ETR1 is a central ethylene receptor that functions as a negative regulator of ethylene signaling through a two-component regulatory system. The protein contains an N-terminal domain with three transmembrane helices that form an ethylene-binding site requiring a copper cofactor, a GAF-like domain for protein interactions, and a C-terminal region containing histidine kinase and receiver domains. ETR1 localizes to the endoplasmic reticulum membrane where it forms disulfide-linked homodimers and heterodimers with other ethylene receptor family members (ERS1, ERS2, ETR2, EIN4). In the absence of ethylene, ETR1 maintains active histidine kinase activity through autophosphorylation, which suppresses downstream ethylene responses via CTR1. Upon ethylene binding, the autokinase activity is inhibited, leading to inactivation of CTR1 and activation of EIN2, thereby propagating the ethylene signal. ETR1 forms high-molecular-weight complexes essential for signal transduction and interacts with regulatory proteins including AHP proteins in phosphorelay signaling and RTE1 for receptor stabilization. The receptor integrates ethylene perception with multiple developmental and stress response pathways, including seed germination, cell elongation, stress adaptation, and hormone cross-talk.
Definition: The formation of heteromeric and homomeric complexes among ethylene receptor family members that are essential for ethylene signal perception and transduction
Justification: ETR1 forms both homodimers and heterodimers with other ethylene receptors (ERS1, ERS2, ETR2, EIN4) which are critical for proper ethylene signal transduction
Parent term: ethylene-activated signaling pathway
Supporting Evidence:
Definition: The process by which ethylene binding to its receptor inhibits the autophosphorylation activity of the histidine kinase domain, leading to signal transduction
Justification: ETR1's unique mechanism involves ethylene binding causing inhibition of its kinase activity, which is the key regulatory switch in ethylene signaling
Parent term: phosphorelay signal transduction system
Supporting Evidence:
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0005783 endoplasmic reticulum | IBA GO_REF:0000033 | ACCEPT | Summary: ETR1 is predominantly localized to the endoplasmic reticulum membrane where it forms high-molecular-weight complexes essential for ethylene signal transduction. UniProt confirms ER membrane localization. Supporting Evidence: file:ARATH/ETR1/ETR1-deep-research-falcon.md Ethylene perception for ETR1 occurs at an **ER-associated membrane** (endomembrane system) rather than the plasma membrane, consistent with the receptor’s N-terminal multi-pass TM region and the localization of downstream pathway components. |
| GO:0051740 ethylene binding | IBA GO_REF:0000033 | ACCEPT | Summary: This is the core molecular function of ETR1. It binds ethylene with high affinity via a copper cofactor in its N-terminal domain. Ethylene binding inhibits its autokinase activity. Supporting Evidence: file:ARATH/ETR1/ETR1-deep-research-falcon.md Ethylene binding requires a **Cu(I)** cofactor associated with the **N-terminal transmembrane sensor domain**. |
| GO:0038199 ethylene receptor activity | IBA GO_REF:0000033 | ACCEPT | Summary: ETR1 is the prototypical ethylene receptor in Arabidopsis. It perceives ethylene and transduces the signal through conformational changes that affect downstream components like CTR1 and EIN2. Supporting Evidence: file:ARATH/ETR1/ETR1-deep-research-falcon.md receptor output is transmitted to **CTR1** (CONSTITUTIVE TRIPLE RESPONSE 1), a Raf-like kinase that represses ethylene responses; binding of ethylene to receptors leads to **deactivation of CTR1**, thereby enabling signaling via **EIN2** and subsequent transcriptional changes. |
| GO:0000155 phosphorelay sensor kinase activity | IEA GO_REF:0000002 | ACCEPT | Summary: ETR1 functions as a histidine kinase with autophosphorylation activity that is inhibited by ethylene binding. This phosphorelay activity is essential for its role as negative regulator of ethylene signaling. |
| GO:0000160 phosphorelay signal transduction system | IEA GO_REF:0000120 | ACCEPT | Summary: ETR1 participates in two-component signal transduction as a histidine kinase. The falcon research and UniProt confirm ETR1 functions in phosphorelay systems with autophosphorylation activity that is inhibited by ethylene binding. Reason: ETR1 is clearly documented as functioning in phosphorelay signal transduction systems. The falcon research extensively documents its role as a histidine kinase with autophosphorylation activity in two-component regulatory systems. Supporting Evidence: PMID:8211181 Arabidopsis ethylene-response gene ETR1: similarity of product to two-component regulators PMID:10930573 Possible His to Asp phosphorelay signaling in an Arabidopsis two-component system |
| GO:0000166 nucleotide binding | IEA GO_REF:0000043 | MODIFY | Summary: ETR1 contains histidine kinase domain that requires ATP binding for autophosphorylation activity. UniProt confirms EC 2.7.13.3 classification and ATP binding is essential for kinase function. Reason: While ETR1 does bind nucleotides (specifically ATP), the more specific "ATP binding" term would be more informative than the general "nucleotide binding" term. Proposed replacements: ATP binding Supporting Evidence: PMID:22467798 Histidine kinase activity of the ethylene receptor ETR1 facilitates the ethylene response in Arabidopsis |
| GO:0004672 protein kinase activity | IEA GO_REF:0000002 | MARK AS OVER ANNOTATED | Summary: ETR1 has kinase activity but specifically histidine kinase activity rather than general protein kinase activity. The specific term protein histidine kinase activity (GO:0004673) is already separately annotated (three times), so the generic parent adds no information. Reason: GO:0004672 (protein kinase activity) is a direct parent of GO:0004673 (protein histidine kinase activity) in the GO hierarchy, and GO:0004673 is already annotated three times (IEA, IMP, TAS). Retaining the generic parent over-annotates the gene; a MODIFY to GO:0004673 would merely duplicate the existing specific annotation. Supporting Evidence: PMID:22467798 Histidine kinase activity of the ethylene receptor ETR1 facilitates the ethylene response in Arabidopsis |
| GO:0004673 protein histidine kinase activity | IEA GO_REF:0000120 | ACCEPT | Summary: This is the core molecular function of ETR1. It functions as a histidine kinase with autophosphorylation activity that is inhibited upon ethylene binding. This is extensively documented in the literature. Reason: ETR1 is definitively a histidine kinase. This is its primary catalytic molecular function and is well-documented across multiple studies. Supporting Evidence: PMID:22467798 Histidine kinase activity of the ethylene receptor ETR1 facilitates the ethylene response in Arabidopsis PMID:15703053 Ethylene-binding activity, gene expression levels, and receptor system output for ethylene receptor family members from Arabidopsis and tomato file:ARATH/ETR1/ETR1-deep-research-falcon.md ETR1 contains a functional **histidine kinase** region in biochemical assays |
