Current Dilemma on Granin Proteins: Proteins Involved in Various Cellular Functions without Known Mechanisms

Regulated secretion empowers stimulus-controlled release of bioactive molecules in all endocrine cells. Chromogranins are known to play an important role in all the steps of the regulated secretion viz. granulogenesis, acidification and maturation of granular matrix of the secretory cells. Over-expression of the granin proteins in the non-secretory cells can induce granulogenesis. Chromogranins modulates the open probability of the IP3Rs (IP3 Receptor type 1) with several folds and hence involved in the calcium homeostasis, involved in the cargo maturation and are processed by prohormone convertase to produce multiple bioactive peptides. Thought researcher accumulated plenty of data about their functional involment in different processes but how chromogranins facilitate these functions is still a point of discussion. In this mini review we are going to discuss about the current perspective of the Chromogranins and the lack of the complete information about their mode of involment in different cellular functions.