On the presence of calmodulin-like protein in mycobacteria

Abstract

A heat-stable factor, antigenically cross-reacting with calmodulin, was found mainly in the soluble fraction of Mycobacterium smegmatis ATTC 14468 and Mycobacterium bovis BCG 14 004 001. Maximum amounts of calmodulin were found in the early logarithmic phase of growth. The cell-free extract of M. smegmatis did not stimulate, rather inhibited cAMP phosphodiesterase due to the presence of certain endogenous inhibitory protein(s). However, the cAMP phosphodiesterase stimulation could be observed, after the removal of inhibitor(s). This is the first report indicating the presence of calmodulin in mycobacteria, a member of the prokaryotes.