Induction of enzymes of the glycerophosphate pathway in leu-5 mutants of Neurospora crassa.

The inducible cytosolic glycerokinase and mitochondrial glycerol-3-phosphate dehydrogenase have been examined during the glycerol-specific induction in Neurospora crassa. Although both the fully induced levels and the respective rates of synthesis of these two enzymes were less than observed with wild-type cells, there were no major differences in the relative rates of induction of the glycerol-3-phosphate dehydrogenase at either permissive or restrictive temperatures. These results indicate that the processes involved in the assembly of this enzyme into the mitochondrial inner membrane are normal in a mutant lacking the mitochondrial leucyl tRNA synthetase and suggest that the functions of the mitochondrial synthetase may be replaced by those of the cytosolic leucyl tRNA synthetase.