ABSTRACT
Several peptides which can cause dispersion of black pigment, melanin, in dermal melanophores of the amphibian skin have been isolated from pituitary glands of a number of different species. With regard to the structural organization of the precursor to α-MSH, biochemical data showed that adrenocorticotropic hormone occupied a central position in the prohormone structure and β-LPH represented the carboxy-terminal portion of the protein. An important prerequisite for such a study is knowledge of the structures of the amphibian melanotropic peptides and of their precursor. In addition to the melanotropic peptides the prohormone can produce corticotropins and peptides with opiate activity, it was named pro-opiomelanocortin (POMC) in order to adequately represent the bioactivities of the products which can be generated from this precursor. The chapter describes structural organization and evolutionary aspects of the Xenopus POMC gene. It considers the structures and evolutionary aspects of the Xenopus POMC mRNAs and proteins.
