Prohormone processing in zebrafish.

Proprotein convertases (PCs) are secretory proteolytic enzymes that activate precursor proteins into biologically active forms by limited proteolysis at one or multiple internal sites. PCs are implicated in the processing of multiple protein precursors, including hormones, proteases, growth factors, angiogenic factors, and receptors. PCs have been linked recently to various pathologies such as Alzheimer's disease, tumorigenesis, and infections. The zebrafish has emerged as an attractive model for studying the role of PCs not only in substrate production but also in development. Herein we describe methods that are used to characterize DNA sequences of PCs in zebrafish, as well as to evaluate the ontogeny and tissue distribution of their transcripts. We also provide information on the morpholino-mediated knockdown of proprotein convertases.