Methylated ubiquitin inhibits cyclin degradation in clam embryo extracts.

摘要: A derivative of ubiquitin in which amino groups were blocked by reductive methylation was used to study the possible role pathway cell cycle-programmed degradation cyclin. It shown previously that methylated can be efficiently ligated protein substrates, but cannot form polyubiquitin chains. In well-characterized ubiquitin-dependent proteolytic system from reticulocytes, it found rates breakdown obtained with are generally slower than those ubiquitin; and thus, this used, some cases, as an inhibitor degradation. The addition a cell-free fertilized clam oocytes inhibited both cyclins B. That due specific interference function indicated observation supplementation excess completely overcame inhibitory action on cyclin These findings suggest chain formation is required for