I. Shin et al., INHIBITION OF 80 KDA PROTEIN-PHOSPHORYLATION BY SHORT-WAVELENGTH UV-LIGHT IN NIH 3T3 CELLS, Photochemistry and photobiology, 58(4), 1993, pp. 536-540
The exposure of NIH 3T3 fibroblast cells to 254 nm UV radiation result
ed in a temporary depression of DNA synthesis and inhibition of 80 kDa
protein phosphorylation. This inhibition of protein phosphorylation w
as correlated with decreased protein kinase C activity in the membrane
fractions of UV-damaged cells. The inositol triphosphate contents mea
sured, by the competitive binding assay using bovine adrenal binding p
rotein, showed 80% reduction in the fibroblasts treated with 15 J/m2 o
f UV light. The intracellular diacylglycerol concentration was also ma
rkedly reduced in UV-damaged cells. The results suggest that UV light
causes acute reductions of inositol triphosphate and diacylglycerol co
ntents in cells along with decreases in membrane protein kinase C acti
vity, which leads to the inhibition of phosphorylation of an acidic pr
otein of 80 kDa.