UCHL1

UniProt ID: P09936
Organism: Homo sapiens
Review Status: COMPLETE
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Gene Description

UCHL1 encodes ubiquitin carboxyl-terminal hydrolase isozyme L1, a cytosolic cysteine-type deubiquitinase/omega peptidase that hydrolyzes small ubiquitin C-terminal adducts and helps maintain monoubiquitin pools for ubiquitin-dependent proteostasis. UCHL1 also has substrate- and context-specific roles in LC3/autophagy regulation, alpha-2A adrenergic receptor/MAPK signaling, HIF-1alpha stabilization, glycolysis-linked Parkinson disease models, and Parkin interaction; these are supported non-core contexts rather than replacements for the core UCH activity.

Proposed New Ontology Terms

ATG8-family protein deubiquitination

Definition: A protein deubiquitination process in which ubiquitin is removed from, or ubiquitin-dependent modification of, an ATG8-family protein is regulated to modulate autophagosome formation or autophagy flux.

Justification: The PN context and PMID:29462615 indicate that UCHL1 affects autophagosome formation through DUB activity and interaction with LC3, but current GOA can only capture broad protein deubiquitination or regulation of macroautophagy.

Parent term: protein deubiquitination

Supporting Evidence:

Existing Annotations Review

GO Term Evidence Action Reason
GO:0030163 protein catabolic process
IBA
GO_REF:0000033
MODIFY
Summary: Protein catabolic process is too broad for UCHL1 and obscures the specific deubiquitination chemistry.
Reason: Replace with protein deubiquitination, the direct process supported by UCH enzymology and Reactome.
Proposed replacements: protein deubiquitination
Supporting Evidence:
Reactome:R-HSA-5688426
Deubiquitinating enzymes (DUBs) catalyze the removal of Ub and regulate Ub-mediated pathways
Reactome:R-HSA-5690319
UCHL1 and UCHL3 can hydrolyze several short C-terminal ubiquitin adducts to generate ubiquitin monomers
PMID:9521656
Ubiquitin C-terminal hydrolases (UCH) are deubiquitinating enzymes which hydrolyze C-terminal esters and amides of ubiquitin
PMID:9521656
to generate free monomeric ubiquitin from ubiquitin proproteins
GO:0004843 cysteine-type deubiquitinase activity
IEA
GO_REF:0000120
ACCEPT
Summary: UCHL1 directly enables cysteine-type deubiquitinase / ubiquitin C-terminal hydrolase activity.
Reason: This is the conserved catalytic function of UCHL1 and is supported by enzymology, variant, structural, Reactome, and substrate-specific studies.
Supporting Evidence:
PMID:9521656
Ubiquitin C-terminal hydrolases (UCH) are deubiquitinating enzymes which hydrolyze C-terminal esters and amides of ubiquitin
PMID:9521656
to generate free monomeric ubiquitin from ubiquitin proproteins
PMID:8639624
Site-directed mutagenesis of UCH-L1 reveals that C90 and H161 are involved in catalytic rate enhancement
PMID:16475834
UCHs cleave Ub-X bonds (Ub is ubiquitin and X an alcohol, an amine, or a protein)
PMID:20439756
reduces ubiquitin binding and severely impairs the catalytic activity of the enzyme
PMID:23359680
near complete loss of UCHL1 hydrolase activity
Reactome:R-HSA-5690319
UCHL1 and UCHL3 can hydrolyze several short C-terminal ubiquitin adducts to generate ubiquitin monomers
GO:0005737 cytoplasm
IEA
GO_REF:0000044
ACCEPT
Summary: UCHL1 is a cytoplasmic/cytosolic enzyme, and cytoplasm is an appropriate cellular location.
Reason: This location is consistent with UniProt, GOA, and receptor-interaction evidence placing UCHL1 in the cytoplasm.
Supporting Evidence:
PMID:19477270
interaction of alpha(2A)AR and Uch-L1 occurred in the cytoplasm
