Robb M J, Wilson M A, Vierula P J
Department of Biology, Carleton University, Ottawa, Canada.
Mol Gen Genet. 1995 Jun 10;247(5):583-90. doi: 10.1007/BF00290350.
The ro-4 mutant of the filamentous fungus Neurospora crassa forms distinctive colonies in which hyphae grow into rope-like aggregates. This unusual morphology coincides with a defect in hyphal nuclear migration. The ro-4 gene was cloned from a cosmid library by complementation of the closely linked pab-2 gene. The deduced 380 amino acid protein is most similar to the vertebrate actin-related protein/centractin. The RO4 protein is not essential for cell viability, and new strains created by inducing point mutations at the ro-4 locus have a phenotype which is very similar to that of the original mutant. This study provides genetic evidence that an actin-related protein plays a role in nuclear motility. Since nuclear motility is believed to be a microtubule-dependent process, the ro-4 gene product may function as a component of the dynactin complex which activates force generation by cytoplasmic dynein.
丝状真菌粗糙脉孢菌的ro-4突变体形成独特的菌落，其中菌丝生长成绳索状聚集体。这种不寻常的形态与菌丝核迁移缺陷相一致。通过紧密连锁的pab-2基因的互补作用，从黏粒文库中克隆出ro-4基因。推导的380个氨基酸的蛋白质与脊椎动物肌动蛋白相关蛋白/中心肌动蛋白最为相似。RO4蛋白对细胞活力不是必需的，通过在ro-4位点诱导点突变产生的新菌株具有与原始突变体非常相似的表型。这项研究提供了遗传证据，证明一种肌动蛋白相关蛋白在核运动中起作用。由于核运动被认为是一个依赖微管的过程，ro-4基因产物可能作为动力蛋白激活复合物的一个组分发挥作用，该复合物通过胞质动力蛋白激活力的产生。
