Cell Structure and Function
Online ISSN : 1347-3700
Print ISSN : 0386-7196
ISSN-L : 0386-7196
REGULAR ARTICLES
An Ultrastructural and Biochemical Study of Foot Structure in “Catch” Smooth Muscle Cells of a Clam
Eiji NotsuAkira Matsuno
Author information
Keywords: ultrastructures, foot, clam
JOURNALS FREE ACCESS FULL-TEXT HTML

2004 Volume 29 Issue 2 Pages 43-48

Details
Abstract

The foot structure of molluscan (clam) catch muscle cells was studied from the structural and biochemical standpoints. In vertebrate cross striated muscle cells, foot structures are situated in the interspaces between T-tubules and sarcoplasmic reticula (SRs). By contrast, T-tubules were not observed in clam catch muscle cells, but foot structures were ultrastructurally identified in the interspaces between the SRs and cell membranes. We isolated the SR fraction from muscle cells which contained vesicles with SRs and cell membranes. Foot structures were also observed in the SR fraction by thin sectioning. The size and shape of the foot structure in both intact muscle cells and the SR fractions appeared to be slightly smaller than those of vertebrates. However, the molecular weight of the foot structures (foot proteins) as determined by SDS-PAGE (450 kD) was similar to ryanodine receptors (RyRs) which were reported previously in cross striated muscle cells from pecten and vertebrates. The protein showing the 450 kD band reacted to an anti-ryanodine receptor by Western blotting. These findings are discussed in comparison with previous studies of foot structures and RyRs of vertebrates and invertebrates.

Information related to the author
© 2004 by Japan Society for Cell Biology
Previous article Next article
feedback
Top