skn-1

UniProt ID: P34707
Organism: Caenorhabditis elegans
Review Status: COMPLETE
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Gene Description

SKN-1 is the C. elegans ortholog of mammalian Nrf1/Nrf2 (CNC/bZIP) transcription factors, functioning as the master regulator of oxidative stress responses and xenobiotic detoxification. SKN-1 has three major isoforms with distinct functions: SKN-1A is ER-associated and mediates proteasome stress responses; SKN-1B localizes to ASI chemosensory neurons and mediates dietary restriction effects on longevity; SKN-1C is the primary intestinal isoform regulating Phase II detoxification genes. SKN-1 binds DNA as a monomer using a unique mechanism combining a bZIP-like basic region with an N-terminal arm for minor groove contacts. Key target genes include glutathione S-transferases (gst-4, gst-1), glutamate-cysteine ligase (gcs-1), and proteasome subunits. SKN-1 is regulated by p38/PMK-1 phosphorylation (activation), WDR-23/CUL4/DDB1 ubiquitin ligase complex (degradation), and insulin/IGF-1 signaling via AKT kinases (inhibition). Beyond stress responses, SKN-1 plays an essential developmental role in mesendoderm specification during embryogenesis, specifying the fate of ventral blastomeres that give rise to the pharynx and intestine.