| GO:0005524 ATP binding | IEA GO_REF:0000043 | ACCEPT | Summary: ETR1 requires ATP binding for its histidine kinase activity. ATP binding is essential for autophosphorylation of the conserved histidine residue. Reason: ATP binding is required for the histidine kinase activity of ETR1. This is a core molecular function necessary for its role in signal transduction. Supporting Evidence: PMID:22467798 Histidine kinase activity of the ethylene receptor ETR1 facilitates the ethylene response in Arabidopsis |
| GO:0005783 endoplasmic reticulum | IEA GO_REF:0000117 | ACCEPT | Summary: ETR1 is predominantly localized to the endoplasmic reticulum where it forms high-molecular-weight complexes. This is well-documented with multiple experimental confirmations. Reason: ER localization is well-established for ETR1 through multiple independent studies and is consistent with IBA and experimental evidence already accepted. Supporting Evidence: PMID:11916973 Localization of the ethylene receptor ETR1 to the endoplasmic reticulum of Arabidopsis PMID:19825542 Subcellular localization and in vivo interactions of the Arabidopsis thaliana ethylene receptor family members |
| GO:0005789 endoplasmic reticulum membrane | IEA GO_REF:0000120 | ACCEPT | Summary: ETR1 is specifically localized to the ER membrane via its transmembrane domains. This is more specific than just ER localization and is the precise subcellular location. Reason: ETR1 is an integral membrane protein of the ER with transmembrane domains. The membrane-specific localization is more precise and well-documented. Supporting Evidence: PMID:11916973 Localization of the ethylene receptor ETR1 to the endoplasmic reticulum of Arabidopsis PMID:19825542 Subcellular localization and in vivo interactions of the Arabidopsis thaliana ethylene receptor family members |
| GO:0007165 signal transduction | IEA GO_REF:0000002 | MARK AS OVER ANNOTATED | Summary: ETR1 is central to ethylene signal transduction, functioning as the receptor that perceives ethylene and transduces the signal to downstream components. However, the more specific ethylene-activated signaling pathway (GO:0009873) is already separately annotated (with ACCEPT), so the generic 'signal transduction' parent adds no information. Reason: The specific child term GO:0009873 (ethylene-activated signaling pathway) is already captured as a separate accepted annotation. Retaining the generic parent GO:0007165 (signal transduction) over-annotates the gene without adding specificity; a MODIFY to GO:0009873 would merely duplicate the existing annotation. Supporting Evidence: PMID:8211181 Arabidopsis ethylene-response gene ETR1: similarity of product to two-component regulators |
| GO:0009723 response to ethylene | IEA GO_REF:0000002 | ACCEPT | Summary: ETR1 is the primary ethylene receptor and directly mediates response to ethylene hormone by changing its kinase activity upon ethylene binding. Reason: ETR1 is fundamentally involved in ethylene response as the receptor that detects and responds to ethylene. This is a core biological process for ETR1. Supporting Evidence: PMID:8211181 Arabidopsis ethylene-response gene ETR1: similarity of product to two-component regulators PMID:9974395 A copper cofactor for the ethylene receptor ETR1 from Arabidopsis |
| GO:0009873 ethylene-activated signaling pathway | IEA GO_REF:0000043 | ACCEPT | Summary: ETR1 is a central component of the ethylene-activated signaling pathway, serving as the receptor that initiates the cascade upon ethylene perception. Reason: This is a core biological process for ETR1. It functions as the receptor that activates the ethylene signaling pathway when ethylene binds. Supporting Evidence: PMID:8211181 Arabidopsis ethylene-response gene ETR1: similarity of product to two-component regulators PMID:15466228 Requirement of the histidine kinase domain for signal transduction by the ethylene receptor ETR1 file:ARATH/ETR1/ETR1-deep-research-falcon.md they are functionally “on” in air (no ethylene) and **ethylene binding inactivates** receptor signaling, resulting in pathway activation downstream |
| GO:0010105 negative regulation of ethylene-activated signaling pathway | IEA GO_REF:0000117 | ACCEPT | Summary: ETR1 functions as a negative regulator of ethylene signaling. In the absence of ethylene, active ETR1 suppresses the ethylene response pathway through CTR1. Reason: This is a well-established core function of ETR1. It acts as a negative regulator, keeping the ethylene response pathway suppressed until ethylene binding inactivates the receptor. Supporting Evidence: PMID:11916973 Localization of the ethylene receptor ETR1 to the endoplasmic reticulum of Arabidopsis PMID:12177468 Loss-of-function mutations in the ethylene receptor ETR1 cause enhanced sensitivity and exaggerated response to ethylene in Arabidopsis file:ARATH/ETR1/ETR1-deep-research-falcon.md Loss-of-function (LOF) mutations in ETR1 can yield **enhanced ethylene sensitivity** and exaggerated ethylene responses, consistent with ETR1 normally acting as a **negative regulator**. |
| GO:0016301 kinase activity | IEA GO_REF:0000043 | MARK AS OVER ANNOTATED | Summary: ETR1 has kinase activity but specifically histidine kinase activity rather than general kinase activity. The specific term protein histidine kinase activity (GO:0004673) is already separately annotated (three times), so this generic parent adds no information. Reason: GO:0016301 (kinase activity) is an ancestor of GO:0004673 (protein histidine kinase activity) in the GO hierarchy, and GO:0004673 is already annotated three times (IEA, IMP, TAS). Retaining the generic parent over-annotates the gene; a MODIFY to GO:0004673 would merely duplicate the existing specific annotation. This is consistent with the over-annotation calls on the sibling parents GO:0004672, GO:0016772, and GO:0016740. Supporting Evidence: PMID:22467798 Histidine kinase activity of the ethylene receptor ETR1 facilitates the ethylene response in Arabidopsis |
| GO:0016740 transferase activity | IEA GO_REF:0000043 | MARK AS OVER ANNOTATED | Summary: ETR1 has transferase activity as a histidine kinase that transfers phosphate groups. However, 'transferase activity' is a root-level generic parent term that conveys no specific information beyond the already-accepted specific term protein histidine kinase activity (GO:0004673). Reason: This is an uninformative high-level parent of the specific molecular function (protein histidine kinase activity, GO:0004673) that is already captured. Retaining the generic 'transferase activity' term over-annotates the gene without adding specificity. Supporting Evidence: file:ARATH/ETR1/ETR1-deep-research-falcon.md ETR1 contains a functional **histidine kinase** region in biochemical assays |
