Cytoplasmic dynein is involved in nuclear migration in Aspergillus nidulans.

Nuclear migration plays an important role in the growth and development of many organisms including the multinuclear fungus Aspergillus nidulans. We have identified four genes, nudA, nudC, nudF, and nudG, in which temperature-sensitive mutations affect nuclear distribution. In this report, we describe the cloning of the nudA gene by complementation of the mutant phenotype by using a chromosome VIII-specific cosmid library. A genomic fragment of nudA hybridized to an mRNA of approximately 14 kb. Sequencing analysis of nudA revealed four ATP-binding sites that are characteristic of the cytoplasmic dynein heavy chain. The amino acid sequence of the nudA gene product shows 52% overall identity with the rat brain cytoplasmic dynein heavy chain. Our study provides in vivo evidence that dynein, a microtubule motor molecule, plays a role in the nuclear migration process. IMAGES:

细胞核迁移在包括多核构巢曲霉（Aspergillus nidulans）在内的多种生物的生长发育过程中发挥着重要作用。本研究已鉴定出nudA、nudC、nudF及nudG四个基因，这些基因的温度敏感型突变会影响细胞核的正常分布。本研究通过利用八号染色体特异性黏粒（cosmid）文库，采用突变表型互补策略完成了nudA基因的克隆。nudA的基因组片段可与一条约14 kb的mRNA杂交结合。对nudA基因的测序分析显示，其包含4个胞质动力蛋白重链（cytoplasmic dynein heavy chain）特有的ATP结合位点。nudA基因编码产物的氨基酸序列与大鼠脑胞质动力蛋白重链的整体同源性达52%。本研究为微管动力分子动力蛋白参与细胞核迁移过程提供了体内实验证据。图像：