Existing Annotations Review

GO Term Evidence Action Reason
GO:0000978 RNA polymerase II cis-regulatory region sequence-specific DNA binding
IBA
GO_REF:0000033
ACCEPT
Summary: SKN-1 binds DNA through a unique mechanism involving a bZIP-like basic region combined with an N-terminal arm that contacts the minor groove. Canonical Phase II response element binding is well-established.
Reason: IBA annotation supported by phylogenetic inference from mammalian Nrf2 orthologs. Crystal structure (PMID:9628487) and extensive biochemical studies demonstrate SKN-1 sequence-specific DNA binding to cis-regulatory regions via its basic region and N-terminal arm.
Supporting Evidence:
PMID:12869585
SKN-1 regulates a key Phase II detoxification gene through constitutive and stress-inducible mechanisms in the ASI chemosensory neurons and intestine, respectively
PMID:9628487
A new DNA-binding motif in the Skn-1 binding domain-DNA complex
file:worm/skn-1/skn-1-deep-research-falcon.md
model: Edison Scientific Literature
GO:0000981 DNA-binding transcription factor activity, RNA polymerase II-specific
IBA
GO_REF:0000033
ACCEPT
Summary: SKN-1 is a well-characterized transcription factor that activates Phase II detoxification genes and developmental target genes through specific binding to promoter regions and recruitment of RNA Pol II machinery.
Reason: IBA annotation reflects conserved transcription factor function. SKN-1 directly activates transcription of gcs-1, gst-4, and other target genes in response to oxidative stress (PMID:16166371, PMID:12869585). Core molecular function of this transcription factor.
Supporting Evidence:
PMID:12869585
During postembryonic stages, SKN-1 regulates a key Phase II detoxification gene through constitutive and stress-inducible mechanisms in the ASI chemosensory neurons and intestine, respectively
PMID:16166371
In response to oxidative stress, PMK-1 phosphorylates SKN-1, leading to its accumulation in intestine nuclei, where SKN-1 activates transcription of gcs-1, a phase II detoxification enzyme gene
GO:0005634 nucleus
IBA
GO_REF:0000033
ACCEPT
Summary: SKN-1 translocates to the nucleus upon oxidative stress to activate target gene transcription. Nuclear localization is dynamically regulated by p38/PMK-1 phosphorylation.
Reason: Core cellular component annotation. Nuclear localization is dynamically regulated and essential for SKN-1 transcriptional activity. Basally present in ASI neuron nuclei, stress-inducible in intestinal nuclei.
Supporting Evidence:
PMID:12869585
SKN-1 is present in ASI nuclei under normal conditions, and accumulates in intestinal nuclei in response to oxidative stress
PMID:16166371
PMK-1 p38 MAPK pathway regulates the oxidative stress response via the CNC transcription factor SKN-1
GO:0006357 regulation of transcription by RNA polymerase II
IBA
GO_REF:0000033
ACCEPT
Summary: SKN-1 regulates transcription of multiple target genes through RNA polymerase II, including Phase II detoxification genes and developmental markers.
Reason: IBA annotation supported by extensive experimental evidence. SKN-1 is a master transcriptional regulator of stress response and developmental programs. Binding to promoters directly activates target gene expression.
Supporting Evidence:
PMID:16166371
SKN-1 activates transcription of gcs-1, a phase II detoxification enzyme gene
PMID:12869585
SKN-1 links C. elegans mesendodermal specification to a conserved oxidative stress response
GO:0000978 RNA polymerase II cis-regulatory region sequence-specific DNA binding
IEA
GO_REF:0000002
ACCEPT
Summary: IEA annotation based on InterPro domain mapping for NFE2-like domain (IPR047167), which characterizes bZIP-like transcription factors.
Reason: InterPro-based annotation is accurate given SKN-1's characterized DNA-binding domain and experimental validation of sequence-specific binding through crystal structure analysis.
Supporting Evidence:
PMID:9628487
A new DNA-binding motif in the Skn-1 binding domain-DNA complex.
GO:0003677 DNA binding
IEA
GO_REF:0000120
ACCEPT
Summary: General DNA binding annotation based on combined automated methods.
Reason: Accurate but general annotation. More specific DNA-binding terms are also annotated.
GO:0003700 DNA-binding transcription factor activity
IEA
GO_REF:0000002
ACCEPT
Summary: IEA annotation from InterPro bZIP domain mappings.
Reason: Accurate annotation consistent with SKN-1's established function as a transcription factor.
GO:0005634 nucleus
IEA
GO_REF:0000044
ACCEPT
Summary: IEA annotation from UniProt subcellular location mapping.
Reason: Duplicates the IBA and IDA annotations but provides additional automated evidence support.
GO:0005737 cytoplasm
IEA
GO_REF:0000044
ACCEPT
Summary: SKN-1 localizes to cytoplasm under basal conditions and translocates to nucleus upon stress activation.
Reason: Accurate annotation. Cytoplasmic localization under non-stress conditions is well-documented.
GO:0005739 mitochondrion
IEA
GO_REF:0000044
ACCEPT
Summary: SKN-1 isoform A has been shown to localize to mitochondria.