GO:0005789 endoplasmic reticulum membrane
IEA
GO_REF:0000044
KEEP AS NON CORE
Summary: A membrane-associated fraction of UCHL1 can localize to the endoplasmic reticulum membrane, but this is not the main site of the soluble UCH catalytic function.
Reason: Retain as a supported non-core localization while keeping cytoplasm/cytosol as the core location.
GO:0006511 ubiquitin-dependent protein catabolic process
IEA
GO_REF:0000120
MODIFY
Summary: Ubiquitin-dependent protein catabolic process is directionally related but too broad for the direct UCHL1 role.
Reason: UCHL1 removes or processes ubiquitin adducts; protein deubiquitination is the more accurate GO process term.
Proposed replacements: protein deubiquitination
Supporting Evidence:
Reactome:R-HSA-5688426
Deubiquitinating enzymes (DUBs) catalyze the removal of Ub and regulate Ub-mediated pathways
Reactome:R-HSA-5690319
UCHL1 and UCHL3 can hydrolyze several short C-terminal ubiquitin adducts to generate ubiquitin monomers
PMID:9521656
Ubiquitin C-terminal hydrolases (UCH) are deubiquitinating enzymes which hydrolyze C-terminal esters and amides of ubiquitin
PMID:9521656
to generate free monomeric ubiquitin from ubiquitin proproteins
GO:0005515 protein binding
IPI
PMID:12082530
Interaction and colocalization of PGP9.5 with JAB1 and p27(K...
MARK AS OVER ANNOTATED
Summary: The cited interaction may be real, but generic protein binding is not an informative molecular function for UCHL1.
Reason: UCHL1 should be curated to specific activities or named binding terms where supported, not to generic protein binding from interaction screens.
GO:0005515 protein binding
IPI
PMID:16049941
A pilot proteomic study of amyloid precursor interactors in ...
MARK AS OVER ANNOTATED
Summary: The cited interaction may be real, but generic protein binding is not an informative molecular function for UCHL1.
Reason: UCHL1 should be curated to specific activities or named binding terms where supported, not to generic protein binding from interaction screens.
GO:0005515 protein binding
IPI
PMID:16169070
A human protein-protein interaction network: a resource for ...
MARK AS OVER ANNOTATED
Summary: The cited interaction may be real, but generic protein binding is not an informative molecular function for UCHL1.
Reason: UCHL1 should be curated to specific activities or named binding terms where supported, not to generic protein binding from interaction screens.
GO:0005515 protein binding
IPI
PMID:19615732
Defining the human deubiquitinating enzyme interaction lands...
MARK AS OVER ANNOTATED
Summary: The cited interaction may be real, but generic protein binding is not an informative molecular function for UCHL1.
Reason: UCHL1 should be curated to specific activities or named binding terms where supported, not to generic protein binding from interaction screens.
GO:0005515 protein binding
IPI
PMID:20029029
Regulation of epidermal growth factor receptor trafficking b...
MARK AS OVER ANNOTATED
Summary: The cited interaction may be real, but generic protein binding is not an informative molecular function for UCHL1.
Reason: UCHL1 should be curated to specific activities or named binding terms where supported, not to generic protein binding from interaction screens.
GO:0005515 protein binding
IPI
PMID:21044950
Genome-wide YFP fluorescence complementation screen identifi...
MARK AS OVER ANNOTATED
Summary: The cited interaction may be real, but generic protein binding is not an informative molecular function for UCHL1.
Reason: UCHL1 should be curated to specific activities or named binding terms where supported, not to generic protein binding from interaction screens.
