Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Assembly of Signaling Complexes

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,...

Small GTPases - Ras and Rho

Small GTPases - Ras and Rho

Ras and Rho are small monomeric GTPases that act downstream of receptor tyrosine kinase (RTK) and regulate various cellular processes. These GTPases switch between active and inactive states by binding to guanine nucleotides.
Three regulatory proteins control their activity:

Intracellular Signaling Affects Focal Adhesions

Intracellular Signaling Affects Focal Adhesions

Integrins act both as extracellular input receivers and as intracellular processing activators. As their name suggests, integrins are entirely integrated into the membrane structure. Their hydrophobic membrane-spanning regions interact with the phospholipid bilayer's hydrophobic region. These membrane receptors provide extracellular attachment sites for effectors like hormones and growth factors. They activate intracellular response cascades when their effectors are bound and active.
Some...

Cell Polarization by Rho Proteins

Cell Polarization by Rho Proteins

Cell polarity is the asymmetric distribution of cellular and membrane components, making one side of the cell different from the other. This polarity is essential to many processes such as embryogenesis, axon migration, glucose transport across epithelial cells, and directional cell migration. A migrating cell responds to intracellular or extracellular signals via molecular cascades that reorganize the actin cytoskeleton to establish this polarity. In these cells, the Rho family proteins Cdc42,...

Catenins

Catenins

Catenins are characterized by multiple binding domains and dynamic structures that allow them to function as linker proteins in cell junction complexes. All catenins, except α-catenin, contain a characteristic protein sequence called the armadillo repeat and are therefore also called armadillo proteins.
Catenins in Cell Junctions
Catenins bind to cell adhesion molecules such as cadherins and link them to different cytoskeletal proteins depending on the type of cell junction. At the adherens...

Cytoskeletal Linker Proteins - Plakins

Cytoskeletal Linker Proteins - Plakins

Plakins are large proteins with binding domains for microtubules, microfilaments, intermediate filaments, and membrane-associated protein complexes at cell junctions. Plakin functions are evolutionarily conserved and are primarily involved in organizing the different components of the cytoskeleton by crosslinking them to each other and connecting them to the cell-matrix and cell adhesion complexes. They are also known to interact with signal transducers, serve as scaffolds for signaling...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

Mechanoreceptor plexin D1 regulates lymphatic valve morphogenesis and lymphedema pathogenesis.

The Journal of clinical investigation·2026

Same author

Design principles of a membrane-spanning ubiquitin ligase.

Molecular cell·2026

Same author

Structure and organization of AMPA receptor-TARP complexes in the mammalian cerebellum.

Science (New York, N.Y.)·2025

Same author

GABA <sub>A</sub> receptor gating imaged on the millisecond timescale.

bioRxiv : the preprint server for biology·2025

Same author

The E3 ubiquitin ligase MGRN1 targets melanocortin receptors MC1R and MC4R via interactions with transmembrane adapters.

Journal of cell science·2025

Same author

Protein Target Highlights in CASP16: Insights From the Structure Providers.

Proteins·2025

Search research articles

Related Experiment Video

Updated: May 29, 2026

Reverse Yeast Two-hybrid System to Identify Mammalian Nuclear Receptor Residues that Interact with Ligands and/or Antagonists

Reverse Yeast Two-hybrid System to Identify Mammalian Nuclear Receptor Residues that Interact with Ligands and/or Antagonists

Published on: November 15, 2013

A dual binding mode for RhoGTPases in plexin signalling.

Christian H Bell¹, A Radu Aricescu, E Yvonne Jones

¹Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom.

|September 14, 2011

Summary

Researchers uncovered a novel RhoGTPase binding site on Plexin-B1, crucial for semaphorin signaling. This discovery explains how cell guidance cues trigger intracellular signal transduction.

More Related Videos

Proteomics to Identify Proteins Interacting with P2X2 Ligand-Gated Cation Channels

Proteomics to Identify Proteins Interacting with P2X2 Ligand-Gated Cation Channels

Published on: May 18, 2009

Detection of Heterodimerization of Protein Isoforms Using an in Situ Proximity Ligation Assay

Detection of Heterodimerization of Protein Isoforms Using an in Situ Proximity Ligation Assay

Published on: October 20, 2018

Related Experiment Videos

Last Updated: May 29, 2026

Reverse Yeast Two-hybrid System to Identify Mammalian Nuclear Receptor Residues that Interact with Ligands and/or Antagonists

Reverse Yeast Two-hybrid System to Identify Mammalian Nuclear Receptor Residues that Interact with Ligands and/or Antagonists

Published on: November 15, 2013

Proteomics to Identify Proteins Interacting with P2X2 Ligand-Gated Cation Channels

Proteomics to Identify Proteins Interacting with P2X2 Ligand-Gated Cation Channels

Published on: May 18, 2009

Detection of Heterodimerization of Protein Isoforms Using an in Situ Proximity Ligation Assay

Detection of Heterodimerization of Protein Isoforms Using an in Situ Proximity Ligation Assay

Published on: October 20, 2018

Area of Science:

Cell biology
Molecular signaling
Structural biology

Background:

Plexins are cell surface receptors binding semaphorin cues.
Their cytoplasmic region has Ras GTPase-activating protein (GAP) and RhoGTPase binding domains.
Semaphorin and RhoGTPase binding activate Plexin-B1 signaling, but the mechanism is unclear.

Purpose of the Study:

To elucidate the regulatory mechanism of Plexin-B1 signaling.
To determine the structural basis for signal transduction triggered by semaphorins and RhoGTPases.

Main Methods:

X-ray crystallography of human Plexin-B1 cytoplasmic region with Rac1.
Site-directed mutagenesis.
Cellular and biophysical assays.

Main Results:

Two crystal structures of Plexin-B1-Rac1 complexes were determined.
A truncated Plexin-B1-Rac1 structure lacked a coupling mechanism.
Including the juxtamembrane helix revealed a trimeric complex stabilized by a novel RhoGTPase binding site.
This new site is essential for Plexin-B1 signaling.

Conclusions:

A novel RhoGTPase binding site adjacent to the Ras site is identified.
This site is critical for Plexin-B1 signal transduction.
Plexin clustering integrates extracellular and intracellular signals for a unified output.