Reason: Mitochondrial localization is specific to SKN-1A isoform and has been experimentally validated (PMID:23040073).
GO:0006351 DNA-templated transcription
IEA
GO_REF:0000043
ACCEPT
Summary: General transcription annotation from UniProt keyword mapping.
Reason: Accurate but general. More specific transcription regulatory terms are also present.
GO:0006355 regulation of DNA-templated transcription
IEA
GO_REF:0000002
ACCEPT
Summary: IEA annotation from InterPro domain mapping.
Reason: Accurate annotation. SKN-1 regulates transcription of stress response and developmental genes.
GO:0006357 regulation of transcription by RNA polymerase II
IEA
GO_REF:0000002
ACCEPT
Summary: IEA annotation from InterPro NFE2-like domain.
Reason: Accurate annotation consistent with SKN-1's established function in RNA polymerase II-dependent transcription.
GO:0006417 regulation of translation
IEA
GO_REF:0000043
REMOVE
Summary: IEA annotation from UniProt keyword mapping. Evidence for SKN-1 directly regulating translation is limited.
Reason: This IEA annotation (from UniProt keyword KW-0810) is an over-annotation and should be removed. SKN-1 is a bZIP/CNC-family transcription factor that lacks any recognized RNA-binding or translation-factor domain, and its only established regulatory activity is transcriptional (RNA polymerase II target genes). An OpenScientist run testing this annotation found that the keyword most likely conflates SKN-1 being activated by translation inhibition (acting as a downstream transcriptional effector) with SKN-1 directly regulating translation; no experimental evidence supports a direct translational role.
Supporting Evidence:
file:worm/skn-1/skn-1-hypotheses/translation-regulation-overannotation/openscientist.md
the protein lacks all recognized RNA-binding and translation-factor domains.
file:worm/skn-1/skn-1-hypotheses/translation-regulation-overannotation/openscientist.md
The curation recommendation is to remove GO:0006417 from P34707 and to flag UniProtKB keyword KW-0810 for removal from this entry.
GO:0010468 regulation of gene expression
IEA
GO_REF:0000117
ACCEPT
Summary: ARBA machine learning annotation for regulation of gene expression.
Reason: Accurate but general annotation. SKN-1 regulates expression of Phase II detoxification genes.
GO:0045944 positive regulation of transcription by RNA polymerase II
IMP
PMID:24068940
Integration of the unfolded protein and oxidative stress res...
ACCEPT
Summary: SKN-1 positively regulates transcription of Phase II detoxification genes in response to oxidative and ER stress.
Reason: Core molecular function annotation. SKN-1 is a transcriptional activator of stress response genes.
Supporting Evidence:
PMID:24068940
Sep 12. Integration of the unfolded protein and oxidative stress responses through SKN-1/Nrf.
GO:1990748 cellular detoxification
IMP
PMID:23721876
The Nrf2/SKN-1-dependent glutathione S-transferase Ο€ homolog...
ACCEPT
Summary: SKN-1 regulates expression of glutathione S-transferases and other Phase II detoxification enzymes.
Reason: Core biological process annotation. SKN-1/Nrf2 is the master regulator of cellular detoxification responses.
Supporting Evidence:
PMID:23721876
GST-1-mediated neuroprotection is dependent on the PD-associated transcription factor Nrf2/SKN-1, as a reduction in SKN-1 gene expression results in a decrease in GST-1 protein expression
GO:0000978 RNA polymerase II cis-regulatory region sequence-specific DNA binding
IDA
PMID:28600327
The Oxidative Stress Response in Caenorhabditis elegans Requ...
ACCEPT
Summary: Direct demonstration of SKN-1 DNA binding in the context of oxidative stress response.
Reason: IDA evidence confirms SKN-1 binds specifically to cis-regulatory regions of target genes.
Supporting Evidence:
PMID:28600327
2017 Jun 9. The Oxidative Stress Response in Caenorhabditis elegans Requires the GATA Transcription Factor ELT-3 and SKN-1/Nrf2.
GO:0005515 protein binding
IPI
PMID:28600327
The Oxidative Stress Response in Caenorhabditis elegans Requ...
MODIFY
Summary: SKN-1 interacts with ELT-3 (GATA transcription factor) to co-activate target gene transcription.
Reason: Protein binding is too general. SKN-1 has specific protein interactions with transcriptional regulators like ELT-3.
Supporting Evidence:
PMID:28600327
2017 Jun 9. The Oxidative Stress Response in Caenorhabditis elegans Requires the GATA Transcription Factor ELT-3 and SKN-1/Nrf2.
GO:0005634 nucleus
IDA
PMID:28600327
The Oxidative Stress Response in Caenorhabditis elegans Requ...
ACCEPT
Summary: IDA evidence for nuclear localization of SKN-1 isoforms B and C during oxidative stress response.
Reason: Consistent with other nuclear localization annotations.
Supporting Evidence:
PMID:28600327
2017 Jun 9. The Oxidative Stress Response in Caenorhabditis elegans Requires the GATA Transcription Factor ELT-3 and SKN-1/Nrf2.
GO:0008340 determination of adult lifespan
IMP
PMID:28600327
The Oxidative Stress Response in Caenorhabditis elegans Requ...
ACCEPT
