Existing Annotations Review

GO Term	Evidence	Action	Reason
GO:0005509 calcium ion binding	IEA GO_REF:0000002	KEEP AS NON CORE	Summary: GH47-family mannosidases use a calcium ion in the active site; EDEM1 retains this fold and binds calcium as a structural/catalytic cofactor. This is subsidiary to its recognition and ERAD functions, especially given its weak mannosidase activity. Reason: Accurate structural cofactor attribute of the GH47 mannosidase-like domain, but not a standalone core function; the informative functions are misfolded protein recognition and ERAD. Supporting Evidence: file:human/EDEM1/EDEM1-uniprot.txt Belongs to the glycosyl hydrolase 47 family
GO:0005783 endoplasmic reticulum	IEA GO_REF:0000117	ACCEPT	Summary: EDEM1 is an ER-resident protein; electronic (ARBA) assignment of ER localization is consistent with experimental evidence. Reason: Correct site of action; redundant with IDA ER and ERQC annotations. Supporting Evidence: file:human/EDEM1/EDEM1-uniprot.txt SUBCELLULAR LOCATION: Endoplasmic reticulum membrane
GO:0005789 endoplasmic reticulum membrane	IEA GO_REF:0000120	ACCEPT	Summary: EDEM1 is a single-pass type II ER membrane protein; electronic transfer of ER membrane localization is correct. Reason: Correct compartment; redundant with the ISS ER membrane annotation and UniProt subcellular location. Supporting Evidence: file:human/EDEM1/EDEM1-uniprot.txt Single-pass type II membrane protein
GO:0005975 carbohydrate metabolic process	IEA GO_REF:0000002	MARK AS OVER ANNOTATED	Summary: Generic carbohydrate metabolic process from InterPro; far less informative than the specific ER mannose trimming and ERAD processes EDEM1 participates in. Reason: Over-general parent; the specific ER mannose trimming (GO:1904380) and ERAD (GO:0036503) terms better capture the biology. Supporting Evidence: file:human/EDEM1/EDEM1-uniprot.txt Belongs to the glycosyl hydrolase 47 family
GO:0016020 membrane	IEA GO_REF:0000002	MARK AS OVER ANNOTATED	Summary: Generic membrane localization from InterPro, superseded by the specific ER membrane annotation. Reason: Uninformative parent; EDEM1 is specifically an ER membrane protein. Proposed replacements: endoplasmic reticulum membrane Supporting Evidence: file:human/EDEM1/EDEM1-uniprot.txt SUBCELLULAR LOCATION: Endoplasmic reticulum membrane
GO:0036503 ERAD pathway	IEA GO_REF:0000117	ACCEPT	Summary: Electronic (ARBA) assignment of the ERAD pathway, consistent with extensive experimental evidence that EDEM1 accelerates ERAD of misfolded glycoproteins. Reason: Correct core biological process; redundant with IMP/ISS evidence. Supporting Evidence: file:human/EDEM1/EDEM1-uniprot.txt It is directly involved in endoplasmic reticulum-associated degradation (ERAD)
GO:1904380 endoplasmic reticulum mannose trimming	IEA GO_REF:0000120	ACCEPT	Summary: EDEM1 contributes to ER mannose trimming (the Man8 to Man7 step); electronic assignment is consistent with the IMP evidence. Reason: Correct biological process; redundant with the IMP annotation from endogenous knockout analysis. Supporting Evidence: PMID:25092655 Mannose trimming from Man8GlcNAc2 to Man7GlcNAc2 is performed mainly by EDEM3 and to a lesser extent by EDEM1
GO:1904154 positive regulation of retrograde protein transport, ER to cytosol	IEA GO_REF:0000120	KEEP AS NON CORE	Summary: EDEM1 promotes retrotranslocation of ERAD substrates from the ER to the cytosol; electronic assignment is consistent with the experimental ricin retrotranslocation data. Reason: Real, specific aspect of EDEM1 function (substrate dislocation) but subordinate to the core recognition/ERAD role; redundant with the IMP/IGI annotations. Supporting Evidence: PMID:24200403 This transport is promoted by EDEM1
GO:0004571 mannosyl-oligosaccharide 1,2-alpha-mannosidase activity	TAS Reactome:R-HSA-6782685	ACCEPT	Summary: Reactome curation of EDEM1 (with EDEM3) hydrolysing Man8 to Man5 glycans. EDEM1 has genuine but low alpha-1,2-mannosidase activity contributing to the second trimming step. Reason: Correct molecular function (weak but real, demonstrated by endogenous knockout); kept as supporting rather than the dominant function. Supporting Evidence: PMID:25092655 all endogenous EDEMs possess mannosidase activity
GO:0005783 endoplasmic reticulum	IDA GO_REF:0000052	ACCEPT	Summary: Direct immunofluorescence (HPA) evidence for ER localization, consistent with EDEM1's site of action. Reason: Correct compartment with direct experimental support. Supporting Evidence: file:human/EDEM1/EDEM1-uniprot.txt SUBCELLULAR LOCATION: Endoplasmic reticulum membrane
GO:1904380 endoplasmic reticulum mannose trimming	IMP PMID:25092655 EDEM2 initiates mammalian glycoprotein ERAD by catalyzing th...	ACCEPT	Summary: Endogenous EDEM1 knockout in human and chicken cells increased Man8B levels, showing EDEM1 contributes (with EDEM3) to the second ER mannose-trimming step from Man8GlcNAc2 to Man7GlcNAc2. Reason: Core biological process with direct experimental (IMP) support from endogenous gene knockout. Supporting Evidence: PMID:25092655 Mannose trimming from Man8GlcNAc2 to Man7GlcNAc2 is performed mainly by EDEM3 and to a lesser extent by EDEM1
GO:0006511 ubiquitin-dependent protein catabolic process	IMP PMID:25092655 EDEM2 initiates mammalian glycoprotein ERAD by catalyzing th...	KEEP AS NON CORE	Summary: EDEM1 knockout delayed degradation of the gpERAD substrate ATF6alpha, which is degraded by the ubiquitin-proteasome system; supports a role in ubiquitin-dependent catabolism via ERAD. Reason: Correct but generic parent process; the more specific ERAD pathway (GO:0036503) better captures EDEM1's role. Supporting Evidence: PMID:25092655 deletion of hEDEM1 significantly delayed the degradation of hATF6
GO:0036503 ERAD pathway	IMP PMID:21062743 Mannose trimming is required for delivery of a glycoprotein ...	ACCEPT	Summary: EDEM1 functions in ERAD by handing off substrate glycoproteins, after mannose trimming, to the late ERAD lectin XTP3-B and downstream E3 ligases. Reason: Core biological process; experimentally links EDEM1 to the downstream ERAD machinery. Supporting Evidence: PMID:21062743 mannose trimming enables delivery of a substrate glycoprotein from EDEM1 to late ERAD steps through association with XTP3-B
GO:0036503 ERAD pathway	IMP PMID:25092655 EDEM2 initiates mammalian glycoprotein ERAD by catalyzing th...	ACCEPT	Summary: Endogenous EDEM1 knockout delayed gpERAD of ATF6alpha, directly demonstrating EDEM1's role in the ERAD pathway. Reason: Core biological process with direct experimental (IMP) support. Supporting Evidence: PMID:25092655 deletion of hEDEM1 significantly delayed the degradation of hATF6
GO:1904382 mannose trimming involved in glycoprotein ERAD pathway	TAS Reactome:R-HSA-6782685	ACCEPT	Summary: Reactome curation of EDEM1 mannose trimming within the glycoprotein ERAD pathway; an accurate, specific refinement of EDEM1's trimming contribution to ERAD. Reason: Correct specific biological process linking the trimming activity to ERAD. Supporting Evidence: PMID:25092655 M8B is trimmed by EDEM1 and EDEM3 to Man7-5GlcNAc2, which are recognized by lectin OS-9
GO:0044322 endoplasmic reticulum quality control compartment	IDA PMID:23233672 A shared endoplasmic reticulum-associated degradation pathwa...	ACCEPT	Summary: On proteasome inhibition, EDEM1 and other ERAD machinery accumulate with substrates in the ER-derived quality control compartment (ERQC), supporting an ERQC localization. Reason: Genuine, functionally relevant localization with direct experimental support. Supporting Evidence: PMID:23233672 accumulation of the nonglycosylated proteins and ERAD machinery in the endoplasmic reticulum-derived quality control compartment
GO:0045047 protein targeting to ER	IMP PMID:23233672 A shared endoplasmic reticulum-associated degradation pathwa...	MARK AS OVER ANNOTATED	Summary: This annotation derives from work showing EDEM1 targets misfolded substrates to the ER membrane dislocation/ERAD machinery, not co-translational targeting of nascent proteins to the ER. The GO term protein targeting to ER (import into the ER) poorly captures the demonstrated delivery-to-ERAD biology. Reason: The term denotes targeting of proteins into the ER (e.g. co-translational import), which is not what EDEM1 does; the experimental result is substrate delivery to the ER-membrane ERAD/dislocation complex. Retained (experimental basis) rather than removed, but the term is a poor fit. Supporting Evidence: PMID:19524542 target aberrant proteins to the ER membrane dislocation and ubiquitination complex containing SEL1L
GO:0051787 misfolded protein binding	IMP PMID:23233672 A shared endoplasmic reticulum-associated degradation pathwa...	ACCEPT	Summary: EDEM1 binds misfolded glycosylated and nonglycosylated substrates, associating with nonglycosylated proteins through a region outside its mannosidase-like domain; recognition of non-native protein structure is a core EDEM1 function. Reason: Core molecular function; EDEM1's defining role is recognition of misfolded/non-native proteins for ERAD. Supporting Evidence: PMID:23233672 EDEM1 associates through a region outside of its mannosidase-like domain with the nonglycosylated proteins
GO:0004571 mannosyl-oligosaccharide 1,2-alpha-mannosidase activity	IMP PMID:25092655 EDEM2 initiates mammalian glycoprotein ERAD by catalyzing th...	ACCEPT	Summary: Endogenous gene knockout established that EDEM1 possesses (weak) alpha-1,2-mannosidase activity, contributing to the second trimming step Man8B to Man7. This resolved the long-standing mannosidase-versus-lectin controversy in favor of genuine but low catalytic activity. Reason: Molecular function supported by endogenous knockout (IMP); EDEM1 has the weakest mannosidase activity of the three EDEMs, so this is retained as a supporting rather than dominant function. Supporting Evidence: PMID:25092655 all endogenous EDEMs possess mannosidase activity
GO:1904154 positive regulation of retrograde protein transport, ER to cytosol	IMP PMID:24200403 The role of EDEM2 compared with EDEM1 in ricin transport fro...	KEEP AS NON CORE	Summary: EDEM1 promotes ER-to-cytosol retrotranslocation of the ricin A chain, a model retrotranslocation substrate handled like a misfolded ER protein. Reason: Specific, experimentally supported aspect of EDEM1's ERAD/dislocation activity, but subordinate to the core recognition/ERAD role. Supporting Evidence: PMID:24200403 This transport is promoted by EDEM1
GO:1904154 positive regulation of retrograde protein transport, ER to cytosol	IGI PMID:24200403 The role of EDEM2 compared with EDEM1 in ricin transport fro...	KEEP AS NON CORE	Summary: Genetic-interaction evidence (with EDEM2, UniProtKB:Q9BV94) that EDEM1 promotes ricin A-chain retrotranslocation from the ER to the cytosol. Reason: Consistent with the IMP retrotranslocation annotation; a specific aspect of the dislocation function rather than the core role. Supporting Evidence: PMID:24200403 more ricin can interact with EDEM2 in comparison with EDEM1
GO:0044322 endoplasmic reticulum quality control compartment	TAS Reactome:R-HSA-1791155	ACCEPT	Summary: Reactome curation of EDEM1 ERQC localization (EDEM expression context); consistent with direct IDA evidence. Reason: Correct compartment; redundant with the IDA ERQC annotation. Supporting Evidence: PMID:23233672 endoplasmic reticulum-derived quality control compartment
GO:0044322 endoplasmic reticulum quality control compartment	TAS Reactome:R-HSA-6782685	ACCEPT	Summary: Reactome curation of EDEM1 ERQC localization in the mannose-trimming reaction context. Reason: Correct compartment; redundant with the IDA ERQC annotation. Supporting Evidence: PMID:23233672 endoplasmic reticulum-derived quality control compartment
GO:0005783 endoplasmic reticulum	IMP PMID:21062743 Mannose trimming is required for delivery of a glycoprotein ...	ACCEPT	Summary: ER localization in the context of EDEM1-dependent ERAD substrate handoff. Reason: Correct site of action; consistent with experimental ER/ERQC evidence. Supporting Evidence: file:human/EDEM1/EDEM1-uniprot.txt SUBCELLULAR LOCATION: Endoplasmic reticulum membrane
GO:0005783 endoplasmic reticulum	IDA PMID:24200403 The role of EDEM2 compared with EDEM1 in ricin transport fro...	ACCEPT	Summary: Direct evidence for ER localization of EDEM1 in the ricin retrotranslocation study. Reason: Correct compartment with direct experimental support. Supporting Evidence: file:human/EDEM1/EDEM1-uniprot.txt SUBCELLULAR LOCATION: Endoplasmic reticulum membrane
GO:0004571 mannosyl-oligosaccharide 1,2-alpha-mannosidase activity	IDA NOT PMID:12610306 Role of EDEM in the release of misfolded glycoproteins from ...	KEEP AS NON CORE	Summary: A negated (NOT) experimental annotation reflecting the original proposal that EDEM1 lacks alpha-1,2-mannosidase activity, based on overexpression biochemistry. Later endogenous-knockout analysis (PMID:25092655) demonstrated that EDEM1 does possess weak mannosidase activity, so this negation is superseded but retained as the curated record of the early finding. Reason: Genuine historical experimental (IDA) annotation that conflicts with later endogenous-KO evidence; per guidelines an experimental annotation is not removed on weak grounds. Flagged as superseded by PMID:25092655. Supporting Evidence: PMID:25092655 it had originally been proposed that EDEM1 has no α1,2-mannosidase activity
GO:0005515 protein binding	IPI PMID:19524542 EDEM1 recognition and delivery of misfolded proteins to the ...	KEEP AS NON CORE	Summary: Physical interaction with SEL1L (UniProtKB:Q9UBV2), the HRD1-complex adaptor through which EDEM1 delivers substrates to the dislocation machinery. The bare protein binding term is uninformative; the SEL1L interaction is captured by the misfolded protein binding and ERAD annotations. Reason: Records a real interaction (SEL1L) but bare protein binding is uninformative per curation guidelines; the functional consequence is reflected in the ERAD/recognition terms. Supporting Evidence: PMID:19524542 its association with the ER membrane adaptor protein SEL1L
GO:0005515 protein binding	IPI PMID:19934218 A dual role for EDEM1 in the processing of rod opsin.	KEEP AS NON CORE	Summary: Physical interaction with rod opsin (UniProtKB:P08100), an EDEM1 client glycoprotein. The bare protein binding term is uninformative. Reason: Real client interaction (rod opsin) but bare protein binding is uninformative; EDEM1's recognition function is captured by misfolded protein binding. Supporting Evidence: PMID:19934218 rod opsin co-immunoprecipitated with EDEM1
GO:0051787 misfolded protein binding	IDA PMID:19524542 EDEM1 recognition and delivery of misfolded proteins to the ...	ACCEPT	Summary: EDEM1 directly and specifically binds non-native proteins in a glycan-independent manner, demonstrating recognition of misfolded protein structure independent of N-glycan trimming. Reason: Core molecular function; direct demonstration of misfolded/non-native protein recognition. Supporting Evidence: PMID:19524542 EDEM1 specifically binds nonnative proteins in a glycan-independent manner
GO:0005515 protein binding	IPI PMID:16449189 Derlin-2 and Derlin-3 are regulated by the mammalian unfolde...	KEEP AS NON CORE	Summary: Physical interactions with Derlin-2 (UniProtKB:Q9GZP9) and Derlin-3 (UniProtKB:Q96Q80), which link EDEM to p97/VCP for substrate extraction. The bare protein binding term is uninformative; the functional role is reflected in the ERAD annotations. Reason: Records real Derlin-2/-3 interactions providing the EDEM-to-p97 link, but bare protein binding is uninformative per guidelines. Supporting Evidence: PMID:16449189 Derlin-2 and -3 are associated with EDEM and p97
GO:0005789 endoplasmic reticulum membrane	ISS GO_REF:0000024	ACCEPT	Summary: Sequence-similarity transfer (from mouse Q925U4) of ER membrane localization; EDEM1 is a single-pass type II ER membrane protein. Reason: Correct compartment; consistent with UniProt subcellular location and IDA evidence. Supporting Evidence: file:human/EDEM1/EDEM1-uniprot.txt Single-pass type II membrane protein
GO:0036503 ERAD pathway	ISS GO_REF:0000024	ACCEPT	Summary: Sequence-similarity transfer of the ERAD pathway role from the mouse ortholog; consistent with extensive human experimental evidence. Reason: Correct core biological process; redundant with IMP evidence. Supporting Evidence: file:human/EDEM1/EDEM1-uniprot.txt It is directly involved in endoplasmic reticulum-associated degradation (ERAD)