| GO:0016772 transferase activity, transferring phosphorus-containing groups | IEA GO_REF:0000002 | MARK AS OVER ANNOTATED | Summary: ETR1 transfers phosphate groups as a histidine kinase. However, 'transferase activity, transferring phosphorus-containing groups' is a high-level parent of the already-accepted specific molecular function protein histidine kinase activity (GO:0004673) and conveys no additional specificity. Reason: GO:0016772 is a direct ancestor of GO:0004673 (protein histidine kinase activity) in the GO hierarchy (GO:0016772 > GO:0016301 kinase activity > ... > GO:0004673), which is already captured. For consistency with the over-annotation call on its parent GO:0016740 (transferase activity), this uninformative intermediate term is also marked as over-annotated. Supporting Evidence: PMID:22467798 Histidine kinase activity of the ethylene receptor ETR1 facilitates the ethylene response in Arabidopsis |
| GO:0038199 ethylene receptor activity | IEA GO_REF:0000002 | ACCEPT | Summary: This is the core molecular function of ETR1 - it is the prototypical ethylene receptor. This duplicates the IBA annotation but with different evidence. Reason: ETR1 is definitively an ethylene receptor. This is its primary function and already confirmed by IBA evidence. Additional evidence codes support this core function. Supporting Evidence: PMID:8211181 Arabidopsis ethylene-response gene ETR1: similarity of product to two-component regulators PMID:15466228 Requirement of the histidine kinase domain for signal transduction by the ethylene receptor ETR1 |
| GO:0046872 metal ion binding | IEA GO_REF:0000043 | MODIFY | Summary: ETR1 binds copper ion specifically for ethylene binding, not general metal ion binding. Reason: ETR1 specifically requires copper for ethylene binding. Copper binding is more specific and accurate than general metal ion binding. Proposed replacements: copper ion binding Supporting Evidence: PMID:9974395 A copper cofactor for the ethylene receptor ETR1 from Arabidopsis file:ARATH/ETR1/ETR1-deep-research-falcon.md A **copper cofactor is required** for ethylene binding at the N-terminal transmembrane region. The copper transporter **RAN1** is implicated in copper delivery to ethylene receptors |
| GO:0051740 ethylene binding | IEA GO_REF:0000120 | ACCEPT | Summary: Ethylene binding is the core ligand-binding function of ETR1. This duplicates the IBA annotation but with different evidence code. Reason: ETR1 definitively binds ethylene with high affinity via copper cofactor. This is well-established and already confirmed by IBA evidence. Supporting Evidence: PMID:9974395 A copper cofactor for the ethylene receptor ETR1 from Arabidopsis PMID:15703053 Ethylene-binding activity, gene expression levels, and receptor system output for ethylene receptor family members from Arabidopsis and tomato |
| GO:0005515 protein binding | IPI PMID:10930573 Possible His to Asp phosphorelay signaling in an Arabidopsis... | MODIFY | Summary: This study demonstrates ETR1 interaction with AHP proteins (AHP1, AHP2, AHP3) in phosphorelay signaling rather than generic protein binding. Reason: While ETR1 does bind proteins, this study specifically demonstrates phosphorelay activity with AHP proteins. The more specific phosphorelay sensor kinase activity is more informative. Proposed replacements: phosphorelay sensor kinase activity Supporting Evidence: PMID:10930573 Possible His to Asp phosphorelay signaling in an Arabidopsis two-component system |
| GO:0005515 protein binding | IPI PMID:12837948 The Arabidopsis cupin domain protein AtPirin1 interacts with... | REMOVE | Summary: This study focuses on AtPirin1-GPA1 interactions in seed germination and does not provide evidence for ETR1 protein binding. ETR1 is mentioned only tangentially. Reason: This annotation appears incorrect. The study examines AtPirin1-GPA1 interactions, not ETR1 protein binding. ETR1 is not a primary focus of the protein interaction studies in this paper. Supporting Evidence: PMID:12837948 The Arabidopsis cupin domain protein AtPirin1 interacts with the G protein alpha-subunit GPA1 and regulates seed germination and early seedling development |
| GO:0005515 protein binding | IPI PMID:17999643 Subcellular co-localization of Arabidopsis RTE1 and ETR1 sup... | MARK AS OVER ANNOTATED | Summary: This study reports subcellular co-localization of RTE1 and ETR1 supporting a regulatory role for RTE1, but the annotation is to the uninformative generic GO:0005515 (protein binding). RTE1 is a regulatory membrane protein (not an enzyme), so no more-specific molecular function binding term clearly applies, and per curation guidelines generic protein binding should not be retained. Reason: Per CLAUDE.md curation guidelines, GO:0005515 (protein binding) is uninformative regardless of how functionally relevant the underlying interaction is. The ETR1-RTE1 association is biologically meaningful but RTE1 has no enzymatic activity that would justify a specific binding child term, so this generic annotation is marked as over-annotated. The functional RTE1 regulatory relationship is captured in the gene description and core functions. Supporting Evidence: PMID:17999643 Subcellular co-localization of Arabidopsis RTE1 and ETR1 supports a regulatory role for RTE1 in ETR1 ethylene signaling |
| GO:0005515 protein binding | IPI PMID:18384742 Ethylene signaling: identification of a putative ETR1-AHP1 p... | MODIFY | Summary: This study demonstrates ETR1 interaction with AHP1 (histidine-containing phosphotransfer protein) in phosphorelay signaling using fluorescence spectroscopy. Reason: While ETR1 does bind proteins, this study specifically demonstrates phosphorelay interactions with AHP1. The more specific phosphorelay sensor kinase activity term is more informative than generic protein binding. Proposed replacements: phosphorelay sensor kinase activity Supporting Evidence: PMID:18384742 Fluorescence polarization studies presented here demonstrate a specific interaction of ETR1 with the histidine-containing transfer protein AHP1, supporting the idea that a phosphorelay module is involved in ethylene signaling |
| GO:0005515 protein binding | IPI PMID:18577522 Heteromeric interactions among ethylene receptors mediate si... | MODIFY | Summary: This study demonstrates heteromeric interactions among ethylene receptors, showing ETR1 interacts with ERS1, ETR2, ERS2, and EIN4 through both covalent and noncovalent mechanisms. This receptor-receptor association is better captured by a specific dimerization molecular function than by the generic GO:0005515 (protein binding). Reason: Per CLAUDE.md curation guidelines, generic GO:0005515 (protein binding) should be replaced with a more informative MF term. The interaction documented here is the heteromeric/oligomeric association of ETR1 with other ethylene receptor subunits, which is precisely protein dimerization activity (GO:0046983). Proposed replacements: protein dimerization activity Supporting Evidence: PMID:18577522 Evidence that ETR1 associates with other ethylene receptors was obtained by co-purification of ETR1 with tagged versions of ERS1, ETR2, ERS2, and EIN4 from Arabidopsis membrane extracts |