Summary: SKN-1 activity extends lifespan in C. elegans.
Reason: Core biological process annotation. SKN-1's role in longevity is well-established.
Supporting Evidence:
PMID:28600327
2017 Jun 9. The Oxidative Stress Response in Caenorhabditis elegans Requires the GATA Transcription Factor ELT-3 and SKN-1/Nrf2.
GO:0045944 positive regulation of transcription by RNA polymerase II
IMP
PMID:28600327
The Oxidative Stress Response in Caenorhabditis elegans Requ...
ACCEPT
Summary: SKN-1 positively regulates transcription of gst-4 and other Phase II detoxification genes.
Reason: Valid experimental evidence for this core function.
Supporting Evidence:
PMID:28600327
2017 Jun 9. The Oxidative Stress Response in Caenorhabditis elegans Requires the GATA Transcription Factor ELT-3 and SKN-1/Nrf2.
GO:0005634 nucleus
IDA
PMID:34407394
Tribbles pseudokinase NIPI-3 regulates intestinal immunity i...
ACCEPT
Summary: Nuclear localization of SKN-1 demonstrated in context of innate immunity responses.
Reason: Confirms nuclear localization during pathogen infection.
Supporting Evidence:
PMID:34407394
Tribbles pseudokinase NIPI-3 regulates intestinal immunity in Caenorhabditis elegans by controlling SKN-1/Nrf activity.
GO:0042742 defense response to bacterium
IMP
PMID:34407394
Tribbles pseudokinase NIPI-3 regulates intestinal immunity i...
ACCEPT
Summary: SKN-1 is required for intestinal defense against bacterial pathogens.
Reason: Important biological process annotation. SKN-1 integrates oxidative stress and innate immunity responses.
Supporting Evidence:
PMID:34407394
Tribbles pseudokinase NIPI-3 regulates intestinal immunity in Caenorhabditis elegans by controlling SKN-1/Nrf activity.
GO:0048565 digestive tract development
IMP
PMID:1547503
skn-1, a maternally expressed gene required to specify the f...
ACCEPT
Summary: SKN-1 is required for specification of mesendoderm during embryogenesis, which gives rise to pharynx and intestine.
Reason: Core developmental function annotation.
Supporting Evidence:
PMID:1547503
skn-1, a maternally expressed gene required to specify the fate of ventral blastomeres in the early C.
GO:0048566 embryonic digestive tract development
IMP
PMID:1547503
skn-1, a maternally expressed gene required to specify the f...
ACCEPT
Summary: More specific annotation for SKN-1's role in embryonic gut development.
Reason: Appropriately specific developmental annotation.
Supporting Evidence:
PMID:1547503
skn-1, a maternally expressed gene required to specify the fate of ventral blastomeres in the early C.
GO:0010468 regulation of gene expression
IMP
PMID:26016853
The Developmental Intestinal Regulator ELT-2 Controls p38-De...
ACCEPT
Summary: SKN-1 regulates expression of innate immunity genes in the adult intestine.
Reason: General annotation but accurate.
Supporting Evidence:
PMID:26016853
SKN-1/Nrf, better known for regulating oxidative stress responses, was further found to contribute to resistance against bacterial pathogens
GO:0050829 defense response to Gram-negative bacterium
IMP
PMID:26016853
The Developmental Intestinal Regulator ELT-2 Controls p38-De...
ACCEPT
Summary: SKN-1 contributes to defense against Gram-negative bacteria like P. aeruginosa.
Reason: Specific innate immunity annotation supported by experimental evidence.
Supporting Evidence:
PMID:26016853
SKN-1/Nrf, better known for regulating oxidative stress responses, was further found to contribute to resistance against bacterial pathogens
GO:0000977 RNA polymerase II transcription regulatory region sequence-specific DNA binding
IDA
PMID:24068940
Integration of the unfolded protein and oxidative stress res...
ACCEPT
Summary: Direct demonstration of SKN-1 binding to regulatory regions of target genes.
Reason: IDA evidence for specific DNA binding to transcription regulatory regions.
Supporting Evidence:
PMID:24068940
Sep 12. Integration of the unfolded protein and oxidative stress responses through SKN-1/Nrf.
GO:0045944 positive regulation of transcription by RNA polymerase II
IMP
PMID:12869585
SKN-1 links C. elegans mesendodermal specification to a cons...
ACCEPT
Summary: Seminal paper demonstrating SKN-1 activates Phase II detoxification genes in response to oxidative stress.
Reason: Key publication establishing SKN-1's role as transcriptional activator.
Supporting Evidence:
PMID:12869585
SKN-1 regulates a key Phase II detoxification gene through constitutive and stress-inducible mechanisms in the ASI chemosensory neurons and intestine, respectively
GO:0045944 positive regulation of transcription by RNA polymerase II
IMP
PMID:25688864
Investigating the role of RIO protein kinases in Caenorhabdi...
ACCEPT
Summary: SKN-1 positively regulates transcription of riok-1 in the intestine.
Reason: Additional experimental evidence for SKN-1's transcriptional activator function.
Supporting Evidence:
PMID:25688864
eCollection 2015. Investigating the role of RIO protein kinases in Caenorhabditis elegans.
GO:0000977 RNA polymerase II transcription regulatory region sequence-specific DNA binding
