Faculty Collaboration Database

Adherens junction-associated protein distribution differs in smooth muscle tissue and acutely isolated cells. Am J Physiol Gastrointest Liver Physiol 2007 Feb;292(2):G684-97

Date

10/21/2006

Pubmed ID

17053160

DOI

10.1152/ajpgi.00277.2006

Scopus ID

2-s2.0-33847012557 (requires institutional sign-in at Scopus site)   12 Citations

Abstract

This study was designed to examine how smooth muscle (SM) cell (SMC) isolation affects the distribution of some adherens junction (AJ) complex-associated proteins. Immunofluorescence procedures for identifying protein distribution were used on gastrointestinal and tracheal SM tissues and freshly isolated SMCs from dogs and rabbits. As confirmed by force measurements, relaxation, Ca(2+) depletion, and cholinergic activation of SM tissues do not cause significant redistribution of the AJ-associated proteins vinculin, talin, or fibronectin away from the plasma membrane. Unlike SMCs in tissue, freshly isolated SMCs show a variable peripheral/cytoplasmic vinculin and talin distribution that is not altered by activation. Enzymatic treatment of SM tissues (as done for the first step of SMC isolation) results in loss of fibronectin immunoreactivity in SMCs still in the tissue but fails to cause redistribution of vinculin, talin, or caveolin away from the periphery. The loss of fibronectin immunofluorescence with enzymatic digestion correlates significantly with loss of tissue force production. These results confirm that the AJ-associated proteins vinculin and talin do not redistribute throughout SMCs in tissues when relaxed, when generating force, or after enzymatic digestion. In addition, in freshly isolated SMCs, the distribution of these proteins is significantly altered in approximately 50% of the SMCs. The cause of this redistribution is currently unknown, as is the impact on intracellular signaling and mechanics of these cells. Use of these two systems (SMCs in tissues vs. freshly isolated SMCs) provides an ideal situation for studying the role of the AJ in SMC signaling and mechanics.

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
Carbachol
Cell Separation
Cell Shape
Colon
Cytoskeletal Proteins
Dogs
Fibronectins
Ileum
Immunohistochemistry
Membrane Glycoproteins
Muscle, Smooth
Myocytes, Smooth Muscle
Phorbol 12,13-Dibutyrate
Protein Kinase C-alpha
Rabbits
Stomach
Talin
Trachea
Vinculin