Under growth condition, the Golgi reassembly-stacking protein of 55 kDa (GRASP55)/GORASP2 serves as the "glue" to hold adjacent Golgi cisternae into stacks by forming trans-oligomers. Upon glucose starvation, GRASP55 is de-O-GlcNAcylated and functions as a membrane tether to facilitate autophagosome-lysosome fusion through the interactions with LC3-II and LAMP2.
Keywords: GRASP55; LAMP2; LC3; O-GlcNAcylation; autophagosome-lysosome fusion.