Intracellular and extracellular roles of S100 proteins
Article first published online: 12 MAR 2003
Copyright © 2003 Wiley-Liss, Inc.
Microscopy Research and Technique
Special Issue: Biology of S100 Proteins
Volume 60, Issue 6, pages 540–551, 15 April 2003
How to Cite
Donato, R. (2003), Intracellular and extracellular roles of S100 proteins. Microsc. Res. Tech., 60: 540–551. doi: 10.1002/jemt.10296
- Issue published online: 12 MAR 2003
- Article first published online: 12 MAR 2003
- Manuscript Accepted: 2 APR 2002
- Manuscript Received: 24 JAN 2002
- European Commission
- MURST-University of Perugia. Grant Numbers: BIO4CT960083, 922, COFIN 1999
- target proteins;
S100, a multigenic family of non-ubiquitous Ca2+-modulated proteins of the EF-hand type expressed in vertebrates exclusively, has been implicated in intracellular and extracellular regulatory activities. Members of this protein family have been shown to interact with several effector proteins within cells thereby regulating enzyme activities, the dynamics of cytoskeleton constituents, cell growth and differentiation, and Ca2+ homeostasis. Structural information indicates that most of S100 proteins exist in the form of antiparallelly packed homodimers (in some cases heterodimers), capable of functionally crossbridging two homologous or heterologous target proteins in a Ca2+-dependent (and, in some instances, Ca2+-independent) manner. In addition, extracellular roles have been described for several S100 members, although secretion (via an unknown mechanism) has been documented for a few of them. Extracellular S100 proteins have been shown to exert regulatory effects on inflammatory cells, neurons, astrocytes, microglia, and endothelial and epithelial cells, and a cell surface receptor, RAGE, has been identified as a potential S100A12 and S100B receptor transducing the effects of these two proteins on inflammatory cells and neurons. Other cell surface molecules with ability to interact with S100 members have been identified, suggesting that RAGE might not be a universal S100 protein receptor and/or that a single S100 protein might interact with more than one receptor. Collectively, these data indicate that members of the S100 protein family are multifunctional proteins implicated in the regulation of a variety of cellular activities. Microsc. Res. Tech. 60:540–551, 2003. © 2003 Wiley-Liss, Inc.