Signal transduction of light through NDP kinase inducing the morphogenesis of perithecia in Neurospora crassa

抄録

Summary: An in vitro system to analyze light signal transduction inducing the morphogenesis of perithecia was developed. A crude membrane fraction prepared from wild type(band)mycelia was mixed with [γ-32P]ATP and irradiated with blue light for 1 sec at 0°C. Five sec after illumination, the reaction was stopped and the proteins were separated by SDS-polyacrylamide gel electrophoresis. The increase in the phosphorylation of 15 kDa protein was detected and the increase lasted till 15 sec after illumination. The 15 kDa protein was purified, identified to be nucleoside diphosphate kinase and designated to be NDK-1. The cDNA and genomic DNA for NDK-1 were isolated. A mutant with no phosphorylation activity of NDK-1 was detected among wc-1 strains as a double mutant. The mutation designated psp(phosphorylation of small protein)was separated from the wc-1 and mapped on LGVR. Wild type and psp formed perithecial beak at random places of perithecia in darkness. Under directional light parallel to the solid medium the wild type perithecia formed the beak facing upward. However, under the same light condition psp formed the perithecial beak at random places on the perithecia. The cDNA for NDK-1 isolated from psp was sequenced. We found that ndk-1 gene in psp included Pro 72 His replacement, and finally psp was determined to be ndk-1Pro72His mutation.