[Psoriasis and the problem of gene expression regulation]

During the epidermis maturation different keratin genes are expressed in strictly definite sequences according to the level of epidermis. In psoriasis this sequence in deranged (permutation) Perhaps this is due to implication of homeobox system similar to what occurs in (Ftz) gene. This problem is reviewed and discussed in this paper. All keratin as well as involukrine genes have been sequenced. Regions of K5 gene have been found which play regulatory role in transcription. It has been achieved using transfection K5 into keratinocytes. Psoriatic injury reversed by yEPP peptide of chick Y. sack cells. It is well established that protooncogenes are involved in transcription regulation. Expression of c-myc is increased in psoriatic plagues whereas that of c-fos and c-jun is decreased. This fact may be regarded as an indirect evidence for abnormal functioning c-myc in regulation. It is not ruled out that the system implicated in shedding in reptiles recapitulate in psoriasis.