IDA
PMID:12869585
SKN-1 links C. elegans mesendodermal specification to a cons...
ACCEPT
Summary: Direct demonstration of SKN-1 binding to gcs-1 regulatory region.
Reason: IDA evidence from seminal paper on SKN-1 function.
Supporting Evidence:
PMID:12869585
SKN-1 is present in ASI nuclei under normal conditions, and accumulates in intestinal nuclei in response to oxidative stress
GO:0000977 RNA polymerase II transcription regulatory region sequence-specific DNA binding
IDA
PMID:24453991
Regulation of synaptic nlg-1/neuroligin abundance by the skn...
ACCEPT
Summary: SKN-1 binds to regulatory regions of nlg-1/neuroligin to regulate its expression.
Reason: IDA evidence for SKN-1 DNA binding with a novel target gene.
Supporting Evidence:
PMID:24453991
2014 Jan 16. Regulation of synaptic nlg-1/neuroligin abundance by the skn-1/Nrf stress response pathway protects against oxidative stress.
GO:0030544 Hsp70 protein binding
IPI
PMID:24068940
Integration of the unfolded protein and oxidative stress res...
ACCEPT
Summary: SKN-1 interacts with Hsp70 family members (hsp-4) during integration of ER stress and oxidative stress responses.
Reason: Specific protein interaction annotation. HSP-4 interaction is relevant to SKN-1A's role in ER/proteasome stress responses.
Supporting Evidence:
PMID:24068940
Sep 12. Integration of the unfolded protein and oxidative stress responses through SKN-1/Nrf.
GO:0036498 IRE1-mediated unfolded protein response
IEP
PMID:24068940
Integration of the unfolded protein and oxidative stress res...
KEEP AS NON CORE
Summary: SKN-1 expression/activity is modulated by IRE1 branch of UPR.
Reason: SKN-1 participates in UPR but this represents an integration point rather than core function.
Supporting Evidence:
PMID:24068940
Sep 12. Integration of the unfolded protein and oxidative stress responses through SKN-1/Nrf.
GO:0036500 ATF6-mediated unfolded protein response
IDA
PMID:26232625
SKN-1/Nrf, stress responses, and aging in Caenorhabditis ele...
KEEP AS NON CORE
Summary: SKN-1 integrates with ATF6 branch of UPR based on review of stress response integration.
Reason: Represents integration of stress pathways rather than core SKN-1 function.
Supporting Evidence:
PMID:26232625
SKN-1/Nrf, stress responses, and aging in Caenorhabditis elegans.
GO:0010628 positive regulation of gene expression
IMP
PMID:23721876
The Nrf2/SKN-1-dependent glutathione S-transferase Ο€ homolog...
ACCEPT
Summary: SKN-1 positively regulates expression of GST-1 and other detoxification genes.
Reason: Accurate annotation. SKN-1 activates expression of Phase II detoxification genes.
Supporting Evidence:
PMID:23721876
a reduction in SKN-1 gene expression results in a decrease in GST-1 protein expression
GO:1905804 positive regulation of cellular response to manganese ion
IMP
PMID:23721876
The Nrf2/SKN-1-dependent glutathione S-transferase Ο€ homolog...
KEEP AS NON CORE
Summary: SKN-1 protects against manganese toxicity by activating detoxification genes.
Reason: This represents a specific application of SKN-1's general detoxification function.
Supporting Evidence:
PMID:23721876
a Caenorhabditis elegans GSTpi homologue, GST-1, inhibits Mn-induced DA neuron degeneration
GO:1905804 positive regulation of cellular response to manganese ion
IGI
PMID:23721876
The Nrf2/SKN-1-dependent glutathione S-transferase Ο€ homolog...
KEEP AS NON CORE
Summary: Genetic interaction evidence for SKN-1's role in manganese response.
Reason: Same term with different evidence code. Represents specific stress context.
Supporting Evidence:
PMID:23721876
2013 May 27. The Nrf2/SKN-1-dependent glutathione S-transferase Ο€ homologue GST-1 inhibits dopamine neuron degeneration in a Caenorhabditis elegans model of manganism.
GO:1901562 response to paraquat
IGI
PMID:19783783
Life-span extension by dietary restriction is mediated by NL...
KEEP AS NON CORE
Summary: SKN-1 is required for response to paraquat-induced oxidative stress.
Reason: Paraquat is a specific oxidative stressor. The core function is response to oxidative stress more generally.
Supporting Evidence:
PMID:19783783
Life-span extension by dietary restriction is mediated by NLP-7 signaling and coelomocyte endocytosis in C.
GO:0008340 determination of adult lifespan
IGI
PMID:19783783
Life-span extension by dietary restriction is mediated by NL...
ACCEPT
Summary: Genetic interaction evidence for SKN-1 in lifespan determination, specifically in context of dietary restriction.
Reason: Core biological process. SKN-1 promotes longevity through multiple mechanisms.
Supporting Evidence:
PMID:19783783
Life-span extension by dietary restriction is mediated by NLP-7 signaling and coelomocyte endocytosis in C.
GO:0048566 embryonic digestive tract development
IGI
PMID:25819561
Centrosome-Associated Degradation Limits Ξ²-Catenin Inheritan...
ACCEPT
Summary: Genetic interaction demonstrating SKN-1's role in embryonic gut specification.
Reason: Core developmental function. Maternal SKN-1 specifies mesendoderm fate.
