PEPTIDES OF INSULIN AND GLUCAGON SUPERFAMILIES IN FISH

Clusters of structurally related biologically active peptides have bee n appropriately dubbed 'families' or 'superfamilies'. However, structu ral resemblance does nor necessary predict similar function. This shor t overview deals with two couples of peptides: insulin and insulin-lik e growth factor-I(IGF-I) belonging to the insulin superfamily, and glu cagon and glucagon-like peptide I (GLP-I) belonging to the glucagon su perfamily. An attempt is made to compare structure, expression and fun ctions of peptides of either fish or mammalian origin. It appears that fish insulin, IGF-I and glucagon share with their mammalian counterpa rts a number of similar features and Functions while glucagon-like pep tide function is strongly different. Insulin and glucagon families of peptides have been extensively reviewed during the past two years. To avoid repetition most attention is paid to the latest findings that ha ve not been included in previous reviews.