[Proteasomal degradation of ribonucleic acids of different NO-synthase isoforms].

Using a developed method of determination of the RNase activity of the proteasome in vitro with the application of reverse transcription followed by subsequent polymerase chain reaction it was shown that 26S proteasome from the proteasomal fraction II effectively cleaves RNA, encoding actin, myosin and all isoforms of NO synthase. The intensity of RNA degradation by proteasome and specific RNases is similar. It was also shown that clasto-lactacystin beta-lactone, a specific proteasome inhibitor significantly depresses RNase activity of the proteasome. Thus, proteasome is capable to degrade certain eukariotic RNA in vitro and the proposed method can be used in order to discover specific substances such as inhibitors of RNase activity of the proteasome.