| GO:0005515 protein binding | IPI PMID:19769567 EIN2, the central regulator of ethylene signalling, is local... | MARK AS OVER ANNOTATED | Summary: This study shows EIN2 is localized at the ER membrane where it interacts with ETR1, but the annotation is to the uninformative generic GO:0005515 (protein binding). EIN2 is a membrane-integral signaling protein (not an enzyme or receptor family member), so no more-specific binding molecular function child term clearly applies. Reason: Per CLAUDE.md curation guidelines, GO:0005515 (protein binding) is uninformative regardless of the biological importance of the ETR1-EIN2 interaction. There is no enzymatic or structural property of EIN2 that would justify a specific binding child term, so this generic annotation is marked as over-annotated. The ETR1-EIN2 functional relationship is captured in the gene description and core functions. Supporting Evidence: PMID:19769567 EIN2, the central regulator of ethylene signalling, is localized at the ER membrane where it interacts with the ethylene receptor ETR1 |
| GO:0005515 protein binding | IPI PMID:20952388 Molecular association of the Arabidopsis ETR1 ethylene recep... | MARK AS OVER ANNOTATED | Summary: This study demonstrates a high-affinity physical association (Kd ~117 nM) between ETR1 and RTE1 (REVERSION-TO-ETHYLENE SENSITIVITY1), but the annotation is to the uninformative generic GO:0005515 (protein binding). RTE1 is a regulatory membrane protein (not an enzyme), so no more-specific binding molecular function child term clearly applies. Reason: Per CLAUDE.md curation guidelines, GO:0005515 (protein binding) is uninformative regardless of the high affinity or biological importance of the ETR1-RTE1 interaction. RTE1 has no enzymatic activity that would justify a specific binding child term, so this generic annotation is marked as over-annotated. The functional RTE1 regulatory relationship is captured in the gene description and core functions. Supporting Evidence: PMID:20952388 Here, we demonstrate a physical association of RTE1 and ETR1 using in vivo and in vitro methods |
| GO:0005515 protein binding | IPI PMID:8417317 Interactions among the subunits of the G protein involved in... | REMOVE | Summary: This study examines yeast G protein subunit interactions in mating pathways and has no relevance to Arabidopsis ETR1 function. This appears to be an incorrect annotation. Reason: This is clearly an incorrect annotation. The study focuses on Saccharomyces cerevisiae G protein interactions in yeast mating signaling, with no connection to Arabidopsis ETR1 ethylene receptor function. Supporting Evidence: PMID:8417317 The SCG1 (GPA1), STE4, and STE18 genes of Saccharomyces cerevisiae encode mating-pathway components |
| GO:0005515 protein binding | IPI PMID:9560288 Association of the Arabidopsis CTR1 Raf-like kinase with the... | MODIFY | Summary: ETR1 associates via its kinase domain with CTR1, a Raf-like Ser/Thr protein kinase that is the key downstream component mediating ethylene signal suppression. Because the binding partner CTR1 is a protein kinase, this interaction is better captured by the specific MF term protein kinase binding than by the generic GO:0005515 (protein binding). Reason: Per CLAUDE.md curation guidelines, generic GO:0005515 (protein binding) should be replaced with a more informative MF term. CTR1 is a Raf-like protein kinase, and ETR1 binds it directly via its kinase domain, so protein kinase binding (GO:0019901) is the accurate and specific molecular function. Proposed replacements: protein kinase binding Supporting Evidence: PMID:9560288 Association of the Arabidopsis CTR1 Raf-like kinase with the ETR1 and ERS ethylene receptors file:ARATH/ETR1/ETR1-deep-research-falcon.md the kinase domain of ETR1 (and ERS1) can interact directly with CTR1 in vitro |
| GO:0042802 identical protein binding | IPI PMID:18384742 Ethylene signaling: identification of a putative ETR1-AHP1 p... | ACCEPT | Summary: ETR1 forms homodimers through disulfide linkages, which is essential for receptor function and signal amplification. Reason: ETR1 homodimerization is well-documented and functionally important. The receptor forms disulfide-linked homodimers that are critical for proper function. Supporting Evidence: PMID:18384742 Ethylene signaling: identification of a putative ETR1-AHP1 phosphorelay complex by fluorescence spectroscopy PMID:7759498 The ethylene response mediator ETR1 from Arabidopsis forms a disulfide-linked dimer file:ARATH/ETR1/ETR1-deep-research-falcon.md ETR1 forms a functional dimer (and likely higher-order oligomers), with dimerization supported by conserved N-terminal cysteines implicated in disulfide-mediated interactions in the receptor family. |
| GO:0042802 identical protein binding | IPI PMID:18577522 Heteromeric interactions among ethylene receptors mediate si... | ACCEPT | Summary: This study demonstrates that ETR1 forms heteromeric interactions with other ethylene receptors and can form disulfide-linked homodimers as well as higher-order noncovalent complexes. Reason: ETR1 forms disulfide-linked homodimers through conserved cysteine residues (Cys-4 and Cys-6), which is essential for receptor function. This is well-established and functionally important. Supporting Evidence: PMID:18577522 Previous work has demonstrated that the basic functional unit for the ethylene receptor, ETR1, is a disulfide-linked homodimer |
| GO:0010087 phloem or xylem histogenesis | IMP PMID:23166504 Plant vascular cell division is maintained by an interaction... | KEEP AS NON CORE | Summary: This study examines PXY-ethylene interactions in vascular cell division. ETR1 may play a role in coordinating ethylene signaling with vascular development. Reason: While ETR1 may influence vascular development through ethylene signaling, this is a secondary developmental process rather than a core molecular function of the ethylene receptor. The primary role of ETR1 is ethylene perception and signal transduction. Supporting Evidence: PMID:23166504 Plant vascular cell division is maintained by an interaction between PXY and ethylene signalling |
| GO:0051301 cell division | IMP PMID:23166504 Plant vascular cell division is maintained by an interaction... | KEEP AS NON CORE | Summary: This study shows ethylene signaling influences vascular cell division patterns. ETR1 involvement in cell division is indirect through its role in ethylene signal transduction. Reason: ETR1 affects cell division indirectly through ethylene signaling regulation, but cell division itself is not a core function of this ethylene receptor. The primary function is ethylene perception and signal transduction. Supporting Evidence: PMID:23166504 Plant vascular cell division is maintained by an interaction between PXY and ethylene signalling |
| GO:0038199 ethylene receptor activity | IMP PMID:15466228 Requirement of the histidine kinase domain for signal transd... | ACCEPT | Summary: This study demonstrates that the histidine kinase domain is required for signal transduction by ETR1, confirming its role as an ethylene receptor. Experimental evidence using domain deletions. Reason: This is the core molecular function of ETR1. The study provides direct experimental evidence (IMP) demonstrating ETR1 functions as an ethylene receptor, which is its primary role. Supporting Evidence: PMID:15466228 Requirement of the histidine kinase domain for signal transduction by the ethylene receptor ETR1 file:ARATH/ETR1/ETR1-deep-research-falcon.md is an **endoplasmic reticulum (ER)-localized**, integral-membrane **ethylene receptor** that functions as a **negative regulator** of ethylene signaling in Arabidopsis |
