Ca2+-dependent interaction of S100A2 with muscle and nonmuscle tropomyosins

Gimona, M., Lando, Z., Dolginov, Y., Vandekerckhove, J., Kobayashi, R., Sobieszek, A., Helfman, D. M. (March 1997) Ca2+-dependent interaction of S100A2 with muscle and nonmuscle tropomyosins. Journal of Cell Science, 110 ( . pp. 611-21. ISSN 0021-9533

URL: http://www.ncbi.nlm.nih.gov/pubmed/9092943

Abstract

Zero-length chemical crosslinking with 1-ethyl-3-[3-(dimethyl amino)propyl]carbodiimide (EDC) indicated an association of the Ca2+-binding protein S100A2 with tropomyosin (TM) in vitro. The mobility of the crosslinked product on SDS-PAGE gels indicated the formation of a 1:1 complex between S100A2 and TM and the interaction was Ca2+ dependent. Monoclonal antibodies were raised against S100A2 and used to determine its cellular localization in the porcine epithelial cell line LLC PK1. It was found that the localization of S100A2 depended on the differentiation state of the cells, being absent from actin stress fibers in sparsely seeded cultures, but present in the actin-containing microvilli characteristic of differentiated cells. Immunoprecipitations of [35S]methionine-labeled extracts using S100A2 as well as TM-specific antibodies failed to co-precipitate TM and S100A2, indicating a transient association between these two molecules in solution. Affinity chromatography of cell extracts on immobilized recombinant TMs, however, confirmed the Ca2+-dependent interaction between S100A2 and both muscle TMs as well as with high and low molecular mass nonmuscle TMs, suggesting that the binding site resides in one of the conserved regions of TM. Our data demonstrate the possible interaction of S100A2 with TM that is not bound to the microfilaments and indicate a differentiation-related function for S100A2 in LLC PK1 cells. The possible functional implications of this interaction are discussed.

Item Type: Paper
Uncontrolled Keywords: Amino Acid Sequence Animals Antibodies, Monoclonal/immunology Biological Markers Birds Calcium/ metabolism Cell Line Chromatography, High Pressure Liquid Cross-Linking Reagents Electrophoresis, Gel, Two-Dimensional Humans Molecular Sequence Data Muscles/ metabolism Precipitin Tests Protein Binding Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, P.H.S. S100 Proteins/chemistry/immunology/ metabolism Sequence Homology, Amino Acid Swine Tropomyosin/ metabolism
Subjects: organs, tissues, organelles, cell types and functions > cell types and functions > cell types > cell line
organs, tissues, organelles, cell types and functions > cell types and functions > cell types > cell line
organs, tissues, organelles, cell types and functions > cell types and functions > cell types > cell line

biotechnology > chromatography
organs, tissues, organelles, cell types and functions > organs types and functions > metabolism
CSHL Authors:
Communities: CSHL labs > Helfman lab
CSHL labs > Kobayashi lab
Depositing User: Kathleen Darby
Date: March 1997
Date Deposited: 08 May 2014 17:25
Last Modified: 08 May 2014 17:25
Related URLs:
URI: http://repository.cshl.edu/id/eprint/29979

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