Related Experiment Video

Updated: Jun 16, 2026

A Photodynamic Approach to Study Function of Intracellular Vesicle Rupture
05:16

A Photodynamic Approach to Study Function of Intracellular Vesicle Rupture

Published on: March 17, 2023

c-Abl and Arg tyrosine kinases regulate lysosomal degradation of the oncoprotein Galectin-3

X Li1, Q Ma, J Wang

  • 1Beijing Institute of Biotechnology, Beijing, China.

Cell Death and Differentiation
|February 13, 2010
PubMed

Insights

The Abl kinase and Galectin-3 (Gal3) interaction impairs Gal3 autophagy, increasing apoptosis sensitivity and reducing tumor growth. Inhibiting Abl kinase may offer a novel cancer therapy strategy.

Area of Science:

  • Oncology
  • Molecular Biology
  • Cell Biology

Background:

  • Galectin-3 (Gal3) plays a significant role in cancer progression, including tumor transformation and metastasis.
  • The Abl and Abl-related gene (Arg) kinases are implicated in various cellular processes, including cancer development.

Purpose of the Study:

  • To investigate the interaction between c-Abl/Arg kinases and Galectin-3.
  • To determine the functional consequences of Gal3 phosphorylation by c-Abl/Arg on autophagy, apoptosis, and tumorigenicity.

Main Methods:

  • Co-immunoprecipitation to study protein interactions.
  • Site-directed mutagenesis to identify phosphorylation sites.
  • Cellular assays to assess autophagy, apoptosis, and tumorigenicity.
  • Treatment with c-Abl/Arg inhibitor STI571.

Main Results:

  • c-Abl and Arg directly bind to and phosphorylate Galectin-3 at Tyr79 and Tyr118.
  • This phosphorylation significantly impairs chaperone-mediated autophagy of Gal3.
  • Cells with altered Gal3 phosphorylation or treated with c-Abl/Arg inhibitors show increased sensitivity to apoptosis and reduced tumorigenicity.

Conclusions:

  • The c-Abl/Arg-mediated phosphorylation of Gal3 disrupts its autophagy, contributing to anti-apoptotic effects and promoting tumor growth.
  • Targeting the lysosomal degradation of Gal3 via c-Abl/Arg inhibition presents a potential therapeutic strategy for cancer treatment, especially in tumors overexpressing Gal3.

More Related Videos

Site-Specific Lysine Lactylation via Genetic Code Expansion in E. coli and Mammalian Cells05:58

Site-Specific Lysine Lactylation via Genetic Code Expansion in E. coli and Mammalian Cells

Published on: February 24, 2026

Related Concept Videos

Amplifying Signals via Enzymatic Cascade01:22

Amplifying Signals via Enzymatic Cascade

When a ligand binds to a cell-surface receptor, the receptor's intracellular domain changes shape, which may either activate its enzyme function or allow its binding to other molecules. The initial signal is amplified by most signal transduction pathways. This means that a single ligand molecule can activate multiple molecules of a downstream target. Proteins that relay a signal are most commonly phosphorylated at one or more sites, activating or inactivating the protein. Kinases catalyze the...
Regulated Protein Degradation02:58

Regulated Protein Degradation

It is vital to regulate the activity of enzymatic as well as non-enzymatic proteins inside the cell. This can be achieved either through creating a balance between their rate of synthesis and degradation or regulating the intrinsic activity of the protein. Both these regulation mechanisms play an essential role in the normal functioning of cells.
Protein degradation plays two important roles in the cells. It helps to protect cells from misfolded or damaged proteins before they lead to a...
Receptor Downregulation in MVBs01:15

Receptor Downregulation in MVBs

Multivesicular bodies (MVBs) are mature endosomes that sort ubiquitinated proteins and then fuse with lysosomes to degrade the sorted proteins. Epidermal growth factor (EGF) and its receptor (EGFR) form a complex that can be internalized through endocytosis, sorted into an MVB, and later degraded.
The EGFR can initiate signaling pathways that  lead to cell proliferation, migration, and differentiation. Overexpression of EGFR  stimulates cells to proliferate. Excessive  EGFR activation may...
Transducer Mechanism: Enzyme-Linked Receptors01:27

Transducer Mechanism: Enzyme-Linked Receptors

Enzyme-linked receptors are cell-surface receptors acting as an enzyme or associating with an enzyme intracellularly. They make excellent drug targets. Drugs can bind to the extracellular ligand-binding domain or directly affect their enzymatic domain and alter their activity.
Major types that are helpful drug targets include:
Enzyme-linked Receptors01:00

Enzyme-linked Receptors

Enzyme-linked receptors are proteins that act as both receptor and enzyme, activating multiple intracellular signals. This is a large group of receptors that include the receptor tyrosine kinase (RTK) family. Many growth factors and hormones bind to and activate the RTKs.
Neurotrophin (NT) receptors are a family of RTKs, including trkA, trkB, and trkC (tropomyosin-related kinase) receptors. TrkA is specific for nerve growth factor (NGF), neurotrophin-6, and neurotrophin-7. TrkB binds...
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...