GID1A

UniProt ID: Q9MAA7
Organism: Arabidopsis thaliana
Review Status: DRAFT
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Gene Description

GID1A (GA INSENSITIVE DWARF1A; locus At3g05120) is one of three soluble nuclear gibberellin (GA) receptors in Arabidopsis thaliana (with the partially redundant paralogs GID1B and GID1C). It belongs to the carboxylesterase / hormone-sensitive lipase superfamily and adopts an alpha/beta-hydrolase fold, but it has lost catalytic hydrolase activity and instead functions as a hormone receptor. GID1A binds bioactive gibberellins (highest affinity for GA4) in a deep pocket that becomes capped by an N-terminal helical switch. GA binding triggers a conformational change in this N-terminal region that creates a surface for direct, GA-dependent interaction with the DELLA growth-repressor proteins (GAI, RGA, RGL1, RGL2, RGL3) via their N-terminal DELLA domain. The resulting GA-GID1-DELLA complex promotes recruitment of the SLEEPY1 (SLY1) F-box subunit of an SCF E3 ubiquitin ligase, leading to polyubiquitination and 26S-proteasomal degradation of DELLA repressors; GA-bound GID1 can also inhibit DELLA repression by a proteolysis-independent mechanism. Through this receptor activity GID1A acts as a positive regulator of GA signaling, derepressing the many developmental processes controlled by gibberellin, including seed germination, stem and root elongation, flower and floral-organ development, fruit-set and fruit growth, and fertility. The receptor is itself subject to regulation, being targeted for ubiquitin- dependent degradation by the RING E3 ligase GARU. GID1A is widely expressed and, among the three receptors, contributes the strongest single-gene effect; loss of all three GID1 genes produces an extreme, GA-insensitive dwarf.

Proposed New Ontology Terms

gibberellin receptor activity

Definition: Binding to a gibberellin and triggering a conformational change that promotes gibberellin-dependent physical interaction with, and subsequent degradation of, DELLA repressor proteins, thereby transducing the gibberellin signal.

Justification: GID1A is a bona fide gibberellin receptor whose ligand binding triggers a conformational change and GA-dependent interaction with DELLA effector proteins. No specific molecular function term for gibberellin receptor activity currently exists in GO (verified absent in OLS); the closest available verified term is GO:0010331 gibberellin binding, which does not capture the receptor (signal transduction) aspect. A child of hormone receptor activity / signaling receptor activity for gibberellin would more accurately represent this function.

Supporting Evidence:

Existing Annotations Review

GO Term Evidence Action Reason
GO:0005634 nucleus
IEA
GO_REF:0000044
ACCEPT
Summary: GID1A is a nuclear gibberellin receptor; nuclear localization is where it perceives GA and interacts with the nuclear-localized DELLA repressors.
Reason: Consistent with UniProt subcellular location (Nucleus) and with the repeated description of GID1 as a nuclear receptor; also supported by experimental IDA evidence (PMID:17416730, PMID:29042542).
Supporting Evidence:
PMID:19037309
By binding to a nuclear receptor, GIBBERELLIN INSENSITIVE DWARF1 (GID1), gibberellins regulate gene expression by promoting degradation of the transcriptional regulator DELLA proteins
GO:0016787 hydrolase activity
IEA
GO_REF:0000002
REMOVE
Summary: This InterPro-based annotation derives from the alpha/beta-hydrolase / carboxylesterase (hormone-sensitive lipase) fold. GID1 proteins retain the fold but lack hydrolase/esterase catalytic activity; they act as GA receptors.
Reason: GID1 was explicitly described as similar to the hormone-sensitive lipase family but WITHOUT hydrolase activity. The protein binds GA as a receptor in a pocket on the hydrolase fold rather than catalyzing hydrolysis. The nominal UniProt EC=3.-.-.- and InterPro fold mapping produce a spurious catalytic MF annotation that does not reflect the true (receptor) function.
Supporting Evidence:
PMID:24961590
GID1 was first described in rice as a nuclear localized protein similar to hormone-sensitive lipase family without hydrolase activity
file:ARATH/GID1A/GID1A-deep-research-falcon.md
the receptor lacks key catalytic features and shows **no detectable hydrolase activity** in a model substrate assay (p-nitrophenyl acetate)
file:ARATH/GID1A/GID1A-hypotheses/gid1a-catalytic-inactivity/openscientist.md
GID1A retains the nucleophile Ser191 (in a GDSSG nucleophile elbow), the acid Asp289, and the HGG oxyanion loop (His113), but the general-base His is gone.
GO:0048530 fruit morphogenesis
IEA
GO_REF:0000117
KEEP AS NON CORE
Summary: GID1A is the major GA receptor controlling fruit-set and fruit growth in Arabidopsis, acting partially redundantly with GID1B and GID1C.
Reason: Supported by mutant analysis (PMID:24961590), but this is a downstream developmental output of GA perception rather than the molecular core function. Also annotated independently with experimental (IMP/IGI) evidence below.
Supporting Evidence:
PMID:24961590
GID1A plays a major role during fruit-set and growth, whereas GID1B and GID1C have specific roles in seed development and pod elongation
GO:0005515 protein binding
IPI
PMID:16709201
Identification and characterization of Arabidopsis gibberell...
REMOVE
Summary: IPI interactions (IntAct) with DELLA proteins RGL2 (Q8GXW1), RGL1 (Q9C8Y3), GAI (Q9LQT8), RGA (Q9SLH3) and GID2 (Q9STX3). These GA-dependent DELLA interactions are central to GID1A's receptor function, but the generic "protein binding" term is uninformative.
Reason: Generic protein binding is uninformative and is not retained under the current protein-binding policy. The GA-dependent GID1A-DELLA interaction is real and central to receptor function, but it is captured by gibberellin binding (GO:0010331), the GA signaling process terms and the proposed gibberellin receptor activity term; GO has no MF term specifically describing DELLA binding by an activated hormone receptor. Removal does not mean the interaction is false.
Supporting Evidence:
PMID:16709201
A two-hybrid yeast system only showed in vivo interaction in the presence of GA(4) between each AtGID1 and the Arabidopsis DELLA proteins (AtDELLAs), negative regulators of GA signaling
GO:0005515 protein binding
IPI
PMID:17194763
Genetic characterization and functional analysis of the GID1...
REMOVE
Summary: IPI interactions with the DELLA proteins GAI (Q9LQT8) and RGA (Q9SLH3), and with the F-box protein SLY1/GID2 (Q9STX3) in yeast three-hybrid assays in which GA-GID1 promotes RGA-SLY1 association. GA enhances GID1A-DELLA interaction; the N-terminal DELLA domain is required for binding.
Reason: Generic protein binding is uninformative and is not retained under the current protein-binding policy. The GA-dependent GID1A-DELLA interaction is real and central to receptor function, but it is captured by gibberellin binding (GO:0010331), the GA signaling process terms and the proposed gibberellin receptor activity term; GO has no MF term specifically describing DELLA binding by an activated hormone receptor. Removal does not mean the interaction is false.
Supporting Evidence:
PMID:17194763
GA enhances the interaction between GID1 and DELLA proteins. In addition, the N-terminal sequence containing the DELLA domain is necessary for GID1 binding
GO:0005515 protein binding
IPI
PMID:17416730
The DELLA domain of GA INSENSITIVE mediates the interaction ...
REMOVE
Summary: IPI interactions with DELLA proteins (GAI/RGA). The GAI DELLA domain is both required and sufficient to mediate GA-dependent interaction with the GID1A receptor, acting as a receiver domain.
