Phorbol ester decreases cytosolic retinoic acid binding protein (CRABP) capacity in normal but not psoriatic epidermis.

Abstract

AbstractThe retinoic acid binding protein (CRABP) characterized in human epidermal cytosol exhibits a three‐fold increased binding capacity in lesional psoriatic epidermis as compared to normal or uninvolved skin. Treatment of epidermal homogenate from normal subjects by phorbol ester + ATP decreases the specific binding capacity of CRABP without affecting its dissociation constant (Kd=10 nM). The same effect was not observed in involved and uninvolved psoriatic epidermis. These results could be related to the previously reported decreased protein kinase C activity in psoriatic skin. They also suggest that posttranslational events could be responsible for pathological and pharmacological variations in CRABP binding capacity.