Distinct Distribution and Localization of Rho-kinase in Mouse Epithelial, Muscle and Neural Tissues

Cell Structure and Function

Kazushi Kimura²  Michiro Iizuka²  Katsuhiro Kato¹  Kozo Kaibuchi¹  Akira Mizoguchi²  Mutsuki Amano¹  Shujie Wang² 

[1] Department of Cell Pharmacology, Nagoya University Graduate School of Medicine;Department of Neural Regeneration and Cell Communication, Mie University Graduate School of Medicine

关键词: Rho;    Rho-kinase;    mouse tissues;    immunofluorescence;    immunoelectron microscopy;   

DOI  :  10.1247/csf.12018

学科分类：分子生物学，细胞生物学和基因

来源: Japan Society for Cell Biology

【 摘 要 】

References(90)Cited-By(11)The small GTP-binding protein Rho plays a crucial role in a wide variety of cellular functions through various effector proteins. Rho-kinase is a key effector protein of Rho, which is composed of two isoforms, ROCK1 and ROCK2. To clarify the site of action of ROCK1 and ROCK2, we performed immunofluorescence and immunoelectron microscopic analyses using isoform-specific antibodies in mouse tissues. In the large and small intestines, ROCK1 immunoreactivity was predominantly identified in epithelial cells, and ROCK2 immunoreactivity was negligible. In these epithelial cells, ROCK1 immunoreactivity was distributed on plasma membranes, while ROCK1 immunogold signals were localized at cell-cell contacts and cell adhesion sites, especially at the adherens junctions at the ultrastructural level. In the bladder epithelium, however, ROCK1 and ROCK2 signals were identified at intermediate filaments, and ROCK2 signals were also observed in nuclei. In the three types of muscular cells—smooth, cardiac, and skeletal muscle cells—ROCK1 and ROCK2 also showed differential distribution. ROCK1 signals were localized at actin filaments, plasma membranes, and vesicles near plasma membranes in smooth muscle cells; at the lysosomes in skeletal muscle cells; and were undetectable in cardiac muscle cells. ROCK2 signals were localized at actin filaments and centrosomes in smooth muscle cells, at intercalated discs in cardiac muscle cells, and at Z-discs and sarcoplasmic reticulum in skeletal muscle cells. In the brain, ROCK1 immunoreactivity was distributed in glia, whereas ROCK2 immunoreactivity was observed in neurons. These results indicate that the two isoforms of Rho-kinase distribute differentially to accomplish their specific functions.

【 授权许可】

Unknown