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S100A16, a novel calcium-binding protein of the EF-hand superfamily.

Authors :
Sturchler E
Cox JA
Durussel I
Weibel M
Heizmann CW
Source :
The Journal of biological chemistry [J Biol Chem] 2006 Dec 15; Vol. 281 (50), pp. 38905-17. Date of Electronic Publication: 2006 Oct 08.
Publication Year :
2006

Abstract

S100A16 protein is a new and unique member of the EF-hand Ca(2+)-binding proteins. S100 proteins are cell- and tissue-specific and are involved in many intra- and extracellular processes through interacting with specific target proteins. In the central nervous system S100 proteins are implicated in cell proliferation, differentiation, migration, and apoptosis as well as in cognition. S100 proteins became of major interest because of their close association with brain pathologies, for example depression or Alzheimer's disease. Here we report for the first time the purification and biochemical characterization of human and mouse recombinant S100A16 proteins. Flow dialysis revealed that both homodimeric S100A16 proteins bind two Ca(2+) ions with the C-terminal EF-hand of each subunit, the human protein exhibiting a 2-fold higher affinity. Trp fluorescence variations indicate conformational changes in the orthologous proteins upon Ca(2+) binding, whereas formation of a hydrophobic patch, implicated in target protein recognition, only occurs in the human S100A16 protein. In situ hybridization analysis and immunohistochemistry revealed a widespread distribution in the mouse brain. Furthermore, S100A16 expression was found to be astrocyte-specific. Finally, we investigated S100A16 intracellular localization in human glioblastoma cells. The protein was found to accumulate within nucleoli and to translocate to the cytoplasm in response to Ca(2+) stimulation.

Details

Language :
English
ISSN :
0021-9258
Volume :
281
Issue :
50
Database :
MEDLINE
Journal :
The Journal of biological chemistry
Publication Type :
Academic Journal
Accession number :
17030513
Full Text :
https://doi.org/10.1074/jbc.M605798200