Homologous IRCM-Serine Protease 1 from pituitary, heart atrium and ventricle: A common pro-hormone maturation enzyme?

Autor: Seidah, Nabil G., Cromlish, James A., Hamelin, Josée, Thibault, Gaétan, Chrétien, Michel
Zdroj: Bioscience Reports; September 1986, Vol. 6 Issue: 9 p835-844, 10p
Abstrakt: IRCM-Serine Protease 1 (IRCM-SP1) has recently been isolated and characterized from porcine pituitary anterior and neurointermediate lobes (Cromlishet al., 1986a,J. Biol. Chem.261:10850–10858; Cromlishet al., 1986b,J. Biol. Chem.261:10859–10870). This pituitary serine protease was shown to selectively cleave human proopiomelanocortin (POMC)-derived peptides at both pairs of basic residues and C-terminal to specific Arg residues, all known to be cleavedin vivo. Here, a similar enzyme was isolated from rat heart atria and ventricles. Rat IRCM-SP1 was shown to be highly specific for the same cleavage sites in POMC, as the porcine pituitary homologue. Furthermore, the rat and the porcine enzymes cleave rat pro-Atrial Natriuretic Factor (pro-ANF 1–126) to yield ANF 103–126, 102–126 and 99–126 in that order of preference. This suggests thatin vitro the cleavage sites preferred in pro-ANF resemble those found in brain and hypothalamus. The enzyme is nine times more abundant in atria versus ventricles/mg protein. It is concluded that IRCM-SP1, could well represent a common pro-hormone maturation enzyme for POMC and Pro-ANF and possibly many other pro-hormones.
Databáze: Supplemental Index