Related Experiment Video
Updated: Jul 2, 2026

Evaluation of Substrate Ubiquitylation by E3 Ubiquitin-ligase in Mammalian Cell Lysates
Published on: May 10, 2022
Lipidation of Atg8: how is substrate specificity determined without a canonical E3 enzyme?
Hitoshi Nakatogawa1, Kyoko Oh-oka, Yoshinori Ohsumi
1Department of Cell Biology, National Institute for Basic Biology, Okazaki, Japan.
Abstract:
Atg8 and its mammalian homolog LC3, ubiquitin-like proteins (Ubls) required for autophagosome formation, are remarkably unique in that their conjugation target is the lipid phosphatidylethanolamine (PE). Although PE was identified as the sole lipid conjugated with Atg8/LC3 in vivo, phosphatidylserine (PS) can be also a good substrate for its conjugation reaction in vitro. This posed a simple, intriguing question: What confers substrate specificity to lipidation of Atg8/LC3 in vivo? Our recent in vitro studies propose that intracellular milieus such as cytosolic pH and acidic phospholipids in membranes significantly contribute to selective production of the Atg8-PE conjugate.
Related Concept Videos
Regulated Protein Degradation
Protein degradation plays two important roles in the cells. It helps to protect cells from misfolded or damaged proteins before they lead to a...
Tail-anchoring of Proteins in the ER Membrane
Allosteric Proteins-ATCase
Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis pathway,...
Lipids as Anchors
The carboxy-terminal of most of the prenylated proteins, such as Ras proteins, contains the...
Directing Proteins to the Rough Endoplasmic Reticulum
Protein Transport to the Thylakoids

