Synthesis and degradation of fructose diphosphate aldolase isoenzymes in avian brain.

The intraccellular proteins of animal cells are continuously turning over; therefore, the concentration of a given protein is regulated both at the level of protein synthesis and at the level of protein degradation. Studies on the relative rates of turnover of isoenzymes, such as those of aldolase and lactate dehydrogenase, may help to clarify the mechanisms involved in protein turnover. The isoenzymes and subunit types are very similar proteins, and are located within the same intracellular compartments; yet, the concentrations of these proteins are independently regulated. The present paper describes the roles of synthesis and degradation in regulating aldolase isoenzyme concentrations in avian brain...