Reason: Generic protein binding is uninformative and is not retained under the current protein-binding policy. The GA-dependent GID1A-DELLA interaction is real and central to receptor function, but it is captured by gibberellin binding (GO:0010331), the GA signaling process terms and the proposed gibberellin receptor activity term; GO has no MF term specifically describing DELLA binding by an activated hormone receptor. Removal does not mean the interaction is false.
Supporting Evidence:
PMID:17416730
we found that the GAI DELLA domain alone can mediate GA-dependent GID1A interactions, we propose that the DELLA domain functions as a receiver domain for activated GA receptors
file:ARATH/GID1A/GID1A-deep-research-falcon.md
The isolated DELLA domain can be **sufficient** for GA-dependent interaction with GID1A in yeast assays, and mutations in this region can confer GA insensitivity by disrupting GID1A binding.
GO:0005515 protein binding
IPI
PMID:18216856
Coordinated regulation of Arabidopsis thaliana development b...
REMOVE
Summary: IPI interactions including DELLA proteins (GAI, RGA, RGL1, RGL2, RGL3) from a study linking GA-GID1-DELLA signaling to light/PIF3 control of growth.
Reason: Generic protein binding is uninformative and is not retained under the current protein-binding policy. The GA-dependent GID1A-DELLA interaction is real and central to receptor function, but it is captured by gibberellin binding (GO:0010331), the GA signaling process terms and the proposed gibberellin receptor activity term; GO has no MF term specifically describing DELLA binding by an activated hormone receptor. Removal does not mean the interaction is false.
Supporting Evidence:
PMID:18216856
DELLA proteins are GA-signalling repressors that block GA-induced development
GO:0005515 protein binding
IPI
PMID:18827182
Proteolysis-independent downregulation of DELLA repression i...
REMOVE
Summary: IPI interaction with DELLA GAI (Q9LQT8). GA-bound GID1 shows increasing interaction with DELLA at increasing GA levels and can block DELLA repression by direct interaction (proteolysis-independent mechanism).
Reason: Generic protein binding is uninformative and is not retained under the current protein-binding policy. The GA-dependent GID1A-DELLA interaction is real and central to receptor function, but it is captured by gibberellin binding (GO:0010331), the GA signaling process terms and the proposed gibberellin receptor activity term; GO has no MF term specifically describing DELLA binding by an activated hormone receptor. Removal does not mean the interaction is false.
Supporting Evidence:
PMID:18827182
GA-bound GID1 can block DELLA repressor activity by direct protein-protein interaction with the DELLA domain
file:ARATH/GID1A/GID1A-deep-research-falcon.md
GA-bound GID1 can reduce DELLA repression without necessarily inducing DELLA degradation
GO:0005515 protein binding
IPI
PMID:19037309
Gibberellin-induced DELLA recognition by the gibberellin rec...
REMOVE
Summary: IPI interaction with DELLA GAI (Q9LQT8); the crystal structure of the GID1A-GA-GAI(DELLA) ternary complex defines the GA-dependent DELLA recognition interface.
Reason: Generic protein binding is uninformative and is not retained under the current protein-binding policy. The GA-dependent GID1A-DELLA interaction is real and central to receptor function, but it is captured by gibberellin binding (GO:0010331), the GA signaling process terms and the proposed gibberellin receptor activity term; GO has no MF term specifically describing DELLA binding by an activated hormone receptor. Removal does not mean the interaction is false.
Supporting Evidence:
PMID:19037309
GID1A occludes gibberellin in a deep binding pocket covered by its N-terminal helical switch region, which in turn interacts with the DELLA domain containing DELLA, VHYNP and LExLE motifs
GO:0005515 protein binding
IPI
PMID:19500306
Differential expression and affinities of Arabidopsis gibber...
REMOVE
Summary: IPI interactions with DELLA proteins (RGL2 and others) examining differential receptor-DELLA affinities that explain phenotypic variation among gid1 mutants.
Reason: Generic protein binding is uninformative and is not retained under the current protein-binding policy. The GA-dependent GID1A-DELLA interaction is real and central to receptor function, but it is captured by gibberellin binding (GO:0010331), the GA signaling process terms and the proposed gibberellin receptor activity term; GO has no MF term specifically describing DELLA binding by an activated hormone receptor. Removal does not mean the interaction is false.
Supporting Evidence:
PMID:19500306
Differential expression and affinities of Arabidopsis gibberellin receptors can explain variation in phenotypes of multiple knock-out mutants
GO:0005515 protein binding
IPI
PMID:32612234
Extensive signal integration by the phytohormone protein net...
REMOVE
Summary: High-throughput yeast two-hybrid phytohormone interaction network; source of GID1A interactions including DELLAs plus non-DELLA partners such as importin alpha-3 (IMPA3, O04294) and MES17 (Q9SG92).
