Related Experiment Video

Updated: May 7, 2026

The Lactate Dehydrogenase Sequestration Assay — A Simple and Reliable Method to Determine Bulk Autophagic Sequestration Activity in Mammalian Cells
09:34

The Lactate Dehydrogenase Sequestration Assay — A Simple and Reliable Method to Determine Bulk Autophagic Sequestration Activity in Mammalian Cells

Published on: July 27, 2018

STAT3 as a new autophagy regulator

Barbara Jonchère1, Audrey Bélanger, Catherine Guette

  • 1Paul Papin ICO Cancer Center; Inserm U892; CNRS 6299 and Angers University; Angers, France.

JAK-STAT
|September 27, 2013
PubMed

Insights

Signal transducers and activators of transcription 3 (STAT3) proteins regulate autophagy. Unphosphorylated STAT3 inhibits autophagy by interacting with PKR kinase, impacting normal and cancer cells.

Area of Science:

  • Molecular Biology
  • Cell Biology
  • Cancer Research

Background:

  • Signal transducers and activators of transcription 3 (STAT3) are transcription factors involved in cell signaling.
  • Aberrant STAT3 activation is implicated in cancer progression, affecting cell cycle and survival pathways.

Purpose of the Study:

  • To identify novel regulators of autophagy.
  • To investigate the role of STAT3 in autophagy.
  • To explore the noncanonical functions of STAT3 in cellular processes.

Main Methods:

  • Investigated STAT3 protein interactions in the cytoplasm.
  • Assessed the impact of STAT3 on eIF2A phosphorylation.
  • Studied the effects on autophagic pathways in normal and cancer cells.

Main Results:

  • Identified STAT3 as a novel regulator of autophagy.
  • Demonstrated that unphosphorylated STAT3 interacts with PKR kinase.
  • Showed this interaction inhibits eIF2A phosphorylation, leading to reduced autophagy.

Conclusions:

  • STAT3 possesses a nonconventional cytoplasmic function in regulating autophagy.
  • This STAT3-mediated autophagy regulation is relevant in normal cells.
  • The findings suggest a potential role in cancer cells and chemotherapy response.
Keywords:
STAT3autophagycell deathoncogenesenescence

More Related Videos

In Situ Immunofluorescent Staining of Autophagy in Muscle Stem Cells08:35

In Situ Immunofluorescent Staining of Autophagy in Muscle Stem Cells

Published on: June 12, 2017

Cell-Based Drug Screening for Inhibitors of Autophagy Related 4B Cysteine Peptidase09:51

Cell-Based Drug Screening for Inhibitors of Autophagy Related 4B Cysteine Peptidase

Published on: June 30, 2023

Related Concept Videos

Autophagy01:27

Autophagy

Autophagy is a self-digesting process by which a cell protects itself from threats both within and outside the cell, ranging from abnormal proteins to invading bacteria. In this process, obsolete components of the cell and invading microbes are degraded by hydrolytic enzymes active in an acidic environment of the lysosomal lumen.
An autophagic pathway consists of a series of signaling events activated in response to diverse stress and physiological conditions such as food deprivation,...
PI3K/mTOR/AKT Signaling Pathway01:22

PI3K/mTOR/AKT Signaling Pathway

The mammalian target of rapamycin  (mTOR) is a serine/threonine kinase that regulates growth, proliferation, and cell survival in response to hormones, growth factors, or nutrient availability. This kinase exists in two structurally and functionally distinct forms: mTOR complex 1  (mTORC1) and mTOR complex 2  (mTORC2). The first form (mTORC1) is composed of a rapamycin-sensitive Raptor and proline-rich Akt substrate, PRAS40. In contrast,  mTORC2 consists of a rapamycin-insensitive companion...
Autophagic Cell Death01:18

Autophagic Cell Death

Christian de Duve discovered “autophagy,” a process in which cellular components are engulfed by membrane-bound organelles called autophagosomes. The autophagosomes then fuse with lysosomes to digest the enclosed contents. Autophagy is generally activated in cells to prevent cell death. However, cell death is triggered when the damage is beyond repair.
Autophagy and Apoptosis
Autophagy can activate apoptosis. In normal conditions, the autophagy activating protein Beclin-1 and pro-apoptotic...
Delivery Pathways to the Lysosome01:36

Delivery Pathways to the Lysosome

Eukaryotic cells use different mechanisms to eliminate toxic waste obsolete and worn-out substances. Lysosomes play a pivotal role in this, and hence, these substances are carried to the lysosome from other parts of the cell and extracellular space through different pathways. The most elaborately studied pathways to the lysosome are the endocytic pathways.
Endocytosis
In endocytosis, the cell membrane takes up macromolecules and particles from the surrounding medium. Clathrin-mediated...
mTOR Signaling and Cancer Progression03:03

mTOR Signaling and Cancer Progression

The mammalian target of rapamycin or mTOR protein was discovered in 1994 due to its direct interaction with rapamycin. The protein gets its name from a yeast homolog called TOR. The mTOR protein complex in mammalian cells plays a major role in balancing anabolic processes such as the synthesis of proteins, lipids, and nucleotides and catabolic processes, such as autophagy in response to environmental cues, such as availability of nutrients and growth factors.
The mTOR pathway or the...
The JAK-STAT Signaling Pathway01:20

The JAK-STAT Signaling Pathway

Several cytokine receptors have tightly bound Janus kinase or JAK proteins attached at their cytosolic tail. Small signaling molecules such as cytokines, growth hormones, or prolactins bind to the cytokine receptors and initiate their dimerization. The dimerization brings the cytosolic JAKs together that trans-phosphorylate and activates each other. The activated JAKs now phosphorylate cytosolic tails of the cytokine receptors, which serve as binding sites for adaptor proteins such as  SH2...