Effects of nucleotides on cyanide-resistant respiratory activity in mitochondria isolated from antimycin A-treated yeast Hansenula anomala.

Mitochondria were isolated from Hansenula anomala induced for cyanide-resistant respiration by antimycin A-treatment. Cyanide-resistant respiratory activity in isolated mitochondria was stimulated by AMP, ADP, dAMP, and GMP, but not by ATP, adenosine, cAMP, 2'(3')-AMP, CMP, and UMP. Effects of nucleotides were also observed on cyanide-resistant and salicylhydroxamate-sensitive decylubiquinol oxidase activity. Carbonylcyanide m-chlorophenylhydrazone, oligomycin, and carboxyatractyloside did not affect activation of decylubiquinol oxidase activity by AMP. It is suggested that purine nucleoside 5'-monophosphate or diphosphate stimulates alternative oxidase activity from the outer surface of the mitochondrial inner membrane with a mechanism different from respiratory control. Alternative oxidase activity might be controlled by adenine nucleotides posttranscriptionally in fungi.