Dataset Information

ErbB1 dimerization is promoted by domain co-confinement and stabilized by ligand binding.

ABSTRACT: The extent to which ligand occupancy and dimerization contribute to erbB1 signaling is controversial. To examine this, we used two-color quantum-dot tracking for visualization of the homodimerization of human erbB1 and quantification of the dimer off-rate (k(off)) on living cells. Kinetic parameters were extracted using a three-state hidden Markov model to identify transition rates between free, co-confined and dimerized states. We report that dimers composed of two ligand-bound receptors are long-lived and their k(off) is independent of kinase activity. By comparison, unliganded dimers have a more than four times faster k(off). Transient co-confinement of receptors promotes repeated encounters and enhances dimer formation. Mobility decreases more than six times when ligand-bound receptors dimerize. Blockade of erbB1 kinase activity or disruption of actin networks results in faster diffusion of receptor dimers. These results implicate both signal propagation and the cortical cytoskeleton in reduced mobility of signaling-competent erbB1 dimers.

SUBMITTER: Low-Nam ST

PROVIDER: S-EPMC3210321 | biostudies-literature | 2011 Oct

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

ErbB1 dimerization is promoted by domain co-confinement and stabilized by ligand binding.

Low-Nam Shalini T ST Lidke Keith A KA Cutler Patrick J PJ Roovers Rob C RC van Bergen en Henegouwen Paul M P PM Wilson Bridget S BS Lidke Diane S DS

Nature structural & molecular biology 20111023 11

The extent to which ligand occupancy and dimerization contribute to erbB1 signaling is controversial. To examine this, we used two-color quantum-dot tracking for visualization of the homodimerization of human erbB1 and quantification of the dimer off-rate (k(off)) on living cells. Kinetic parameters were extracted using a three-state hidden Markov model to identify transition rates between free, co-confined and dimerized states. We report that dimers composed of two ligand-bound receptors are lo ...[more]

PMID: 22020299

Similar Datasets

Project description:The protein encoded by GmRLK18-1 (Glyma_18_02680 on chromosome 18) was a receptor like kinase (RLK) encoded within the soybean (Glycine max L. Merr.) Rhg1/Rfs2 locus. The locus underlies resistance to the soybean cyst nematode (SCN) Heterodera glycines (I.) and causal agent of sudden death syndrome (SDS) Fusarium virguliforme (Aoki). Previously the leucine rich repeat (LRR) domain was expressed in Escherichia coli.The aims here were to evaluate the LRRs ability to; homo-dimerize; bind larger proteins; and bind to small peptides. Western analysis suggested homo-dimers could form after protein extraction from roots. The purified LRR domain, from residue 131-485, was seen to form a mixture of monomers and homo-dimers in vitro. Cross-linking experiments in vitro showed the H274N region was close (<11.1 A) to the highly conserved cysteine residue C196 on the second homo-dimer subunit. Binding constants of 20-142 nM for peptides found in plant and nematode secretions were found. Effects on plant phenotypes including wilting, stem bending and resistance to infection by SCN were observed when roots were treated with 50 pM of the peptides. Far-Western analyses followed by MS showed methionine synthase and cyclophilin bound strongly to the LRR domain. A second LRR from GmRLK08-1 (Glyma_08_g11350) did not show these strong interactions.The LRR domain of the GmRLK18-1 protein formed both a monomer and a homo-dimer. The LRR domain bound avidly to 4 different CLE peptides, a cyclophilin and a methionine synthase. The CLE peptides GmTGIF, GmCLE34, GmCLE3 and HgCLE were previously reported to be involved in root growth inhibition but here GmTGIF and HgCLE were shown to alter stem morphology and resistance to SCN. One of several models from homology and ab-initio modeling was partially validated by cross-linking. The effect of the 3 amino acid replacements present among RLK allotypes, A87V, Q115K and H274N were predicted to alter domain stability and function. Therefore, the LRR domain of GmRLK18-1 might underlie both root development and disease resistance in soybean and provide an avenue to develop new variants and ligands that might promote reduced losses to SCN.

Dataset Information

ErbB1 dimerization is promoted by domain co-confinement and stabilized by ligand binding.

Publications

ErbB1 dimerization is promoted by domain co-confinement and stabilized by ligand binding.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets