Chromogranins A, B, and C: Widespread Constituents of Secretory Vesiclesa

Chromogranin A: current status as a precursor for bioactive peptides and a granulogenic/sorting factor in the regulated secretory pathway

“…This critical concentration would depend in turn on the critical calcium concentration required for aggregation for each granin protein. Differences in critical concentration for self-aggregation, and calcium binding affinity may dictate the differential distribution and potential functions of CGA and CGB, as well as other granins, in the nervous system [92][93][94] and endocrine cells [20].…”

“…Exonic organization of the CGA genes of human, cow and mouse. Schematic representation of bovine [25], human [26], and mouse [24] The granins are found, along with various peptides derived from them by proteolytic processing, in secretory granules throughout the diffuse neuroendocrine system [2,[8][9][10][11][12][13][14][15][16][17][18][19][20][21]. The granin proteins have been variously considered for a number of intracellular and extracellular roles in neuroendocrine function because of their ubiquity and abundance.…”

Divergent changes of chromogranin A/secretogranin II levels in differentiating human neuroblastoma cells

“…Chromogranin A and secretogranin II are constituents of chromaffin granules [2] and of large dense core vesicles in nerve [23]. SV2 and synaptin/synaptophysin are also present in these organelles [24-261 but are also found in translucent synaptic vesicles in apparently higher concentration [27].…”

“…Apart from the hormones these vesicles comprise neuropeptides and the so-called chromogranins [2,3]. Previous studies have already established that the biosynthesis of these components is not regulated en bloc allowing a significant blending of the secretory cocktail (adrenal medulla [4,5]; PClZcells [6]; see also [7]).…”

Chromogranin A processing in sympathetic neurons and release of chromogranin A fragments from sheep spleen

“…Yet, although it is clear that different CGA storage granules may exhibit different cleavage patterns [4,5], very few data are available on CGA breakdown in sympathetic nerve axons [2,14] and almost none in nerve terminals, presumably because of difficulties in obtaining the appropriate vesicle preparations [16]. Moreover, while the release of CGA from sympathetic neurons has already been demonstrated [17,19], no evidence has yet been provided for the release of CGA 9roducts from adrenergic nerve terminals.…”