QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

First published online July 2, 2008

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Related articles in JCS Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Search for Related Content Social Bookmarking                         What's this?

A fatty route for ApoB processing

Apolipoprotein B-100 (ApoB) is the major protein component of very-low-density lipoprotein (VLDL), and its synthesis and degradation in hepatocytes is highly regulated. It is known that ApoB, which is co-translationally lipidated, undergoes ER-associated degradation (ERAD) by the proteasome when lipidation is perturbed. Mechanisms to degrade lipidated ApoB are also thought to exist, but these have been poorly understood. Toyoshi Fujimoto and colleagues (p. 2415) have previously demonstrated that ubiquitylated ApoB can accumulate in a crescent-shaped area that surrounds lipid droplets (LDs) in hepatocytes; they now show that the ApoB within the crescent is lipidated and so is likely to be processed by a mechanism other than ERAD. Using immunofluorescence microscopy, the authors show that the ApoB crescent colocalises with several ER markers; moreover, they use immunoelectron microscopy to show that the ApoB crescent is an ER subcompartment that is fused to an LD. Crescent formation is suppressed by the expression of proteins that promote LD formation and lipidated ApoB binds tightly to the LD surface, which suggests that the degradation of lipidated ApoB is linked to LD biogenesis. These results emphasise the complexity of ApoB regulation.

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?

Related articles in JCS:

Lipid droplets are arrested in the ER membrane by tight binding of lipidated apolipoprotein B-100

Yuki Ohsaki, Jinglei Cheng, Michitaka Suzuki, Akikazu Fujita, and Toyoshi Fujimoto
JCS 2008 121: 2415-2422. [Abstract] [Full Text]  

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Related articles in JCS Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Search for Related Content Social Bookmarking                         What's this?