GO:0005515 protein binding
IPI
PMID:23543736
Ubiquitin C-terminal hydrolase L1 (UCH-L1) acts as a novel p...
MARK AS OVER ANNOTATED
Summary: The cited interaction may be real, but generic protein binding is not an informative molecular function for UCHL1.
Reason: UCHL1 should be curated to specific activities or named binding terms where supported, not to generic protein binding from interaction screens.
GO:0005515 protein binding
IPI
PMID:31980649
Extensive rewiring of the EGFR network in colorectal cancer ...
MARK AS OVER ANNOTATED
Summary: The cited interaction may be real, but generic protein binding is not an informative molecular function for UCHL1.
Reason: UCHL1 should be curated to specific activities or named binding terms where supported, not to generic protein binding from interaction screens.
GO:0005515 protein binding
IPI
PMID:32814053
Interactome Mapping Provides a Network of Neurodegenerative ...
MARK AS OVER ANNOTATED
Summary: The cited interaction may be real, but generic protein binding is not an informative molecular function for UCHL1.
Reason: UCHL1 should be curated to specific activities or named binding terms where supported, not to generic protein binding from interaction screens.
GO:0005654 nucleoplasm
IDA
GO_REF:0000052
KEEP AS NON CORE
Summary: Nucleoplasm is a high-throughput immunofluorescence location and not the main compartment for UCHL1 catalytic function.
Reason: Retain as non-core localization context because the strongest functional evidence supports cytoplasmic/cytosolic deubiquitinase activity.
GO:0005829 cytosol
IDA
GO_REF:0000052
ACCEPT
Summary: Cytosol is an appropriate core cellular location for soluble UCHL1 deubiquitinase activity.
Reason: UCHL1 is described as a cytoplasmic/cytosolic neuronal deubiquitinase; Reactome also places the UCHL1 reaction in this context.
Supporting Evidence:
PMID:19477270
interaction of alpha(2A)AR and Uch-L1 occurred in the cytoplasm
GO:0016579 protein deubiquitination
TAS
Reactome:R-HSA-5688426
ACCEPT
Summary: UCHL1 participates in protein deubiquitination through hydrolysis of ubiquitin C-terminal adducts and recycling of monoubiquitin.
Reason: Protein deubiquitination is the correct biological-process framing for the core UCHL1 catalytic activity.
Supporting Evidence:
Reactome:R-HSA-5688426
Deubiquitinating enzymes (DUBs) catalyze the removal of Ub and regulate Ub-mediated pathways
Reactome:R-HSA-5690319
UCHL1 and UCHL3 can hydrolyze several short C-terminal ubiquitin adducts to generate ubiquitin monomers
PMID:9521656
Ubiquitin C-terminal hydrolases (UCH) are deubiquitinating enzymes which hydrolyze C-terminal esters and amides of ubiquitin
PMID:9521656
to generate free monomeric ubiquitin from ubiquitin proproteins
GO:0004843 cysteine-type deubiquitinase activity
TAS
Reactome:R-HSA-5690319
ACCEPT
Summary: UCHL1 directly enables cysteine-type deubiquitinase / ubiquitin C-terminal hydrolase activity.
Reason: This is the conserved catalytic function of UCHL1 and is supported by enzymology, variant, structural, Reactome, and substrate-specific studies.
Supporting Evidence:
Reactome:R-HSA-5690319
UCHL1 and UCHL3 can hydrolyze several short C-terminal ubiquitin adducts to generate ubiquitin monomers
GO:0004843 cysteine-type deubiquitinase activity
EXP
PMID:12408865
The UCH-L1 gene encodes two opposing enzymatic activities th...
ACCEPT
Summary: UCHL1 directly enables cysteine-type deubiquitinase / ubiquitin C-terminal hydrolase activity.