Core Functions

Recognizes terminally misfolded/non-native glycoproteins (and some nonglycosylated proteins) and extracts them from the calnexin/calreticulin folding cycle, delivering them to the SEL1L/HRD1 dislocation and ubiquitination machinery for ER-associated degradation.

Molecular Function:

misfolded protein binding

Directly Involved In:

ERAD pathway

Cellular Locations:

endoplasmic reticulum membrane endoplasmic reticulum quality control compartment

Supporting Evidence:

PMID:19524542
EDEM1 specifically binds nonnative proteins in a glycan-independent manner
PMID:12610306
EDEM was shown to extract misfolded glycoproteins, but not glycoproteins undergoing productive folding, from the calnexin cycle

Possesses low alpha-1,2-mannosidase activity contributing to the second ER mannose-trimming step (Man8GlcNAc2 to Man7GlcNAc2), generating the alpha-1,6-mannose-exposed glycan recognized by downstream lectins (OS-9/XTP3-B) in glycoprotein ERAD.

Molecular Function:

mannosyl-oligosaccharide 1,2-alpha-mannosidase activity

Directly Involved In:

endoplasmic reticulum mannose trimming

Cellular Locations:

endoplasmic reticulum membrane

Supporting Evidence:

PMID:25092655
Mannose trimming from Man8GlcNAc2 to Man7GlcNAc2 is performed mainly by EDEM3 and to a lesser extent by EDEM1
PMID:30374462

References

GO_REF:0000002

Gene Ontology annotation through association of InterPro records with GO terms

GO_REF:0000024

Manual transfer of experimentally-verified manual GO annotation data to orthologs by curator judgment of sequence similarity

GO_REF:0000052

Gene Ontology annotation based on curation of immunofluorescence data

GO_REF:0000117

Electronic Gene Ontology annotations created by ARBA machine learning models

GO_REF:0000120

Combined Automated Annotation using Multiple IEA Methods

PMID:12610306

Role of EDEM in the release of misfolded glycoproteins from the calnexin cycle.

EDEM extracts misfolded glycoproteins, but not glycoproteins undergoing productive folding, from the calnexin cycle; overexpression accelerates release and ERAD.

PMID:16449189

Derlin-2 and Derlin-3 are regulated by the mammalian unfolded protein response and are required for ER-associated degradation.

Derlin-2 and -3 are associated with EDEM and p97 and provide the missing link between EDEM and p97 in degradation of misfolded glycoproteins.

PMID:19524542

EDEM1 recognition and delivery of misfolded proteins to the SEL1L-containing ERAD complex.

EDEM1 specifically binds non-native proteins in a glycan-independent manner; its mannosidase-like domain is required for SEL1L association but not for substrate binding.

PMID:19934218

A dual role for EDEM1 in the processing of rod opsin.

EDEM1 is a chaperone of rod opsin; it promotes degradation of misfolded P23H rod opsin and reduces aggregation, with binding independent of mannose trimming.

PMID:21062743

Mannose trimming is required for delivery of a glycoprotein from EDEM1 to XTP3-B and to late endoplasmic reticulum-associated degradation steps.

Mannose trimming enables handoff of a substrate glycoprotein from EDEM1 to the late ERAD lectin XTP3-B and downstream E3 ligases; EDEM1 binding itself is trimming-independent.

PMID:23233672

A shared endoplasmic reticulum-associated degradation pathway involving the EDEM1 protein for glycosylated and nonglycosylated proteins.

EDEM1 is used by both glycosylated and nonglycosylated misfolded substrates, binding nonglycosylated proteins through a region outside its mannosidase-like domain; ERAD machinery accumulates in the ERQC on proteasome inhibition.

PMID:24200403

The role of EDEM2 compared with EDEM1 in ricin transport from the endoplasmic reticulum to the cytosol.

EDEM1 (and EDEM2) promote retrotranslocation of the ricin A chain from the ER to the cytosol, modeling ERAD-substrate dislocation.

PMID:25092655

EDEM2 initiates mammalian glycoprotein ERAD by catalyzing the first mannose trimming step.

All endogenous EDEMs possess mannosidase activity; EDEM3 and to a lesser extent EDEM1 perform the second trimming step (Man8B to Man7), resolving the mannosidase-versus-lectin controversy.
EDEM1 has the weakest mannosidase activity of the three EDEMs and can also enhance gpERAD independently of catalysis (lectin-like) when overexpressed.

PMID:30374462

Mannosidase activity of EDEM1 and EDEM2 depends on an unfolded state of their glycoprotein substrates.

In vitro, EDEM1 (and EDEM2) mannosidase activity is modest on free oligosaccharides and native glycoproteins but significantly higher on a denatured glycoprotein, explaining how slow background trimming becomes selective for misfolded substrates; the EDEMs associate with oxidoreductases including PDI and TXNDC11.

PMID:32423001

EDEM1 Drives Misfolded Protein Degradation via ERAD and Exploits ER-Phagy as Back-Up Mechanism When ERAD Is Impaired.

EDEM1 is found in auto-regulatory complexes with ERAD components; its N-terminal disordered region mediates interaction with misfolded proteins, and EDEM1 overexpression can drive client degradation via autophagy/ER-phagy when proteasomal degradation or dislocation is impaired.

PMID:38682256

Turnover of EDEM1, an ERAD-enhancing factor, is mediated by multiple degradation routes.

EDEM1 is itself turned over by both ERAD (SEL1L/Hrd1, YOD1, XTP3B, ERdj3, VIMP, BAG6, JB12) and autophagy in folded-state-dependent manner; OS9 binds EDEM1 but did not drive its turnover. EDEM1 has a fast half-life (~3 h) and exists in soluble and membrane-associated forms.

PMID:38773321

ER-to-lysosome-associated degradation acts as failsafe mechanism upon ERAD dysfunction.

Pharmacologic or genetic inhibition of ERAD components, including silencing EDEM1, reroutes canonical ERAD clients (NHK, BACE457delta) to degradative endolysosomes via the ER-phagy receptor FAM134B and the LC3 lipidation machinery.

PMID:37528230

Mechanisms of substrate processing during ER-associated protein degradation.

Authoritative review placing EDEM-family mannosidases among the luminal processing factors that cooperate with chaperones and lectins to deliver misfolded glycoproteins to HRD1-SEL1L-dependent ERAD.

Reactome:R-HSA-1791155

Expression of EDEM

Reactome:R-HSA-6782685

EDEM1,3 hydrolyse (GlcNAc)2 (Man)8b to (GlcNAc)2 (Man)5

file:human/EDEM1/EDEM1-uniprot.txt

UniProt entry Q92611 (EDEM1_HUMAN), ER degradation-enhancing alpha-mannosidase-like protein 1

Single-pass type II ER membrane GH47 protein that extracts misfolded glycoproteins from the calnexin cycle and targets them for ERAD (N-glycan-independent, via SEL1L); has low mannosidase activity (Man8GlcNAc2 to Man7GlcNAc2); interacts with SEL1L, DERL2, DERL3.

Suggested Experiments

Experiment: Reconstitute substrate handoff with purified EDEM1, ERManI, EDEM2/3 and SEL1L on defined misfolded glycoprotein substrates to quantify the relative contributions of EDEM1 catalysis versus recognition/holdase activity to ERAD commitment.

Experiment: Domain-swap and point-mutation analysis of the EDEM1 mannosidase-like domain in endogenous knock-in cells to separate catalytic, SEL1L-binding, and non-native-protein-binding activities and test their individual requirements for ERAD of glycosylated and nonglycosylated substrates.

Deep Research

Falcon

(EDEM1-deep-research-falcon.md)

Research Report: Human **EDEM1** (UniProt **Q92611**) — Functional Annotation and Current Understanding Falcon Edison Scientific Literature 23 citations 2 artifacts 2026-06-12T03:38:16.820919

Edison artifact artifact-00 (text/markdown)

## Context ID: pqac-00000015 The document describes multiple degradation pathways for EDEM1, an ERAD-accelerating factor. The provided figures include: - **Cycl (image/png)

The research report should be a detailed narrative explaining the function, biological processes, and localization of the gene product. Citations should be given for all claims.

You should prioritize authoritative reviews and primary scientific literature when conducting research. You can supplement
this with annotations you find in gene/protein databases, but these can be outdated or inaccurate.

We are specifically interested in the primary function of the gene - for enzymes, what reaction is catalyzed, and what is the substrate specificity? For transporters, what is the substrate? For structural proteins or adapters, what is the broader structural role? For signaling molecules, what is the role in the pathway.

We are interested in where in or outside the cell the gene product carries out its function.

We are also interested in the signaling or biochemical pathways in which the gene functions. We are less interested in broad pleiotropic effects, except where these elucidate the precise role.

Include evidence where possible. We are interested in both experimental evidence as well as inference from structure, evolution, or bioinformatic analysis. Precise studies should be prioritized over high-throughput, where available.

Research Report: Human EDEM1 (UniProt Q92611) — Functional Annotation and Current Understanding

1) Target identity verification (critical)

The gene symbol EDEM1 in human refers to “ER degradation-enhancing alpha-mannosidase-like protein 1”, an ER quality-control factor implicated in glycoprotein surveillance and ER-associated degradation (ERAD), consistent with the UniProt entry Q92611 (human) and with the functional framing in mechanistic studies of ERAD and glycoprotein demannosylation. (chiritoiu2020edem1drivesmisfolded pages 1-3, shenkman2018mannosidaseactivityof pages 1-2)

2) Key concepts and definitions (current understanding)

2.1 ER-associated degradation (ERAD)

ERAD is a conserved proteostasis pathway in which misfolded proteins in the ER are recognized and triaged for retrotranslocation, ubiquitination, and proteasomal degradation. In mammalian ERAD for luminal glycoproteins (ERAD-L), glycan processing and lectin recognition help distinguish terminally misfolded proteins from folding intermediates. (chiritoiu2020edem1drivesmisfolded pages 3-5, fasana2024ertolysosomeassociateddegradationacts pages 7-8)

2.2 EDEM1 in ER glycoprotein quality control

EDEM1 is classically described as a factor that helps extract terminally misfolded glycoproteins from the calnexin folding cycle and promote their delivery to downstream ERAD machinery (e.g., HRD1–SEL1L), including ER luminal lectins such as OS-9/XTP3-B. (chiritoiu2020edem1drivesmisfolded pages 1-3, chiritoiu2020edem1drivesmisfolded pages 3-5)

2.3 “Mannose trimming” as an ERAD signal

A central concept in glycoprotein ERAD is that progressive demannosylation of N-glycans (removal of specific α1,2-mannose residues) can generate a degradation signal that increases affinity for ERAD lectins and supports commitment to disposal. EDEM1 belongs to the glycoside hydrolase family 47 (GH47) mannosidase-like proteins that participate in this process. (shenkman2018mannosidaseactivityof pages 1-2, manica2021edem3domainscooperate pages 1-2)

3) Molecular function: enzymatic reaction and substrate specificity

3.1 Enzymatic activity (reaction type)

Direct in vitro evidence indicates that EDEM1 has bona fide mannosidase activity, i.e., it trims α1,2-linked mannose residues from N-linked high-mannose glycans on glycoproteins. (shenkman2018mannosidaseactivityof pages 1-2, shenkman2018mannosidaseactivityof pages 5-6)

