Bufalin-induced cardiotoxicity: new findings into mechanisms.

Bufalin is one of the main pharmacological and toxicological components of Venenum Bufonis and many traditional Chinese medicine preparations. The cardiotoxicity clearly limits its application to patients living in countries. Hence, an investigation of its toxicological mechanism is helpful for new drug development and treatment of the related clinical adverse reactions.

Studies on the Potential Phosphorylation Sites of the Yeast PHO2 Factor.

We report here that PHO2 protein is also phosphorylated by an unidentified protein kinase. A Ser-230 to Ala mutation in the consensus sequence (SPIK) recognized by cc2/CDC28-related kinase in the PHO2 protein led to the complete loss of its ability to activate the transcription of PHO5 gene. Further work showed that Pro-231 to Ser mutation inactivated PHO2 protein as well, while Ser-230 to Asp mutation did not affect PHO2 activity.