The effect of ultraviolet (UV) B irradiation on pi class @entity2041 transferase ( @entity10625 ) gene expression was examined in cultured @entity35 keratinocytes. Immunoblotting demonstrated @entity10625 to be the major GST form in the cells, and it was significantly decreased following irradiation. Northern blot analysis revealed that the mRNA decreased to 10-25% of the initial value 24 h after irradiation at a dose of 40 mJ/cm2. No remarkable changes were observed at earlier time points. @entity273 treatment enhanced @entity10625 mRNA expression, with a 70% increase at 250 microM concentration. Alterations in possible trans-acting factors were examined to clarify the mechanism of repression by UV irradiation. c-Jun mRNA was induced 3.5-fold at 4 h after irradiation, but by 24 h fell to a lower level than that observed initially. @entity5019 mRNA was increased 10-fold at 1 h but was completely suppressed at 12 and 24 h. Thus, the changes of c-Jun and @entity5019 mRNA differed from that of @entity10625 mRNA. The level of mRNA for @entity16597 was decreased to less than 10% at 12 h. UV irradiation of cells transfected with the @entity2755 acetyltransferase (CAT) reporter gene containing enhancer (GPE I) or silencer regions of the @entity10625 gene did not suppress CAT activity. Although basal expression of the @entity10625 gene was mainly dependent on GPE I, altered expression of c-jun, @entity5019 and other genes coding for factors possibly trans-acting on GPE I did not appear to be responsible for the decreased @entity10625 mRNA levels.

Decrease in class pi glutathione transferase mRNA levels by ultraviolet irradiation of cultured XXXX keratinocytes.

@entity35 :: ('10116', 'Species') :: ['rat'] @entity16597 :: ('24253(Tax:10116)', 'Gene') :: ['silencer factor-B'] @entity2041 :: ('MESH:D005978', 'Chemical') :: ['glutathione'] @entity5019 :: ('314322(Tax:10116)', 'Gene') :: ['c-fos', 'c-Fos'] @entity273 :: ('MESH:D006861', 'Chemical') :: ['Hydrogen peroxide'] @entity10625 :: ('24426(Tax:10116)', 'Gene') :: ['GST-P'] @entity2755 :: ('MESH:D002701', 'Chemical') :: ['chloramphenicol']
@entity35 :: (10116,Species) :: ['rat']
