FIGURE 4:

TMEM-COG4 and TMEM-COG7 support Golgi glycosylation and stability of COG-sensitive proteins. HEK293T cells stably expressing TMEM-COG4 in COG4 KO cells, TMEM-COG7 in COG7 KO cells, and TMEM-COG8 in COG8 KO cells. COG4-GFP and COG7-GFP stable expression in COG4 KO cells and COG7 KO cells, respectively. (A) TMEM-COG4 and TMEM-COG7, but not TMEM-COG8, rescue abundance of COG-sensitive proteins: GPP130, LAMP2, and B4GalT1. (B) TMEM-COG mostly restores Lamp2 glycosylation. Western blot and quantification of LAMP2 fully glycosylated species. Dotted line is an arbitrary separation of fully glycosylated and underglycosylated LAMP2. Quantification of three replicates. *p < 0.05 in a Student’s t test compared with 293T. Error bars represent SD.