| GO:0004673 protein histidine kinase activity | IMP PMID:22467798 Histidine kinase activity of the ethylene receptor ETR1 faci... | ACCEPT | Summary: This study provides direct experimental evidence that ETR1 has histidine kinase activity, which facilitates ethylene response. This is the core catalytic function of ETR1. Reason: This is a core molecular function of ETR1. The histidine kinase activity is well documented biochemically (autophosphorylation on His353). Note that genetic studies indicate canonical transmitter-domain histidine kinase activity is not strictly required for ethylene signal transmission, so the kinase domain may contribute regulatory/scaffolding roles rather than being essential for the core ethylene response; the molecular function annotation nonetheless remains supported by direct biochemical evidence. Supporting Evidence: PMID:22467798 Histidine kinase activity of the ethylene receptor ETR1 facilitates the ethylene response in Arabidopsis file:ARATH/ETR1/ETR1-deep-research-falcon.md Autophosphorylation was abolished by mutation of **His353** (presumptive phosphorylation site) or catalytic residues, and the reaction required **Mn2+** as a cation. |
| GO:0009723 response to ethylene | IMP PMID:22467798 Histidine kinase activity of the ethylene receptor ETR1 faci... | ACCEPT | Summary: ETR1 is the primary ethylene receptor that directly mediates response to ethylene through its kinase activity. This study provides experimental evidence of ETR1 role in ethylene response. Reason: This is a core biological process for ETR1. As the ethylene receptor, ETR1 is fundamentally involved in ethylene response and this study provides direct experimental evidence (IMP) of this function. Supporting Evidence: PMID:22467798 Histidine kinase activity of the ethylene receptor ETR1 facilitates the ethylene response in Arabidopsis |
| GO:1900140 regulation of seedling development | IMP PMID:22467798 Histidine kinase activity of the ethylene receptor ETR1 faci... | KEEP AS NON CORE | Summary: ETR1 regulates seedling development indirectly through its role in ethylene signaling. Ethylene affects various aspects of seedling growth and development. Reason: While ETR1 affects seedling development through ethylene signaling, this is a downstream developmental process rather than a core molecular function. ETR1 primary role is ethylene perception and signal transduction. Supporting Evidence: PMID:22467798 Histidine kinase activity of the ethylene receptor ETR1 facilitates the ethylene response in Arabidopsis |
| GO:0005783 endoplasmic reticulum | IDA PMID:19825542 Subcellular localization and in vivo interactions of the Ara... | ACCEPT | Summary: This study provides direct experimental evidence (IDA) for ETR1 localization to the endoplasmic reticulum using subcellular localization studies of ethylene receptor family members. Reason: ER localization is well-established for ETR1 and this study provides direct experimental evidence. This is consistent with previous IBA and other experimental evidence already accepted. Supporting Evidence: PMID:19825542 Subcellular localization and in vivo interactions of the Arabidopsis thaliana ethylene receptor family members |
| GO:0002237 response to molecule of bacterial origin | IMP PMID:20592040 Ethylene signaling regulates accumulation of the FLS2 recept... | KEEP AS NON CORE | Summary: This study shows ethylene signaling regulates accumulation of FLS2 receptor and oxidative burst in plant immunity. ETR1 involvement is indirect through ethylene signaling regulation. Reason: ETR1 affects bacterial response indirectly through its role in ethylene signaling, which modulates plant defense responses. This is a secondary function rather than a core molecular function of the ethylene receptor. Supporting Evidence: PMID:20592040 Ethylene signaling regulates accumulation of the FLS2 receptor and is required for the oxidative burst contributing to plant immunity |
| GO:0042742 defense response to bacterium | IMP PMID:19095898 Glucosinolate metabolites required for an Arabidopsis innate... | KEEP AS NON CORE | Summary: This study examines glucosinolate metabolites in innate immune response. ETR1 may influence defense through ethylene signaling effects on glucosinolate pathways. Reason: ETR1 affects bacterial defense responses indirectly through ethylene signaling regulation of defense pathways. This is a secondary function downstream of its primary role as ethylene receptor. Supporting Evidence: PMID:19095898 Glucosinolate metabolites required for an Arabidopsis innate immune response |
| GO:0052544 defense response by callose deposition in cell wall | IMP PMID:19095898 Glucosinolate metabolites required for an Arabidopsis innate... | MARK AS OVER ANNOTATED | Summary: This study focuses on glucosinolate metabolites in immune responses. ETR1 connection to callose deposition would be very indirect through ethylene signaling effects. Reason: This is a very specific defense mechanism that is distantly related to ETR1 core function. ETR1 is an ethylene receptor, and its connection to callose deposition is indirect and represents over-annotation. Supporting Evidence: PMID:19095898 Glucosinolate metabolites required for an Arabidopsis innate immune response |
| GO:0010119 regulation of stomatal movement | IMP PMID:16961732 Ethylene-induced stomatal closure in Arabidopsis occurs via ... | KEEP AS NON CORE | Summary: This study demonstrates ethylene-induced stomatal closure via AtrbohF-mediated hydrogen peroxide synthesis. ETR1 regulates this process through ethylene signaling. Reason: ETR1 regulates stomatal movement indirectly through ethylene signaling pathways. While functionally relevant, this is a downstream physiological process rather than a core molecular function of the ethylene receptor. Supporting Evidence: PMID:16961732 Ethylene-induced stomatal closure in Arabidopsis occurs via AtrbohF-mediated hydrogen peroxide synthesis |
| GO:0050665 hydrogen peroxide biosynthetic process | IMP PMID:16961732 Ethylene-induced stomatal closure in Arabidopsis occurs via ... | MARK AS OVER ANNOTATED | Summary: This study shows ethylene signaling leads to hydrogen peroxide synthesis for stomatal closure. ETR1 role is very indirect through ethylene signal transduction. Reason: ETR1 does not directly participate in hydrogen peroxide biosynthesis. Its role is as an ethylene receptor that regulates signaling pathways that eventually affect H2O2 synthesis. This represents over-annotation - too distantly related to core ETR1 function. Supporting Evidence: PMID:16961732 Ethylene-induced stomatal closure in Arabidopsis occurs via AtrbohF-mediated hydrogen peroxide synthesis |
