Prevents ENO1-mediated transcriptional repression and antagonizes ENO1-mediated cell death. May play a role in vesicular transport from endoplasmic reticulum to Golgi (By similarity). Part of the multisubunit TRAPP (transport protein particle) complex. Interacts with ENO1, PITX1, SF1 and TRAPPC2L (By similarity). Interacts with TRAPPC3. Localized in perinuclear granular structures. Expressed in chondrocytes at various stages of differentiation, including proliferating, prehypertrophic and hypertrophic chondrocytes in the distal femoral joint. Belongs to the TRAPP small subunits family. Sedlin subfamily.