Related Experiment Video

Updated: Jan 25, 2026

Clinical Application of 24 G Cannula Needle and 3-0 Polypropylene Suture in Vas Deferens Exploration
07:21

Clinical Application of 24 G Cannula Needle and 3-0 Polypropylene Suture in Vas Deferens Exploration

Published on: February 10, 2023

3.1K

TORC1 specifically inhibits microautophagy through ESCRT-0

Riko Hatakeyama1, Claudio De Virgilio2

  • 1Department of Biology, University of Fribourg, 1700, Fribourg, Switzerland.

Current Genetics
|May 2, 2019
PubMed

Insights

Nutrient starvation triggers protein degradation via multivesicular body (MVB) and microautophagy pathways, both needing Vps27. Target of rapamycin complex 1 (TORC1) specifically inhibits microautophagy by phosphorylating Vps27.

Area of Science:

  • Cellular Biology
  • Molecular Biology
  • Biochemistry

Background:

  • Nutrient starvation induces protein degradation via the multivesicular body (MVB) pathway and microautophagy.
  • Both pathways depend on the Vps27 protein, a component of the endosomal sorting complex required for transport (ESCRT-0).
  • The target of rapamycin complex 1 (TORC1) regulates cell growth and antagonizes Vps27 function in microautophagy via phosphorylation.

Purpose of the Study:

  • To investigate whether TORC1-mediated phosphorylation of Vps27 also restrains MVB sorting at endosomes.
  • To elucidate the specific mechanisms by which TORC1 controls protein degradation pathways.

Main Methods:

  • Utilized a Vps277D variant mimicking TORC1-phosphorylated Vps27.
  • Assessed the degradation of plasma membrane proteins (Mup1, Itr1) via MVB and vacuolar membrane proteins (Vph1) via microautophagy.
  • Compared the sensitivity of cargo sorting to TORC1-modified Vps27 in different pathways.

Main Results:

  • TORC1 inhibits both MVB-driven turnover of Mup1 and Itr1, and microautophagy-dependent degradation of Vph1.
  • Cargo sorting of Vph1 at the vacuolar membrane is sensitive to TORC1-controlled Vps27 modifications.
  • Cargo sorting of Mup1 and Itr1 at endosomes is not sensitive to these modifications, indicating alternative control mechanisms.

Conclusions:

  • TORC1 specifically modulates microautophagy through Vps27 phosphorylation.
  • TORC1 controls MVB sorting through mechanisms independent of Vps27 phosphorylation.
  • This study reveals pathway-specific regulation of protein degradation by TORC1.
Keywords:
Endosomal sorting complex required for transport (ESCRT)MicroautophagyMultivesicular bodyTarget of rapamycin complex 1 (TORC1)Vps27

More Related Videos

Quantification of Violacein in Chromobacterium violaceum and Its Inhibition by Bioactive Compounds07:13

Quantification of Violacein in Chromobacterium violaceum and Its Inhibition by Bioactive Compounds

Published on: August 8, 2025

1.6K
Herbal Munziq Ameliorates Myocardial Ischemia-Reperfusion Injury by Inhibiting Inflammation09:53

Herbal Munziq Ameliorates Myocardial Ischemia-Reperfusion Injury by Inhibiting Inflammation

Published on: January 10, 2025

824

Related Concept Videos

Feedback Inhibition00:46

Feedback Inhibition

Biochemical reactions are occurring constantly in cells, converting starting substances to different products, usually with the help of enzymes that speed the reactions. Without enzymes, it would take far too long for most reactions to occur to be useful to the cell!
57.0K
Enzyme Inhibition01:30

Enzyme Inhibition

Inhibitors are molecules that reduce enzyme activity by binding to the enzyme. In a normally functioning cell, enzymes are regulated by a variety of inhibitors. Drugs and other toxins can also inhibit enzymes. Some inhibitors bind to the enzyme’s active site, while others inhibit enzymatic activity by binding to other sites on the protein structure.
91.8K
Inhibition of Cdk Activity02:34

Inhibition of Cdk Activity

The orderly progression of the cell cycle depends on the activation of Cdk protein by binding to its cyclin partner. However, the cell cycle must be restricted when undergoing abnormal changes. Most cancers correlate to the deregulated cell cycle, and since Cdks are a central component of the cell cycle, Cdk inhibitors are extensively studied to develop anticancer agents. For instance, cyclin D associates with several Cdks, such as Cdk 4/6, to form an active complex. The cyclin D-Cdk4/6 complex...
5.8K
Eukaryotic Transcription Inhibitors01:52

Eukaryotic Transcription Inhibitors

Certain biochemical processes, such as embryonic development and cell growth regulation, depend on the repression of specific genes. DNA binding proteins known as eukaryotic transcription inhibitors regulate the repression of gene expression in eukaryotes. The presence of these inhibitors at the required location and time in the cell is triggered by the presence of hormones and additional signals from other cells.
Eukaryotic transcription inhibitors usually contain two distinct domains, a...
10.9K
MicroRNAs01:22

MicroRNAs

MicroRNA (miRNA) are short, regulatory RNA transcribed from introns—non-coding regions of a gene—or intergenic regions—stretches of DNA present between genes. Several processing steps are required to form biologically active, mature miRNA. The initial transcript, called primary miRNA (pri-mRNA), base-pairs with itself forming a stem-loop structure. Within the nucleus, an endonuclease enzyme, called Drosha, shortens the stem-loop structure into hairpin-shaped pre-miRNA. After...
24.1K
What is Gene Expression?01:42

What is Gene Expression?

Overview
Gene expression is the process in which DNA directs the synthesis of functional products, that is, proteins. Cells can regulate gene expression at various stages. It allows organisms to generate different cell types and enables cells to adapt to internal and external factors.
Genetic Information Flows from DNA to RNA to Protein
A gene is a stretch of DNA that serves as the blueprint for functional RNAs and proteins. Since DNA is made up of nucleotides and proteins consist of amino...
195.2K