Acid phosphatase (EC 3.1.3.2) synthesis by phosphorus regulatory mutant strains of Neurospora crassa.

1. Even though altered forms of acid phosphatase II were synthesized by the mutant strains nuc-1A and nuc-2A of N. crassa, their synthesis was independent of exogenous phosphate concentrations. 2. Synthesis of acid phosphatase I by nuc-2A was also insensitive to exogenous phosphate concentrations. When nuc-1A was grown on a low-phosphate medium, it also produced a heat-labile acid phosphatase in addition to a I-like acid phosphatase. I-like acid phosphatase was not detected in the mycelium of the pregc mutant strain grown on low-phosphate medium. 3. These results are consistent with the participation of the nuc-2, preg and nuc-1 genes in regulating the transport and/or secretion of acid phosphatase and probably other phosphatases by Neurospora crassa.