This is the C-terminal domain of C-type lectin domain family 16, member A (CLEC16A, the Drosophila orthologue Ema and GOP-1 in C. elegans), an evolutionarily conserved endosomal membrane protein required for trafficking of fluid-phase and receptor-mediated endocytic cargos. It is required for mitophagy, autophagy and endosome maturation [1-3]. This protein has been identified as a susceptibility gene for autoimmune diseases like type 1 diabetes, multiple sclerosis and adrenal dysfunction. This domain is also present in GFS9/TT9 (TRANSPARENT TESTA 9) a protein from Arabidopsis required for vacuolar development through membrane fusion at vacuoles and for membrane trafficking machinery and accumulation of flavonoids in the seed coat [4].

1: Drosophila Golgi membrane protein Ema promotes autophagosomal growth and function. Kim S, Naylor SA, DiAntonio A; Proc Natl Acad Sci U S A. 2012;109:E1072-E1081. PMID:22493244

2: The novel endosomal membrane protein Ema interacts with the class C Vps-HOPS complex to promote endosomal maturation. Kim S, Wairkar YP, Daniels RW, DiAntonio A; J Cell Biol. 2010;188:717-734. PMID:20194640

3: The diabetes susceptibility gene Clec16a regulates mitophagy. Soleimanpour SA, Gupta A, Bakay M, Ferrari AM, Groff DN, Fadista J, Spruce LA, Kushner JA, Groop L, Seeholzer SH, Kaufman BA, Hakonarson H, Stoffers DA; Cell. 2014;157:1577-1590. PMID:24949970

4: GFS9/TT9 contributes to intracellular membrane trafficking and flavonoid accumulation in Arabidopsis thaliana. Ichino T, Fuji K, Ueda H, Takahashi H, Koumoto Y, Takagi J, Tamura K, Sasaki R, Aoki K, Shimada T, Hara-Nishimura I; Plant J. 2014;80:410-423. PMID:25116949