Reason: This is the conserved catalytic function of UCHL1 and is supported by enzymology, variant, structural, Reactome, and substrate-specific studies.
Supporting Evidence:
PMID:12408865
comparable hydrolase activity as the wild-type enzyme
GO:0004843 cysteine-type deubiquitinase activity
EXP
PMID:12705903
Alterations of structure and hydrolase activity of parkinson...
ACCEPT
Summary: UCHL1 directly enables cysteine-type deubiquitinase / ubiquitin C-terminal hydrolase activity.
Reason: This is the conserved catalytic function of UCHL1 and is supported by enzymology, variant, structural, Reactome, and substrate-specific studies.
Supporting Evidence:
PMID:12705903
examined their structure (using circular dichroism) and hydrolase activities
GO:0004843 cysteine-type deubiquitinase activity
EXP
PMID:16475834
Mechanistic studies of ubiquitin C-terminal hydrolase L1.
ACCEPT
Summary: UCHL1 directly enables cysteine-type deubiquitinase / ubiquitin C-terminal hydrolase activity.
Reason: This is the conserved catalytic function of UCHL1 and is supported by enzymology, variant, structural, Reactome, and substrate-specific studies.
Supporting Evidence:
PMID:16475834
UCHs cleave Ub-X bonds (Ub is ubiquitin and X an alcohol, an amine, or a protein)
GO:0004843 cysteine-type deubiquitinase activity
EXP
PMID:20439756
Ubiquitin vinyl methyl ester binding orients the misaligned ...
ACCEPT
Summary: UCHL1 directly enables cysteine-type deubiquitinase / ubiquitin C-terminal hydrolase activity.
Reason: This is the conserved catalytic function of UCHL1 and is supported by enzymology, variant, structural, Reactome, and substrate-specific studies.
Supporting Evidence:
PMID:20439756
reduces ubiquitin binding and severely impairs the catalytic activity of the enzyme
GO:0004843 cysteine-type deubiquitinase activity
EXP
PMID:23359680
Recessive loss of function of the neuronal ubiquitin hydrola...
ACCEPT
Summary: UCHL1 directly enables cysteine-type deubiquitinase / ubiquitin C-terminal hydrolase activity.
Reason: This is the conserved catalytic function of UCHL1 and is supported by enzymology, variant, structural, Reactome, and substrate-specific studies.
Supporting Evidence:
PMID:23359680
near complete loss of UCHL1 hydrolase activity
GO:0004843 cysteine-type deubiquitinase activity
EXP
PMID:25615526
UCHL1 provides diagnostic and antimetastatic strategies due ...
ACCEPT
Summary: UCHL1 directly enables cysteine-type deubiquitinase / ubiquitin C-terminal hydrolase activity.
Reason: This is the conserved catalytic function of UCHL1 and is supported by enzymology, variant, structural, Reactome, and substrate-specific studies.
Supporting Evidence:
PMID:25615526
UCHL1 promotes metastases as a deubiquitinating enzyme for HIF-1Ξ±
GO:0004843 cysteine-type deubiquitinase activity
EXP
PMID:8639624
Substrate binding and catalysis by ubiquitin C-terminal hydr...
ACCEPT
Summary: UCHL1 directly enables cysteine-type deubiquitinase / ubiquitin C-terminal hydrolase activity.
Reason: This is the conserved catalytic function of UCHL1 and is supported by enzymology, variant, structural, Reactome, and substrate-specific studies.
Supporting Evidence:
PMID:8639624
Site-directed mutagenesis of UCH-L1 reveals that C90 and H161 are involved in catalytic rate enhancement
GO:0004843 cysteine-type deubiquitinase activity
EXP
PMID:9774100
The ubiquitin pathway in Parkinson's disease.
ACCEPT
Summary: UCHL1 directly enables cysteine-type deubiquitinase / ubiquitin C-terminal hydrolase activity.
Reason: This is the conserved catalytic function of UCHL1 and is supported by enzymology, variant, structural, Reactome, and substrate-specific studies.
