Oda K, Hasunuma K
Department of Cytogenetics, Kihara Institute for Biological Research, Yokohama City University, Japan.
Mol Gen Genet. 1997 Nov;256(6):593-601. doi: 10.1007/s004380050607.
We have previously demonstrated that blue light induces the phosphorylation of a 15-kDa protein in crude membrane fractions of Neurospora crassa mycelia. Here we report the isolation and characterization of a mutant (psp; phosphorylation of small proteins that is completely defective for phosphorylation of that protein, as assayed in both crude membrane and soluble fractions. This mutation defines a unique locus that maps to linkage group VR between al-3 and his-6. To elucidate the photobiological significance of the phosphorylation of the protein, we analyzed known photobiological phenomena and discovered that the positioning of beaks on the perithecia, defined as perithecial polarity, was light-dependent in the wild type. In the psp mutant, beaks were phototropic as in the wild type, but their position was random. In a wc-l mutant, however, beaks were positioned at random and were not phototropic. Thus light-induced perithecial polarity and phototropism of perithecial beaks are controlled differently. A psp; wc-l double mutant showed the same phenotype as that of wc-l with respect to these two photomorphogenetic characters. These results indicate that the wc-l gene is epistatic to psp in the light-signal transduction pathway that controls both phototropism and perithecial polarity.
我们之前已经证明，蓝光可诱导粗糙脉孢菌菌丝体粗膜组分中一种15 kDa蛋白质的磷酸化。在此，我们报告了一个突变体（psp；小蛋白磷酸化）的分离和鉴定，在粗膜和可溶组分中检测发现该突变体对该蛋白的磷酸化完全有缺陷。此突变定义了一个独特的基因座，该基因座定位于al-3和his-6之间的连锁群VR上。为阐明该蛋白磷酸化的光生物学意义，我们分析了已知的光生物学现象，发现子囊壳上喙的定位（定义为子囊壳极性）在野生型中是光依赖性的。在psp突变体中，喙与野生型一样具有向光性，但其位置是随机的。然而，在wc-1突变体中，喙的位置是随机的，且没有向光性。因此，光诱导的子囊壳极性和子囊壳喙的向光性受到不同的控制。psp；wc-1双突变体在这两个光形态建成特征方面表现出与wc-1相同的表型。这些结果表明，在控制向光性和子囊壳极性的光信号转导途径中，wc-1基因对psp是上位性的。
