Related Experiment Video

Updated: Jun 18, 2026

Myeloid Innate Signaling Pathway Regulation by MALT1 Paracaspase Activity
07:09

Myeloid Innate Signaling Pathway Regulation by MALT1 Paracaspase Activity

Published on: January 7, 2019

TRAF2-MLK3 interaction is essential for TNF-alpha-induced MLK3 activation

Gautam Sondarva1, Chanakya N Kundu, Suneet Mehrotra

  • 1Department of Pharmacology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL 60153, USA.

Cell Research
|November 18, 2009
PubMed

Insights

Tumor necrosis factor-alpha (TNF-alpha) activates Mixed lineage kinase 3 (MLK3) through direct interaction with TRAF2. This TRAF2-MLK3 association is crucial for activating MLK3 and its downstream target, c-Jun N-terminal kinase (JNK).

Area of Science:

  • Cellular signaling pathways
  • Protein kinase regulation
  • Immunology and inflammation

Background:

  • Mixed lineage kinase 3 (MLK3) is a kinase activated by tumor necrosis factor-alpha (TNF-alpha), which activates c-Jun N-terminal kinase (JNK).
  • The precise mechanism of TNF-alpha-induced MLK3 activation remains unclear.
  • TNF receptor-associated factors (TRAFs) are key adapter molecules in TNF receptor signaling.

Purpose of the Study:

  • To elucidate the mechanism by which TNF-alpha activates MLK3.
  • To investigate the role of TRAFs in MLK3 activation.
  • To identify the specific TRAF protein(s) involved in MLK3 signaling.

Main Methods:

  • Co-immunoprecipitation assays to detect protein-protein interactions between MLK3 and TRAFs.
  • Analysis of MLK3 kinase activity in response to TNF-alpha stimulation with various TRAF constructs.
  • Mapping of interaction domains between MLK3 and TRAF2.
  • Western blotting to assess JNK activation.

Main Results:

  • MLK3 associates with TRAF2, TRAF5, and TRAF6, but only TRAF2 significantly enhances MLK3 kinase activity.
  • The interaction occurs between TRAF2's TRAF domain and MLK3's C-terminal region (amino acids 511-847).
  • Endogenous TRAF2 and MLK3 associate in a time-dependent manner following TNF-alpha treatment.
  • TRAF2-mediated MLK3 activation is essential for downstream JNK activation by TNF-alpha.

Conclusions:

  • Direct interaction between TRAF2 and MLK3 is essential for TNF-alpha-induced MLK3 activation.
  • TRAF2 acts as a critical mediator in the TNF-alpha signaling pathway leading to MLK3 and JNK activation.
  • This interaction provides a key mechanistic insight into inflammatory signaling.

More Related Videos

Characterization of Thymus-dependent and Thymus-independent Immunoglobulin Isotype Responses in Mice Using Enzyme-linked Immunosorbent Assay06:15

Characterization of Thymus-dependent and Thymus-independent Immunoglobulin Isotype Responses in Mice Using Enzyme-linked Immunosorbent Assay

Published on: September 7, 2018

Characterization of MLKL-mediated Plasma Membrane Rupture in Necroptosis08:55

Characterization of MLKL-mediated Plasma Membrane Rupture in Necroptosis

Published on: August 7, 2018

Related Concept Videos

TGF - β Signaling Pathway01:16

TGF - β Signaling Pathway

The TGF-β signaling pathway regulates cell growth, differentiation, adhesion, motility, and development. TGF-β ligands that induce TGF-β signaling are synthesized in their latent form. Several proteases or cell surface receptors such as integrins act upon the latent form, releasing the active ligand. There are three types of mammalian TGF-βs: (TGF-β1, TGF-β2, and TGF-β3) that bind as homodimers or heterodimers to TGF-β receptors. The TGF-β receptors are of three kinds RI, RII, and RIII. The RI...
MAPK Signaling Cascades01:07

MAPK Signaling Cascades

Mitogen-activated protein kinase, or MAPK pathway, activates three sequential kinases to regulate cellular responses such as proliferation, differentiation, survival, and apoptosis. The canonical MAPK pathway starts with a mitogen or growth factor binding to an RTK. The activated RTKs stimulate Ras, which recruits Raf or MAP3 Kinase (MAPKKK), the first kinase of the MAPK signaling cascade. Raf further phosphorylates and activates MEK or MAP2 Kinases (MAPKK), which in turn phosphorylates MAP...
NF-κB-dependent Signaling Pathway02:26

NF-κB-dependent Signaling Pathway

The transcription factor NF-κB was discovered in 1986 in the lab of Nobel laureate Professor David Baltimore, for its interaction with the immunoglobulin light chain enhancer in B-cells. After more than three decades of study, it is now evident that NF-κB regulates the expression of over 100 genes. Most of these genes play an essential role in the innate and adaptive immune responses as well as the inflammatory responses of animals.
NF-κB-dependent Signaling Mechanism
The heterodimer of NF-κB...
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...
T Cell Types and Functions01:24

T Cell Types and Functions

When T cells with CD4 markers are activated, they give rise to two types of effector cells: helper T cells and regulatory T cells. Meanwhile, T cells with CD8 markers differentiate into effector cytotoxic T cells. The differentiation of CD4 T cells into helper T cell subsets, such as Th1, Th2, and Th17 cells, is dependent on the antigen type, antigen-presenting cell, and regulatory cytokines.
Th1 cells stimulate dendritic cells to express necessary co-stimulatory molecules on their surfaces for...
T Cell Activation and Clonal Selection01:22

T Cell Activation and Clonal Selection

T cells are integral to our adaptive immune system, recognizing and effectively responding to foreign antigens. T cell activation and clonal selection are pivotal in orchestrating this immune response. This article elucidates these mechanisms, detailing the roles of cluster of differentiation (CD) markers, major histocompatibility complex (MHC) molecules, costimulatory signals, and the process of clonal selection.
Naive T cells that have not yet encountered an antigen express two primary CD...