Reason: Generic protein binding from a large-scale yeast two-hybrid screen; the DELLA interactions are captured by the receptor annotations and the non-DELLA partners (e.g. IMPA3, MES17) lack functional follow-up. Uninformative; removal does not mean the interactions are false.
Supporting Evidence:
PMID:32612234
Extensive signal integration by the phytohormone protein network
GO:0071456 cellular response to hypoxia
HEP
PMID:31519798
Integrative Analysis from the Epigenome to Translatome Uncov...
MARK AS OVER ANNOTATED
Summary: GID1A was identified as transcriptionally regulated in a genome-wide epigenome-to-translatome survey of seedling hypoxia/reoxygenation. This is a high-throughput expression pattern (HEP) observation, not direct evidence that GID1A functions in the hypoxia response.
Reason: HEP from a global stress profiling study captures co-regulation rather than a dedicated function. GID1A's characterized role is GA perception; there is no focused evidence that it acts within the hypoxia response specifically.
Supporting Evidence:
PMID:31519798
we performed a survey spanning the epigenome to translatome of Arabidopsis (Arabidopsis thaliana) seedlings in response to hypoxia and reoxygenation
GO:0005634 nucleus
ISM
GO_REF:0000122
ACCEPT
Summary: Computational (AtSubP) prediction of nuclear localization, consistent with GID1A being a nuclear GA receptor and with experimental IDA evidence.
Reason: Redundant computational support for a nuclear location that is also backed by experimental IDA annotations and the receptor mechanism.
Supporting Evidence:
PMID:19037309
By binding to a nuclear receptor, GIBBERELLIN INSENSITIVE DWARF1 (GID1), gibberellins regulate gene expression
GO:0005515 protein binding
IPI
PMID:29042542
Tyrosine phosphorylation of the GARU E3 ubiquitin ligase pro...
REMOVE
Summary: IPI interaction (TAIR) with GARU (AT2G40830), the RING E3 ubiquitin ligase that targets GID1 for ubiquitin-dependent degradation, regulating receptor abundance and thus GA signaling.
Reason: Generic protein binding is uninformative. The interaction documents GID1A as a substrate of the RING E3 ligase GARU, which regulates receptor abundance; being a ubiquitination substrate is not a molecular function of GID1A, so no informative MF replacement applies. Removal does not mean the interaction is false.
Supporting Evidence:
PMID:29042542
GARU (GA receptor RING E3 ubiquitin ligase) mediates ubiquitin-dependent degradation of GID1
GO:0005634 nucleus
IDA
PMID:29042542
Tyrosine phosphorylation of the GARU E3 ubiquitin ligase pro...
ACCEPT
Summary: Direct experimental evidence localizing GID1A to the nucleus, consistent with its function as a nuclear GA receptor acting on nuclear DELLA proteins.
Reason: Experimental IDA support for the core nuclear localization.
Supporting Evidence:
PMID:29042542
Tyrosine phosphorylation of the GARU E3 ubiquitin ligase promotes gibberellin signalling by preventing GID1 degradation
GO:0009739 response to gibberellin
IGI NOT
PMID:24961590
Role of the gibberellin receptors GID1 during fruit-set in A...
REMOVE
Summary: NOT|involved_in response to gibberellin (IGI, with GID1B UniProtKB:Q9LYC1) from the fruit-set redundancy study, based on the absence of a GA-response defect in a mutant combination that still retains a redundant GID1 paralog.
Reason: The negation is contradicted by direct evidence that GID1A is a functional GA receptor (GA binding, GA-dependent DELLA interaction, rescue of rice gid1) and by the IMP/IGI annotations from the same paper showing GID1A is required for pistil GA responses. A missing phenotype in a background retaining redundant receptors reflects genetic redundancy, not absence of involvement. Handled the same way as the equivalent NOT rows on GID1B and GID1C.
Supporting Evidence:
PMID:16709201
These results demonstrate that all three AtGID1s functioned as GA receptors in Arabidopsis
PMID:24961590
the gid1a gid1c pistils displayed little or no GA response
GO:0009739 response to gibberellin
IMP
PMID:24961590
Role of the gibberellin receptors GID1 during fruit-set in A...
ACCEPT
Summary: Mutant phenotype evidence that GID1A is involved in GA responses during fruit-set; gid1 mutant combinations show GA-perception defects in maternal pistil tissues.
Reason: Experimental (IMP) support for GID1A involvement in response to gibberellin, the expected role of a GA receptor.
Supporting Evidence:
PMID:24961590
the gid1a gid1c pistils displayed little or no GA response
GO:0009739 response to gibberellin
IGI
PMID:24961590
Role of the gibberellin receptors GID1 during fruit-set in A...
ACCEPT
Summary: Genetic-interaction evidence (with GID1C, UniProtKB:Q940G6) that GID1A acts partially redundantly with the other GID1 receptors in GA responses.
Reason: Supports involvement in response to gibberellin via redundancy analysis; consistent with the receptor's role.
Supporting Evidence:
PMID:24961590
our data suggest that the three GID1 GA receptors act partially redundantly in pistil development
