Linked Life Data

9645951

Source:http://linkedlifedata.com/resource/pubmed/id/9645951

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
1998-9-16
pubmed:abstractText
Changes in cytosolic Ca2+ concentration control a wide range of cellular responses, and intracellular Ca2+-binding proteins are the key molecules to transduce Ca2+ signaling via interactions with different types of target proteins. Among these, S100 Ca2+-binding proteins, characterized by a common structural motif, the EF-hand, have recently attracted major interest due to their cell- and tissue-specific expression pattern and involvement in various pathological processes. The aim of our study was to identify the subcellular localization of S100 proteins in vascular smooth muscle cell lines derived from human aorta and intestinal smooth muscles, and in primary cell cultures derived from arterial smooth muscle tissue under normal conditions and after stimulation of the intracellular Ca2+ concentration. Confocal laser scanning microscopy was used with a specially designed colocalization software. Distinct intracellular localization of S100 proteins was observed: S100A6 was present in the sarcoplasmic reticulum as well as in the cell nucleus. S100A1 and S100A4 were found predominantly in the cytosol where they were strongly associated with the sarcoplasmic reticulum and with actin stress fibers. In contrast, S100A2 was located primarily in the cell nucleus. Using a sedimentation assay and subsequent electron microscopy after negative staining, we demonstrated that S100A1 directly interacts with filamentous actin in a Ca2+-dependent manner. After thapsigargin (1 microM) induced increase of the intracellular Ca2+ concentration, specific vesicular structures in the sarcoplasmic reticulum region of the cell were formed with high S100 protein content. In conclusion, we demonstrated a distinct subcellular localization pattern of S100 proteins and their interaction with actin filaments and the sarcoplasmic reticulum in human smooth muscle cells. The specific translocation of S100 proteins after intracellular Ca2+ increase supports the hypothesis that S100 proteins exert several important functions in the regulation of Ca2+ homeostasis in smooth muscle cells.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0021-9533
pubmed:author
pubmed:issnType
Print
pubmed:day
30
pubmed:volume
111 ( Pt 14)
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2043-54
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Distinct subcellular localization of calcium binding S100 proteins in human smooth muscle cells and their relocation in response to rises in intracellular calcium.
pubmed:affiliation
Maurice E. Müller-Institute, Biocentrum, University of Basel, Switzerland.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't