Faculty Collaboration Database

Smooth muscle adherens junctions associated proteins are stable at the cell periphery during relaxation and activation. Am J Physiol Cell Physiol 2005 Dec;289(6):C1379-87

Date

07/22/2005

Pubmed ID

16033907

DOI

10.1152/ajpcell.00193.2005

Scopus ID

2-s2.0-27744457281 (requires institutional sign-in at Scopus site)   14 Citations

Abstract

This study was performed to determine the stability of the adherens junction (AJ)-associated proteins at the smooth muscle cell (SMC) plasma membrane during relaxing and activating conditions. Dog stomach, ileum, colon, and trachea tissues were stored in Ca2+-free PSS or regular PSS or were activated in 10 muM carbachol in PSS before rapid freezing. The tissues were subsequently sectioned and immunoreacted using antibodies for vinculin, talin, fibronectin, and caveolin to determine their cellular distribution in these tissues under these conditions. In all four tissues and under all three conditions, the distribution of these four proteins remained localized to the periphery of the cell. In transverse tissue sections, the AJ-associated proteins formed a distinct punctate pattern around the periphery of the SMCs at the plasma membrane. These domains alternated with the caveolae (as identified by the presence of caveolin). In longitudinal tissue sections, the AJ-associated proteins formed continuous tracks or staves, while the caveolae remained punctate in this dimension as well. Caveolin is not present in the tapered ends of the SMCs, where the AJ-associated proteins appear continuous around the periphery. Densitometry of the fluorophore distribution of these proteins showed no shift in their localization from the SMC periphery when the tissues were relaxed or when they were activated before freezing. These results suggest that under physiologically relaxing and activating conditions, AJ-associated proteins remain stably localized at the plasma membrane.

Author List

Eddinger TJ, Schiebout JD, Swartz DR

Author

Thomas Eddinger PhD Bioological Sciences in the Biology department at Marquette University

MESH terms used to index this publication - Major topics in bold

Adherens Junctions
Animals
Calcium
Caveolae
Caveolins
Cell Membrane
Colon
Dogs
Fibronectins
Gastric Mucosa
Ileum
In Vitro Techniques
Membrane Proteins
Muscle Contraction
Muscle Relaxation
Muscle, Smooth
Stomach
Talin
Trachea
Vinculin