Related Experiment Video

Updated: Jan 21, 2026

In Vitro Polymerization of F-actin on Early Endosomes
12:15

In Vitro Polymerization of F-actin on Early Endosomes

Published on: August 28, 2017

9.6K

PTPN3 suppresses lung cancer cell invasiveness by counteracting Src-mediated DAAM1 activation and actin

Meng-Yen Li1, Wen-Hsin Peng1, Chien-Hsun Wu2

  • 1Institute of Biological Chemistry, Academia Sinica, Taipei, 115, Taiwan.

Oncogene
|August 14, 2019
PubMed

Insights

Depleting PTPN3, a protein tyrosine phosphatase, boosts lung cancer cell metastasis by enhancing actin assembly. This occurs via PTPN3 regulating DAAM1 phosphorylation, crucial for actin polymerization and cell invasion.

Area of Science:

  • Molecular Biology
  • Cell Biology
  • Cancer Research

Background:

  • Cancer cell migration is key to metastasis.
  • Protein tyrosine kinases (PTKs) and phosphatases (PTPs) regulate migration, but mechanisms are unclear.
  • PTPN3 is a FERM and PDZ domain-containing protein tyrosine phosphatase.

Purpose of the Study:

  • To elucidate the role of PTPN3 in lung cancer cell migration, invasion, and metastasis.
  • To identify PTPN3 interactors and their function in regulating the actin cytoskeleton.
  • To reveal the mechanism of PTPN3-mediated regulation of lung cancer invasiveness.

Main Methods:

  • Depletion of PTPN3 using genetic methods.
  • Identification of PTPN3 interacting proteins (Src, DAAM1).
  • Analysis of actin filament assembly, focal adhesion dynamics, and DAAM1 phosphorylation.

Main Results:

  • PTPN3 depletion enhanced lung cancer cell migration, invasion, and metastasis.
  • PTPN3 interacts with Src and DAAM1, inhibiting Src activity and DAAM1 phosphorylation at Tyr652.
  • DAAM1 tyrosine phosphorylation is essential for its homodimerization and actin polymerization; a phosphodeficient mutant suppressed invasion.

Conclusions:

  • PTPN3 regulates lung cancer cell migration and metastasis by modulating actin dynamics.
  • PTPN3 inhibits Src-mediated DAAM1 phosphorylation, which is critical for actin polymerization and cell invasiveness.
  • This study reveals a novel mechanism involving PTPN3, Src, and DAAM1 in controlling lung cancer progression.

More Related Videos

Chick Heart Invasion Assay for Testing the Invasiveness of Cancer Cells and the Activity of Potentially Anti-invasive Compounds10:16

Chick Heart Invasion Assay for Testing the Invasiveness of Cancer Cells and the Activity of Potentially Anti-invasive Compounds

Published on: June 6, 2015

9.5K
A Modified In vitro Invasion Assay to Determine the Potential Role of Hormones, Cytokines and/or Growth Factors in Mediating Cancer Cell Invasion06:36

A Modified In vitro Invasion Assay to Determine the Potential Role of Hormones, Cytokines and/or Growth Factors in Mediating Cancer Cell Invasion

Published on: April 24, 2015

11.4K

Related Concept Videos

Actin Polymerization and Cell Motility01:13

Actin Polymerization and Cell Motility

Actin is a family of globular proteins that are highly abundant in eukaryotic cells. It makes up approximately 1-5% of total cell protein concentration. Actin monomers polymerize to form a complex network of polarized filaments, the actin cytoskeleton, that plays a crucial role in many cellular processes, including cell motility, division, endocytosis, and metastasis of cancer cells.
Actin cytoskeleton dynamics can produce pushing, pulling, and resistance forces that help the cell to migrate....
6.5K
Actin Polymerization01:42

Actin Polymerization

Actin polymerization occurs through the head-to-tail association of binding sites on monomeric actin or G-actin to form filamentous or F-actin. The polymerization can be divided into three phases ̶  nucleation, elongation, and steady-state phase.
The nucleation phase involves forming a stable nucleus consisting of three actin monomers to form a new actin filament. Actin-binding proteins such as formins and Arp2/3 complex help filament growth post-nucleation. The Formins form straight...
8.4K
The Role of Actin and Myosin in Non-muscle Cells01:10

The Role of Actin and Myosin in Non-muscle Cells

Actin and myosin or actomyosin filaments also play a significant role in cells other than those involved in muscle contraction (which occurs within the sarcomere of muscle cells). The mechanism of non-muscle cell contractile bundles was first observed in Dictyostelium and Acanthamoeba. In non-muscle cells, two bundles are commonly found: stress fibers and actomyosin adherence belts. These contractile bundles are smaller and less organized than the ones found in muscle cells. They  are held...
4.7K
Actin Treadmilling01:18

Actin Treadmilling

Actin filaments undergo polymerization and depolymerization from either end. The polymerization and depolymerization rates depend on the cytosolic concentration of free G-actins. The polymerization rate is generally higher at the plus or barbed end, while the depolymerization rate is higher at the minus or pointed end. At a steady state, critical concentration describes the concentration of free G-actin monomers at which the polymerization rate at the plus end is equal to that of the...
9.6K
Lung Capacity01:47

Lung Capacity

The air in the lungs is measured in volumes and capacities. Lung volume measures reflect the amount of air taken in, released, or left over after a lung function, like a single inhalation. Lung capacity measures are sums of two or more lung volume measures.
56.1K
Introduction to Actin01:26

Introduction to Actin

Actin is a highly conserved cytoskeletal protein found abundantly in eukaryotic cells. It constitutes 10% weight of the total cellular protein in muscle cells, while in non-muscle cells, it is lower and makes up around 1–5 percent of the total cell protein. Actin found in the unicellular amoebae and complex multicellular animals is around 80% similar, demonstrating their conservation over a billion years of evolution.  Actin coding genes are conserved within species and across...
6.4K