GENE PHO-2 CODES FOR THE MULTIPLE ACTIVE FORMS OF P-I-REPRESSIBLE ALKALINE-PHOSPHATASE IN THE MOLD NEUROSPORA-CRASSA

The mycelial P-i-repressible alkaline phosphatase of the wild-type str ain 74A of Neurospora crassa was separated into at least ten isoforms by isoelectric focusing. The components visualized by activity with so dium a-naphthyl phosphate as the substrate were predominantly acidic p roteins with isoelectric points ranging from pH 4.5 to 7.6. The number of these isoforms was a function of growth pH. Strain pho-2A did not produce active P-i-repressible alkaline phosphatase (the pho-2 gene co des for its amino acid sequence), which gives an indication that these isoforms are encoded by the same structural gene.