Yamazaki Harutake, Yamazaki Daisuke, Takaya Naoki, Takagi Masamichi, Ohta Akinori, Horiuchi Hiroyuki
Department of Biotechnology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan.
Curr Genet. 2007 Feb;51(2):89-98. doi: 10.1007/s00294-006-0109-7. Epub 2006 Nov 22.
Chitinases are thought to be involved in the morphogenesis and autolysis of filamentous fungi. We cloned a gene (chiB) encoding a class V chitinase from Aspergillus nidulans. ChiB expressed in Escherichia coli had chitin-hydrolyzing activity, indicating that chiB encoded a chitinase. Deletion of chiB affected neither germination efficiency nor hyphal growth rate, but considerably reduced the intracellular and extracellular chitinase activities. The decrease in hyphal dry weight during autolytic phase was slower in the mutant than in the wild-type strain. Western blot analysis indicated that the quantity of ChiB significantly increased when the wild-type mycelia were starved for carbon sources, a condition that induced hyphal autolysis. These results suggest that chiB plays an important role in the autolytic process in A. nidulans.
几丁质酶被认为参与丝状真菌的形态发生和自溶过程。我们从构巢曲霉中克隆了一个编码V类几丁质酶的基因（chiB）。在大肠杆菌中表达的ChiB具有几丁质水解活性，这表明chiB编码一种几丁质酶。chiB的缺失既不影响萌发效率，也不影响菌丝生长速率，但显著降低了细胞内和细胞外的几丁质酶活性。在自溶阶段，突变体菌丝干重的减少比野生型菌株慢。蛋白质免疫印迹分析表明，当野生型菌丝体缺乏碳源（一种诱导菌丝自溶的条件）时，ChiB的量显著增加。这些结果表明，chiB在构巢曲霉的自溶过程中起重要作用。
