孕烯醇酮生物合成
中文名称
通路描述
所有类固醇激素合成的第一个过程是从胆固醇合成孕烯醇酮。在此过程中，从细胞质脂滴或溶酶体动员的胆固醇被转运至线粒体并定位于线粒体内膜。胆固醇转运似乎是类固醇激素合成的限速步骤，其在 StAR 介导的线粒体膜穿越步骤中起关键作用，决定了体内合成的类固醇激素的种类和数量。在线粒体内膜中，胆固醇通过三个反应转化为孕烯醇酮，均由 CYP11A（侧链裂解酶）催化。最后，孕烯醇酮重新进入细胞质（Payne and Hales 2004; Stocco 2001）。
英文描述
Pregnenolone biosynthesis The first process in the synthesis of all steroid hormones is the synthesis of pregnenolone from cholesterol. In this process, cholesterol mobilized from cytosolic lipid droplets or from lysosomes is transported to mitochondria and becomes localized to the inner mitochondrial membrane. Cholesterol transport appears to be rate-limiting for steroid hormone synthesis and its regulation, at the step of StAR-mediated traversal of the mitochondrial membrane, plays a central role in determining the amounts and identities of steroid hormones made in the body. In the inner mitochondrial membrane, cholesterol is converted to pregnenolone in a sequence of three reactions, all catalyzed by CYP11A (side chain cleavage enzyme). Finally, pregnenolone re-enters the cytosol (Payne and Hales 2004; Stocco 2001).
所含基因
12 个基因