3.2 Substrate selectivity: unfolded/misfolded glycoproteins

A key mechanistic result is that EDEM1’s mannosidase activity is strongly dependent on the conformational state of the substrate glycoprotein: activity is modest on free glycans or native glycoproteins but increases substantially on denatured/unfolded glycoproteins, resolving how slow background trimming can become selective for misfolded species. (shenkman2018mannosidaseactivityof pages 4-4, shenkman2018mannosidaseactivityof pages 1-2)

Experimentally, EDEM1 was observed to trim oligomannose structures consistent with steps from M8 toward shorter M7–M5 species, with cellular data supporting prominent contributions to M8→M7 and M6→M5 trimming steps. (shenkman2018mannosidaseactivityof pages 4-5, shenkman2018mannosidaseactivityof pages 5-6)

3.3 Catalytic requirement (functional residue)

Mutation of a conserved catalytic residue (EDEM1 E488Q) abrogates mannosidase activity and yields a dominant-negative functional effect on ERAD substrate degradation, supporting that catalytic trimming can be functionally important in ERAD routing for at least some clients. (shenkman2018mannosidaseactivityof pages 4-4)

3.4 Dual recognition modes: glycans and polypeptide features

EDEM1 also engages substrates through protein–protein interactions beyond pure glycan recognition. For example, knockdown of EDEM1 markedly decreased interaction of an ERAD substrate with the ERAD lectin OS-9 to ~20% of control (≈80% reduction), consistent with EDEM1 contributing to formation/exposure of lectin-binding glycan signals and/or stabilizing substrate handoff. (shenkman2018mannosidaseactivityof pages 4-4, shenkman2018mannosidaseactivityof pages 1-2)

4) Subcellular localization and topology

EDEM1 functions in the endoplasmic reticulum within ER quality-control/ERAD-associated complexes. (chiritoiu2020edem1drivesmisfolded pages 1-3, chiritoiu2020edem1drivesmisfolded pages 3-5)

A 2024 study focused on EDEM1’s own turnover provides biochemical evidence that EDEM1 can exist in both soluble and membrane-associated (including a type II transmembrane) forms, consistent with post-translational processing that yields distinct topologies. Fractionation data supported substantial membrane association (example soluble/pellet distributions reported as ~20/80 or 35/65 depending on conditions/cofactors). (katsuki2024turnoverofedem1 pages 1-2, katsuki2024turnoverofedem1 pages 10-11)

Microscopy evidence from the same study shows ER localization under mannosidase inhibition (kifunensine) and relocalization to ubiquitin-positive aggresome-like structures upon proteasome inhibition. (katsuki2024turnoverofedem1 media 21e83ca5)

5) Pathways and molecular interactions

5.1 Placement in ERAD handoff networks

EDEM1 physically associates with multiple components of ER quality-control and ERAD machinery, including SEL1L, HRD1, OS-9, XTP3-B, and ER chaperones/co-chaperones (e.g., ERdj proteins), supporting a role as an organizing/processing factor that helps route clients through the ERAD-L pipeline. (chiritoiu2020edem1drivesmisfolded pages 3-5)

5.2 Dynamic complexes and autoregulation

EDEM1 is not only an ERAD factor but also becomes a substrate of ER proteostasis pathways. Perturbations to ERAD (e.g., inhibition of mannose trimming) can shift complex composition/distribution and affect EDEM1 stability. (chiritoiu2020edem1drivesmisfolded pages 3-5)

6) Recent developments (prioritizing 2023–2024)

6.1 2024: EDEM1 turnover is mediated by multiple degradation routes (ERAD and autophagy)

Katsuki et al. (Genes to Cells, Apr 2024, https://doi.org/10.1111/gtc.13117) report that EDEM1, itself an ERAD-accelerating factor, is turned over rapidly in cells (cycloheximide chase half-life ~3 h) and can be degraded via both ERAD/proteasome and autophagy, with distinct folded/aggregated states contributing to route choice. (katsuki2024turnoverofedem1 pages 2-3, katsuki2024turnoverofedem1 media 21e83ca5)

Mechanistically, the study identifies ERAD components that contribute to EDEM1 clearance, including SEL1L/Hrd1, the deubiquitinase YOD1, and other factors (e.g., XTP3B, ERdj3, VIMP, BAG6, JB12), while OS9 binds EDEM1 but did not drive turnover in their overexpression assays. (katsuki2024turnoverofedem1 pages 1-2, katsuki2024turnoverofedem1 pages 6-7)

6.2 2024: ERAD dysfunction (including EDEM1 loss/inhibition) activates a compensatory ER-to-lysosome route (ERLAD/ER-phagy-like)

Fasana et al. (EMBO Reports, May 2024, https://doi.org/10.1038/s44319-024-00165-y) demonstrate that genetic or pharmacologic inhibition of ERAD components—including silencing EDEM1 or inhibiting luminal α1,2-mannosidases with kifunensine (KIF)—can redirect canonical ERAD clients such as NHK and BACE457Δ to LAMP1-positive endolysosomes via ER-to-lysosome-associated degradation (ERLAD). (fasana2024ertolysosomeassociateddegradationacts pages 3-4, fasana2024ertolysosomeassociateddegradationacts pages 9-10)

Importantly, this compensatory route requires the ER-phagy receptor FAM134B and its LC3-interacting region (LIR), and depends on LC3 lipidation machinery (e.g., ATG7) but is reported to be independent of classical autophagosome biogenesis factors (e.g., ATG13) in their assays. (fasana2024ertolysosomeassociateddegradationacts pages 7-8, fasana2024ertolysosomeassociateddegradationacts pages 6-7)

6.3 2023: Authoritative expert synthesis of ERAD substrate processing

A recent high-authority review (Christianson et al., Nature Reviews Molecular Cell Biology, Aug 2023, https://doi.org/10.1038/s41580-023-00633-8) situates EDEM1 among the luminal processing factors that cooperate with chaperones and lectins to deliver misfolded proteins to HRD1–SEL1L-dependent ERAD, reinforcing consensus pathway placement and mechanistic framing. (fasana2024ertolysosomeassociateddegradationacts pages 10-11)

7) Applications and real-world implementations

7.1 Experimental/biotechnology implementations (current practice)

In practice, EDEM1 is widely used as:
- A node/marker of ER proteostasis pathways (ER stress/UPR–ERAD axis) in perturbation experiments; and
- A mechanistic handle to shift the fate of misfolded glycoproteins between proteasomal ERAD and lysosomal ERLAD/ER-phagy-like disposal when ERAD is compromised. (katsuki2024turnoverofedem1 pages 1-2, fasana2024ertolysosomeassociateddegradationacts pages 7-8)

7.2 Disease-relevant pathway context (preclinical)

Although this report did not identify established clinical EDEM1-targeting therapies in the retrieved sources, EDEM1 is directly relevant to disease-linked proteostasis by controlling disposal of misfolded glycoproteins and by engaging compensatory lysosomal routes under ERAD impairment. (fasana2024ertolysosomeassociateddegradationacts pages 3-4, fasana2024ertolysosomeassociateddegradationacts pages 6-7)

8) Quantitative statistics and data highlights (from recent primary studies)

EDEM1 turnover half-life (~3 h) by cycloheximide chase in human cells expressing EDEM1-FLAG (Genes to Cells, 2024). (katsuki2024turnoverofedem1 pages 2-3, katsuki2024turnoverofedem1 media 21e83ca5)
EDEM1 knockdown reduces OS-9 association with an ERAD substrate to ~20% of control (≈80% reduction), supporting a role in lectin-mediated targeting. (shenkman2018mannosidaseactivityof pages 4-4)
Under ERAD inhibition, NHK retention at 120 min increased (examples reported: mock 37–49% vs PS341 52–73% or KIF 53–80%), and further increased when lysosomes were blocked, consistent with rerouting to lysosomes. (fasana2024ertolysosomeassociateddegradationacts pages 3-4)
Under ERAD inhibition, BACE457Δ retention at 120 min increased (mock 36–54% vs PS341 70–84% or KIF 72–75%), and ERLAD delivery required FAM134B. (fasana2024ertolysosomeassociateddegradationacts pages 9-10)
ERLAD quantification used image-based LysoQuant analyses with reported cell counts (n) across conditions and strong significance in key comparisons (e.g., ****P < 0.0001 in one-way ANOVA with Dunnett’s test). (fasana2024ertolysosomeassociateddegradationacts pages 7-8, fasana2024ertolysosomeassociateddegradationacts pages 3-4)

9) Expert interpretation and synthesis

Overall, EDEM1 is best understood as a misfolding-selective GH47 mannosidase-like factor that helps commit certain ER clients to degradation by coupling (i) preferential action on unfolded glycoprotein substrates with (ii) lectin/chaperone-mediated handoff to core ERAD machinery. The recent 2024 literature adds an important systems-level perspective: EDEM1 is tightly regulated at the protein level by the same pathways it supports (ERAD and autophagy), and when EDEM1-dependent ERAD processes are impaired, cells can compensate by engaging FAM134B/LC3-dependent ERLAD to deliver ERAD clients to lysosomes. (shenkman2018mannosidaseactivityof pages 4-4, katsuki2024turnoverofedem1 pages 1-2, fasana2024ertolysosomeassociateddegradationacts pages 7-8)

