Shimuta M, Komazaki S, Nishi M, Iino M, Nakagawara K, Takeshima H
Department of Pharmacology, Faculty of Medicine, University of Tokyo, Japan.
FEBS Lett. 1998 Jul 17;431(2):263-7. doi: 10.1016/s0014-5793(98)00770-4.
Recently mitsugumin29 unique to the triad junction in skeletal muscle was identified as a novel member of the synaptophysin family; the members of this family have four transmembrane segments and are distributed on intracellular vesicles. In this study, we isolated and analyzed mouse mitsugumin29 cDNA and genomic DNA containing the gene. The mitsugumin29 gene mapped to the mouse chromosome 3 F3-H2 is closely related to the synaptophysin gene in exon-intron organization, which indicates their intimate relationship in molecular evolution. RNA blot hybridization and immunoblot analysis revealed that mitsugumin29 is expressed abundantly in skeletal muscle and at lower levels in the kidney. Immunofluorescence microscopy demonstrated that mitsugumin29 exists specifically in cytoplasmic regions of the proximal and distal tubule cells in the kidney. The results obtained may suggest that mitsugumin29 is involved in the formation of specialized endoplasmic reticulum systems in skeletal muscle and renal tubule cells.
最近，在骨骼肌三联体连接处特有的mitsugumin29被鉴定为突触素家族的一个新成员；该家族成员有四个跨膜片段，分布于细胞内囊泡上。在本研究中，我们分离并分析了包含小鼠mitsugumin29基因的cDNA和基因组DNA。定位到小鼠3号染色体F3-H2的mitsugumin29基因在外显子-内含子组织上与突触素基因密切相关，这表明它们在分子进化中关系密切。RNA印迹杂交和免疫印迹分析显示，mitsugumin29在骨骼肌中大量表达，在肾脏中表达水平较低。免疫荧光显微镜检查表明，mitsugumin29特异性存在于肾脏近端和远端小管细胞的细胞质区域。所得结果可能提示mitsugumin29参与骨骼肌和肾小管细胞中特化内质网系统的形成。