| GO:0051740 ethylene binding | IDA PMID:15703053 Ethylene-binding activity, gene expression levels, and recep... | ACCEPT | Summary: This study provides direct experimental evidence for ethylene-binding activity of ETR1 and other ethylene receptors, measuring binding affinities and receptor system output. Reason: Ethylene binding is the core ligand-binding function of ETR1. This study provides direct experimental evidence (IDA) for this essential molecular function, which is already well-established. Supporting Evidence: PMID:15703053 Ethylene-binding activity, gene expression levels, and receptor system output for ethylene receptor family members from Arabidopsis and tomato |
| GO:0004673 protein histidine kinase activity | TAS PMID:15703053 Ethylene-binding activity, gene expression levels, and recep... | ACCEPT | Summary: This study confirms ETR1 histidine kinase activity in the context of ethylene receptor family analysis. TAS evidence supports the well-established kinase function. Reason: Protein histidine kinase activity is a core molecular function of ETR1. This study provides traceable author statement (TAS) evidence supporting this well-established catalytic function. Supporting Evidence: PMID:15703053 Ethylene-binding activity, gene expression levels, and receptor system output for ethylene receptor family members from Arabidopsis and tomato |
| GO:0005783 endoplasmic reticulum | IDA PMID:11916973 Localization of the ethylene receptor ETR1 to the endoplasmi... | ACCEPT | Summary: ETR1 is localized to the endoplasmic reticulum membrane where it functions as an ethylene receptor. This IDA annotation provides direct experimental evidence for ER localization, which is essential for ETR1 function as a membrane-bound ethylene receptor. Reason: ER localization is fundamental to ETR1 function as an ethylene receptor. The IDA evidence provides direct experimental support for this essential cellular localization. Supporting Evidence: PMID:11916973 Examination by aqueous two-phase partitioning, sucrose density-gradient centrifugation, and immunoelectron microscopy indicates that ETR1 is predominantly localized to the endoplasmic reticulum |
| GO:0006952 defense response | TAS PMID:16255250 Potato homologs of Arabidopsis thaliana genes functional in ... | KEEP AS NON CORE | Summary: This study examines potato homologs of Arabidopsis defense signaling genes including ETR1. ETR1 affects defense responses through ethylene signaling regulation. Reason: ETR1 affects defense responses indirectly through its role in ethylene signaling, which modulates plant defense pathways. This is a secondary function rather than a core molecular function of the ethylene receptor. Supporting Evidence: PMID:16255250 Potato homologs of Arabidopsis thaliana genes functional in defense signaling--identification, genetic mapping, and molecular cloning |
| GO:0009408 response to heat | IMP PMID:15923322 Heat stress phenotypes of Arabidopsis mutants implicate mult... | KEEP AS NON CORE | Summary: This study examines heat stress phenotypes in Arabidopsis mutants including ethylene signaling components. ETR1 role in heat response is through ethylene signaling modulation. Reason: ETR1 affects heat stress responses indirectly through ethylene signaling pathways. While ethylene signaling can be modulated by temperature stress, this is a secondary function rather than a core molecular function. Supporting Evidence: PMID:15923322 Heat stress phenotypes of Arabidopsis mutants implicate multiple signaling pathways in the acquisition of thermotolerance |
| GO:0009625 response to insect | IMP PMID:15923339 Major signaling pathways modulate Arabidopsis glucosinolate ... | KEEP AS NON CORE | Summary: This study examines signaling pathways modulating glucosinolate accumulation and insect response. ETR1 involvement would be through ethylene signaling effects on defense pathways. Reason: ETR1 affects insect responses indirectly through ethylene signaling regulation of defense pathways including glucosinolate metabolism. This is a secondary defense function rather than a core molecular function. Supporting Evidence: PMID:15923339 Major signaling pathways modulate Arabidopsis glucosinolate accumulation and response to both phloem-feeding and chewing insects |
| GO:0009651 response to salt stress | IEP PMID:15044023 Effect of salt and osmotic stress upon expression of the eth... | KEEP AS NON CORE | Summary: This study examines the effect of salt stress on ETR1 gene expression levels. ETR1 expression is modulated by osmotic stress conditions. Reason: While ETR1 expression responds to salt stress and ethylene signaling can be modulated by abiotic stress, this is a secondary stress response rather than a core molecular function of the ethylene receptor. Supporting Evidence: PMID:15044023 Effect of salt and osmotic stress upon expression of the ethylene receptor ETR1 in Arabidopsis thaliana |
| GO:0009690 cytokinin metabolic process | IMP PMID:15773852 The etr1-2 mutation in Arabidopsis thaliana affects the absc... | KEEP AS NON CORE | Summary: This study shows etr1-2 mutation affects cytokinin metabolic pathways during seed dormancy and germination. ETR1 affects cytokinin metabolism through cross-talk between hormone signaling pathways. Reason: ETR1 affects cytokinin metabolism indirectly through hormone signaling cross-talk. While functionally relevant, this represents interaction between hormone pathways rather than a core function of the ethylene receptor. Supporting Evidence: PMID:15773852 The etr1-2 mutation in Arabidopsis thaliana affects the abscisic acid, auxin, cytokinin and gibberellin metabolic pathways during maintenance of seed dormancy, moist-chilling and germination |
| GO:0009727 detection of ethylene stimulus | IMP PMID:9974395 A copper cofactor for the ethylene receptor ETR1 from Arabid... | ACCEPT | Summary: This study demonstrates the copper cofactor requirement for ethylene binding by ETR1, which is essential for ethylene detection and perception. Reason: Detection of ethylene stimulus is a core biological process for ETR1. This study provides direct experimental evidence for the copper cofactor requirement in ethylene detection, which is fundamental to ETR1 function. Supporting Evidence: PMID:9974395 A copper cofactor for the ethylene receptor ETR1 from Arabidopsis file:ARATH/ETR1/ETR1-deep-research-falcon.md ETR1’s primary biochemical role is **ethylene perception** via its N-terminal transmembrane sensor domain, requiring a **Cu(I)** cofactor. |
| GO:0009733 response to auxin | IMP PMID:15773852 The etr1-2 mutation in Arabidopsis thaliana affects the absc... | KEEP AS NON CORE | Summary: This study shows etr1-2 mutation affects auxin metabolic pathways during seed dormancy processes. ETR1 affects auxin responses through hormone signaling cross-talk. Reason: ETR1 affects auxin responses indirectly through hormone signaling cross-talk. While this demonstrates functional interaction between hormone pathways, it is not a core function of the ethylene receptor. Supporting Evidence: PMID:15773852 The etr1-2 mutation in Arabidopsis thaliana affects the abscisic acid, auxin, cytokinin and gibberellin metabolic pathways during maintenance of seed dormancy, moist-chilling and germination |
