Hormone Storage Vesicle Proteins

Abstract

Chromogranin A (CgA) is an acidic soluble protein found in the core of secretory vesicles throughout the neuroendocrine system, from which it is coreleased by exocytosis with a variety of amine and peptide hormones and neurotransmitters. Much has now been learned about the structure of CgA, and there is emerging evidence that it plays several biological roles, both within secretory granules and after release from neuroendocrine cells. Factors governing its gene's widespread yet restricted (neuroendocrine) pattern of expression are only now being explored. In an attempt to understand how cells throughout the neuroendocrine system (but not exocrine or other nonendocrine cells) turn on and control the expression of CgA, we have isolated and begun to characterize functional 5' promoter elements from the rodent CgA genes. Within the sympathoadrenal system, interest focuses on a recently proposed (though as yet incompletely investigated) function of CgA: its ability to suppress catecholamine release from adrenal chromaffin cells when such cells are stimulated by their usual physiologic secretagogue. We anticipate that such studies will contribute to an understanding of this abundant, yet previously mysterious protein's role in neuroendocrine function.

Tissue Plasminogen Activator (t-PA) Is Targeted to the Regulated Secretory Pathway

“…In addition, the widespread distribution of t-PA in neuroendocrine tissue has suggested that t-PA may contribute to prohormone processing (20). Recently, we have obtained evidence that chromaffin cell t-PA can participate in plasmin-dependent processing of chromogranin A (69), the major soluble protein present in chromaffin granules as well as in regulated secretory granules throughout the neuroendocrine system (70), and a prohormone precursor of pancreastatin (71)(72)(73) and other bioactive peptides (74), including peptides which modulate catecholamine release (75). The present study, therefore, supports a link between the neuroendocrine and fibrinolytic systems, a link with multiple functional consequences.…”

Neuroendocrine profiling in inherited stress-induced arterial hypertension rat strain with stress-sensitive arterial hypertension

“…In both strains, a considerable increase in the sympathetic adrenal medullary activity was observed (for the SHRs, see Judy et al 1976, Korner et al 1993, O'Connor et al 1999, Cabassi et al 2002, Reja et al 2002, Kuo et al 2004. Emotional stress caused by air jet induced a significantly threefold greater tachycardia and a tenfold greater activation of the sympathetic adrenal system in the SHR than in the Wistar Kyoto (WKY) rats (Zhang & Thoren 1998).…”

Sp1 and CREB Mediate Gastrin-dependent Regulation of Chromogranin A Promoter Activity in Gastric Carcinoma Cells

“…1 is a 48-kDa acidic protein which was initially identified as the major soluble protein co-stored and released with neurotransmitters and secretory peptides in the neuroendocrine system (1)(2)(3). In neuroendocrine cells, CgA stabilizes secretory granules, influences pro-hormone processing, and regulates peptide sorting into the regulated secretory pathway (1)(2)(3).…”

“…In neuroendocrine cells, CgA stabilizes secretory granules, influences pro-hormone processing, and regulates peptide sorting into the regulated secretory pathway (1)(2)(3). Cleavage products of CgA are able to regulate endocrine and exocrine secretory functions after release into the bloodstream (1)(2)(3).…”

“…In neuroendocrine cells, CgA stabilizes secretory granules, influences pro-hormone processing, and regulates peptide sorting into the regulated secretory pathway (1)(2)(3). Cleavage products of CgA are able to regulate endocrine and exocrine secretory functions after release into the bloodstream (1)(2)(3). In the stomach, enterochromaffin-like cells (ECL cells) of the corpus mucosa, which are responsible for synthesis, storage, and release of histamine controlling gastric acid secretion, have been identified as the main source for CgA expression (4,5).…”