GO:0048530 fruit morphogenesis
IMP
PMID:24961590
Role of the gibberellin receptors GID1 during fruit-set in A...
KEEP AS NON CORE
Summary: Mutant phenotype evidence that GID1A is the major GA receptor driving fruit-set and fruit (pod) growth and endocarp differentiation.
Reason: Genuine, experimentally supported developmental role, but a downstream output of GA perception rather than the molecular core function; partially redundant with paralogs.
Supporting Evidence:
PMID:24961590
GID1A has a major role in the regulation of the differentiation of the inner cell layers of the fruit pod
GO:0048530 fruit morphogenesis
IGI
PMID:24961590
Role of the gibberellin receptors GID1 during fruit-set in A...
KEEP AS NON CORE
Summary: Genetic-interaction evidence (with GID1C, UniProtKB:Q940G6) for GID1A function in fruit morphogenesis through partial redundancy with other GID1 receptors.
Reason: Downstream developmental output, redundant with paralogs; retained as non-core.
Supporting Evidence:
PMID:24961590
GID1A and GID1C are expressed in valves, while GID1A and GID1B are expressed in ovules
GO:1905516 positive regulation of fertilization
IGI
PMID:24961590
Role of the gibberellin receptors GID1 during fruit-set in A...
KEEP AS NON CORE
Summary: Genetic-interaction evidence (with UniProtKB:Q9LYC1) implicating GID1A in fertility/fertilization; gid1a-containing double mutants show reduced seed-set from maternal pistil defects.
Reason: A GA-dependent reproductive output downstream of GA perception; supported genetically but not the molecular core function. Retained as non-core.
Supporting Evidence:
PMID:24961590
the single gid1a and the double gid1a gid1b and gid1a gid1c mutants display compromised fertility
GO:0010476 gibberellin mediated signaling pathway
IGI
PMID:17521411
Multiple loss-of-function of Arabidopsis gibberellin recepto...
ACCEPT
Summary: Loss-of-function genetics show that the GID1 receptors are required for GA signaling; the triple mutant completely loses the ability to respond to GA, placing GID1A within the GA-mediated signaling pathway.
Reason: Core function. GID1A is a GA receptor that initiates the GA-mediated signaling pathway; strongly supported by genetic shutdown of GA signaling in gid1 multiple mutants.
Supporting Evidence:
PMID:17521411
the triple knockout seedlings completely lost their ability to respond to exogenously applied GA
file:ARATH/GID1A/GID1A-deep-research-falcon.md
GA **perception** occurs when a bioactive GA binds the soluble receptor **GID1**, enabling GID1 to recognize DELLA repressors and thereby switch GA signaling β€œon.”
GO:0010331 gibberellin binding
IDA
PMID:19037309
Gibberellin-induced DELLA recognition by the gibberellin rec...
ACCEPT
Summary: GID1A directly binds bioactive gibberellins (GA3, GA4) in a deep pocket, as established biochemically and by the crystal structures of GID1A-GA complexes. This is the defining molecular activity of the GA receptor.
Reason: Core molecular function, supported by direct biochemical binding assays and X-ray structures. There is currently no specific "gibberellin receptor activity" GO term, so gibberellin binding is the best available verified MF term for the receptor's ligand-binding activity (see proposed_new_terms).
Supporting Evidence:
PMID:19037309
GID1A occludes gibberellin in a deep binding pocket covered by its N-terminal helical switch region
PMID:16709201
The GA-binding activities of the three recombinant proteins were confirmed by an in vitro assay
file:ARATH/GID1A/GID1A-deep-research-falcon.md
**GA4** is highlighted as the **highest-affinity** GA and the most effective for driving GID1–DELLA complex formation in planta
GO:0009739 response to gibberellin
IEP
PMID:17933900
Global analysis of della direct targets in early gibberellin...
ACCEPT
Summary: GID1A is among the early GA-/DELLA-responsive genes; DELLA feedback regulates expression of GA receptor genes, placing GID1A in the response to gibberellin (here as an expression-pattern annotation).
Reason: Consistent with GID1A's involvement in GA responses; the IEP reflects feedback regulation of the receptor gene by GA/DELLA. Redundant with the stronger signaling annotations.
Supporting Evidence:
PMID:17933900
they help establish GA homeostasis by direct feedback regulation on the expression of GA biosynthetic and GA receptor genes
GO:0009739 response to gibberellin
IGI
PMID:18827182
Proteolysis-independent downregulation of DELLA repression i...
ACCEPT
Summary: Genetic-interaction evidence (with GA1, AGI AT4G02780, the ent-copalyl diphosphate synthase locus of the GA-deficient ga1-3 background) supporting GID1A's role in GA responses; GA-bound GID1 downregulates DELLA repression both by SLY1-dependent degradation and by a proteolysis-independent mechanism, and GID1 overexpression rescue requires GA.
Reason: Supports involvement in response to gibberellin through the GA-GID1-DELLA mechanism; the GA1 (AT4G02780) interaction reflects the GA requirement of GID1 action. Consistent with the core receptor function.
Supporting Evidence:
PMID:18827182
GA-bound GID1 can block DELLA repressor activity by direct protein-protein interaction with the DELLA domain
GO:0005634 nucleus
IDA
PMID:17416730
The DELLA domain of GA INSENSITIVE mediates the interaction ...
ACCEPT
Summary: Direct experimental localization of GID1A to the nucleus, the compartment in which it engages nuclear DELLA repressors.
Reason: Experimental IDA support for the core nuclear localization.
Supporting Evidence:
PMID:17416730
mutants lacking the three GA INSENSITIVE DWARF1 (GID1) GA receptor genes are GA insensitive
GO:0005737 cytoplasm
IDA
PMID:17416730
The DELLA domain of GA INSENSITIVE mediates the interaction ...
ACCEPT
Summary: GID1A was also experimentally detected in the cytoplasm. As a soluble receptor, GID1A shows nucleo-cytoplasmic distribution in addition to its nuclear pool.
Reason: Direct experimental (IDA) evidence for cytoplasmic localization. Consistent with GID1A being a soluble receptor distributed between nucleus and cytoplasm; kept although the nuclear pool is most functionally relevant for DELLA interaction.
Supporting Evidence:
PMID:17416730
The DELLA domain of GA INSENSITIVE mediates the interaction with the GA INSENSITIVE DWARF1A gibberellin receptor of Arabidopsis
file:ARATH/GID1A/GID1A-deep-research-falcon.md
GFP-tagged Arabidopsis GID1A localized to both nucleus and cytoplasm, and this distribution was not altered by GA or paclobutrazol treatment.
GO:0005634 nucleus
IBA
GO_REF:0000033
ACCEPT
Summary: Nuclear localization inherited from the GID1 receptor clade node PTN000546395, whose seed is GID1A itself.
Reason: Consistent with the experimental (IDA) nuclear rows for GID1A and with the same IBA on GID1B. GID1A appears in its own WITH/FROM because its experimental nuclear localization is one of the descendant evidences behind the IBD; the IBA adds that nuclear residence is inherited across the GID1 clade.
Supporting Evidence:
PMID:19037309
By binding to a nuclear receptor, GIBBERELLIN INSENSITIVE DWARF1 (GID1), gibberellins regulate gene expression by promoting degradation of the transcriptional regulator DELLA proteins
GO:0005737 cytoplasm
IBA
GO_REF:0000033
ACCEPT
Summary: Cytoplasmic pool inherited from the GID1 clade node PTN000546395, seeded by the experimental nucleocytoplasmic localization of GID1A.
Reason: Same claim as the GID1A cytoplasm IDA row (PMID:17416730), which this review ACCEPTs, so the action matches it. GID1A is a soluble receptor found in both nucleus and cytoplasm; the nuclear pool is the one that engages DELLA.
Supporting Evidence:
file:ARATH/GID1A/GID1A-deep-research-falcon.md
GFP-tagged Arabidopsis GID1A localized to both nucleus and cytoplasm, and this distribution was not altered by GA or paclobutrazol treatment.
GO:0010331 gibberellin binding
IBA
GO_REF:0000033
ACCEPT
Summary: Gibberellin binding inherited from the GID1 receptor clade node PTN000546395, seeded by Arabidopsis GID1A and rice GID1 (Q6L545).
Reason: Core molecular function of the GA receptor, shown directly for GID1A by binding assays and crystal structures (IDA row PMID:19037309). The IBD placement on the GID1 clade, not the deeper esterase nodes, matches where GA binding arose. GID1A appearing among its own sources marks experimental grounding on the target.
Supporting Evidence:
PMID:19037309
GID1A occludes gibberellin in a deep binding pocket covered by its N-terminal helical switch region
PMID:16709201
The GA-binding activities of the three recombinant proteins were confirmed by an in vitro assay
GO:0016787 hydrolase activity
IBA
GO_REF:0000033
REMOVE
Summary: Hydrolase activity propagated from the deep PAINT node PTN009058710, seeded by active carboxylesterases that share the hormone-sensitive-lipase fold.
Reason: GID1A keeps the HSL fold, the Ser nucleophile and the oxyanion hole, but the general-base His of the catalytic triad is replaced by Val319, and GID1 proteins have no detectable hydrolase activity. The fold now forms the GA-binding pocket. Same action as the GID1A IEA hydrolase row and the GID1B IBA row (pseudoenzyme over-propagation).
Propagation Review
Root cause: PROPAGATION BAD
Failure modes: PSEUDO OR SUBACTIVITY LOSS FUNCTIONAL DIVERGENCE
Sources checked:
PANTHER:PTN009058710 Β· PTN009058710 SUPPORTS SOURCE BUT NOT TARGET
Deep PTHR23024 node seeded by catalytically active carboxylesterases and arylacetamide deacetylases (Arabidopsis CXEs, human AADAC P22760, mouse, yeast and bacterial esterases). The GID1 receptor clade nested within it lost the catalytic His (GID1A Val319) and was repurposed for GA binding; the IBD needs a loss (NOT) at the GID1 clade node. Same assessment as the GID1B row.
Supporting Evidence:
PMID:24961590
GID1 was first described in rice as a nuclear localized protein similar to hormone-sensitive lipase family without hydrolase activity
file:ARATH/GID1A/GID1A-hypotheses/gid1a-catalytic-inactivity/openscientist.md
GID1A retains the nucleophile Ser191 (in a GDSSG nucleophile elbow), the acid Asp289, and the HGG oxyanion loop (His113), but the general-base His is gone.