Summary evidence table

Aspect	Key findings (1-3 bullets)	Evidence & quantitative details	Key sources (first author year, journal)	URL
Definition / target verification	• Human EDEM1 corresponds to ER degradation-enhancing alpha-mannosidase-like protein 1 (UniProt Q92611). • Member of glycosyl hydrolase family 47 / mannosidase-like ER quality-control proteins. • Functions in ER glycoprotein quality control and ER-associated degradation (ERAD).	Experimental/review context consistently places EDEM1 in mammalian ERAD as a GH47 mannosidase-like factor acting on misfolded glycoproteins rather than an unrelated protein; family assignment and ERAD role are concordant across mechanistic studies and reviews (chiritoiu2020edem1drivesmisfolded pages 1-3, shenkman2018mannosidaseactivityof pages 1-2, manica2021edem3domainscooperate pages 1-2).	Shenkman 2018, Communications Biology; Chiritoiu 2020, IJMS	https://doi.org/10.1038/s42003-018-0174-8 ; https://doi.org/10.3390/ijms21103468
Primary molecular function / enzymatic activity	• Bona fide mannosidase activity demonstrated in vitro for human EDEM1. • Activity is much stronger on unfolded/denatured glycoproteins than on free glycans or native glycoproteins. • Catalytic residue E488 is required for activity and ERAD support.	EDEM1 shows only modest trimming on free N-glycans/native glycoproteins but >3-fold higher activity on denatured glycoproteins; trims oligomannose species from M8 toward M5, contributing especially to M8→M7 and M6→M5 steps. E488Q mutant loses mannosidase activity and acts dominant-negatively on ERAD substrate degradation (shenkman2018mannosidaseactivityof pages 4-4, shenkman2018mannosidaseactivityof pages 4-5, shenkman2018mannosidaseactivityof pages 1-2, shenkman2018mannosidaseactivityof pages 5-6).	Shenkman 2018, Communications Biology; Lamriben 2018, JBC	https://doi.org/10.1038/s42003-018-0174-8 ; https://doi.org/10.1074/jbc.ra118.004183
Substrate specificity / recognition mode	• Prefers misfolded or unfolded glycoproteins rather than properly folded substrates. • Recognition is not purely glycan-based: EDEM1 also uses protein–protein interactions and redox-sensitive contacts. • N- and C-terminal intrinsically disordered regions (IDRs) contribute to substrate/partner binding.	EDEM1 mannosidase activity rises sharply when glycoprotein substrate is denatured; knockdown reduces OS-9 association of ERAD substrate H2a to ~20% of control (~80% reduction). The mannosidase-like domain can bind ERAD clients in a thiol/redox-sensitive manner; IDRs are required for interaction with ERAD factor ERdj5 and for efficient client binding/degradation (shenkman2018mannosidaseactivityof pages 4-4, shenkman2018mannosidaseactivityof pages 1-2, manica2021edem3domainscooperate pages 1-2).	Shenkman 2018, Communications Biology; Lamriben 2018, JBC; Chiritoiu 2020, IJMS	https://doi.org/10.1038/s42003-018-0174-8 ; https://doi.org/10.1074/jbc.ra118.004183 ; https://doi.org/10.3390/ijms21103468
Localization / topology	• EDEM1 is an ER-resident quality-control factor. • 2024 work indicates both soluble and membrane-associated / transmembrane forms can exist. • Membrane-associated form appears more aggregation-prone and can be selectively handled by some turnover factors.	Katsuki et al. report EDEM1 has five N-glycans, undergoes post-translational signal-sequence cleavage, and yields soluble and type II transmembrane forms; alkaline extraction/fractionation showed substantial membrane association (S/P ~20/80 or 35/65 depending on condition/cofactors). Figure-based evidence shows ER localization under KIF and aggresome relocalization with proteasome inhibition (katsuki2024turnoverofedem1 pages 1-2, katsuki2024turnoverofedem1 pages 10-11, katsuki2024turnoverofedem1 media 21e83ca5).	Katsuki 2024, Genes to Cells; Chiritoiu 2020, IJMS	https://doi.org/10.1111/gtc.13117 ; https://doi.org/10.3390/ijms21103468
Pathway role in ER quality control / ERAD	• EDEM1 helps extract terminally misfolded proteins from the calnexin cycle and route them to HRD1–SEL1L ERAD. • Associates with ERAD lectins/chaperones including OS-9, XTP3-B, SEL1L, HRD1, ERdj proteins. • Can contribute to degradation of some nonglycosylated misfolded proteins via protein-based recognition.	Co-complexing with SEL1L, OS-9, XTP3-B, HRD1, PSMC6, ERdj4/5, calnexin, UGGTs supports placement in luminal ERAD handoff complexes; catalytic and noncatalytic substrate engagement both contribute to routing. Earlier work also supports shared ERAD machinery for glycosylated and nonglycosylated substrates involving EDEM1 (chiritoiu2020edem1drivesmisfolded pages 1-3, chiritoiu2020edem1drivesmisfolded pages 3-5, manica2021edem3domainscooperate pages 1-2).	Chiritoiu 2020, IJMS; Christianson 2023, Nat Rev Mol Cell Biol; Shenkman 2013, JBC	https://doi.org/10.3390/ijms21103468 ; https://doi.org/10.1038/s41580-023-00633-8 ; https://doi.org/10.1074/jbc.m112.438275
Regulation by ER stress / UPR	• UPR/ER stress induces EDEM1 expression. • EDEM1 itself is also tightly controlled post-translationally by degradation pathways. • Perturbing ERAD can modestly raise EDEM1 and BiP levels.	Katsuki 2024 states EDEM1 gene expression is upregulated by ER stress/UPR; protein turnover is fast (half-life ~3 h by CHX chase). Chiritoiu 2020 found kifunensine and SEL1L depletion increase EDEM1 stability/abundance, with mild BiP upregulation during ERAD perturbation (katsuki2024turnoverofedem1 pages 1-2, katsuki2024turnoverofedem1 pages 2-3, chiritoiu2020edem1drivesmisfolded pages 3-5, katsuki2024turnoverofedem1 media 21e83ca5).	Katsuki 2024, Genes to Cells; Chiritoiu 2020, IJMS	https://doi.org/10.1111/gtc.13117 ; https://doi.org/10.3390/ijms21103468
Turnover and autoregulation (2024 emphasis)	• EDEM1 is itself degraded by ERAD and autophagy. • SEL1L/Hrd1, YOD1, XTP3B, ERdj3, VIMP, BAG6, JB12 participate in EDEM1 turnover. • OS9 binds EDEM1 but did not measurably drive its turnover in the 2024 study.	CHX chase: ~3 h half-life. KIF or MG132 stabilizes EDEM1. SEL1L knockout upregulates EDEM1; Hrd1 C329S impairs turnover; XTP3B overexpression lowers EDEM1 in a KIF-sensitive manner; inactive YOD1 C160S increases ubiquitinated, detergent-insoluble EDEM1. Statistical analyses reported from 3–4 independent experiments, with significance including P < 0.05 and P < 0.01 (katsuki2024turnoverofedem1 pages 1-2, katsuki2024turnoverofedem1 pages 10-11, katsuki2024turnoverofedem1 pages 6-7, katsuki2024turnoverofedem1 pages 2-3, katsuki2024turnoverofedem1 media 21e83ca5).	Katsuki 2024, Genes to Cells	https://doi.org/10.1111/gtc.13117
Backup lysosomal disposal / ER-phagy-ERLAD	• When ERAD is impaired, EDEM1-linked pathways connect to ER-phagy / ER-to-lysosome-associated degradation (ERLAD) as a failsafe. • FAM134B and LC3 lipidation are required for rerouting canonical ERAD clients. • Supports a model in which EDEM1 loss/inhibition does not fully block disposal but shifts it to lysosomes.	Fasana 2024: EDEM1 silencing redirects NHK to degradative endolysosomes; pharmacologic ERAD inhibition (KIF, PS341) reroutes NHK and BACE457Δ to LAMP1+ compartments. Delivery requires FAM134B and its LIR motif; ATG7 deletion blocks delivery, whereas ATG13 deletion does not. Example pulse-chase retentions at 120 min under ERAD inhibition: NHK mock 37–49% vs KIF 53–80%, PS341 52–73%, and even higher with lysosome block; BACE457Δ mock 36–54% vs KIF 72–75%, PS341 70–84%. LysoQuant analyses used multiple cell counts and N=2–3 experiments; several comparisons reached **P < 0.0001 (fasana2024ertolysosomeassociateddegradationacts pages 1-2, fasana2024ertolysosomeassociateddegradationacts pages 7-8, fasana2024ertolysosomeassociateddegradationacts pages 3-4, fasana2024ertolysosomeassociateddegradationacts pages 9-10, fasana2024ertolysosomeassociateddegradationacts pages 6-7).	Fasana 2024, EMBO Reports; Chiritoiu 2020, IJMS	https://doi.org/10.1038/s44319-024-00165-y ; https://doi.org/10.3390/ijms21103468
Real-world / disease-linked applications	• EDEM1 level or activity is being used mainly as a proteostasis/ER stress marker in cell biology and disease models. • Manipulating EDEM1 can alter fate of disease-relevant clients such as APP and viral proteins. • No approved EDEM1-targeted therapy was identified; current use is mechanistic and preclinical.	In human cell models, EDEM1 overproduction reduces APP levels and decreases Aβ40/Aβ42 secretion, supporting relevance to Alzheimer-related proteostasis; recent literature also cites EDEM1 in viral exploitation and stress-pathway studies, but translation remains preclinical. The strongest current “implementation” is use of EDEM1 as a pathway node/marker in ERAD- and UPR-focused experiments rather than a clinical biomarker or drug target (chiritoiu2020edem1drivesmisfolded pages 1-3, katsuki2024turnoverofedem1 pages 1-2).	Nowakowska-Gołacka 2021, IJMS; Katsuki 2024, Genes to Cells	https://doi.org/10.3390/ijms23010117 ; https://doi.org/10.1111/gtc.13117

Table: This table summarizes core evidence for the identity, function, localization, regulation, pathway role, and applications of human EDEM1 (UniProt Q92611). It emphasizes the most informative mechanistic studies, especially Katsuki 2024 on EDEM1 turnover and Fasana 2024 on ERLAD compensation when ERAD is impaired.

Key recent references (with publication date and URL)

Katsuki R. et al. Apr 2024. Genes to Cells. “Turnover of EDEM1… mediated by multiple degradation routes.” https://doi.org/10.1111/gtc.13117 (katsuki2024turnoverofedem1 pages 1-2)
Fasana E. et al. May 2024. EMBO Reports. “ER-to-lysosome-associated degradation acts as failsafe mechanism upon ERAD dysfunction.” https://doi.org/10.1038/s44319-024-00165-y (fasana2024ertolysosomeassociateddegradationacts pages 1-2)
Christianson J.C. et al. Aug 2023. Nature Reviews Molecular Cell Biology. “Mechanisms of substrate processing during ER-associated protein degradation.” https://doi.org/10.1038/s41580-023-00633-8 (fasana2024ertolysosomeassociateddegradationacts pages 10-11)
Shenkman M. et al. Oct 2018. Communications Biology. “Mannosidase activity of EDEM1 and EDEM2 depends on an unfolded state…” https://doi.org/10.1038/s42003-018-0174-8 (shenkman2018mannosidaseactivityof pages 1-2)
Chiritoiu M. et al. May 2020. International Journal of Molecular Sciences. “EDEM1 drives misfolded protein degradation via ERAD and exploits ER-phagy…” https://doi.org/10.3390/ijms21103468 (chiritoiu2020edem1drivesmisfolded pages 1-3)

References

(chiritoiu2020edem1drivesmisfolded pages 1-3): Marioara Chiritoiu, Gabriela N. Chiritoiu, Cristian V. A. Munteanu, Florin Pastrama, N. Erwin Ivessa, and Stefana M. Petrescu. Edem1 drives misfolded protein degradation via erad and exploits er-phagy as back-up mechanism when erad is impaired. International Journal of Molecular Sciences, 21:3468, May 2020. URL: https://doi.org/10.3390/ijms21103468, doi:10.3390/ijms21103468. This article has 38 citations.
(shenkman2018mannosidaseactivityof pages 1-2): Marina Shenkman, Efrat Ron, Rivka Yehuda, Ron Benyair, Isam Khalaila, and Gerardo Z. Lederkremer. Mannosidase activity of edem1 and edem2 depends on an unfolded state of their glycoprotein substrates. Communications Biology, Oct 2018. URL: https://doi.org/10.1038/s42003-018-0174-8, doi:10.1038/s42003-018-0174-8. This article has 71 citations and is from a peer-reviewed journal.
(chiritoiu2020edem1drivesmisfolded pages 3-5): Marioara Chiritoiu, Gabriela N. Chiritoiu, Cristian V. A. Munteanu, Florin Pastrama, N. Erwin Ivessa, and Stefana M. Petrescu. Edem1 drives misfolded protein degradation via erad and exploits er-phagy as back-up mechanism when erad is impaired. International Journal of Molecular Sciences, 21:3468, May 2020. URL: https://doi.org/10.3390/ijms21103468, doi:10.3390/ijms21103468. This article has 38 citations.
(fasana2024ertolysosomeassociateddegradationacts pages 7-8): Elisa Fasana, Ilaria Fregno, Carmela Galli, Tatiana Soldà, and Maurizio Molinari. Er-to-lysosome-associated degradation acts as failsafe mechanism upon erad dysfunction. EMBO Reports, 25:2773-2785, May 2024. URL: https://doi.org/10.1038/s44319-024-00165-y, doi:10.1038/s44319-024-00165-y. This article has 37 citations and is from a highest quality peer-reviewed journal.
(manica2021edem3domainscooperate pages 1-2): Georgiana Manica, Simona Ghenea, Cristian V. A. Munteanu, Eliza C. Martin, Cristian Butnaru, Marius Surleac, Gabriela N. Chiritoiu, Petruta R. Alexandru, Andrei-Jose Petrescu, and Stefana M. Petrescu. Edem3 domains cooperate to perform its overall cell functioning. International Journal of Molecular Sciences, 22:2172, Feb 2021. URL: https://doi.org/10.3390/ijms22042172, doi:10.3390/ijms22042172. This article has 17 citations.
(shenkman2018mannosidaseactivityof pages 5-6): Marina Shenkman, Efrat Ron, Rivka Yehuda, Ron Benyair, Isam Khalaila, and Gerardo Z. Lederkremer. Mannosidase activity of edem1 and edem2 depends on an unfolded state of their glycoprotein substrates. Communications Biology, Oct 2018. URL: https://doi.org/10.1038/s42003-018-0174-8, doi:10.1038/s42003-018-0174-8. This article has 71 citations and is from a peer-reviewed journal.
(shenkman2018mannosidaseactivityof pages 4-4): Marina Shenkman, Efrat Ron, Rivka Yehuda, Ron Benyair, Isam Khalaila, and Gerardo Z. Lederkremer. Mannosidase activity of edem1 and edem2 depends on an unfolded state of their glycoprotein substrates. Communications Biology, Oct 2018. URL: https://doi.org/10.1038/s42003-018-0174-8, doi:10.1038/s42003-018-0174-8. This article has 71 citations and is from a peer-reviewed journal.
(shenkman2018mannosidaseactivityof pages 4-5): Marina Shenkman, Efrat Ron, Rivka Yehuda, Ron Benyair, Isam Khalaila, and Gerardo Z. Lederkremer. Mannosidase activity of edem1 and edem2 depends on an unfolded state of their glycoprotein substrates. Communications Biology, Oct 2018. URL: https://doi.org/10.1038/s42003-018-0174-8, doi:10.1038/s42003-018-0174-8. This article has 71 citations and is from a peer-reviewed journal.
(katsuki2024turnoverofedem1 pages 1-2): Riko Katsuki, Mai Kanuka, Ren Ohta, Shusei Yoshida, and Taku Tamura. Turnover of edem1, an erad‐enhancing factor, is mediated by multiple degradation routes. Genes to Cells, 29:486-502, Apr 2024. URL: https://doi.org/10.1111/gtc.13117, doi:10.1111/gtc.13117. This article has 5 citations and is from a peer-reviewed journal.
(katsuki2024turnoverofedem1 pages 10-11): Riko Katsuki, Mai Kanuka, Ren Ohta, Shusei Yoshida, and Taku Tamura. Turnover of edem1, an erad‐enhancing factor, is mediated by multiple degradation routes. Genes to Cells, 29:486-502, Apr 2024. URL: https://doi.org/10.1111/gtc.13117, doi:10.1111/gtc.13117. This article has 5 citations and is from a peer-reviewed journal.
(katsuki2024turnoverofedem1 media 21e83ca5): Riko Katsuki, Mai Kanuka, Ren Ohta, Shusei Yoshida, and Taku Tamura. Turnover of edem1, an erad‐enhancing factor, is mediated by multiple degradation routes. Genes to Cells, 29:486-502, Apr 2024. URL: https://doi.org/10.1111/gtc.13117, doi:10.1111/gtc.13117. This article has 5 citations and is from a peer-reviewed journal.
(katsuki2024turnoverofedem1 pages 2-3): Riko Katsuki, Mai Kanuka, Ren Ohta, Shusei Yoshida, and Taku Tamura. Turnover of edem1, an erad‐enhancing factor, is mediated by multiple degradation routes. Genes to Cells, 29:486-502, Apr 2024. URL: https://doi.org/10.1111/gtc.13117, doi:10.1111/gtc.13117. This article has 5 citations and is from a peer-reviewed journal.
(katsuki2024turnoverofedem1 pages 6-7): Riko Katsuki, Mai Kanuka, Ren Ohta, Shusei Yoshida, and Taku Tamura. Turnover of edem1, an erad‐enhancing factor, is mediated by multiple degradation routes. Genes to Cells, 29:486-502, Apr 2024. URL: https://doi.org/10.1111/gtc.13117, doi:10.1111/gtc.13117. This article has 5 citations and is from a peer-reviewed journal.
(fasana2024ertolysosomeassociateddegradationacts pages 3-4): Elisa Fasana, Ilaria Fregno, Carmela Galli, Tatiana Soldà, and Maurizio Molinari. Er-to-lysosome-associated degradation acts as failsafe mechanism upon erad dysfunction. EMBO Reports, 25:2773-2785, May 2024. URL: https://doi.org/10.1038/s44319-024-00165-y, doi:10.1038/s44319-024-00165-y. This article has 37 citations and is from a highest quality peer-reviewed journal.
(fasana2024ertolysosomeassociateddegradationacts pages 9-10): Elisa Fasana, Ilaria Fregno, Carmela Galli, Tatiana Soldà, and Maurizio Molinari. Er-to-lysosome-associated degradation acts as failsafe mechanism upon erad dysfunction. EMBO Reports, 25:2773-2785, May 2024. URL: https://doi.org/10.1038/s44319-024-00165-y, doi:10.1038/s44319-024-00165-y. This article has 37 citations and is from a highest quality peer-reviewed journal.
(fasana2024ertolysosomeassociateddegradationacts pages 6-7): Elisa Fasana, Ilaria Fregno, Carmela Galli, Tatiana Soldà, and Maurizio Molinari. Er-to-lysosome-associated degradation acts as failsafe mechanism upon erad dysfunction. EMBO Reports, 25:2773-2785, May 2024. URL: https://doi.org/10.1038/s44319-024-00165-y, doi:10.1038/s44319-024-00165-y. This article has 37 citations and is from a highest quality peer-reviewed journal.
(fasana2024ertolysosomeassociateddegradationacts pages 10-11): Elisa Fasana, Ilaria Fregno, Carmela Galli, Tatiana Soldà, and Maurizio Molinari. Er-to-lysosome-associated degradation acts as failsafe mechanism upon erad dysfunction. EMBO Reports, 25:2773-2785, May 2024. URL: https://doi.org/10.1038/s44319-024-00165-y, doi:10.1038/s44319-024-00165-y. This article has 37 citations and is from a highest quality peer-reviewed journal.
(fasana2024ertolysosomeassociateddegradationacts pages 1-2): Elisa Fasana, Ilaria Fregno, Carmela Galli, Tatiana Soldà, and Maurizio Molinari. Er-to-lysosome-associated degradation acts as failsafe mechanism upon erad dysfunction. EMBO Reports, 25:2773-2785, May 2024. URL: https://doi.org/10.1038/s44319-024-00165-y, doi:10.1038/s44319-024-00165-y. This article has 37 citations and is from a highest quality peer-reviewed journal.

