ABSTRACT
This chapter outlines the prohormone processing pathway as it acts in most neuro/endocrine tissues, and describes the major enzymes constituting this pathway. It introduces mouse models with defects in prohormone processing, and describes two human conditions in which processing defects lead to obesity syndromes. The chapter discusses a genetic approach for identifying factors that act downstream of the processing pathway in mediating the effects of prohormone maturation on energy homeostasis. Important neuro/endocrine signals that govern energy homeostasis involve the neuropeptides. A potentially powerful approach to revealing downstream factors that are important in mediating the effects of a mutation on the phenotype of a whole animal is quantitative trait locus analysis. The discovery of rare forms of obesity syndromes caused by defects in prohormone processing prompted a search for such defects as causes for more common forms of obesity and non-insulin-dependent diabetes mellitus.