Supporting Evidence:
PMID:25819561
2015 Mar 26. Centrosome-Associated Degradation Limits Ξ²-Catenin Inheritance by Daughter Cells after Asymmetric Division.
GO:0001714 endodermal cell fate specification
IMP
PMID:25819561
Centrosome-Associated Degradation Limits Ξ²-Catenin Inheritan...
ACCEPT
Summary: SKN-1 specifies endodermal cell fates through activation of downstream transcription factors.
Reason: Core developmental function. SKN-1 activates MED-1/2 which in turn activate END-1/3 for endoderm specification.
Supporting Evidence:
PMID:25819561
2015 Mar 26. Centrosome-Associated Degradation Limits Ξ²-Catenin Inheritance by Daughter Cells after Asymmetric Division.
GO:0043565 sequence-specific DNA binding
IDA
PMID:9303538
SKN-1 domain folding and basic region monomer stabilization ...
ACCEPT
Summary: Biochemical demonstration of SKN-1's sequence-specific DNA binding through its unique Skn domain.
Reason: Core molecular function. SKN-1 binds DNA as a monomer through a unique mechanism.
Supporting Evidence:
PMID:9303538
SKN-1 domain folding and basic region monomer stabilization upon DNA binding.
GO:0005783 endoplasmic reticulum
IDA
PMID:24068940
Integration of the unfolded protein and oxidative stress res...
ACCEPT
Summary: SKN-1A isoform localizes to the ER via N-terminal transmembrane domain.
Reason: Accurate isoform-specific localization. SKN-1A is ER-associated.
Supporting Evidence:
PMID:24068940
Sep 12. Integration of the unfolded protein and oxidative stress responses through SKN-1/Nrf.
GO:0000303 response to superoxide
IEP
PMID:12869585
SKN-1 links C. elegans mesendodermal specification to a cons...
ACCEPT
Summary: SKN-1 expression/activity is induced by superoxide/oxidative stress.
Reason: Core stress response function. SKN-1 is activated by and protects against oxidative stress.
Supporting Evidence:
PMID:12869585
skn-1 mutants are sensitive to oxidative stress and have shortened lifespans
GO:0000303 response to superoxide
IMP
PMID:12869585
SKN-1 links C. elegans mesendodermal specification to a cons...
ACCEPT
Summary: SKN-1 is required for proper response to superoxide stress.
Reason: IMP evidence for same term. Both evidence codes are appropriate.
Supporting Evidence:
PMID:12869585
SKN-1 links C. elegans mesendodermal specification to a conserved oxidative stress response.
GO:0005634 nucleus
IDA
PMID:12869585
SKN-1 links C. elegans mesendodermal specification to a cons...
ACCEPT
Summary: Nuclear localization of SKN-1 in ASI neurons and intestinal cells during stress response.
Reason: Key publication demonstrating stress-induced nuclear translocation.
Supporting Evidence:
PMID:12869585
SKN-1 is present in ASI nuclei under normal conditions, and accumulates in intestinal nuclei in response to oxidative stress
GO:0006979 response to oxidative stress
IEP
PMID:12869585
SKN-1 links C. elegans mesendodermal specification to a cons...
ACCEPT
Summary: SKN-1 expression/activity is induced by oxidative stress.
Reason: Core biological process annotation. SKN-1 is the master regulator of oxidative stress responses in C. elegans.
Supporting Evidence:
PMID:12869585
SKN-1 functions similarly to resist oxidative stress in C. elegans
GO:0008340 determination of adult lifespan
IMP
PMID:12869585
SKN-1 links C. elegans mesendodermal specification to a cons...
ACCEPT
Summary: SKN-1 mutants have shortened lifespan, demonstrating its role in longevity.
Reason: Core phenotype. SKN-1 promotes longevity through stress resistance.
Supporting Evidence:
PMID:12869585
skn-1 mutants are sensitive to oxidative stress and have shortened lifespans
GO:0009408 response to heat
IEP
PMID:12869585
SKN-1 links C. elegans mesendodermal specification to a cons...
KEEP AS NON CORE
Summary: SKN-1 activity is induced by heat stress.
Reason: Heat stress response is one of many stress contexts where SKN-1 is activated, but oxidative stress response is the core function.
Supporting Evidence:
PMID:12869585
SKN-1 links C. elegans mesendodermal specification to a conserved oxidative stress response.
GO:0005739 mitochondrion
IDA
PMID:23040073
Mitochondrial SKN-1/Nrf mediates a conserved starvation resp...
ACCEPT
Summary: SKN-1A isoform localizes to mitochondria where it interacts with PGAM-5.
Reason: Isoform-specific localization with functional significance for metabolic stress responses.
Supporting Evidence:
PMID:23040073
Mitochondrial SKN-1/Nrf mediates a conserved starvation response.
GO:0005634 nucleus
IDA
PMID:16166371
The C. elegans p38 MAPK pathway regulates nuclear localizati...
ACCEPT
Summary: Nuclear localization demonstrated in context of p38 MAPK regulation.
Reason: Key publication showing PMK-1-dependent nuclear translocation.
Supporting Evidence:
PMID:16166371
In response to oxidative stress, PMK-1 phosphorylates SKN-1, leading to its accumulation in intestine nuclei
GO:0008340 determination of adult lifespan
IMP
PMID:22560223
TOR signaling and rapamycin influence longevity by regulatin...
ACCEPT
Summary: SKN-1 mediates lifespan extension by rapamycin and reduced TOR signaling.