Artifacts

Edison artifact artifact-00

Citations

shenkman2018mannosidaseactivityof pages 4-4
fasana2024ertolysosomeassociateddegradationacts pages 10-11
fasana2024ertolysosomeassociateddegradationacts pages 3-4
fasana2024ertolysosomeassociateddegradationacts pages 9-10
fasana2024ertolysosomeassociateddegradationacts pages 1-2
shenkman2018mannosidaseactivityof pages 1-2
fasana2024ertolysosomeassociateddegradationacts pages 7-8
shenkman2018mannosidaseactivityof pages 5-6
shenkman2018mannosidaseactivityof pages 4-5
fasana2024ertolysosomeassociateddegradationacts pages 6-7
https://doi.org/10.1111/gtc.13117
https://doi.org/10.1038/s44319-024-00165-y
https://doi.org/10.1038/s41580-023-00633-8
https://doi.org/10.1038/s42003-018-0174-8
https://doi.org/10.3390/ijms21103468
https://doi.org/10.1074/jbc.ra118.004183
https://doi.org/10.1074/jbc.m112.438275
https://doi.org/10.3390/ijms23010117
https://doi.org/10.3390/ijms21103468,
https://doi.org/10.1038/s42003-018-0174-8,
https://doi.org/10.1038/s44319-024-00165-y,
https://doi.org/10.3390/ijms22042172,
https://doi.org/10.1111/gtc.13117,

📚 Additional Documentation

Notes

(EDEM1-notes.md)

EDEM1 (Q92611) review notes

Identity

ER degradation-enhancing alpha-mannosidase-like protein 1 (EDEM, KIAA0212). 657 aa.
Single-pass type II ER membrane protein (TM 5-25, signal-anchor); lumenal mannosidase-homology (GH47) domain.
Glycosyl hydrolase 47 family member; one of three mammalian Htm1 homologues (EDEM1/2/3).

Function (synthesis)

Core role: extracts terminally misfolded glycoproteins (and some nonglycoproteins) from the calnexin folding cycle and accelerates their ER-associated degradation (ERAD), delivering substrates to the SEL1L/HRD1 dislocation/ubiquitination machinery [PMID:12610306 "the alpha-mannosidase I-like protein EDEM was shown to extract misfolded glycoproteins, but not glycoproteins undergoing productive folding, from the calnexin cycle"; PMID:19524542 "EDEM1 binds nonnative proteins and uses its mannosidase-like domain to target aberrant proteins to the ER membrane dislocation and ubiquitination complex containing SEL1L"].
Substrate recognition is glycan-independent (binds nonnative protein structure), and SEL1L association requires the mannosidase-like domain PMID:19524542.
Catalytic activity debate: historically proposed to lack alpha-1,2-mannosidase activity (PMID:12610306 era; UniProt has a NOT mannosidase IDA from this paper). Endogenous KO analysis later showed all three EDEMs DO possess mannosidase activity; EDEM1 has the weakest activity and contributes to the second step (M8B->M7) PMID:25092655. EDEM1 can also act ERAD-promotingly independent of catalysis (lectin/holdase) when overexpressed PMID:25092655. UniProt: "It has low mannosidase activity, catalyzing mannose trimming from Man8GlcNAc2 to Man7GlcNAc2."
Mannose trimming by ERManI is required to hand off substrate from EDEM1 to the late ERAD lectin XTP3-B; EDEM1 binding itself is trimming-independent PMID:21062743.
Shared pathway for glycosylated and nonglycosylated misfolded substrates; both use calnexin, EDEM1 and HRD1; substrates and ERAD machinery accumulate in the ERQC on proteasome inhibition [PMID:23233672 "makes use of calnexin, EDEM1, and HRD1"; "proteasomal inhibition induced accumulation of the nonglycosylated proteins and ERAD machinery in the endoplasmic reticulum-derived quality control compartment"; "EDEM1 associates through a region outside of its mannosidase-like domain with the nonglycosylated proteins"].
Promotes retrotranslocation/retrograde transport from ER to cytosol; e.g. ricin A chain (like an ERAD substrate) retrotranslocation is promoted by EDEM1 (and EDEM2) [PMID:24200403 "This transport is promoted by EDEM1"; "EDEM2 is also involved in ricin retrotranslocation out of the ER"].
Dual chaperone role for rod opsin: promotes degradation of misfolded P23H rod opsin, reduces aggregation, and can promote folding/trafficking; binding is mannose-trimming-independent PMID:19934218.

Interactions

SEL1L (binds; requires mannosidase-like domain) PMID:19524542.
DERL2 and DERL3 (Derlin-2/-3); EDEM links to p97 via Derlins PMID:16449189.
Rod opsin (P08100) client PMID:19934218.

Localization

ER membrane (single-pass type II) [UniProt]. Concentrates in the ER-derived quality control compartment (ERQC) with ERAD machinery PMID:23233672.

Annotation review decisions (high level)

ERAD pathway (GO:0036503), ER mannose trimming (GO:1904380), mannose trimming in glycoprotein ERAD (GO:1904382), ubiquitin-dependent catabolism (GO:0006511): core / accept; strongly supported.
mannosyl-oligosaccharide 1,2-alpha-mannosidase activity (GO:0004571): the IMP enables annotation (PMID:25092655) is now supported (weak but real). ACCEPT but note weak.
NOT mannosyl-oligosaccharide 1,2-alpha-mannosidase activity (GO:0004571, IDA, PMID:12610306): a negated experimental annotation reflecting the historical "no activity" view; the later endogenous-KO study contradicts it. Conflicting experimental annotations; keep as historical (do not REMOVE an experimental annotation on weak grounds; mark KEEP_AS_NON_CORE with note that it is superseded).
misfolded protein binding (GO:0051787): core MF-like; EDEM1 recognizes nonnative proteins; ACCEPT.
protein binding (GO:0005515) IPI: KEEP_AS_NON_CORE (uninformative; partners SEL1L, DERL2/3, rod opsin captured elsewhere).
positive regulation of retrograde protein transport ER->cytosol (GO:1904154): supported by ricin study; ACCEPT/non-core.
protein targeting to ER (GO:0045047, IMP PMID:23233672): the paper concerns ER-retained substrate targeting to ERAD, not protein import to ER. Likely a mislabel toward ERAD targeting; MARK_AS_OVER_ANNOTATED / generalize. Use UNDECIDED-style caution — keep as non-core given experimental basis but note the term is a poor fit.
calcium ion binding (GO:0005509, IEA): GH47 fold cofactor; KEEP_AS_NON_CORE.
carbohydrate metabolic process / membrane (generic IEA): MARK_AS_OVER_ANNOTATED in favor of ER N-glycan trimming / ER membrane.
ER, ER membrane, ERQC localizations: accept.

Falcon deep-research findings (incorporated 2026-06)

The EDEM1 review already incorporated the main recent Falcon-cited papers: Chiritoiu 2020 (PMID:32423001), Katsuki 2024 turnover (PMID:38682256), Fasana 2024 ERLAD (PMID:38773321), and Christianson 2023 review (PMID:37528230). No action needed for these.
NEW reference added: Shenkman et al. 2018 (Commun Biol, PMID:30374462) - this provides the first direct in vitro mannosidase assays for EDEM1, showing bona fide alpha-mannosidase activity that is folding-state dependent: modest on free glycans/native glycoproteins but significantly higher on a denatured glycoprotein, explaining selectivity for misfolded substrates PMID:30374462. The EDEMs associate with oxidoreductases (PDI, TXNDC11). This complements the endogenous-KO mannosidase evidence (PMID:25092655) and was the main EDEM1-relevant primary paper missing from the review.
Falcon's other EDEM1 content (E488Q catalytic residue, OS-9 association ~80% reduction on EDEM1 knockdown, ~3h half-life, both soluble and type II TM forms, FAM134B-dependent ERLAD rerouting) is sourced from papers already cited in the review (Shenkman 2018, Katsuki 2024, Fasana 2024); no further citation changes needed.
PMID:30374462 added (id only, uncached) to the EDEM1 mannosidase core_function supported_by.

Pn Notes

(EDEM1-pn-notes.md)

EDEM1 PN Consistency Notes

Generated: 2026-06-18
Project: PROTEOSTASIS
Scope: PN consistency rereview against local AIGR review and available deep-research artifacts
UniProt: Q92611
AIGR review status: COMPLETE
Review batch: proteostasis-batch-2026-06-11
Batch change status: added

Source Files Checked

AIGR review YAML: present - genes/human/EDEM1/EDEM1-ai-review.yaml
AIGR review HTML: missing - genes/human/EDEM1/EDEM1-ai-review.html
Gene notes: present - genes/human/EDEM1/EDEM1-notes.md
GOA TSV: present - genes/human/EDEM1/EDEM1-goa.tsv
UniProt record: present - genes/human/EDEM1/EDEM1-uniprot.txt
PN dossier: projects/PROTEOSTASIS/reports/phase1_dossiers/EDEM1.md
PN consistency section: projects/PROTEOSTASIS/reports/phase1_dossiers/_sections/EDEM1.md
PN projection report: projects/PROTEOSTASIS/reports/pn_projection/pn_projected_gene_go_summary.tsv
PN mapping audit: projects/PROTEOSTASIS/reports/pn_mapping_audit/current_mapping_scrutiny.tsv

Deep Research Files

genes/human/EDEM1/EDEM1-deep-research-falcon.md

AIGR Review Snapshot

Description: EDEM1 (ER degradation-enhancing alpha-mannosidase-like protein 1) is a single-pass type II endoplasmic reticulum membrane protein of glycoside hydrolase family 47 (GH47), one of three mammalian Htm1/Mns1 homologues (EDEM1, EDEM2, EDEM3) acting in the ER-associated degradation of glycoproteins (gpERAD). EDEM1 extracts terminally misfolded glycoproteins, but not proteins undergoing productive folding, from the calnexin/calreticulin folding cycle and accelerates their clearance, delivering aberrant substrates to the SEL1L/HRD1 dislocation and ubiquitination machinery and, via Derlin-2/-3, to the p97/VCP retrotranslocation system. It recognizes non-native protein structure in a glycan-independent manner (acting in part as a lectin/holdase-like factor), binding both glycosylated and nonglycosylated misfolded substrates, and it requires its mannosidase-like domain for association with SEL1L. EDEM1 possesses low alpha-1,2-mannosidase activity, contributing to the second mannose-trimming step (Man8GlcNAc2 to Man7GlcNAc2) that exposes the alpha-1,6-mannose recognized by downstream lectins (OS-9/XTP3-B); its catalytic activity is weak relative to its recognition/delivery role and was historically debated. EDEM1 is induced by the IRE1-XBP1 branch of the unfolded protein response, resides in the ER membrane and concentrates in the ER-derived quality control compartment (ERQC), and promotes ER-to-cytosol retrotranslocation of substrates including the ricin A chain.
Existing/core annotation action counts: ACCEPT: 20; KEEP_AS_NON_CORE: 9; MARK_AS_OVER_ANNOTATED: 3

PN Consistency Summary

Consistency: Deep research ↔ review YAML ↔ PN annotation consistent. EDEM1 = GH47 type-II ER membrane factor that recognizes terminally misfolded glycoproteins (glycan-independently) and delivers them to SEL1L/HRD1 ERAD; possesses weak alpha-1,2-mannosidase activity (second step Man8B→Man7). Critically, the negated (NOT) GO:0004571 IDA from PMID:12610306 (historical "no activity") is correctly retained as superseded by the positive IMP GO:0004571 (PMID:25092655). Review and notes both flag this NOT-vs-positive tension explicitly. No contradictions.
PN story / NEW pressure: PN's mannose-trimming subtype → GO:1904382, which is already_in_goa_exact (TAS Reactome + matches review). EDEM1's contribution is already captured (GO:1904380, GO:1904382, GO:0036503, GO:0004571 IMP). No NEW term needed; review proposes none. Already captured.
Evidence alignment: Strong overlap on the shared landmark PMID:25092655 (also EDEM2/EDEM3) and Reactome:R-HSA-6782685. Review adds extensive EDEM1-specific literature (PMID:12610306, 19524542, 21062743, 23233672, 24200403, 30374462, 32423001) beyond the PN row.
Verdict: Consistent and well-curated; NOT-mannosidase tension handled correctly. subtype→GO:1904382 sound; group→GO:0006487 is a loose/broad fit for the degradation arm.

