睾丸和男性生殖细胞中的个体作用。这些研究可能证明sAC是避孕干预的目标。本文提出的研究可能揭示了精子cAMP信号转导调控的独特方面，这可能为避孕干预确定新的靶点。公共卫生相关性：这里提出的研究可能揭示了精子cAMP信号转导调节的独特方面，这可能定义避孕干预的新目标。

DESCRIPTION (provided by applicant): The ubiquitous second messenger, cAMP, plays multiple roles in male germ cells critical for mammalian fertilization. The major source of cAMP in sperm is the bicarbonate and calcium regulated soluble adenylyl cyclase (sAC). In testis, alternative splicing produces two isoforms, sACt and sACfl, and their deletion (in Sacytm1Lex knockout mice) or inhibition (by small molecule, sAC-specific inhibitor) blocks sperm motility, capacitation, and in vitro fertilization. Since both sACt and sACfl are removed in the Sacytm1Lex knockout and inhibited by the small molecule inhibitor, their individual contributions to the multiple sAC-derived cAMP-dependent processes in sperm remains unclear. In this application, we propose immunological, biochemical, and genetic experiments to determine whether there is a functional necessity for multiple sAC splice variants and to distinguish their individual roles in testis and male germ cells. These studies may justify sAC to be target for contraceptive intervention. The studies proposed here may reveal unique aspects to the regulation of sperm cAMP signal transduction which could define a new target for contraceptive intervention. PUBLIC HEALTH RELEVANCE: The studies proposed here may reveal unique aspects to the regulation of sperm cAMP signal transduction which could define a new target for contraceptive intervention.