Supporting Evidence:
PMID:9521656
Ubiquitin C-terminal hydrolases (UCH) are deubiquitinating enzymes which hydrolyze C-terminal esters and amides of ubiquitin
PMID:9521656
to generate free monomeric ubiquitin from ubiquitin proproteins
PMID:8639624
Site-directed mutagenesis of UCH-L1 reveals that C90 and H161 are involved in catalytic rate enhancement
PMID:16475834
UCHs cleave Ub-X bonds (Ub is ubiquitin and X an alcohol, an amine, or a protein)
PMID:20439756
reduces ubiquitin binding and severely impairs the catalytic activity of the enzyme
PMID:23359680
near complete loss of UCHL1 hydrolase activity
Reactome:R-HSA-5690319
UCHL1 and UCHL3 can hydrolyze several short C-terminal ubiquitin adducts to generate ubiquitin monomers
GO:0030547 signaling receptor inhibitor activity
IDA
PMID:19477270
Interaction of the ubiquitin carboxyl terminal esterase L1 w...
KEEP AS NON CORE
Summary: UCHL1 inhibits alpha-2 adrenergic receptor agonist-mediated p44/42 MAPK activation in the cited receptor study.
Reason: This is a specific signaling side context and not the conserved core UCH enzymatic function.
Supporting Evidence:
PMID:19477270
Uch-L1 binds preferentially to the alpha(2A)AR subtype
PMID:19477270
p44/42 MAP Kinase was drastically decreased in the presence of Uch-L1
GO:0043409 negative regulation of MAPK cascade
IDA
PMID:19477270
Interaction of the ubiquitin carboxyl terminal esterase L1 w...
KEEP AS NON CORE
Summary: UCHL1 interaction with alpha-2A adrenergic receptor decreases agonist-mediated p44/42 MAPK activation.
Reason: Retain as a supported non-core receptor/signaling process downstream of a specific interaction.
Supporting Evidence:
PMID:19477270
Uch-L1 binds preferentially to the alpha(2A)AR subtype
PMID:19477270
p44/42 MAP Kinase was drastically decreased in the presence of Uch-L1
GO:0004843 cysteine-type deubiquitinase activity
IMP
PMID:34244144
Loss of UCHL1 rescues the defects related to Parkinson's dis...
ACCEPT
Summary: UCHL1 directly enables cysteine-type deubiquitinase / ubiquitin C-terminal hydrolase activity.
Reason: This is the conserved catalytic function of UCHL1 and is supported by enzymology, variant, structural, Reactome, and substrate-specific studies.
Supporting Evidence:
PMID:34244144
The DUB activity of each UCHL1 or UCH mutant protein was measured using a DUB activity assay kit
GO:0045821 positive regulation of glycolytic process
IMP
PMID:34244144
Loss of UCHL1 rescues the defects related to Parkinson's dis...
KEEP AS NON CORE
Summary: UCHL1 loss reduces glycolytic metabolites and destabilizes PKM in Parkinson disease models, implying that UCHL1 can support glycolysis in that context.
Reason: This is a supported disease/metabolic context, but not the core UCHL1 deubiquitinase function.
Supporting Evidence:
PMID:34244144
loss of UCHL1 destabilizes pyruvate kinase (PKM)
PMID:34244144
specific glycolytic metabolites are decreased
GO:0004843 cysteine-type deubiquitinase activity
IDA
PMID:9521656
Substrate specificity of deubiquitinating enzymes: ubiquitin...
ACCEPT
Summary: UCHL1 directly enables cysteine-type deubiquitinase / ubiquitin C-terminal hydrolase activity.
Reason: This is the conserved catalytic function of UCHL1 and is supported by enzymology, variant, structural, Reactome, and substrate-specific studies.
Supporting Evidence:
PMID:9521656
Ubiquitin C-terminal hydrolases (UCH) are deubiquitinating enzymes which hydrolyze C-terminal esters and amides of ubiquitin
GO:0005829 cytosol
TAS
Reactome:R-HSA-5690319
ACCEPT
Summary: Cytosol is an appropriate core cellular location for soluble UCHL1 deubiquitinase activity.
