Premium
Calmodulin mediated activation of acetyl‐CoA carboxylase during aflatoxin production by Aspergillus parasiticus
Author(s) -
Praveen Rao J.,
Subramanyam C.
Publication year - 2000
Publication title -
letters in applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.698
H-Index - 110
eISSN - 1472-765X
pISSN - 0266-8254
DOI - 10.1046/j.1472-765x.2000.00717.x
Subject(s) - trifluoperazine , aspergillus parasiticus , calmodulin , aflatoxin , pyruvate carboxylase , biochemistry , chemistry , acetyl coa , enzyme , biology , food science
The relevance of Ca 2+ ‐calmodulin‐mediated processes in channelling acetate for aflatoxin formation was investigated by studying the influence of trifluoperazine (an anticalmodulin agent) on [ 14 C]‐acetate incorporation and activity of acetyl‐CoA carboxylase in Aspergillus parasiticus NRRL 2999. Culturing the organism in presence of 0·14 mmol l −1 trifluoperazine resulted in 55% decrease of [ 14 C]‐acetate incorporation into aflatoxin B 1 , along with an 80% decrease in acetyl‐CoA carboxylase activity at periods corresponding to maximal aflatoxin production. Concomitant decrement (35%) in the activity of glucose‐6‐phosphate dehydrogenase indicated decreased availability of reduction potential (NADPH) required for aflatoxin biosynthesis. The ability of calmodulin to activate and trifluoperazine to inhibit acetyl‐CoA carboxylase activity in a dose‐dependent manner was also noted under in vitro conditions. The combined results suggest calmodulin‐mediated activation of acetyl‐CoA carboxylase as an important event for aflatoxin production.