prothorm
Prothorm is a term sometimes used to describe a precursor form of a hormone that requires enzymatic processing to become active. In many contexts, prothorm is synonymous with prohormone, though the latter term is far more widely used in contemporary biology and medicine. Prothorms are typically synthesized as larger, biologically inactive polypeptides in secretory cells and stored in secretory vesicles until they are cleaved by proteases to release one or more active hormones, and sometimes additional peptide fragments.
Activation of a prothorm usually involves endoproteolytic cleavage at specific sites, such as dibasic residues, by
Examples commonly cited in physiology include proinsulin, which is cleaved to generate insulin and C-peptide, and
Clinical relevance arises when processing steps are defective or dysregulated, leading to imbalanced hormone levels or