Reason: Core longevity function. SKN-1 is required for lifespan extension in multiple genetic and pharmacological contexts.
Supporting Evidence:
PMID:22560223
TOR signaling and rapamycin influence longevity by regulating SKN-1/Nrf and DAF-16/FoxO.
GO:1900409 positive regulation of cellular response to oxidative stress
IMP
PMID:22560223
TOR signaling and rapamycin influence longevity by regulatin...
ACCEPT
Summary: SKN-1 positively regulates oxidative stress responses downstream of TOR signaling.
Reason: Core function. SKN-1 activates protective stress response programs.
Supporting Evidence:
PMID:22560223
TOR signaling and rapamycin influence longevity by regulating SKN-1/Nrf and DAF-16/FoxO.
GO:0048382 mesendoderm development
IMP
PMID:1547503
skn-1, a maternally expressed gene required to specify the f...
ACCEPT
Summary: SKN-1 is required for mesendoderm specification in early embryogenesis.
Reason: Core developmental function. This is the original embryonic function described for SKN-1.
Supporting Evidence:
PMID:1547503
skn-1, a maternally expressed gene required to specify the fate of ventral blastomeres in the early C.
GO:0001714 endodermal cell fate specification
IGI
PMID:15979606
Genetic redundancy in endoderm specification within the genu...
ACCEPT
Summary: Genetic interactions with end-1 and end-3 for endoderm specification.
Reason: Core developmental function. SKN-1 acts upstream of END-1/3 GATA factors.
Supporting Evidence:
PMID:15979606
Genetic redundancy in endoderm specification within the genus Caenorhabditis.
GO:0008340 determination of adult lifespan
IGI
PMID:20523893
Manipulation of behavioral decline in Caenorhabditis elegans...
ACCEPT
Summary: Genetic interaction evidence for SKN-1 in lifespan regulation.
Reason: Additional genetic evidence for core longevity function.
Supporting Evidence:
PMID:20523893
Manipulation of behavioral decline in Caenorhabditis elegans with the Rag GTPase raga-1.
GO:0005515 protein binding
IPI
PMID:19273594
The WD40 repeat protein WDR-23 functions with the CUL4/DDB1 ...
MODIFY
Summary: SKN-1 interacts with WDR-23, the adaptor for CUL4/DDB1 ubiquitin ligase that targets SKN-1 for degradation.
Reason: Protein binding is too general. WDR-23 is a specific regulatory interaction.
Proposed replacements: ubiquitin protein ligase binding
Supporting Evidence:
PMID:19273594
Mar 9. The WD40 repeat protein WDR-23 functions with the CUL4/DDB1 ubiquitin ligase to regulate nuclear abundance and activity of SKN-1 in Caenorhabditis elegans.
GO:0008340 determination of adult lifespan
IMP
PMID:18358814
Direct inhibition of the longevity-promoting factor SKN-1 by...
ACCEPT
Summary: SKN-1 promotes longevity when insulin-like signaling is reduced or when SKN-1 is constitutively active.
Reason: Seminal paper demonstrating SKN-1's role in longevity downstream of insulin/IGF-1 signaling.
Supporting Evidence:
PMID:18358814
Direct inhibition of the longevity-promoting factor SKN-1 by insulin-like signaling in C.
GO:0043565 sequence-specific DNA binding
IDA
PMID:9628487
A new DNA-binding motif in the Skn-1 binding domain-DNA comp...
ACCEPT
Summary: Crystal structure demonstrates SKN-1's unique DNA-binding mechanism.
Reason: Structural evidence for DNA binding mechanism.
Supporting Evidence:
PMID:9628487
A new DNA-binding motif in the Skn-1 binding domain-DNA complex.
GO:0005634 nucleus
IDA
PMID:8348611
The maternal gene skn-1 encodes a protein that is distribute...
ACCEPT
Summary: Early demonstration of SKN-1 nuclear localization in embryos.
Reason: Original publication on SKN-1 protein localization.
Supporting Evidence:
PMID:8348611
The maternal gene skn-1 encodes a protein that is distributed unequally in early C.
GO:0001708 cell fate specification
IMP
PMID:8861906
Spatial and temporal controls target pal-1 blastomere-specif...
ACCEPT
Summary: SKN-1 specifies cell fates during early embryonic patterning.
Reason: Core developmental function.
Supporting Evidence:
PMID:8861906
Spatial and temporal controls target pal-1 blastomere-specification activity to a single blastomere lineage in C.
GO:0009880 embryonic pattern specification
IMP
PMID:8861906
Spatial and temporal controls target pal-1 blastomere-specif...
ACCEPT
Summary: SKN-1 contributes to embryonic pattern specification along with PAL-1.
Reason: Core developmental function. SKN-1 is part of the maternal gene network that patterns the early embryo.
Supporting Evidence:
PMID:8861906
Spatial and temporal controls target pal-1 blastomere-specification activity to a single blastomere lineage in C.
GO:0003700 DNA-binding transcription factor activity
NAS
PMID:1547503
skn-1, a maternally expressed gene required to specify the f...
ACCEPT
Summary: Original publication identifying SKN-1 as transcription factor.
Reason: NAS from original discovery paper. Later confirmed by extensive experimental evidence.
Supporting Evidence:
PMID:1547503
skn-1, a maternally expressed gene required to specify the fate of ventral blastomeres in the early C.

