Melatonin modifies calmodulin cell levels in MDCK and N1E-115 cell lines and inhibits phosphodiesterase activity in vitro

Abstract The interaction between melatonin and calmodulin was explored. Calmodulin cell levels in MDCK and N1E-115 cells cultured with 10 −9 M melatonin were increased after 3 days but decreased after 6 days. Melatonin inhibited calmodulin-dependent phosphodiesterase and when either melatonin or [ 3 H]melatonin was preincubated with calmodulin and separated by electrophoresis, comigration of calmodulin with the radioactivity as well as modification of the Ca 2+ calmodulin shift were observed. The results point out that one of the mechanisms of action of melatonin is a calmodulin-melatonin interaction.