Reason: UCHL1 is described as a cytoplasmic/cytosolic neuronal deubiquitinase; Reactome also places the UCHL1 reaction in this context.
Supporting Evidence:
PMID:19477270
interaction of alpha(2A)AR and Uch-L1 occurred in the cytoplasm
GO:0016241 regulation of macroautophagy
TAS
PMID:24879150
UCHL1 deficiency exacerbates human islet amyloid polypeptide...
KEEP AS NON CORE
Summary: UCHL1 affects autophagosome formation and autophagy/lysosomal pathway readouts, including LC3 puncta and beta-cell proteotoxicity models.
Reason: This is a real proteostasis context, but the direct function is deubiquitination rather than core autophagy machinery activity.
Supporting Evidence:
PMID:29462615
UCHL1 overexpression inhibits LC3 puncta formation and is dependent on its DUB activity
PMID:29462615
UCHL1 may affect autophagy by interacting with LC3
PMID:24879150
UCHL1 dysfunction aggravated the hIAPP-induced defect in the autophagy/lysosomal pathway
GO:0031625 ubiquitin protein ligase binding
IPI
PMID:19725078
Proteomic analysis of increased Parkin expression and its in...
KEEP AS NON CORE
Summary: UCHL1 was identified as a potential Parkin interactor in a Parkin proteomic study.
Reason: Retain as non-core interaction context; UCHL1 is not itself an E3 ligase, and the core activity remains deubiquitinase/UCH activity.
Supporting Evidence:
PMID:19725078
Tandem affinity purification/MS revealed 14 potential interactants of Parkin; CKB, DBT, HSPD1, HSPA9, LRPPRC, NDUFS2, PRDX6, SLC25A5, TPI1, UCHL1, UQCRC1, VCL, YWHAZ, YWHAE
GO:0043161 proteasome-mediated ubiquitin-dependent protein catabolic process
NAS
PMID:24252804
The role of oxidative stress in Parkinson's disease.
KEEP AS NON CORE
Summary: UCHL1 participates in ubiquitin homeostasis that can influence proteasome-mediated protein catabolism.
Reason: Retain as non-core pathway context because the direct mechanism is ubiquitin adduct hydrolysis/protein deubiquitination, and the cited PMID is a broad Parkinson oxidative-stress review.
Supporting Evidence:
Reactome:R-HSA-5688426
Deubiquitinating enzymes (DUBs) catalyze the removal of Ub and regulate Ub-mediated pathways
Reactome:R-HSA-5690319
UCHL1 and UCHL3 can hydrolyze several short C-terminal ubiquitin adducts to generate ubiquitin monomers
PMID:24252804
cellular homeostatic processes including the ubiquitin-proteasome system and mitophagy are impacted by oxidative stress
GO:0005737 cytoplasm
IDA
PMID:19477270
Interaction of the ubiquitin carboxyl terminal esterase L1 w...
ACCEPT
Summary: UCHL1 is a cytoplasmic/cytosolic enzyme, and cytoplasm is an appropriate cellular location.
Reason: This location is consistent with UniProt, GOA, and receptor-interaction evidence placing UCHL1 in the cytoplasm.
Supporting Evidence:
PMID:19477270
interaction of alpha(2A)AR and Uch-L1 occurred in the cytoplasm
GO:0005886 plasma membrane
IDA
PMID:19477270
Interaction of the ubiquitin carboxyl terminal esterase L1 w...
KEEP AS NON CORE
Summary: UCHL1 colocalization with plasma membrane in the receptor study reflects alpha-2A adrenergic receptor interaction context rather than the main UCHL1 compartment.
Reason: Retain as non-core localization; cytoplasm/cytosol are the better supported core locations.
Supporting Evidence:
PMID:19477270
Uch-L1 binds preferentially to the alpha(2A)AR subtype
PMID:19477270
p44/42 MAP Kinase was drastically decreased in the presence of Uch-L1
GO:0031694 alpha-2A adrenergic receptor binding
IPI
PMID:19477270
Interaction of the ubiquitin carboxyl terminal esterase L1 w...
KEEP AS NON CORE