| GO:0009737 response to abscisic acid | IMP PMID:15773852 The etr1-2 mutation in Arabidopsis thaliana affects the absc... | KEEP AS NON CORE | Summary: This study shows etr1-2 mutation affects ABA metabolic pathways during seed dormancy. ETR1 affects ABA responses through hormone signaling cross-talk. Reason: ETR1 affects ABA responses indirectly through hormone signaling cross-talk during seed dormancy processes. This represents interaction between hormone pathways rather than a core function of the ethylene receptor. Supporting Evidence: PMID:15773852 The etr1-2 mutation in Arabidopsis thaliana affects the abscisic acid, auxin, cytokinin and gibberellin metabolic pathways during maintenance of seed dormancy, moist-chilling and germination |
| GO:0009739 response to gibberellin | IMP PMID:15773852 The etr1-2 mutation in Arabidopsis thaliana affects the absc... | KEEP AS NON CORE | Summary: This study shows etr1-2 mutation affects gibberellin metabolic pathways during seed dormancy. ETR1 affects GA responses through hormone signaling cross-talk. Reason: ETR1 affects gibberellin responses indirectly through hormone signaling cross-talk. This represents interaction between hormone pathways during development rather than a core function of the ethylene receptor. Supporting Evidence: PMID:15773852 The etr1-2 mutation in Arabidopsis thaliana affects the abscisic acid, auxin, cytokinin and gibberellin metabolic pathways during maintenance of seed dormancy, moist-chilling and germination |
| GO:0010182 sugar mediated signaling pathway | TAS PMID:12663220 Sugar and hormone connections. | KEEP AS NON CORE | Summary: This study examines connections between sugar and hormone signaling pathways. ETR1 involvement in sugar signaling would be indirect through ethylene-sugar signaling cross-talk. Reason: ETR1 affects sugar signaling indirectly through hormone signaling cross-talk. While ethylene and sugar signaling pathways interact, this is not a core function of the ethylene receptor but rather represents pathway interactions. Supporting Evidence: PMID:12663220 Sugar and hormone connections |
| GO:0010105 negative regulation of ethylene-activated signaling pathway | TAS PMID:11916973 Localization of the ethylene receptor ETR1 to the endoplasmi... | ACCEPT | Summary: This study demonstrates ETR1 localization to ER and its role as negative regulator of ethylene signaling. TAS evidence supports the well-established negative regulatory function. Reason: Negative regulation of ethylene signaling is a core biological process function of ETR1. This study provides traceable author statement evidence supporting this fundamental role. Supporting Evidence: PMID:11916973 Localization of the ethylene receptor ETR1 to the endoplasmic reticulum of Arabidopsis |
| GO:0010105 negative regulation of ethylene-activated signaling pathway | TAS PMID:11950991 Mutational analysis of the ethylene receptor ETR1. Role of t... | ACCEPT | Summary: This study examines the histidine kinase domain role in ETR1 negative regulation of ethylene responses through mutational analysis. Reason: Negative regulation of ethylene signaling is a core function of ETR1. This study provides TAS evidence examining the molecular mechanism of this negative regulation. Supporting Evidence: PMID:11950991 Mutational analysis of the ethylene receptor ETR1. Role of the histidine kinase domain in dominant ethylene insensitivity |
| GO:0010105 negative regulation of ethylene-activated signaling pathway | TAS PMID:12177468 Loss-of-function mutations in the ethylene receptor ETR1 cau... | ACCEPT | Summary: This study demonstrates that loss-of-function ETR1 mutations cause enhanced ethylene sensitivity, confirming ETR1 role as negative regulator. Reason: This is core evidence for ETR1 negative regulatory function. Loss-of-function studies provide direct genetic evidence that ETR1 normally suppresses ethylene responses. Supporting Evidence: PMID:12177468 Loss-of-function mutations in the ethylene receptor ETR1 cause enhanced sensitivity and exaggerated response to ethylene in Arabidopsis |
| GO:0010105 negative regulation of ethylene-activated signaling pathway | TAS PMID:12481081 Effect of ethylene pathway mutations upon expression of the ... | ACCEPT | Summary: This study examines the effect of ethylene pathway mutations on ETR1 gene expression in context of negative regulation. Reason: Core function of ETR1 as negative regulator of ethylene signaling. This study provides TAS evidence in the context of ethylene pathway regulation. Supporting Evidence: PMID:12481081 Effect of ethylene pathway mutations upon expression of the ethylene receptor ETR1 from Arabidopsis |
| GO:0010105 negative regulation of ethylene-activated signaling pathway | TAS PMID:12509505 Canonical histidine kinase activity of the transmitter domai... | ACCEPT | Summary: This study examines canonical histidine kinase activity of ETR1 transmitter domain and its role in negative regulation of ethylene signaling. Reason: Core function of ETR1 as negative regulator. This study provides TAS evidence examining the molecular mechanism of negative regulation through kinase activity. Supporting Evidence: PMID:12509505 Canonical histidine kinase activity of the transmitter domain of the ETR1 ethylene receptor from Arabidopsis is not required for signal transmission |
| GO:0010105 negative regulation of ethylene-activated signaling pathway | TAS PMID:12953109 Analysis of combinatorial loss-of-function mutants in the Ar... | ACCEPT | Summary: This study analyzes combinatorial loss-of-function mutants in ethylene receptors, demonstrating the negative regulatory role of ETR1 and ERS1. Reason: Core function of ETR1 as negative regulator. This study provides TAS evidence through genetic analysis of receptor loss-of-function combinations. Supporting Evidence: PMID:12953109 Analysis of combinatorial loss-of-function mutants in the Arabidopsis ethylene receptors reveals that the ers1 etr1 double mutant has severe developmental defects that are EIN2 dependent |
| GO:0010105 negative regulation of ethylene-activated signaling pathway | TAS PMID:7759498 The ethylene response mediator ETR1 from Arabidopsis forms a... | ACCEPT | Summary: This study demonstrates ETR1 forms disulfide-linked dimers and establishes its negative regulatory role in ethylene signaling. Reason: Core function of ETR1 as negative regulator. This is one of the foundational studies establishing ETR1 negative regulatory role and dimer formation. Supporting Evidence: PMID:7759498 The ethylene response mediator ETR1 from Arabidopsis forms a disulfide-linked dimer |
| GO:0010105 negative regulation of ethylene-activated signaling pathway | TAS PMID:8211181 Arabidopsis ethylene-response gene ETR1: similarity of produ... | ACCEPT | Summary: This is the original foundational study that identified ETR1 as an ethylene response gene with similarity to two-component regulators and established its negative regulatory role. Reason: Core function of ETR1 as negative regulator. This is the seminal study that first identified ETR1 and established its fundamental role as negative regulator of ethylene responses. Supporting Evidence: PMID:8211181 Arabidopsis ethylene-response gene ETR1: similarity of product to two-component regulators |
