Title : Subcellular localization and N-glycosylation of human
ABCC6 , expressed in MDCKII cells
Abstract :
- Mutations in the gene coding for a human ABC transporter protein , ABCC6 ( MRP6 ), are responsible for the development of pseudoxanthoma elasticum
- Here, we demonstrate that human ABCC6 , when expressed by retroviral transduction in polarized mammalian (MDCKII) cells, is exclusively localized to the basolateral membrane
- The human ABCC6 in MDCKII cells was found to be glycosylated, in contrast to the underglycosylated form of the protein , as expressed in Sf9 cells
- In order to localize the major glycosylation site (s) in ABCC6 , we applied limited proteolysis on the fully glycosylated and underglycosylated forms, followed by immunodetection with region-specific antibodies for ABCC6
- Our results indicate that Asn15 , which is located in the extracellular N-terminal region of human ABCC6 , is the only N-glycosylation site in this protein
- The polarized mammalian expression system characterized here provides a useful tool for further examination of routing, glycosylation, and function of the normal and pathological variants of human ABCC6