Clark S G, Shurland D L, Meyerowitz E M, Bargmann C I, van der Bliek A M
Howard Hughes Medical Institute Programs in Developmental Biology, Neuroscience, and Genetics, Department of Anatomy, University of California, San Francisco, CA 94143, USA.
Proc Natl Acad Sci U S A. 1997 Sep 16;94(19):10438-43. doi: 10.1073/pnas.94.19.10438.
Drosophila shibire and its mammalian homologue dynamin regulate an early step in endocytosis. We identified a Caenorhabditis elegans dynamin gene, dyn-1, based upon hybridization to the Drosophila gene. The dyn-1 RNA transcripts are trans-spliced to the spliced leader 1 and undergo alternative splicing to code for either an 830- or 838-amino acid protein. These dyn-1 proteins are highly similar in amino acid sequence, structure, and size to the Drosophila and mammalian dynamins: they contain an N-terminal GTPase, a pleckstrin homology domain, and a C-terminal proline-rich domain. We isolated a recessive temperature-sensitive dyn-1 mutant containing an alteration within the GTPase domain that becomes uncoordinated when shifted to high temperature and that recovers when returned to lower temperatures, similar to D. shibire mutants. When maintained at higher temperatures, dyn-1 mutants become constipated, egg-laying defective, and produce progeny that die during embryogenesis. Using a dyn-1::lacZ gene fusion, a high level of dynamin expression was observed in motor neurons, intestine, and pharyngeal muscle. Our results suggest that dyn-1 function is required during development and for normal locomotion.
果蝇的发动蛋白及其哺乳动物同源物发动蛋白调节内吞作用的早期步骤。我们基于与果蝇基因的杂交鉴定出一种秀丽隐杆线虫的发动蛋白基因dyn-1。dyn-1 RNA转录本被反式剪接至剪接前导序列1，并经历可变剪接以编码830个或838个氨基酸的蛋白质。这些dyn-1蛋白在氨基酸序列、结构和大小上与果蝇和哺乳动物的发动蛋白高度相似：它们包含一个N端GTP酶、一个普列克底物蛋白同源结构域和一个C端富含脯氨酸的结构域。我们分离出一个隐性温度敏感型dyn-1突变体，其GTP酶结构域内存在改变，转移至高温时会变得不协调，回到较低温度时恢复正常，这与果蝇发动蛋白突变体相似。当维持在较高温度时，dyn-1突变体出现便秘、产卵缺陷，并产生在胚胎发育期间死亡的后代。使用dyn-1::lacZ基因融合，在运动神经元、肠道和咽部肌肉中观察到高水平的发动蛋白表达。我们的结果表明，dyn-1功能在发育过程中以及正常运动中是必需的。