Core Functions

Binds bioactive gibberellins (preferentially GA4) as a soluble receptor, the ligand-binding event that activates GA signaling.

Molecular Function:
gibberellin binding
Cellular Locations:
Supporting Evidence:
  • PMID:19037309
    GID1A occludes gibberellin in a deep binding pocket covered by its N-terminal helical switch region, which in turn interacts with the DELLA domain
  • PMID:16709201
    The GA-binding activities of the three recombinant proteins were confirmed by an in vitro assay
  • file:ARATH/GID1A/GID1A-deep-research-falcon.md
    creates hydrophobic surfaces needed for DELLA binding

Acts as a positive regulator of GA signaling by forming a GA-dependent complex with DELLA repressor proteins via their N-terminal DELLA domain, promoting SCF(SLY1)-mediated DELLA ubiquitination/degradation (and proteolysis-independent inhibition), thereby derepressing GA responses.

Molecular Function:
gibberellin receptor activity (proposed)
Cellular Locations:
Supporting Evidence:
  • PMID:17194763
    the GA-GID1 complex promotes the interaction between RGA and the F-box protein SLY1, a component of the SCF(SLY1) E3 ubiquitin ligase that targets the DELLA protein for degradation
  • PMID:17416730
    the DELLA domain functions as a receiver domain for activated GA receptors
  • file:ARATH/GID1A/GID1A-deep-research-falcon.md
    cryo-EM structures resolve a **GA3–GID1A–RGA–SLY1–ASK1** complex, supporting the model that GA-bound GID1A positions DELLA for recognition by SCF-type ubiquitin ligase components

References

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Suggested Questions for Experts

Q: Does GID1A have any residual catalytic (esterase/lipase) activity in vivo, or is the alpha/beta-hydrolase fold entirely repurposed for ligand binding and the N-terminal switch?

Q: To what extent are the non-DELLA high-throughput interactors (e.g., importin alpha-3 IMPA3, MES17) functionally meaningful for GID1A regulation or trafficking, versus screen artifacts?

Q: What governs the nucleo-cytoplasmic partitioning of GID1A, and is GA perception by GID1A functionally restricted to the nucleus?

Deep Research

Falcon

(GID1A-deep-research-falcon.md)

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OpenScientist

(GID1A-hypotheses/gid1a-catalytic-inactivity/openscientist.md)

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πŸ“š Additional Documentation

Notes

(GID1A-notes.md)

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πŸ“„ View Raw YAML

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