Regulation of potassium-dependent Kdp-ATPase expression in the nitrogen-fixing cyanobacterium Anabaena torulosa

Abstract

The KdpB polypeptides in the cyanobacterium Anabaena torulosa were shown to be two membrane-bound proteins of about 78 kDa, expressed strictly under K⁺ deficiency and repressed or degraded upon readdition of K⁺. In both Anabaena and Escherichia coli strain MC4100, osmotic and ionic stresses caused no significant induction of steady-state KdpB levels during extreme potassium starvation.