Tatsumi Akinori, Kikuma Takashi, Arioka Manabu, Kitamoto Katsuhiko
Department of Biotechnology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
Biochem Biophys Res Commun. 2006 Sep 8;347(4):970-8. doi: 10.1016/j.bbrc.2006.06.183. Epub 2006 Jul 20.
Vps24 (vacuolar protein sorting) is a component of ESCRT III (endosomal sorting complex required for transport), which is required for the formation of MVB (multivesicular body). We have isolated the VPS24 homologue gene, Aovps24, from the filamentous fungus Aspergillus oryzae, and analyzed the localization of AoVps24 using EGFP. AoVps24 was localized in the cytoplasm and late endosome-like structures. Furthermore, we constructed an Aovps24 disruptant, which showed impaired growth, conidiation, and hyphal morphology. In addition, normal vacuoles were not observed in the Aovps24 disruptant. In the Saccharomyces cerevisiae vps24 disruptant, the normal vacuoles are formed and it does not show the impaired growth and abnormal cell shape as the A. oryzae Aovps24 disruptant. The results suggest that AoVps24 is required for vacuolar formation and normal vacuoles could have the function to maintain the normal hyphal elongation and conidiation in A. oryzae.
Vps24(液泡蛋白分选蛋白)是ESCRT III(运输所需的内体分选复合体)的一个组成部分,而ESCRT III是多泡体(MVB)形成所必需的。我们从丝状真菌米曲霉中分离出了VPS24同源基因Aovps24,并利用增强型绿色荧光蛋白(EGFP)分析了AoVps24的定位情况。AoVps24定位于细胞质和晚期内体样结构中。此外,我们构建了一个Aovps24缺失突变体,该突变体表现出生长、产孢和菌丝形态受损。另外,在Aovps24缺失突变体中未观察到正常的液泡。在酿酒酵母vps24缺失突变体中,能形成正常的液泡,且未表现出如米曲霉Aovps24缺失突变体那样的生长受损和细胞形状异常。结果表明,AoVps24是液泡形成所必需的,正常的液泡可能具有维持米曲霉正常菌丝伸长和产孢的功能。