Alesenko A V, Burlakova E B, Pantaz E A
Biokhimiia. 1984 Apr;49(4):621-8.
Using a model of regenerating rat liver, it was shown that the activities of RNA polymerases I and II, and the ratio of free to template engaged form of the enzyme are correlated with the changes in the contents of sphingomyelin in chromatin isolated from cell nuclei of hepatectomized animals. Injections of sphingomyelin to intact and hepatectomized animals in doses increasing its contents in chromatin, stimulate the activity of RNA polymerases I and II and increase the ratio of free to engaged form of the enzyme. Addition of sphingomyelin as a micellar suspension to heterochromatin in vitro facilitates RNA polymerase binding to the template. Removal of sphingomyelin from the intranuclear structures by its degradation with sphingomyelinase results in a loss of activities of both RNA polymerases. It is assumed that sphingomyelin plays a role in the transcriptional activity by changing the structure of the template and that of the enzymes.
利用大鼠肝脏再生模型研究发现，RNA聚合酶I和II的活性以及该酶游离形式与模板结合形式的比例，与从肝切除动物的细胞核中分离出的染色质中鞘磷脂含量的变化相关。向完整和肝切除的动物注射鞘磷脂，剂量以增加其在染色质中的含量，可刺激RNA聚合酶I和II的活性，并增加该酶游离形式与结合形式的比例。在体外将鞘磷脂以胶束悬浮液的形式添加到异染色质中，有助于RNA聚合酶与模板结合。用鞘磷脂酶降解核内结构中的鞘磷脂，导致两种RNA聚合酶的活性丧失。据推测，鞘磷脂通过改变模板和酶的结构在转录活性中发挥作用。
