Early Events in the Interaction of Melanotropin with Cloudman S91 Melanoma Cells

Melanotropin stimulates melanin synthesis in Cloudman S91 melanomacells, the accumulation of melanin being preceded by a numberof events which are understood to various degrees. In this reviewI will discuss the control of melanogenesis by melanotropin;emphasis will be on the early events of the process, althoughother aspects will be discussed. The probes (fluorescent andradioactive labels) used to examine the binding of the hormoneto the cells will be described, as will be the results of initialbinding studies. One of the events immediately following thebinding of the hormone is the activation of adenylate cyclase:the evidence supporting this, plus the role of cyclic AMP instimulating melanin synthesis, will be discussed. Also examinedis the role which internalization of the melanotropin-receptor-adenylatecyclase complex may play in mediating hormone action.