Related Experiment Video

Updated: Aug 16, 2026

Conjugative Mating Assays for Sequence-specific Analysis of Transfer Proteins Involved in Bacterial Conjugation
10:41

Conjugative Mating Assays for Sequence-specific Analysis of Transfer Proteins Involved in Bacterial Conjugation

Published on: January 4, 2017

TRAF2: a double-edged sword?

Zong-Ping Xia1, Zhijian J Chen

  • 1Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9148, USA.

Science'S STKE : Signal Transduction Knowledge Environment
|February 25, 2005
PubMed

Insights

Ubiquitin chains act as dynamic switches in cell signaling. Different ubiquitin chain types, like K63 and K48, control protein fate, mediating either signaling pathway activation or proteasomal degradation.

Area of Science:

  • Cellular Biology
  • Molecular Biology
  • Biochemistry

Background:

  • Ubiquitination traditionally targets proteins for proteasomal degradation.
  • Emerging evidence highlights non-proteolytic roles of ubiquitin in cellular regulation.
  • Tumor necrosis factor (TNF) receptor-associated factor (TRAF) proteins are key ubiquitin ligases.

Purpose of the Study:

  • To investigate the non-proteolytic functions of ubiquitin.
  • To elucidate the distinct roles of TRAF proteins in nuclear factor kappaB (NF-kappaB) signaling pathways.
  • To understand how different polyubiquitin chain linkages regulate protein fate and signaling outcomes.

Main Methods:

  • Studying TRAF proteins as ubiquitin ligases.
  • Analyzing the synthesis of lysine 63 (K63)-linked polyubiquitin chains.
  • Investigating the noncanonical and canonical NF-kappaB pathways involving IKKalpha and IKKbeta.
  • Examining the ubiquitination of RIP protein by K63 and K48 chains.

Main Results:

  • TRAF proteins synthesize K63-linked polyubiquitin chains, mediating proteasome-independent protein kinase activation.
  • TRAF2 and TRAF3 positively regulate the canonical NF-kappaB pathway (via IKKbeta) but negatively regulate the noncanonical pathway (via IKKalpha).
  • RIP protein is activated by K63 ubiquitination but degraded by K48 ubiquitination mediated by A20.

Conclusions:

  • Polyubiquitin chain types act as critical switches in cellular signaling.
  • K63-linked chains promote signaling pathway activation, while K48-linked chains target proteins for degradation.
  • TRAF proteins' opposing roles in NF-kappaB pathways are linked to their ability to generate distinct ubiquitin chain types.

More Related Videos

Dynamic Imaging of Chimeric Antigen Receptor T Cells with [18F]Tetrafluoroborate Positron Emission Tomography/Computed Tomography09:34

Dynamic Imaging of Chimeric Antigen Receptor T Cells with [18F]Tetrafluoroborate Positron Emission Tomography/Computed Tomography

Published on: February 17, 2022

Probing Structural and Dynamic Properties of Trafficking Subcellular Nanostructures by Spatiotemporal Fluctuation Spectroscopy08:17

Probing Structural and Dynamic Properties of Trafficking Subcellular Nanostructures by Spatiotemporal Fluctuation Spectroscopy

Published on: August 16, 2021

Related Concept Videos

Directionality of Nuclear Transport01:42

Directionality of Nuclear Transport

Ras-related nuclear protein or Ran is a small G protein that cycles between its GTP and GDP bound states. Ran specific regulators, a Ran GTPase Activating Protein or RanGAP present in the cytosol and a Ran guanine nucleotide exchange factor or RanGEF present inside the nucleus regulate GTP/GDP exchange. A high concentration of GTP inside the cells, in addition to this asymmetric distribution of  Ran-specific regulators, leads to a higher RanGTP concentration inside the nucleus. This...
Membrane Asymmetry Regulating Transporters01:19

Membrane Asymmetry Regulating Transporters

Enzymes like flippase, floppase, and scramblase transfer phospholipids from one layer to another in the membrane, thereby affecting membrane asymmetry.
Flippase
Eukaryotic flippases are type-IV P-type ATPases or P4-ATPases belonging to P-type ATPase family proteins that are membrane-bound pumps involved in the ATP-mediated transport of ions and molecules across the membrane. Flippases flip specific phospholipids from the outer to the inner leaflet of a membrane. All P4-ATPases have one...
Torts II01:13

Torts II

Intentional torts in healthcare refer to deliberate actions that cause harm or infringe on the rights of others. Understanding these torts is crucial for healthcare professionals to avoid legal liabilities and maintain ethical standards in patient care.
Tandem Mass Spectrometry01:21

Tandem Mass Spectrometry

Tandem mass spectrometry is a technique that uses multiple mass analyzers in series to obtain a higher selectivity and reduce chemical noise during analyte detection. Instruments with multiple analyzers separated by an interaction cell enable secondary fragmentation and selected study of the fragment ions.Secondary fragmentations occur in the interaction cell and can be induced by various factors. Fragmentation induced by collision with inert gases, such as N2, Ar, He, etc., is called...
Carrier Transport01:21

Carrier Transport

The generation of electrical current in semiconductors is fundamentally driven by two mechanisms: drift and diffusion. These processes are essential for the functionality and performance of semiconductor-based devices.
Drift Current:
The drift of charge carriers is started by an external electric field (E). Charged particles, such as electrons and holes, experience an acceleration between collisions with lattice atoms. For electrons, this results in a drift velocity (vd) given by:
Transport Number01:31

Transport Number

The transport number is the fraction of the total current carried by an ion in an electrolyte solution. It is defined as the ratio of the current carried by a specific ion to the total current flowing through the solution. The transport number, t, is central to understanding ionic mobility, which describes how fast an ion moves under the influence of an electric field. This link connects the physical behavior of ions in solution to the chemical processes that occur during electrochemical...