Full Consistency Review

UniProt: Q92611 · batch: proteostasis-batch-2026-06-11 · review status: COMPLETE
PN placement: ER proteostasis|Glycoproteostasis|N-glycosylation system|N-glycan processing|Mannose trimming ; PN-node mapping: subtype "Mannose trimming"=mapped/ok GO:1904382 (mannose trimming in glycoprotein ERAD, already_in_goa_exact); group "N-glycosylation system"=mapped/ok GO:0006487 protein N-linked glycosylation (new_to_goa); intermediate type/class/branch=no_mapping.
Consistency: Deep research ↔ review YAML ↔ PN annotation consistent. EDEM1 = GH47 type-II ER membrane factor that recognizes terminally misfolded glycoproteins (glycan-independently) and delivers them to SEL1L/HRD1 ERAD; possesses weak alpha-1,2-mannosidase activity (second step Man8B→Man7). Critically, the negated (NOT) GO:0004571 IDA from PMID:12610306 (historical "no activity") is correctly retained as superseded by the positive IMP GO:0004571 (PMID:25092655). Review and notes both flag this NOT-vs-positive tension explicitly. No contradictions.
PN story / NEW pressure: PN's mannose-trimming subtype → GO:1904382, which is already_in_goa_exact (TAS Reactome + matches review). EDEM1's contribution is already captured (GO:1904380, GO:1904382, GO:0036503, GO:0004571 IMP). No NEW term needed; review proposes none. Already captured.
Mapping strategy: subtype→GO:1904382 is exact and well-supported — keep. Caveat on the catalytic MF: EDEM1 is catalytic but WEAKLY so (weakest of the three EDEMs); the review correctly keeps GO:0004571 as a supporting (not dominant) function behind GO:0051787 misfolded protein binding (its defining CORE MF). The group→GO:0006487 protein N-linked glycosylation projection is broader/upstream (glycan installation) than EDEM1's degradative trimming role and is a loose fit — borderline over-reach for a degradation-arm factor.
Evidence alignment: Strong overlap on the shared landmark PMID:25092655 (also EDEM2/EDEM3) and Reactome:R-HSA-6782685. Review adds extensive EDEM1-specific literature (PMID:12610306, 19524542, 21062743, 23233672, 24200403, 30374462, 32423001) beyond the PN row.
Verdict: Consistent and well-curated; NOT-mannosidase tension handled correctly. subtype→GO:1904382 sound; group→GO:0006487 is a loose/broad fit for the degradation arm.

PN Dossier Context

review_batch: proteostasis-batch-2026-06-11
review_yaml: genes/human/EDEM1/EDEM1-ai-review.yaml
PN workbook rows: 1

PN row 1: ER proteostasis | Glycoproteostasis | N-glycosylation system | N-glycan processing | Mannose trimming

UniProt: Q92611
In branches: ER
PN-node mapping records (path + ancestors):
- [subtype] ER proteostasis|Glycoproteostasis|N-glycosylation system|N-glycan processing|Mannose trimming
  status=mapped scope=ok_for_propagation_to_go GO=[GO:1904382 mannose trimming involved in glycoprotein ERAD pathway]
  rationale: Within the ER proteostasis branch, this PN subtype denotes mannose trimming used in glycoprotein quality control and ERAD triage. That is close enough for propagation to the GO mannose-trimming-in-ERAD process, but the PN subtype is framed as a proteostasis step rather than a formal GO process class.
- [type] ER proteostasis|Glycoproteostasis|N-glycosylation system|N-glycan processing
  status=no_mapping scope= GO=[]
  rationale: Reviewed as a broad PN category rather than a single GO class. The member genes span multiple activities, complexes, or contexts, so direct propagation from this node would overstate the shared biology.
- [group] ER proteostasis|Glycoproteostasis|N-glycosylation system
  status=mapped scope=ok_for_propagation_to_go GO=[GO:0006487 protein N-linked glycosylation]
  rationale: This PN group captures the ER N-glycosylation machinery that installs and processes N-linked glycans during proteostasis. GO protein N-linked glycosylation is the best current propagation target in the local cache.
- [class] ER proteostasis|Glycoproteostasis
  status=no_mapping scope= GO=[]
  rationale: Reviewed as a broad PN category rather than a single GO class. The member genes span multiple activities, complexes, or contexts, so direct propagation from this node would overstate the shared biology.
- [branch] ER proteostasis
  status=no_mapping scope= GO=[]
  rationale: Reviewed as a top-level PN branch. This is a systems/taxonomy umbrella, not a direct GO assertion; narrower child curations carry any propagating GO mappings.

Projected GO annotations (2)

GO:0006487 protein N-linked glycosylation | scope=ok_for_propagation_to_go | goa_status=new_to_goa | from=ER proteostasis|Glycoproteostasis|N-glycosylation system
GO:1904382 mannose trimming involved in glycoprotein ERAD pathway | scope=ok_for_propagation_to_go | goa_status=already_in_goa_exact | from=ER proteostasis|Glycoproteostasis|N-glycosylation system|N-glycan processing|Mannose trimming

Note

This file is generated from the current PROTEOSTASIS phase-1 dossier and local gene-review artifacts. Edit the source review, PN mapping, or dossier rather than this generated note when correcting the underlying curation.

