An Activin/Furin Regulatory Loop Modulates the Processing and Secretion of Inhibin α- and βB-Subunit Dimers in Pituitary Gonadotrope Cells

摘要: Of all ligands of the transforming growth factor β superfamily, inhibins and activins are a physiologically relevant pair that functional antagonists each other. Activin stimulates whereas inhibin blocks follicle-stimulating hormone biosynthesis secretion from pituitary gonadotrope cells, together, activin control gonadal axis essential for normal reproductive function. Sharing similar β-subunit, heterodimers (α/β) or homodimers (β/β) as mature bioactive depends, in part, on proteolytic processing precursor proteins. A short loop regulatory pathway controlling dimer was discovered. endogenous α- βB-subunit mRNA, protein, processing. Simultaneously, stimulated proconvertase furin through Smad2/3-dependent process. The data provide mechanism where regulation subunits cooperates an important positive feedback loop. This augments B, well B dimers, necessary local regulation.