THE MITOGEN-ACTIVATED PROTEIN-KINASES SYSTEM (MAP KINASE CASCADE) - ITS ROLE IN SKIN SIGNAL-TRANSDUCTION - A REVIEW

Mitogen-activated protein (MAP) kinases are proline-directed kinases w hich are downstream components of a pathway involving p21(ras) and the serine/threonine kinase Raf-1. They represent an important link betwe en the signal transduction processes at the level of the plasma membra ne and the final nuclear events. Not only various growth factors and c ytokines, but also other signals such as UV-light or extracellular mat rix components are able to activate MAP kinases. We believe that the M AP kinase cascade may play a significant role in regulating cell proli feration and differentiation in human epidermis. In this review we sum marize the rapidly increasing knowledge in this held of signal transdu ction and discuss some very recent results on MAP kinases and their ro le in skin biology.