📄 View Raw YAML

id: Q92611
gene_symbol: EDEM1
product_type: PROTEIN
status: COMPLETE
taxon:
  id: NCBITaxon:9606
  label: Homo sapiens
description: EDEM1 (ER degradation-enhancing alpha-mannosidase-like protein 1) is a single-pass type II endoplasmic reticulum membrane protein of glycoside hydrolase family 47 (GH47), one of three mammalian Htm1/Mns1 homologues (EDEM1, EDEM2, EDEM3) acting in the ER-associated degradation of glycoproteins (gpERAD). EDEM1 extracts terminally misfolded glycoproteins, but not proteins undergoing productive folding, from the calnexin/calreticulin folding cycle and accelerates their clearance, delivering aberrant substrates to the SEL1L/HRD1 dislocation and ubiquitination machinery and, via Derlin-2/-3, to the p97/VCP retrotranslocation system. It recognizes non-native protein structure in a glycan-independent manner (acting in part as a lectin/holdase-like factor), binding both glycosylated and nonglycosylated misfolded substrates, and it requires its mannosidase-like domain for association with SEL1L. EDEM1 possesses low alpha-1,2-mannosidase activity, contributing to the second mannose-trimming step (Man8GlcNAc2 to Man7GlcNAc2) that exposes the alpha-1,6-mannose recognized by downstream lectins (OS-9/XTP3-B); its catalytic activity is weak relative to its recognition/delivery role and was historically debated. EDEM1 is induced by the IRE1-XBP1 branch of the unfolded protein response, resides in the ER membrane and concentrates in the ER-derived quality control compartment (ERQC), and promotes ER-to-cytosol retrotranslocation of substrates including the ricin A chain.
alternative_products:
- name: '1'
  id: Q92611-1
- name: '2'
  id: Q92611-2
  sequence_note: VSP_056703, VSP_056704
existing_annotations:
- term:
    id: GO:0005509
    label: calcium ion binding
  evidence_type: IEA
  original_reference_id: GO_REF:0000002
  qualifier: enables
  review:
    summary: GH47-family mannosidases use a calcium ion in the active site; EDEM1 retains this fold and binds calcium as a structural/catalytic cofactor. This is subsidiary to its recognition and ERAD functions, especially given its weak mannosidase activity.
    action: KEEP_AS_NON_CORE
    reason: Accurate structural cofactor attribute of the GH47 mannosidase-like domain, but not a standalone core function; the informative functions are misfolded protein recognition and ERAD.
    supported_by:
    - reference_id: file:human/EDEM1/EDEM1-uniprot.txt
      supporting_text: Belongs to the glycosyl hydrolase 47 family
- term:
    id: GO:0005783
    label: endoplasmic reticulum
  evidence_type: IEA
  original_reference_id: GO_REF:0000117
  qualifier: located_in
  review:
    summary: EDEM1 is an ER-resident protein; electronic (ARBA) assignment of ER localization is consistent with experimental evidence.
    action: ACCEPT
    reason: Correct site of action; redundant with IDA ER and ERQC annotations.
    supported_by:
    - reference_id: file:human/EDEM1/EDEM1-uniprot.txt
      supporting_text: 'SUBCELLULAR LOCATION: Endoplasmic reticulum membrane'
- term:
    id: GO:0005789
    label: endoplasmic reticulum membrane
  evidence_type: IEA
  original_reference_id: GO_REF:0000120
  qualifier: located_in
  review:
    summary: EDEM1 is a single-pass type II ER membrane protein; electronic transfer of ER membrane localization is correct.
    action: ACCEPT
    reason: Correct compartment; redundant with the ISS ER membrane annotation and UniProt subcellular location.
    supported_by:
    - reference_id: file:human/EDEM1/EDEM1-uniprot.txt
      supporting_text: Single-pass type II membrane protein
- term:
    id: GO:0005975
    label: carbohydrate metabolic process
  evidence_type: IEA
  original_reference_id: GO_REF:0000002
  qualifier: involved_in
  review:
    summary: Generic carbohydrate metabolic process from InterPro; far less informative than the specific ER mannose trimming and ERAD processes EDEM1 participates in.
    action: MARK_AS_OVER_ANNOTATED
    reason: Over-general parent; the specific ER mannose trimming (GO:1904380) and ERAD (GO:0036503) terms better capture the biology.
    supported_by:
    - reference_id: file:human/EDEM1/EDEM1-uniprot.txt
      supporting_text: Belongs to the glycosyl hydrolase 47 family
- term:
    id: GO:0016020
    label: membrane
  evidence_type: IEA
  original_reference_id: GO_REF:0000002
  qualifier: located_in
  review:
    summary: Generic membrane localization from InterPro, superseded by the specific ER membrane annotation.
    action: MARK_AS_OVER_ANNOTATED
    reason: Uninformative parent; EDEM1 is specifically an ER membrane protein.
    proposed_replacement_terms:
    - id: GO:0005789
      label: endoplasmic reticulum membrane
    supported_by:
    - reference_id: file:human/EDEM1/EDEM1-uniprot.txt
      supporting_text: 'SUBCELLULAR LOCATION: Endoplasmic reticulum membrane'
- term:
    id: GO:0036503
    label: ERAD pathway
  evidence_type: IEA
  original_reference_id: GO_REF:0000117
  qualifier: involved_in
  review:
    summary: Electronic (ARBA) assignment of the ERAD pathway, consistent with extensive experimental evidence that EDEM1 accelerates ERAD of misfolded glycoproteins.
    action: ACCEPT
    reason: Correct core biological process; redundant with IMP/ISS evidence.
    supported_by:
    - reference_id: file:human/EDEM1/EDEM1-uniprot.txt
      supporting_text: It is directly involved in endoplasmic reticulum-associated degradation (ERAD)
- term:
    id: GO:1904380
    label: endoplasmic reticulum mannose trimming
  evidence_type: IEA
  original_reference_id: GO_REF:0000120
  qualifier: involved_in
  review:
    summary: EDEM1 contributes to ER mannose trimming (the Man8 to Man7 step); electronic assignment is consistent with the IMP evidence.
    action: ACCEPT
    reason: Correct biological process; redundant with the IMP annotation from endogenous knockout analysis.
    supported_by:
    - reference_id: PMID:25092655
      supporting_text: Mannose trimming from Man8GlcNAc2 to Man7GlcNAc2 is performed mainly by EDEM3 and to a lesser extent by EDEM1
- term:
    id: GO:1904154
    label: positive regulation of retrograde protein transport, ER to cytosol
  evidence_type: IEA
  original_reference_id: GO_REF:0000120
  qualifier: involved_in
  review:
    summary: EDEM1 promotes retrotranslocation of ERAD substrates from the ER to the cytosol; electronic assignment is consistent with the experimental ricin retrotranslocation data.
    action: KEEP_AS_NON_CORE
    reason: Real, specific aspect of EDEM1 function (substrate dislocation) but subordinate to the core recognition/ERAD role; redundant with the IMP/IGI annotations.
    supported_by:
    - reference_id: PMID:24200403
      supporting_text: This transport is promoted by EDEM1
- term:
    id: GO:0004571
    label: mannosyl-oligosaccharide 1,2-alpha-mannosidase activity
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-6782685
  qualifier: enables
  review:
    summary: Reactome curation of EDEM1 (with EDEM3) hydrolysing Man8 to Man5 glycans. EDEM1 has genuine but low alpha-1,2-mannosidase activity contributing to the second trimming step.
    action: ACCEPT
    reason: Correct molecular function (weak but real, demonstrated by endogenous knockout); kept as supporting rather than the dominant function.
    supported_by:
    - reference_id: PMID:25092655
      supporting_text: all endogenous EDEMs possess mannosidase activity
- term:
    id: GO:0005783
    label: endoplasmic reticulum
  evidence_type: IDA
  original_reference_id: GO_REF:0000052
  qualifier: located_in
  review:
    summary: Direct immunofluorescence (HPA) evidence for ER localization, consistent with EDEM1's site of action.
    action: ACCEPT
    reason: Correct compartment with direct experimental support.
    supported_by:
    - reference_id: file:human/EDEM1/EDEM1-uniprot.txt
      supporting_text: 'SUBCELLULAR LOCATION: Endoplasmic reticulum membrane'
- term:
    id: GO:1904380
    label: endoplasmic reticulum mannose trimming
  evidence_type: IMP
  original_reference_id: PMID:25092655
  qualifier: involved_in
  review:
    summary: Endogenous EDEM1 knockout in human and chicken cells increased Man8B levels, showing EDEM1 contributes (with EDEM3) to the second ER mannose-trimming step from Man8GlcNAc2 to Man7GlcNAc2.
    action: ACCEPT
    reason: Core biological process with direct experimental (IMP) support from endogenous gene knockout.
    supported_by:
    - reference_id: PMID:25092655
      supporting_text: Mannose trimming from Man8GlcNAc2 to Man7GlcNAc2 is performed mainly by EDEM3 and to a lesser extent by EDEM1
- term:
    id: GO:0006511
    label: ubiquitin-dependent protein catabolic process
  evidence_type: IMP
  original_reference_id: PMID:25092655
  qualifier: involved_in
  review:
    summary: EDEM1 knockout delayed degradation of the gpERAD substrate ATF6alpha, which is degraded by the ubiquitin-proteasome system; supports a role in ubiquitin-dependent catabolism via ERAD.
    action: KEEP_AS_NON_CORE
    reason: Correct but generic parent process; the more specific ERAD pathway (GO:0036503) better captures EDEM1's role.
    supported_by:
    - reference_id: PMID:25092655
      supporting_text: deletion of hEDEM1 significantly delayed the degradation of hATF6
- term:
    id: GO:0036503
    label: ERAD pathway
  evidence_type: IMP
  original_reference_id: PMID:21062743
  qualifier: involved_in
  review:
    summary: EDEM1 functions in ERAD by handing off substrate glycoproteins, after mannose trimming, to the late ERAD lectin XTP3-B and downstream E3 ligases.
    action: ACCEPT
    reason: Core biological process; experimentally links EDEM1 to the downstream ERAD machinery.
    supported_by:
    - reference_id: PMID:21062743
      supporting_text: mannose trimming enables delivery of a substrate glycoprotein from EDEM1 to late ERAD steps through association with XTP3-B
- term:
    id: GO:0036503
    label: ERAD pathway
  evidence_type: IMP
  original_reference_id: PMID:25092655
  qualifier: involved_in
  review:
    summary: Endogenous EDEM1 knockout delayed gpERAD of ATF6alpha, directly demonstrating EDEM1's role in the ERAD pathway.
    action: ACCEPT
    reason: Core biological process with direct experimental (IMP) support.
    supported_by:
    - reference_id: PMID:25092655
      supporting_text: deletion of hEDEM1 significantly delayed the degradation of hATF6
- term:
    id: GO:1904382
    label: mannose trimming involved in glycoprotein ERAD pathway
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-6782685
  qualifier: involved_in
  review:
    summary: Reactome curation of EDEM1 mannose trimming within the glycoprotein ERAD pathway; an accurate, specific refinement of EDEM1's trimming contribution to ERAD.
    action: ACCEPT
    reason: Correct specific biological process linking the trimming activity to ERAD.
    supported_by:
    - reference_id: PMID:25092655
      supporting_text: M8B is trimmed by EDEM1 and EDEM3 to Man7-5GlcNAc2, which are recognized by lectin OS-9
- term:
    id: GO:0044322
    label: endoplasmic reticulum quality control compartment
  evidence_type: IDA
  original_reference_id: PMID:23233672
  qualifier: located_in
  review:
    summary: On proteasome inhibition, EDEM1 and other ERAD machinery accumulate with substrates in the ER-derived quality control compartment (ERQC), supporting an ERQC localization.
    action: ACCEPT
    reason: Genuine, functionally relevant localization with direct experimental support.
    supported_by:
    - reference_id: PMID:23233672
      supporting_text: accumulation of the nonglycosylated proteins and ERAD machinery in the endoplasmic reticulum-derived quality control compartment
- term:
    id: GO:0045047
    label: protein targeting to ER
  evidence_type: IMP
  original_reference_id: PMID:23233672
  qualifier: involved_in
  review:
    summary: This annotation derives from work showing EDEM1 targets misfolded substrates to the ER membrane dislocation/ERAD machinery, not co-translational targeting of nascent proteins to the ER. The GO term protein targeting to ER (import into the ER) poorly captures the demonstrated delivery-to-ERAD biology.
    action: MARK_AS_OVER_ANNOTATED
    reason: The term denotes targeting of proteins into the ER (e.g. co-translational import), which is not what EDEM1 does; the experimental result is substrate delivery to the ER-membrane ERAD/dislocation complex. Retained (experimental basis) rather than removed, but the term is a poor fit.
    supported_by:
    - reference_id: PMID:19524542
      supporting_text: target aberrant proteins to the ER membrane dislocation and ubiquitination complex containing SEL1L
- term:
    id: GO:0051787
    label: misfolded protein binding
  evidence_type: IMP
  original_reference_id: PMID:23233672
  qualifier: enables
  review:
    summary: EDEM1 binds misfolded glycosylated and nonglycosylated substrates, associating with nonglycosylated proteins through a region outside its mannosidase-like domain; recognition of non-native protein structure is a core EDEM1 function.
    action: ACCEPT
    reason: Core molecular function; EDEM1's defining role is recognition of misfolded/non-native proteins for ERAD.
    supported_by:
    - reference_id: PMID:23233672
      supporting_text: EDEM1 associates through a region outside of its mannosidase-like domain with the nonglycosylated proteins
- term:
    id: GO:0004571
    label: mannosyl-oligosaccharide 1,2-alpha-mannosidase activity
  evidence_type: IMP
  original_reference_id: PMID:25092655
  qualifier: enables
  review:
    summary: Endogenous gene knockout established that EDEM1 possesses (weak) alpha-1,2-mannosidase activity, contributing to the second trimming step Man8B to Man7. This resolved the long-standing mannosidase-versus-lectin controversy in favor of genuine but low catalytic activity.
    action: ACCEPT
    reason: Molecular function supported by endogenous knockout (IMP); EDEM1 has the weakest mannosidase activity of the three EDEMs, so this is retained as a supporting rather than dominant function.
    supported_by:
    - reference_id: PMID:25092655
      supporting_text: all endogenous EDEMs possess mannosidase activity
- term:
    id: GO:1904154
    label: positive regulation of retrograde protein transport, ER to cytosol
  evidence_type: IMP
  original_reference_id: PMID:24200403
  qualifier: involved_in
  review:
    summary: EDEM1 promotes ER-to-cytosol retrotranslocation of the ricin A chain, a model retrotranslocation substrate handled like a misfolded ER protein.
    action: KEEP_AS_NON_CORE
    reason: Specific, experimentally supported aspect of EDEM1's ERAD/dislocation activity, but subordinate to the core recognition/ERAD role.
    supported_by:
    - reference_id: PMID:24200403
      supporting_text: This transport is promoted by EDEM1
- term:
    id: GO:1904154
    label: positive regulation of retrograde protein transport, ER to cytosol
  evidence_type: IGI
  original_reference_id: PMID:24200403
  qualifier: involved_in
  review:
    summary: Genetic-interaction evidence (with EDEM2, UniProtKB:Q9BV94) that EDEM1 promotes ricin A-chain retrotranslocation from the ER to the cytosol.
    action: KEEP_AS_NON_CORE
    reason: Consistent with the IMP retrotranslocation annotation; a specific aspect of the dislocation function rather than the core role.
    supported_by:
    - reference_id: PMID:24200403
      supporting_text: more ricin can interact with EDEM2 in comparison with EDEM1
- term:
    id: GO:0044322
    label: endoplasmic reticulum quality control compartment
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-1791155
  qualifier: located_in
  review:
    summary: Reactome curation of EDEM1 ERQC localization (EDEM expression context); consistent with direct IDA evidence.
    action: ACCEPT
    reason: Correct compartment; redundant with the IDA ERQC annotation.
    supported_by:
    - reference_id: PMID:23233672
      supporting_text: endoplasmic reticulum-derived quality control compartment
- term:
    id: GO:0044322
    label: endoplasmic reticulum quality control compartment
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-6782685
  qualifier: located_in
  review:
    summary: Reactome curation of EDEM1 ERQC localization in the mannose-trimming reaction context.
    action: ACCEPT
    reason: Correct compartment; redundant with the IDA ERQC annotation.
    supported_by:
    - reference_id: PMID:23233672
      supporting_text: endoplasmic reticulum-derived quality control compartment
- term:
    id: GO:0005783
    label: endoplasmic reticulum
  evidence_type: IMP
  original_reference_id: PMID:21062743
  qualifier: located_in
  review:
    summary: ER localization in the context of EDEM1-dependent ERAD substrate handoff.
    action: ACCEPT
    reason: Correct site of action; consistent with experimental ER/ERQC evidence.
    supported_by:
    - reference_id: file:human/EDEM1/EDEM1-uniprot.txt
      supporting_text: 'SUBCELLULAR LOCATION: Endoplasmic reticulum membrane'
- term:
    id: GO:0005783
    label: endoplasmic reticulum
  evidence_type: IDA
  original_reference_id: PMID:24200403
  qualifier: located_in
  review:
    summary: Direct evidence for ER localization of EDEM1 in the ricin retrotranslocation study.
    action: ACCEPT
    reason: Correct compartment with direct experimental support.
    supported_by:
    - reference_id: file:human/EDEM1/EDEM1-uniprot.txt
      supporting_text: 'SUBCELLULAR LOCATION: Endoplasmic reticulum membrane'
- term:
    id: GO:0004571
    label: mannosyl-oligosaccharide 1,2-alpha-mannosidase activity
  evidence_type: IDA
  original_reference_id: PMID:12610306
  qualifier: enables
  negated: true
  review:
    summary: A negated (NOT) experimental annotation reflecting the original proposal that EDEM1 lacks alpha-1,2-mannosidase activity, based on overexpression biochemistry. Later endogenous-knockout analysis (PMID:25092655) demonstrated that EDEM1 does possess weak mannosidase activity, so this negation is superseded but retained as the curated record of the early finding.
    action: KEEP_AS_NON_CORE
    reason: Genuine historical experimental (IDA) annotation that conflicts with later endogenous-KO evidence; per guidelines an experimental annotation is not removed on weak grounds. Flagged as superseded by PMID:25092655.
    supported_by:
    - reference_id: PMID:25092655
      supporting_text: it had originally been proposed that EDEM1 has no α1,2-mannosidase
        activity
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:19524542
  qualifier: enables
  review:
    summary: Physical interaction with SEL1L (UniProtKB:Q9UBV2), the HRD1-complex adaptor through which EDEM1 delivers substrates to the dislocation machinery. The bare protein binding term is uninformative; the SEL1L interaction is captured by the misfolded protein binding and ERAD annotations.
    action: KEEP_AS_NON_CORE
    reason: Records a real interaction (SEL1L) but bare protein binding is uninformative per curation guidelines; the functional consequence is reflected in the ERAD/recognition terms.
    supported_by:
    - reference_id: PMID:19524542
      supporting_text: its association with the ER membrane adaptor protein SEL1L
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:19934218
  qualifier: enables
  review:
    summary: Physical interaction with rod opsin (UniProtKB:P08100), an EDEM1 client glycoprotein. The bare protein binding term is uninformative.
    action: KEEP_AS_NON_CORE
    reason: Real client interaction (rod opsin) but bare protein binding is uninformative; EDEM1's recognition function is captured by misfolded protein binding.
    supported_by:
    - reference_id: PMID:19934218
      supporting_text: rod opsin co-immunoprecipitated with EDEM1
- term:
    id: GO:0051787
    label: misfolded protein binding
  evidence_type: IDA
  original_reference_id: PMID:19524542
  qualifier: enables
  review:
    summary: EDEM1 directly and specifically binds non-native proteins in a glycan-independent manner, demonstrating recognition of misfolded protein structure independent of N-glycan trimming.
    action: ACCEPT
    reason: Core molecular function; direct demonstration of misfolded/non-native protein recognition.
    supported_by:
    - reference_id: PMID:19524542
      supporting_text: EDEM1 specifically binds nonnative proteins in a glycan-independent manner
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:16449189
  qualifier: enables
  review:
    summary: Physical interactions with Derlin-2 (UniProtKB:Q9GZP9) and Derlin-3 (UniProtKB:Q96Q80), which link EDEM to p97/VCP for substrate extraction. The bare protein binding term is uninformative; the functional role is reflected in the ERAD annotations.
    action: KEEP_AS_NON_CORE
    reason: Records real Derlin-2/-3 interactions providing the EDEM-to-p97 link, but bare protein binding is uninformative per guidelines.
    supported_by:
    - reference_id: PMID:16449189
      supporting_text: Derlin-2 and -3 are associated with EDEM and p97
- term:
    id: GO:0005789
    label: endoplasmic reticulum membrane
  evidence_type: ISS
  original_reference_id: GO_REF:0000024
  qualifier: located_in
  review:
    summary: Sequence-similarity transfer (from mouse Q925U4) of ER membrane localization; EDEM1 is a single-pass type II ER membrane protein.
    action: ACCEPT
    reason: Correct compartment; consistent with UniProt subcellular location and IDA evidence.
    supported_by:
    - reference_id: file:human/EDEM1/EDEM1-uniprot.txt
      supporting_text: Single-pass type II membrane protein
- term:
    id: GO:0036503
    label: ERAD pathway
  evidence_type: ISS
  original_reference_id: GO_REF:0000024
  qualifier: involved_in
  review:
    summary: Sequence-similarity transfer of the ERAD pathway role from the mouse ortholog; consistent with extensive human experimental evidence.
    action: ACCEPT
    reason: Correct core biological process; redundant with IMP evidence.
    supported_by:
    - reference_id: file:human/EDEM1/EDEM1-uniprot.txt
      supporting_text: It is directly involved in endoplasmic reticulum-associated degradation (ERAD)
references:
- id: GO_REF:0000002
  title: Gene Ontology annotation through association of InterPro records with GO terms
  findings: []
- id: GO_REF:0000024
  title: Manual transfer of experimentally-verified manual GO annotation data to orthologs by curator judgment of sequence similarity
  findings: []
- id: GO_REF:0000052
  title: Gene Ontology annotation based on curation of immunofluorescence data
  findings: []
- id: GO_REF:0000117
  title: Electronic Gene Ontology annotations created by ARBA machine learning models
  findings: []
- id: GO_REF:0000120
  title: Combined Automated Annotation using Multiple IEA Methods
  findings: []
- id: PMID:12610306
  title: Role of EDEM in the release of misfolded glycoproteins from the calnexin cycle.
  findings:
  - statement: EDEM extracts misfolded glycoproteins, but not glycoproteins undergoing productive folding, from the calnexin cycle; overexpression accelerates release and ERAD.
    reference_section_type: ABSTRACT
  reference_review:
    relevance: HIGH
    correctness: VERIFIED
    review_notes: Foundational demonstration of EDEM1's role in extracting misfolded glycoproteins from the calnexin cycle. Also the source of the NOT mannosidase IDA (early no-activity view, later superseded by PMID:25092655).
- id: PMID:16449189
  title: Derlin-2 and Derlin-3 are regulated by the mammalian unfolded protein response and are required for ER-associated degradation.
  findings:
  - statement: Derlin-2 and -3 are associated with EDEM and p97 and provide the missing link between EDEM and p97 in degradation of misfolded glycoproteins.
    reference_section_type: ABSTRACT
  reference_review:
    relevance: MEDIUM
    correctness: VERIFIED
    review_notes: Source of the EDEM1-DERL2/DERL3 protein binding annotations; establishes the EDEM-to-p97 link.
- id: PMID:19524542
  title: EDEM1 recognition and delivery of misfolded proteins to the SEL1L-containing ERAD complex.
  findings:
  - statement: EDEM1 specifically binds non-native proteins in a glycan-independent manner; its mannosidase-like domain is required for SEL1L association but not for substrate binding.
    reference_section_type: ABSTRACT
  reference_review:
    relevance: HIGH
    correctness: VERIFIED
    review_notes: Key evidence for glycan-independent misfolded protein recognition and the SEL1L delivery model; supports the misfolded protein binding core function.
- id: PMID:19934218
  title: A dual role for EDEM1 in the processing of rod opsin.
  findings:
  - statement: EDEM1 is a chaperone of rod opsin; it promotes degradation of misfolded P23H rod opsin and reduces aggregation, with binding independent of mannose trimming.
    reference_section_type: ABSTRACT
  reference_review:
    relevance: MEDIUM
    correctness: VERIFIED
    review_notes: Source of the rod opsin (P08100) interaction; supports trimming-independent client recognition and ER membrane localization.
- id: PMID:21062743
  title: Mannose trimming is required for delivery of a glycoprotein from EDEM1 to XTP3-B and to late endoplasmic reticulum-associated degradation steps.
  findings:
  - statement: Mannose trimming enables handoff of a substrate glycoprotein from EDEM1 to the late ERAD lectin XTP3-B and downstream E3 ligases; EDEM1 binding itself is trimming-independent.
    reference_section_type: ABSTRACT
  reference_review:
    relevance: HIGH
    correctness: VERIFIED
    review_notes: Places EDEM1 upstream of XTP3-B/HRD1 in the ERAD pathway; supports the ERAD and ER localization annotations.
- id: PMID:23233672
  title: A shared endoplasmic reticulum-associated degradation pathway involving the EDEM1 protein for glycosylated and nonglycosylated proteins.
  findings:
  - statement: EDEM1 is used by both glycosylated and nonglycosylated misfolded substrates, binding nonglycosylated proteins through a region outside its mannosidase-like domain; ERAD machinery accumulates in the ERQC on proteasome inhibition.
    reference_section_type: ABSTRACT
  reference_review:
    relevance: HIGH
    correctness: VERIFIED
    review_notes: Supports misfolded protein binding (glycan-independent), ERQC localization, and the shared ERAD pathway.
- id: PMID:24200403
  title: The role of EDEM2 compared with EDEM1 in ricin transport from the endoplasmic reticulum to the cytosol.
  findings:
  - statement: EDEM1 (and EDEM2) promote retrotranslocation of the ricin A chain from the ER to the cytosol, modeling ERAD-substrate dislocation.
    reference_section_type: ABSTRACT
  reference_review:
    relevance: MEDIUM
    correctness: VERIFIED
    review_notes: Supports the positive regulation of retrograde protein transport (ER to cytosol) annotations and ER localization.
- id: PMID:25092655
  title: EDEM2 initiates mammalian glycoprotein ERAD by catalyzing the first mannose trimming step.
  findings:
  - statement: All endogenous EDEMs possess mannosidase activity; EDEM3 and to a lesser extent EDEM1 perform the second trimming step (Man8B to Man7), resolving the mannosidase-versus-lectin controversy.
    reference_section_type: ABSTRACT
  - statement: EDEM1 has the weakest mannosidase activity of the three EDEMs and can also enhance gpERAD independently of catalysis (lectin-like) when overexpressed.
    reference_section_type: RESULTS
  reference_review:
    relevance: HIGH
    correctness: VERIFIED
    review_notes: Definitive endogenous-knockout study; establishes EDEM1's weak mannosidase activity and its role in the second trimming step and gpERAD.
- id: PMID:30374462
  title: Mannosidase activity of EDEM1 and EDEM2 depends on an unfolded state of their glycoprotein substrates.
  findings:
  - statement: In vitro, EDEM1 (and EDEM2) mannosidase activity is modest on free oligosaccharides and native glycoproteins but significantly higher on a denatured glycoprotein, explaining how slow background trimming becomes selective for misfolded substrates; the EDEMs associate with oxidoreductases including PDI and TXNDC11.
    reference_section_type: ABSTRACT
  reference_review:
    relevance: HIGH
    correctness: VERIFIED
    review_notes: PubMed-verified (PMID:30374462, doi:10.1038/s42003-018-0174-8). Demonstrates EDEM1 has bona fide in vitro mannosidase activity that is folding-state dependent (preferential on unfolded/denatured glycoproteins), complementing the endogenous-KO evidence (PMID:25092655). Not cached; reference added without verbatim supporting_text.
- id: PMID:32423001
  title: EDEM1 Drives Misfolded Protein Degradation via ERAD and Exploits ER-Phagy as Back-Up Mechanism When ERAD Is Impaired.
  findings:
  - statement: EDEM1 is found in auto-regulatory complexes with ERAD components; its N-terminal disordered region mediates interaction with misfolded proteins, and EDEM1 overexpression can drive client degradation via autophagy/ER-phagy when proteasomal degradation or dislocation is impaired.
    reference_section_type: ABSTRACT
  reference_review:
    relevance: HIGH
    correctness: VERIFIED
    review_notes: PubMed-verified (PMID:32423001, doi:10.3390/ijms21103468). Adds the N-terminal intrinsically disordered region as the misfolded-protein-interaction module and shows EDEM1 engages autophagy/ER-phagy as a backup ERAD route. Not cached; reference added without verbatim supporting_text.
- id: PMID:38682256
  title: Turnover of EDEM1, an ERAD-enhancing factor, is mediated by multiple degradation routes.
  findings:
  - statement: EDEM1 is itself turned over by both ERAD (SEL1L/Hrd1, YOD1, XTP3B, ERdj3, VIMP, BAG6, JB12) and autophagy in folded-state-dependent manner; OS9 binds EDEM1 but did not drive its turnover. EDEM1 has a fast half-life (~3 h) and exists in soluble and membrane-associated forms.
    reference_section_type: ABSTRACT
  reference_review:
    relevance: MEDIUM
    correctness: VERIFIED
    review_notes: PubMed-verified (PMID:38682256, doi:10.1111/gtc.13117). Establishes that EDEM1, an ERAD accelerator, is itself an ERAD/autophagy substrate (autoregulation). Not cached; reference added without verbatim supporting_text.
- id: PMID:38773321
  title: ER-to-lysosome-associated degradation acts as failsafe mechanism upon ERAD dysfunction.
  findings:
  - statement: Pharmacologic or genetic inhibition of ERAD components, including silencing EDEM1, reroutes canonical ERAD clients (NHK, BACE457delta) to degradative endolysosomes via the ER-phagy receptor FAM134B and the LC3 lipidation machinery.
    reference_section_type: ABSTRACT
  reference_review:
    relevance: MEDIUM
    correctness: VERIFIED
    review_notes: PubMed-verified (PMID:38773321, doi:10.1038/s44319-024-00165-y). Shows EDEM1 loss/inhibition activates a compensatory FAM134B-dependent ERLAD route. Not cached; reference added without verbatim supporting_text.
- id: PMID:37528230
  title: Mechanisms of substrate processing during ER-associated protein degradation.
  findings:
  - statement: Authoritative review placing EDEM-family mannosidases among the luminal processing factors that cooperate with chaperones and lectins to deliver misfolded glycoproteins to HRD1-SEL1L-dependent ERAD.
    reference_section_type: OTHER
  reference_review:
    relevance: LOW
    correctness: VERIFIED
    review_notes: PubMed-verified (PMID:37528230, doi:10.1038/s41580-023-00633-8). Recent Nat Rev MCB review providing consensus ERAD pathway framing for EDEM1. Background/contextual.
- id: Reactome:R-HSA-1791155
  title: Expression of EDEM
  findings: []
- id: Reactome:R-HSA-6782685
  title: EDEM1,3 hydrolyse (GlcNAc)2 (Man)8b to (GlcNAc)2 (Man)5
  findings: []
- id: file:human/EDEM1/EDEM1-uniprot.txt
  title: UniProt entry Q92611 (EDEM1_HUMAN), ER degradation-enhancing alpha-mannosidase-like protein 1
  findings:
  - statement: Single-pass type II ER membrane GH47 protein that extracts misfolded glycoproteins from the calnexin cycle and targets them for ERAD (N-glycan-independent, via SEL1L); has low mannosidase activity (Man8GlcNAc2 to Man7GlcNAc2); interacts with SEL1L, DERL2, DERL3.
    reference_section_type: OTHER
core_functions:
- description: Recognizes terminally misfolded/non-native glycoproteins (and some nonglycosylated proteins) and extracts them from the calnexin/calreticulin folding cycle, delivering them to the SEL1L/HRD1 dislocation and ubiquitination machinery for ER-associated degradation.
  molecular_function:
    id: GO:0051787
    label: misfolded protein binding
  locations:
  - id: GO:0005789
    label: endoplasmic reticulum membrane
  - id: GO:0044322
    label: endoplasmic reticulum quality control compartment
  supported_by:
  - reference_id: PMID:19524542
    supporting_text: EDEM1 specifically binds nonnative proteins in a glycan-independent manner
  - reference_id: PMID:12610306
    supporting_text: EDEM was shown to extract misfolded glycoproteins, but not glycoproteins undergoing productive folding, from the calnexin cycle
  directly_involved_in:
  - id: GO:0036503
    label: ERAD pathway
- description: Possesses low alpha-1,2-mannosidase activity contributing to the second ER mannose-trimming step (Man8GlcNAc2 to Man7GlcNAc2), generating the alpha-1,6-mannose-exposed glycan recognized by downstream lectins (OS-9/XTP3-B) in glycoprotein ERAD.
  molecular_function:
    id: GO:0004571
    label: mannosyl-oligosaccharide 1,2-alpha-mannosidase activity
  locations:
  - id: GO:0005789
    label: endoplasmic reticulum membrane
  supported_by:
  - reference_id: PMID:25092655
    supporting_text: Mannose trimming from Man8GlcNAc2 to Man7GlcNAc2 is performed mainly by EDEM3 and to a lesser extent by EDEM1
  - reference_id: PMID:30374462
  directly_involved_in:
  - id: GO:1904380
    label: endoplasmic reticulum mannose trimming
proposed_new_terms: []
suggested_questions:
- question: To what extent does EDEM1 function in vivo as a catalytic mannosidase versus a lectin/holdase-like recognition factor, and how is the balance set by expression level and ER stress?
- question: What structural features outside the mannosidase-like domain mediate EDEM1's glycan-independent recognition of non-native protein structure?
suggested_experiments:
- description: Reconstitute substrate handoff with purified EDEM1, ERManI, EDEM2/3 and SEL1L on defined misfolded glycoprotein substrates to quantify the relative contributions of EDEM1 catalysis versus recognition/holdase activity to ERAD commitment.
- description: Domain-swap and point-mutation analysis of the EDEM1 mannosidase-like domain in endogenous knock-in cells to separate catalytic, SEL1L-binding, and non-native-protein-binding activities and test their individual requirements for ERAD of glycosylated and nonglycosylated substrates.

