Stacks of Flattened Smooth Endoplasmic Reticulum Highly Enriched in Inositol 1, 4, 5-Trisphosphate (InsP3) Receptor in Mouse Cerebellar Purkinje Cells

Cell Structure and Function

Akitsugu Yamamoto¹  Yutaka Tashiro¹  Nobuaki Maeda²  Katsuhiko Mikoshiba²  Tamotsu Yoshimori¹  Hiroko Otsu³ 

[1] Department of Physiology, Kansai Medical University;Division of Regulation of Macromolecular Function, Institute for Protein Research, Osaka University;Third Department of Medicine, Kansai Medical University

关键词: cerebellar Purkinje cells;    inositol 1;    4;    5-trisphosphate receptor;    smooth endoplasmic reticulum;    stacks;   

DOI  :  10.1247/csf.16.419

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(43)Cited-By(19)By immunogoldelectron microscopy we have shown that in mouse cerebellar Purkinje cells fixed by per fusion with formaldehyde-glutaraldehyde solution, the InsP3 receptor are numeously detected on the stacks of flattened cisterns (OTSU et al, (1990) Cell Struct. Funct., 15: 163-173). In the present experiment we investigated distribution, structure and properties of the stacks by conventional electronmicroscopy, lectin cytochemistry and immunoelectron microscopy. The size and number of stacks were variable depending on their intracellular localization; short stacks with 2-4 parallel cisterns predominate in the perikaryon, long stacks with 4-15 cisterns in the proximal dendrite, and long stacks with 3-4 cisterns in the distal dendrites. The flattened cisterns bind with concanavalin A but not with wheat-germ agglutinin and may contain KDEL proteins loaded with Lys-Asp-Glu-Leu at their C-terminin in their lumens, indicating that the cisterns are derived from ER membranes. The electron dense materials sandwiched between the cisternal membranesare composed of small particles, short cylindrical in shape and 20 nm in diameter, and markedly labeled with anti InsP3R antibody. We suggest that they correspond to the tetramer of the InsP3R or their related molecules. It is not clear whether the stacks of flattened cisterns exist per se in the Purkinje cells or smooth ER existing in singlet in vivo in the Purkinje cells forms stacks during fixation. It is strongly suggested, however, that the smooth ER membranes covered by the InsP3R or their related molecules can easily interact and stack each other in the Purkinje cells.

【 授权许可】

Unknown