The Hepta-? -Glucoside Elicitor-Binding Proteins from Legumes Represent a Putative Receptor Family
-
A. Mithöfer
Abstract
The ability of legumes to recognize and respond to β-glucan elicitors by synthesizing phytoalexins is consistent with the existence of a membrane-bound β-glucan-binding site. Related proteins of approximately 75 kDa and the corresponding mRNAs were detected in various species of legumes which respond to β-glucans. The cDNAs for the β-glucan-binding proteins of bean and soybean were cloned. The deduced 75-kDa proteins are predominantly hydrophilic and constitute a unique class of glucan-binding proteins with no currently recognizable functional domains. Heterologous expression of the soybean β-glucan-binding protein in tomato cells resulted in the generation of a high-affinity binding site for the elicitor-active hepta-β-glucoside conjugate (Kd = 4.5nM). Ligand competition experiments with the recombinant binding sites demonstrated similar ligand specificities when compared with soybean. In both soybean and transgenic tomato, membrane-bound, active forms of the glucan-binding proteins coexist with immunologically detectable, soluble but inactive forms of the proteins. Reconstitution of a soluble protein fraction into lipid vesicles regained β-glucoside-binding activity but with lower affinity (Kd = 130 nM). We conclude that the β-glucan elicitor receptors of legumes are composed of the 75 kDa glucan-binding proteins as the critical components for ligand-recognition, and of an as yet unknown membrane anchor constituting the plasma membrane-associated receptor complex.
Copyright © 2000 by Walter de Gruyter GmbH & Co. KG
Articles in the same Issue
- To Our Authors, Readers and Subscribers
- Highlight: Plant Biological Chemistry
- The Structural Properties of Plant Peroxisomes and Their Metabolic Significance
- Active Oxygen Species as Mediators of Plant Immunity: Three Case Studies
- Post-Transcriptional Regulation of Phenylalanine Ammonia-Lyase Expression in Tobacco Following Recovery from Gene Silencing
- Two Differentially Regulated Class II Chitinases from Parsley
- IAA-Synthase, an Enzyme Complex from Arabidopsis thaliana Catalyzing the Formation of Indole-3-Acetic Acid from (S)-Tryptophan
- Topology Studies of the Chloroplast Protein Import Channel Toc75
- Plant Methionine Synthase: New Insights into Properties and Expression
- The Hepta-? -Glucoside Elicitor-Binding Proteins from Legumes Represent a Putative Receptor Family
- Octadecanoid and Jasmonate Signaling in Tomato (Lycopersicon esculentum Mill.) Leaves: Endogenous Jasmonates Do Not Induce Jasmonate Biosynthesis
- Metabolic Activity Decreases as an Adaptive Response to Low Internal Oxygen in Growing Potato Tubers
- Structure-Activity Relationships of Synthetic Analogs of Jasmonic Acid and Coronatine on Induction of Benzophenanthridine Alkaloid Accumulation in Eschscholzia californica Cell Cultures
- Identification of the Arabidopsis thaliana Flavonoid 3'-Hydroxylase Gene and Functional Expression of the Encoded P450 Enzyme
- Gut Bacteria May Be Involved in Interactions between Plants, Herbivores and Their Predators: Microbial Biosynthesis of N-Acylglutamine Surfactants as Elicitors of Plant Volatiles
- Different Signaling Pathways Are Involved in CCKB Receptor-Mediated MAP Kinase Activation in COS-7 Cells
- Non-Specific Depurination Activity of Saporin-S6, a Ribosome-Inactivating Protein, under Acidic Conditions
- Molecular Evolution in the Hypervariable Regions of Fetuin: Comparison between Human and African Green Monkey Fetuin
Articles in the same Issue
- To Our Authors, Readers and Subscribers
- Highlight: Plant Biological Chemistry
- The Structural Properties of Plant Peroxisomes and Their Metabolic Significance
- Active Oxygen Species as Mediators of Plant Immunity: Three Case Studies
- Post-Transcriptional Regulation of Phenylalanine Ammonia-Lyase Expression in Tobacco Following Recovery from Gene Silencing
- Two Differentially Regulated Class II Chitinases from Parsley
- IAA-Synthase, an Enzyme Complex from Arabidopsis thaliana Catalyzing the Formation of Indole-3-Acetic Acid from (S)-Tryptophan
- Topology Studies of the Chloroplast Protein Import Channel Toc75
- Plant Methionine Synthase: New Insights into Properties and Expression
- The Hepta-? -Glucoside Elicitor-Binding Proteins from Legumes Represent a Putative Receptor Family
- Octadecanoid and Jasmonate Signaling in Tomato (Lycopersicon esculentum Mill.) Leaves: Endogenous Jasmonates Do Not Induce Jasmonate Biosynthesis
- Metabolic Activity Decreases as an Adaptive Response to Low Internal Oxygen in Growing Potato Tubers
- Structure-Activity Relationships of Synthetic Analogs of Jasmonic Acid and Coronatine on Induction of Benzophenanthridine Alkaloid Accumulation in Eschscholzia californica Cell Cultures
- Identification of the Arabidopsis thaliana Flavonoid 3'-Hydroxylase Gene and Functional Expression of the Encoded P450 Enzyme
- Gut Bacteria May Be Involved in Interactions between Plants, Herbivores and Their Predators: Microbial Biosynthesis of N-Acylglutamine Surfactants as Elicitors of Plant Volatiles
- Different Signaling Pathways Are Involved in CCKB Receptor-Mediated MAP Kinase Activation in COS-7 Cells
- Non-Specific Depurination Activity of Saporin-S6, a Ribosome-Inactivating Protein, under Acidic Conditions
- Molecular Evolution in the Hypervariable Regions of Fetuin: Comparison between Human and African Green Monkey Fetuin