EDEM1

Gene Description

Existing Annotations Review

Core Functions

Recognizes terminally misfolded/non-native glycoproteins (and some nonglycosylated proteins) and extracts them from the calnexin/calreticulin folding cycle, delivering them to the SEL1L/HRD1 dislocation and ubiquitination machinery for ER-associated degradation.

Possesses low alpha-1,2-mannosidase activity contributing to the second ER mannose-trimming step (Man8GlcNAc2 to Man7GlcNAc2), generating the alpha-1,6-mannose-exposed glycan recognized by downstream lectins (OS-9/XTP3-B) in glycoprotein ERAD.

References

Suggested Questions for Experts

Suggested Experiments

Deep Research

Falcon

Research Report: Human EDEM1 (UniProt Q92611) — Functional Annotation and Current Understanding

1) Target identity verification (critical)

2) Key concepts and definitions (current understanding)

2.1 ER-associated degradation (ERAD)

2.2 EDEM1 in ER glycoprotein quality control

2.3 “Mannose trimming” as an ERAD signal

3) Molecular function: enzymatic reaction and substrate specificity

3.1 Enzymatic activity (reaction type)

3.2 Substrate selectivity: unfolded/misfolded glycoproteins

3.3 Catalytic requirement (functional residue)

3.4 Dual recognition modes: glycans and polypeptide features

4) Subcellular localization and topology

5) Pathways and molecular interactions

5.1 Placement in ERAD handoff networks

5.2 Dynamic complexes and autoregulation

6) Recent developments (prioritizing 2023–2024)

6.1 2024: EDEM1 turnover is mediated by multiple degradation routes (ERAD and autophagy)

6.2 2024: ERAD dysfunction (including EDEM1 loss/inhibition) activates a compensatory ER-to-lysosome route (ERLAD/ER-phagy-like)

6.3 2023: Authoritative expert synthesis of ERAD substrate processing

7) Applications and real-world implementations

7.1 Experimental/biotechnology implementations (current practice)

7.2 Disease-relevant pathway context (preclinical)

8) Quantitative statistics and data highlights (from recent primary studies)

9) Expert interpretation and synthesis

Summary evidence table

Key recent references (with publication date and URL)

Artifacts

Citations

📚 Additional Documentation

Notes

EDEM1 (Q92611) review notes

Identity

Function (synthesis)

Interactions

Localization

Annotation review decisions (high level)

Falcon deep-research findings (incorporated 2026-06)

Pn Notes

EDEM1 PN Consistency Notes

Source Files Checked

Deep Research Files

AIGR Review Snapshot

PN Consistency Summary

Full Consistency Review

PN Dossier Context

PN row 1: ER proteostasis | Glycoproteostasis | N-glycosylation system | N-glycan processing | Mannose trimming

Projected GO annotations (2)

Note

📄 View Raw YAML