Related Experiment Video

Updated: Aug 11, 2026

Detection of Neu1 Sialidase Activity in Regulating TOLL-like Receptor Activation
09:04

Detection of Neu1 Sialidase Activity in Regulating TOLL-like Receptor Activation

Published on: September 8, 2010

Biochemical analysis of the ligand for the neu oncogenic receptor

Y Yarden1, E Peles

  • 1Department of Chemical Immunology, Weizmann Institute of Science, Rehovot, Israel.

Biochemistry
|April 9, 1991
PubMed

Insights

Researchers identified a 35-kDa glycoprotein ligand that stimulates the neu receptor (HER2). This factor also activates the epidermal growth factor (EGF) receptor, suggesting functional coupling between these key signaling molecules.

Area of Science:

  • Molecular Biology
  • Cell Signaling
  • Oncology

Background:

  • The neu protooncogene (HER2/c-erbB2) encodes a cell-surface tyrosine kinase.
  • It is structurally related to the epidermal growth factor (EGF) receptor.
  • A candidate ligand for the neu receptor is secreted by ras-transformed fibroblasts.

Purpose of the Study:

  • To biochemically characterize the neu receptor stimulatory factor.
  • To investigate the functional relationship between the neu and EGF receptors.

Main Methods:

  • Partial purification using selective precipitation, heparin-agarose chromatography, and gel filtration.
  • Biochemical analyses of the ligand's properties (heat stability, sensitivity to reduction, precipitation).
  • Assays to test the ligand's activity on protooncogenic neu and EGF receptors.

Main Results:

  • The neu stimulatory factor is a 35-kDa glycoprotein, heat-stable but reduction-sensitive.
  • The partially purified ligand stimulated the protooncogenic neu receptor but not the constitutively active oncogenic neu protein.
  • The purified fraction also stimulated the EGF receptor, indicating potential functional coupling.

Conclusions:

  • The identified glycoprotein ligand plays a role in neu receptor activation.
  • Functional coupling or simultaneous interaction between neu and EGF receptors is suggested.
  • Further purification is needed to fully elucidate the ligand's mechanism of action.

More Related Videos

Measuring Transcellular Interactions through Protein Aggregation in a Heterologous Cell System04:47

Measuring Transcellular Interactions through Protein Aggregation in a Heterologous Cell System

Published on: May 22, 2020

Oncogene Expression Analysis with Alterations in pH in a Pancreatic Ductal Cell Line06:24

Oncogene Expression Analysis with Alterations in pH in a Pancreatic Ductal Cell Line

Published on: April 11, 2025

Related Concept Videos

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...
Ligand Binding Sites02:40

Ligand Binding Sites

Proteins are dynamic macromolecules that carry out a wide variety of essential processes; however, the activities of most proteins depend on their interactions with other molecules or ions, known as ligands.
Protein-ligand interactions are quite specific; even though numerous potential ligands surround a cellular protein at any given time, only a particular ligand can bind to that protein. Moreover, a ligand binds only to a dedicated area on the surface of the protein, known as the...
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...
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: