Secretion, exocytosis, calcium binding proteins

Figure 5 Proteomics reveals functional secretory vesicle protein systems for neuropeptide biosynthesis, storage, and secretion. Chromaffin secretory vesicles (also known as chromaffin granules) were isolated and subjected to proteomic analyses of proteins in the soluble and membrane components of the vesicles. Protein systems in secretory vesicle function consisted of those for 1) production of hormones, neurotransmitters, and neuromodulatory factors, 2) generating selected internal vesicular conditions for reducing condition, acidic pH conditions maintained by ATPases, and chaperones for protein folding, and 3) vesicular trafficking mechanisms to allow the mobilization of secretory vesicles for exocytosis, which uses proteins for nucleotide-binding, calcium regulation, and vesicle exocytosis. These protein systems are coordinated to allow the secretory vesicle to synthesize and release neuropeptides for cell-cell communication in the control of neuroendocrine functions.

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