Garcia-Paramio P, Carmena M J, Gutierrez-Ocaña M T, Recio M N, Prieto J C
Departamento de Bioquímica y Biología Molecular, Universidad de Alcalá, Alcalá de Henares, Spain.
Biochem Biophys Res Commun. 1993 Aug 31;195(1):166-72. doi: 10.1006/bbrc.1993.2025.
Protein kinase C activity is present in rat prostatic epithelial cells in both cytosolic and membrane subcellular fractions. Partial purification by ion-exchange chromatography and characterization of cofactor requirements showed its behavior as a classical Ca(2+)- and phospholipid-dependent enzyme activated by 1,2-diacylglycerol (or by mimicking agents such as tumor-promoting phorbol esters). Streptozotocin-induced diabetes resulted in an increase of the membrane/cytosolic enzyme ratio suggesting a redistribution of protein kinase C from the cytosolic to the membrane fraction (an index of enzyme activation) that could be reversed toward control conditions by insulin treatment. Differences observed in cofactor requirements for maximal enzyme activation argue for a some distinct expression of protein kinase C isozymes in control and diabetic conditions. These results are a new aspect of the complex set of alterations exhibited by the diabetic prostate in the signal transduction mechanisms that mediate cell functions and proliferation in this gland which could be related to the prostate atrophy and impaired fertility characteristic of this disease.
蛋白激酶C活性存在于大鼠前列腺上皮细胞的胞质和膜亚细胞组分中。通过离子交换色谱法进行部分纯化并对辅因子需求进行表征，结果显示其表现为一种经典的钙和磷脂依赖性酶，可被1,2 - 二酰甘油（或通过模拟剂如促肿瘤佛波酯）激活。链脲佐菌素诱导的糖尿病导致膜/胞质酶比率增加，表明蛋白激酶C从胞质组分重新分布到膜组分（酶激活的一个指标），胰岛素治疗可使其恢复到对照条件。在最大酶激活的辅因子需求方面观察到的差异表明，在对照和糖尿病条件下，蛋白激酶C同工酶存在一些不同的表达。这些结果是糖尿病前列腺在介导该腺体细胞功能和增殖的信号转导机制中所表现出的一系列复杂改变的一个新方面，这可能与该疾病的前列腺萎缩和生育能力受损特征有关。
