Summary: Thirty-two yeast species belonging to twelve genera were examined for the occurrence of inhibition of ornithine carbamoyltransferase by arginase (epiarginasic regulation) and related properties. Obligate aerobes were devoid of this regulation. Among fermenting species, and budding genera had different properties: all species were devoid of this regulation whereas all species of budding yeasts showing a weak or absent Pasteur effect had this regulation. Strains showing a strong Pasteur effect and taxonomically related to had the regulation, whereas species classified in genera that include species which are obligate aerobes did not.

We confirm that the absence of epiarginasic regulation is correlated with a mitochondrial localization of ornithine carbamoyltransferase but not with the function of the mitochondria in . In this case, compartmentation could serve to channel anabolic and catabolic functions. Although, in general, the arginase of ‘negative epiarginasic’ species had no affinity for cytosolic ornithine carbamoyltransferase, one exception was found ().

Regulation by repression of ornithine carbamoyltransferase and induction of arginase by arginine was the general rule. These types of regulation of enzyme synthesis were only absent in yeasts in which compartmentation is present and could serve as the basis for anabolism—catabolism exclusion.


Article metrics loading...

Loading full text...

Full text loading...


Most cited this month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error