Core Functions

SKN-1 is a CNC/bZIP family transcription factor that binds DNA as a monomer through a unique mechanism. It activates transcription of Phase II detoxification genes, stress response genes, and developmental target genes.

SKN-1 binds DNA through the Skn domain which has a novel fold combining a bZIP-like basic region with an N-terminal arm for minor groove contacts.

Maternal SKN-1 is essential for specification of the EMS blastomere fate during early embryogenesis. SKN-1 activates MED-1/2 which in turn activate END-1/3 for endoderm specification.

SKN-1 promotes longevity through activation of stress resistance and metabolic adaptation programs. SKN-1 is required for lifespan extension by reduced insulin/IGF-1 signaling, TOR inhibition, and dietary restriction.

References

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Suggested Questions for Experts

Q: What are the specific DNA binding sites and target gene repertoires for each SKN-1 isoform?

Q: How does SKN-1 coordinate with other stress-responsive transcription factors like DAF-16 and HSF-1?

Q: What determines whether SKN-1 activates oxidative stress genes versus innate immunity genes?

Suggested Experiments

Experiment: ChIP-seq analysis comparing SKN-1 binding sites under different stress conditions

Experiment: Isoform-specific RNA-seq to distinguish SKN-1A, B, and C target genes

Experiment: Genetic screens for additional SKN-1 regulators in the WDR-23-independent pathway

Tags

caeel-proteostasis caeel-mitophagy caeel-surveillance-immunity

Deep Research

Falcon

(skn-1-deep-research-falcon.md)

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OpenScientist

(skn-1-hypotheses/translation-regulation-overannotation/openscientist.md)

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πŸ“š Additional Documentation

Bioreason Rl Predictions

(skn-1-bioreason-rl-predictions.md)

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Bioreason Rl Review

(skn-1-bioreason-rl-review.md)

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Readme

(README.md)

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Skn 1 Curation Summary

(SKN-1-CURATION-SUMMARY.md)

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Skn 1 Review Report

(SKN-1-REVIEW-REPORT.md)

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πŸ“„ View Raw YAML

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