Related Experiment Video

Updated: Aug 15, 2026

A TIRF Microscopy Technique for Real-time, Simultaneous Imaging of the TCR and its Associated Signaling Proteins
16:10

A TIRF Microscopy Technique for Real-time, Simultaneous Imaging of the TCR and its Associated Signaling Proteins

Published on: March 22, 2012

Association of Raf with the CD3 delta and gamma chains of the T cell receptor-CD3 complex

C Loh1, C Romeo, B Seed

  • 1Division of Tumor Virology and Harvard Medical School, Boston, Massachusetts 02115.

The Journal of Biological Chemistry
|March 25, 1994
PubMed

Insights

Raf serine/threonine kinase associates with the T cell receptor-CD3 complex in T cells. This suggests Raf mediates signal transduction from CD3 gamma and delta chains, similar to ZAP-70

Area of Science:

  • Immunology
  • Cell Biology
  • Molecular Biology

Background:

  • Protein kinases and phosphatases are crucial for cellular signal transduction.
  • T cell activation involves complex phosphorylation events initiated by the T cell receptor-CD3 complex.
  • Raf serine/threonine kinase is a known signaling molecule in various receptor pathways.

Purpose of the Study:

  • To investigate the association of Raf kinase with the T cell receptor-CD3 complex in T cells.
  • To determine which specific CD3 chains interact with Raf.
  • To elucidate the role of Raf in T cell receptor-mediated signal transduction.

Main Methods:

  • Co-immunoprecipitation assays to detect protein interactions.
  • Expression of Raf and CD3 chains in a COS cell system.
  • Analysis of Raf association with different CD3 subunits (gamma, delta, epsilon, zeta).

Main Results:

  • Raf kinase was found to be associated with the T cell receptor-CD3 complex in unstimulated murine T cells.
  • A hypophosphorylated form of Raf specifically associated with the CD3 gamma and delta chains.
  • No association was observed between Raf and the CD3 epsilon or zeta chains.

Conclusions:

  • Raf kinase plays a role in signal transduction originating from the CD3 gamma and delta chains of the T cell receptor-CD3 complex.
  • This interaction is analogous to the function of ZAP-70 with the CD3 zeta chain.
  • Raf's association provides a new insight into the early events of T cell activation.

More Related Videos

Generating De Novo Antigen-specific Human T Cell Receptors by Retroviral Transduction of Centric Hemichain08:48

Generating De Novo Antigen-specific Human T Cell Receptors by Retroviral Transduction of Centric Hemichain

Published on: October 25, 2016

Ligand Nano-cluster Arrays in a Supported Lipid Bilayer10:34

Ligand Nano-cluster Arrays in a Supported Lipid Bilayer

Published on: April 23, 2017

Related Concept Videos

Rab Proteins01:14

Rab Proteins

Rab proteins constitute the largest family of monomeric GTPases, of which 70 members are present in humans. Rab proteins and their effectors regulate consecutive stages of vesicle transport such as vesicle transport, docking, and fusion to the correct recipient membrane.
Rab proteins switch between a cytosolic, GDP-bound inactive state and a membrane-anchored, GTP-bound active state. By themselves, Rabs show slow rates of GDP/GTP exchange and GTP hydrolysis. Thus, Rab proteins are considered...
Tail-anchoring of Proteins in the ER Membrane01:45

Tail-anchoring of Proteins in the ER Membrane

Tail-anchored, or TA, proteins are estimated to make up to 3-5% of membrane proteins found in the eukaryotic cell. Such proteins have a single transmembrane domain located approximately 30 amino acid residues upstream from the C-terminal end. As a result, the signal recognition particle (SRP) cannot guide a TA protein to the ER membrane for cotranslational insertion. Hence, they are integrated into the ER membrane post-translationally using their C-terminal end as the anchor. TA proteins...
Rab Cascades01:25

Rab Cascades

Rab GTPases act in a regulated cascade during membrane fusion, helping the lipid bilayers mix. The Rab family of proteins are active when bound to GTP, and inactive when bound to GDP. Hence, they act as guanine nucleotide-dependent molecular switches. Rab-GTP recognizes and binds to long or short-range tethering proteins to capture the target vesicle. These tethers coordinate with SNAREs on the vesicle and the target membrane to assemble the trans SNARE complex that locks the mixing bilayers.
Assembly of Signaling Complexes01:30

Assembly of Signaling Complexes

Multiprotein signaling complexes are formed in a dynamic process involving protein-protein interactions at the cytoplasmic domain of transmembrane receptors or enzymatic and non-enzymatic proteins associated with the receptor. These complexes ensure the activation and propagation of intracellular signals that regulate cell functions.
Interaction domains in cell signaling
Interaction domains recognize exposed features of their binding partners containing post-translationally modified sequences,...
Diversity of Antigen Receptors01:28

Diversity of Antigen Receptors

Antigen receptors are essential components of the immune system crucial in defending the body against foreign invaders. These receptors are present on the surface of B and T cells, enabling them to recognize antigens and mount an appropriate immune response.
Before encountering any antigen, lymphocytes express these receptors. On B cells, the antigen receptor is a membrane-bound antibody molecule called BCR; on T cells, it is a T cell receptor or TCR. B and T cell receptors are composed of two...
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...