Pro-hormone Secretogranin II Regulates Dense Core Secretory Granule Biogenesis in Catecholaminergic Cells

• DOI: 10.1074/jbc.m109.064196
• Publication Date: 2010-01-09T02:06:43Z
• Authors: Maïté Courel; Alex Soler-Jover; Juan L. Rodriguez...; Sushil K. Mahata; Salah Elias; Maïté Montero-Had...; Youssef Anouar; Richard J. Giuly; Daniel T. O'Connor; Laurent Taupenot
• Keywords: Granule (geology); Secretory protein; Secretory Vesicle

Processes underlying the formation of dense core secretory granules (DCGs) neuroendocrine cells are poorly understood. Here, we present evidence that DCG biogenesis is dependent on protein secretogranin (Sg) II, a member granin family pro-hormone cargo DCGs in cells. Depletion SgII expression PC12 leads to decrease both number and size impairs trafficking other regulated hormones. Expression fusion proteins secretory-deficient variant rescues pathway. SgII-containing vesicles share morphological physical properties with bona fide DCGs, competent for exocytosis, maintain an acidic luminal pH through V-type H(+)-translocating ATPase. The granulogenic activity requires gradient along this We conclude critical factor regulation cells, mediating functional via its pH-dependent aggregation at trans-Golgi network.