Protein discharge from immature secretory granules displays both regulated and constitutive characteristics.

摘要: At physiological glucose concentrations, isolated pancreatic islets release a minor portion of their newly synthesized insulin and precursors in phase secretion which is largely complete by 4 h chase. Discharge during this period can be amplified secretagogues, yet not abolished conditions fully suppress regulated from dense core secretory granules. The ability to stimulate the biochemical profile released proinsulin-related peptides indicate that originates immature stoichiometry labeled C-peptide:insulin 1:1 at high concentrations. However, physiologic or low C-peptide molar excess as if exocytotic vesicles carrying were budding post-Golgi compartment lumen was composed condensing soluble C-peptide. These findings explained model for protein traffic direct exocytosis young granules stimulated higher concentrations vesicle occurs lower Thus, targeting exhibits both constitutive-like characteristics.