Summary: UCHL1 binds preferentially to the alpha-2A adrenergic receptor subtype in the cited study.
Reason: This is a specific, supported binding function but is a non-core receptor/signaling context relative to UCHL1 deubiquitinase activity.
Supporting Evidence:
PMID:19477270
Uch-L1 binds preferentially to the alpha(2A)AR subtype
PMID:19477270
p44/42 MAP Kinase was drastically decreased in the presence of Uch-L1
GO:0005737 cytoplasm
TAS
PMID:16130169
Proteomics of human umbilical vein endothelial cells applied...
ACCEPT
Summary: UCHL1 is a cytoplasmic/cytosolic enzyme, and cytoplasm is an appropriate cellular location.
Reason: This location is consistent with UniProt, GOA, and receptor-interaction evidence placing UCHL1 in the cytoplasm.
Supporting Evidence:
PMID:19477270
interaction of alpha(2A)AR and Uch-L1 occurred in the cytoplasm
GO:0005737 cytoplasm
ISS
GO_REF:0000024
ACCEPT
Summary: UCHL1 is a cytoplasmic/cytosolic enzyme, and cytoplasm is an appropriate cellular location.
Reason: This location is consistent with UniProt, GOA, and receptor-interaction evidence placing UCHL1 in the cytoplasm.
Supporting Evidence:
PMID:19477270
interaction of alpha(2A)AR and Uch-L1 occurred in the cytoplasm
GO:0004197 cysteine-type endopeptidase activity
IDA
PMID:8639624
Substrate binding and catalysis by ubiquitin C-terminal hydr...
MODIFY
Summary: Cysteine-type endopeptidase activity is too broad for UCHL1 and does not capture the ubiquitin C-terminal specificity.
Reason: Replace with cysteine-type deubiquitinase activity, the specific cysteine protease activity supported by the same active-site evidence.
Supporting Evidence:
PMID:8639624
Site-directed mutagenesis of UCH-L1 reveals that C90 and H161 are involved in catalytic rate enhancement
GO:0008242 omega peptidase activity
IDA
PMID:9521656
Substrate specificity of deubiquitinating enzymes: ubiquitin...
ACCEPT
Summary: UCHL1 has omega peptidase / ubiquitin C-terminal hydrolase activity, cleaving small adducts from the C-terminus of ubiquitin.
Reason: This term captures the C-terminal peptidase chemistry of the core UCHL1 enzymatic function.
Supporting Evidence:
PMID:9521656
cleave small leaving groups such as amino acids and oligopeptides from the C-terminus of ubiquitin
GO:0016579 protein deubiquitination
IDA
PMID:9521656
Substrate specificity of deubiquitinating enzymes: ubiquitin...
ACCEPT
Summary: UCHL1 participates in protein deubiquitination through hydrolysis of ubiquitin C-terminal adducts and recycling of monoubiquitin.
Reason: Protein deubiquitination is the correct biological-process framing for the core UCHL1 catalytic activity.
Supporting Evidence:
Reactome:R-HSA-5688426
Deubiquitinating enzymes (DUBs) catalyze the removal of Ub and regulate Ub-mediated pathways
Reactome:R-HSA-5690319
UCHL1 and UCHL3 can hydrolyze several short C-terminal ubiquitin adducts to generate ubiquitin monomers
PMID:9521656
Ubiquitin C-terminal hydrolases (UCH) are deubiquitinating enzymes which hydrolyze C-terminal esters and amides of ubiquitin
PMID:9521656
to generate free monomeric ubiquitin from ubiquitin proproteins
GO:0043130 ubiquitin binding
IDA
PMID:9521656
Substrate specificity of deubiquitinating enzymes: ubiquitin...
KEEP AS NON CORE
Summary: UCHL1 binds ubiquitin as the substrate for its C-terminal hydrolase reaction.
Reason: Retain as a substrate-binding context, but the core molecular function should be deubiquitinase/UCH catalytic activity rather than binding alone.
Supporting Evidence:
PMID:8639624
indicates the existence of a specific and extensive binding site for ubiquitin on the surface of the enzyme