| GO:0010105 negative regulation of ethylene-activated signaling pathway | TAS PMID:8525372 Ethylene-binding sites generated in yeast expressing the Ara... | ACCEPT | Summary: This study demonstrates ethylene-binding sites generated in yeast expressing ETR1, confirming its role as ethylene receptor and negative regulator. Reason: Core function of ETR1 as negative regulator. This study provides TAS evidence by demonstrating ETR1 ethylene binding in heterologous system, supporting its negative regulatory role. Supporting Evidence: PMID:8525372 Ethylene-binding sites generated in yeast expressing the Arabidopsis ETR1 gene |
| GO:0010105 negative regulation of ethylene-activated signaling pathway | TAS PMID:9695954 Ethylene responses are negatively regulated by a receptor ge... | ACCEPT | Summary: This study demonstrates that ethylene responses are negatively regulated by the receptor gene family including ETR1 in Arabidopsis. Reason: Core function of ETR1 as negative regulator. This study provides direct TAS evidence that the ethylene receptor family, including ETR1, negatively regulates ethylene responses. Supporting Evidence: PMID:9695954 Ethylene responses are negatively regulated by a receptor gene family in Arabidopsis thaliana |
| GO:0009739 response to gibberellin | IMP PMID:12121467 Characterization of mutants with reduced seed dormancy at tw... | KEEP AS NON CORE | Summary: This study characterizes mutants with reduced seed dormancy and examines gibberellin response. ETR1 affects GA responses through hormone signaling cross-talk during seed dormancy. Reason: ETR1 affects gibberellin responses indirectly through hormone signaling cross-talk during seed dormancy processes. This represents interaction between hormone pathways rather than a core function. Supporting Evidence: PMID:12121467 Characterization of mutants with reduced seed dormancy at two novel rdo loci and a further characterization of rdo1 and rdo2 in Arabidopsis |
| GO:0010162 seed dormancy process | IMP PMID:12121467 Characterization of mutants with reduced seed dormancy at tw... | KEEP AS NON CORE | Summary: This study examines mutants with reduced seed dormancy. ETR1 affects seed dormancy indirectly through ethylene signaling effects on dormancy regulation. Reason: ETR1 affects seed dormancy indirectly through ethylene signaling regulation. While functionally relevant, this is a developmental process downstream of ethylene signaling rather than a core molecular function. Supporting Evidence: PMID:12121467 Characterization of mutants with reduced seed dormancy at two novel rdo loci and a further characterization of rdo1 and rdo2 in Arabidopsis |
| GO:0005789 endoplasmic reticulum membrane | IDA PMID:11916973 Localization of the ethylene receptor ETR1 to the endoplasmi... | ACCEPT | Summary: This study provides direct experimental evidence for ETR1 localization to the ER membrane, which is the specific subcellular location where ETR1 functions as a transmembrane receptor. Reason: ETR1 is an integral membrane protein of the ER with transmembrane domains. This study provides direct experimental evidence (IDA) for the specific membrane localization, which is more precise than general ER localization. Supporting Evidence: PMID:11916973 Localization of the ethylene receptor ETR1 to the endoplasmic reticulum of Arabidopsis file:ARATH/ETR1/ETR1-deep-research-falcon.md Ethylene perception for ETR1 occurs at an **ER-associated membrane** (endomembrane system) rather than the plasma membrane |
| GO:0009871 jasmonic acid and ethylene-dependent systemic resistance, ethylene mediated signaling pathway | TAS PMID:9191038 Histidine kinases in signal transduction pathways of eukaryo... | KEEP AS NON CORE | Summary: This study examines histidine kinases in eukaryotic signal transduction pathways. ETR1 participates in ethylene-mediated signaling within systemic resistance responses. Reason: While ETR1 participates in ethylene signaling that contributes to systemic resistance, this is a complex multi-hormone defense response. The primary function of ETR1 is ethylene perception and signal transduction. Supporting Evidence: PMID:9191038 Histidine kinases in signal transduction pathways of eukaryotes |
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Download this section (compressed HTML)Q: How does the copper cofactor coordinate ethylene binding in the transmembrane domain and what is the precise molecular mechanism of ethylene perception?
Suggested experts: Plant hormone perception specialists, Membrane protein structural biologists
Q: What determines the specificity of CTR1 interaction with different ethylene receptor family members and how does this affect downstream signaling?
Suggested experts: Two-component system researchers, Plant kinase signaling specialists
Q: How do the GAF domain and receiver domain coordinate to transduce the ethylene signal from the transmembrane sensor to the histidine kinase?
Suggested experts: Signal transduction researchers, Two-component system specialists
Q: What are the mechanisms governing ETR1 homo- and hetero-dimerization and how do different receptor combinations affect ethylene sensitivity?
Suggested experts: Membrane protein complex researchers, Plant receptor biology specialists
Experiment: Use hydrogen-deuterium exchange mass spectrometry to map conformational changes in ETR1 upon ethylene treatment. Generate cysteine-scanning mutagenesis of transmembrane regions and use cross-linking mass spectrometry to determine structural rearrangements. Test kinase activity of domain mutants using autophosphorylation assays.
Hypothesis: Ethylene binding induces conformational changes in the transmembrane domain that are transmitted to the cytoplasmic kinase domain through the GAF domain
Experiment: Generate copper-binding site mutants and test ethylene binding affinity using radioactive ethylene binding assays. Analyze the effect of copper chelators and copper supplementation on ethylene sensitivity in vivo. Use X-ray absorption spectroscopy to characterize copper coordination geometry in different functional states.
Hypothesis: The copper cofactor is essential for ethylene binding specificity and can be modulated by cellular copper availability
Experiment: Generate phosphomimetic and phosphodeficient mutants of predicted autophosphorylation sites and test their effects on downstream signaling using ethylene response assays. Use quantitative phosphoproteomics to map phosphorylation dynamics and measure phosphotransfer rates to AHP proteins using kinetic assays.
Hypothesis: ETR1 phosphorelay activity requires specific phosphorylation sites and phosphotransfer kinetics that determine signal strength
Experiment: Use super-resolution microscopy to analyze ETR1 clustering and organization in ER membranes under different ethylene conditions. Test the role of membrane lipid composition on receptor function using lipidomics and reconstitution experiments. Analyze protein complex composition using proximity biotinylation and co-immunoprecipitation.
Hypothesis: ETR1 subcellular localization and membrane organization are regulated by receptor activation state and affect signaling complex assembly
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