2.A.82.1.10
Sdmg1 (TMEM184a) of 425 aas and 7 or 8 TMSs in a 3 or 4 + 4 TMS arrangement. Sdmg1 is a component of secretory granules in mouse secretory exocrine tissues. It is mainly expressed in the gonads where it may have a role in mediating signaling between somatic cells and germ cells. Secretory exocrine cells in the pancreas, salivary gland, and mammary gland also have Sdmg1. Expression is up-regulated during pancreas development when regulated secretory granules start to appear, and Sdmg1 colocalizes with secretory granule markers in adult pancreatic acinar cells. It co-purifies with secretory granules during subcellular fractionation of the pancreas, but Sdmg1 and the secretory granule marker Vamp2 are localized to distinct subdomains in the secretory granule membrane. Thus, Sdmg1 is a component of regulated secretory granules in exocrine secretory cells and the developmental regulation of Sdmg1 expression is related to post-Golgi membrane trafficking (Best and Adams 2009). It is associated with germ cell sex determination and germline-soma interactions in mice (Best et al. 2008).