Core Functions

Cytosolic ubiquitin C-terminal hydrolase activity that cleaves small ubiquitin C-terminal adducts/proproteins to recycle monomeric ubiquitin and support ubiquitin-dependent proteostasis.

Directly Involved In:
Cellular Locations:
Supporting Evidence:
  • PMID:9521656
    Ubiquitin C-terminal hydrolases (UCH) are deubiquitinating enzymes which hydrolyze C-terminal esters and amides of ubiquitin
  • PMID:9521656
    to generate free monomeric ubiquitin from ubiquitin proproteins
  • PMID:8639624
    Site-directed mutagenesis of UCH-L1 reveals that C90 and H161 are involved in catalytic rate enhancement
  • PMID:16475834
    UCHs cleave Ub-X bonds (Ub is ubiquitin and X an alcohol, an amine, or a protein)
  • PMID:20439756
    reduces ubiquitin binding and severely impairs the catalytic activity of the enzyme
  • PMID:23359680
    near complete loss of UCHL1 hydrolase activity
  • Reactome:R-HSA-5690319
    UCHL1 and UCHL3 can hydrolyze several short C-terminal ubiquitin adducts to generate ubiquitin monomers
  • Reactome:R-HSA-5688426
    Deubiquitinating enzymes (DUBs) catalyze the removal of Ub and regulate Ub-mediated pathways
  • Reactome:R-HSA-5690319
    UCHL1 and UCHL3 can hydrolyze several short C-terminal ubiquitin adducts to generate ubiquitin monomers

References

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Suggested Questions for Experts

Q: Should UCHL1 be annotated to a new ATG8-family protein deubiquitination term when the substrate/context is LC3-dependent autophagosome formation?

Suggested experts: Yanfen Liu, Cong Yan, GO autophagy editors

Q: Should UCHL1 catalytic activity be represented primarily by cysteine-type deubiquitinase activity, omega peptidase activity, or a more specific ubiquitin C-terminal hydrolase term?

Suggested experts: Keith D. Wilkinson, Catherine Larsen, GO molecular function editors

Q: Which UCHL1 substrate-specific contexts, such as HIF-1alpha, EGFR/BACE1, alpha-2A adrenergic receptor signaling, or PKM/glycolysis, should remain gene-level non-core annotations?

Suggested experts: Harada Hiraoka, Brendie Weber, GO proteostasis editors

Suggested Experiments

Experiment: Map LC3 ubiquitination sites and test whether catalytically inactive UCHL1, I93M UCHL1, and substrate-binding mutants alter LC3 ubiquitination, LC3 puncta, and autophagy flux in matched rescue cells.

Hypothesis: UCHL1 regulates autophagosome formation by deubiquitinating LC3/ATG8-family proteins or an LC3-proximal substrate.

Type: substrate mapping and autophagy flux rescue assay

Experiment: Compare Ub-AMC, ubiquitin proprotein, small ubiquitin adduct, and ubiquitinated protein substrates across UCHL1 variants to separate omega-peptidase/proprotein processing from protein deubiquitination.

Hypothesis: UCHL1 core activity is optimized for small ubiquitin C-terminal adducts, while substrate-specific protein deubiquitination depends on cellular context or binding partners.

Type: comparative enzymology

Experiment: Use substrate-selective UCHL1 mutants in neuronal and cancer-cell models to test whether LC3/autophagy, HIF-1alpha stabilization, PKM/glycolysis, and alpha-2A receptor/MAPK effects can be separated genetically.

Hypothesis: UCHL1 non-core pathway annotations reflect separable substrate contexts built on the same core deubiquitinase activity.

Type: domain-function and substrate-specific rescue

πŸ“š Additional Documentation

Notes

(UCHL1-notes.md)

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Pn Notes

(UCHL1-pn-notes.md)

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πŸ“„ View Raw YAML

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