Abstract
Non-alcoholic fatty liver disease (NAFLD) is characterized by triglyceride (TG) accumulation in hepatocytes. Very low density lipoprotein (VLDL) is a major secretory product of the liver that transports endogenously synthesized TG. Disrupted VLDL secretion may contribute to the accumulation of TG in hepatocytes. ApoB100 (apolipoprotein B100) is a glycoprotein and an essential protein component of VLDL. Its glycosylation may affect VLDL assembly and secretion. However, which glycosyltransferase catalyzes apoB100 glycosylation is unknown. In this study, we cloned the GLT8D2 (glycosyltransferase 8 domain containing 2) gene from HepG2 cells and generated a series of plasmids for in vitro studies of its molecular functions. We discovered that GLT8D2 was localized in the ER, interacted with apoB100, and positively regulated the levels of apoB100 protein in HepG2 cells. Based on these results, we propose that GLT8D2 is a glycosyltransferase of apoB100 that regulates apoB100 levels in hepatocytes.
Highlights
Non-alcoholic fatty liver disease (NAFLD) has become the most common chronic liver disease in the United States and other western countries [1,2]
Double- fluorescence analysis showed that the expression of GLT8D2 in HepG2 cells overlapped with calreticulin (Figure 4), indicating that GLT8D2 protein is localized in the endoplasmic reticulum (ER) around the nucleus in HepG2 cells
Synthesized apoB100 is translocated across the rough endoplasmic reticulum membrane into the lumen, where apoB100 is in at least two pools: a heavy pool, most of which is degraded in situ, and a lighter pool, which moves from the rough endoplasmic reticulum lumen through the secretory compartments to the trans-Golgi; it is packaged with lipid and secreted as Very low density lipoprotein (VLDL) [16]
Summary
Non-alcoholic fatty liver disease (NAFLD) has become the most common chronic liver disease in the United States and other western countries [1,2]. Disrupted VLDL secretion may contribute to the accumulation of triglyceride in hepatocytes. We observed that GLT8D2 interacted with apoB100, and this interaction affected apoB100 protein expression in hepatoma cell line (HepG2 cells). These results suggested that GLT8D2 may be a glycosyltransferase of apoB100
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
