GOLPH3 and GOLPH3L
have an N-terminal acidic region but that only GOLPH3 has a C-terminal leucine zipper motif. Northern blot analysis detected a 2.5-kb GOLPH3L transcript in HeLa cells. Expression of GOLPH3L was higher in HeLa cells that lacked mitochondrial DNA.
Tu et al. (2008) found that yeast Vps74, a homolog of human GOLPH3 and GOLPH3-like, binds to a pentameric motif present in the cytoplasmic tails of the majority of yeast Golgi-localized glycosyltransferases, as well as to coat protein complex I (COPI). Tu et al. (2008) proposed that Vps74p maintains a steady-state localization of Golgi glycosyltransferases dynamically, by promoting their incorporation into COPI-coated vesicles.