S100A6 mediates nuclear translocation of Sgt1: a heat shock-regulated protein.
Sgt1 was originally identified in yeast as a suppressor of the Skp1 protein. Later, it was found that Sgt1 is present in plant and mammalian organisms and that it binds other ligands such as S100A6, a calcium-binding protein. In this work we show that in HEp-2 cells Sgt1 translocates to the nucleus due to heat shock. We also found that in HEp-2 cells with diminished level of S100A6, due to stable transfection with siRNA against S100A6, such translocation occurred at a much smaller scale in comparison with cells expressing a normal level of S100A6. Moreover, translocation of Sgt1 was observed in HEp-2 cells treated with thapsigargin instead of heat shock. In contrast thapsigargin was ineffective in cells with diminished level of S100A6. Thus, our results suggest that increase in intracellular concentration of Ca(2+), transduced by S100A6, is necessary for nuclear translocation of the Sgt1 protein.
Prus
Wiktor
W
Nencki Institute of Experimental Biology, 3 Pasteur Street, 02-093, Warsaw, Poland.
Filipek
Anna
A
D021581:Active Transport, Cell Nucleus / Q000187:drug effects; D002118:Calcium / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D018869:Heat-Shock Response; D006801:Humans; D034741:RNA, Small Interfering; D000075383:S100 Calcium Binding Protein A6; D009418:S100 Proteins / Q000235:genetics / Q000378:metabolism*; D019284:Thapsigargin / Q000494:pharmacology
D018797:Cell Cycle Proteins; D034741:RNA, Small Interfering; D000075383:S100 Calcium Binding Protein A6; D009418:S100 Proteins; C490164:SUGT1 protein, human; C055351:S100A6 protein, human; D019284:Thapsigargin; D002118:Calcium