Affinage

ASGR1

Asialoglycoprotein receptor 1 · UniProt P07306

Length
291 aa
Mass
33.2 kDa
Annotated
2026-06-09
41 papers in source corpus 14 papers cited in narrative 14 extracted findings
Cross-family judge vs UniProt: Affinage preferred faithfulness: 6/6 claims corpus-supported (100%)

Mechanistic narrative

Synthesis pass · prose summary of the discoveries below

ASGR1 is a liver-expressed endocytic C-type lectin that internalizes and targets glycoproteins for lysosomal degradation, and it functions as a master node coupling this clearance pathway to systemic lipid homeostasis (PMID:35922515). Loss of ASGR1 blocks glycoprotein endocytosis, depletes lysosomal amino acids, inhibits mTORC1 and activates AMPK, which stabilizes LXRα by reducing its BRCA1/BARD1 ubiquitin ligases and suppresses SREBP1, driving ABCA1/ABCG5-G8-mediated cholesterol efflux to HDL and biliary/fecal excretion (PMID:35922515). The lipid-lowering output is reinforced through an INSIG1/SREBP axis that traps SREBPs in the ER and lowers MTTP and PCSK9 to reduce VLDL/LDL secretion while raising LDLR-mediated uptake (PMID:34622799), and through downregulation of HMGCR de novo cholesterol synthesis, effects confirmed bidirectionally in knockout and overexpression rodent and large-animal models with attenuated atherosclerosis (PMID:39387120, PMID:34762653). Beyond bulk glycoprotein clearance, ASGR1 directly binds the ER-stress mediator GP73 and routes it for lysosomal degradation, limiting GP73-BIP-driven ER stress and liver injury (PMID:38459023), and it physically interacts with ATF5 to promote NF-κB-dependent monocyte-to-macrophage differentiation (PMID:36621538). ASGR1 also serves as an ACE2-independent entry receptor for SARS-CoV-2 spike, identified by membrane-protein interaction screening and acting in combination with KREMEN1 or DC-SIGN/TMEM106B (PMID:34837059, PMID:39791910). Its hepatic abundance is regulated by interacting proteins including PON2, which promotes ASGR1 degradation to lower lipid levels (PMID:39055948).

Mechanistic history

Synthesis pass · year-by-year structured walk · 11 steps
  1. 2000 Low

    Establishing why ASGR1 is liver-restricted defined the cis-regulatory basis for its tissue-specific receptor function.

    Evidence Exon mapping and promoter-reporter assays in HepG2 cells

    PMID:10675034

    Open questions at the time
    • Single reporter assay in one cell line
    • Trans-acting hepatic factors driving the promoter not identified
    • No link to functional receptor activity
  2. 2011 Medium

    Demonstrating ASGR1-mediated platelet phagocytosis extended its role beyond hepatocytes to liver sinusoidal endothelial clearance of desialylated cells.

    Evidence siRNA knockdown, anti-ASGR1 and asialofetuin competition, flow cytometry in primary porcine cells

    PMID:21848542

    Open questions at the time
    • Only ~20% knockdown achieved
    • Single lab and species (porcine)
    • Downstream fate of phagocytosed platelets not characterized
  3. 2021 High

    Genetic knockout in mice and pigs established ASGR1 as a regulator of VLDL/LDL handling and de novo cholesterol synthesis, connecting receptor loss to an INSIG1/SREBP axis and reduced atherosclerosis.

    Evidence Asgr1-KO mice with INSIG1 knockdown/overexpression rescue; CRISPR ASGR1-deficient pigs on atherogenic diet with transcriptomics

    PMID:34622799 PMID:34762653

    Open questions at the time
    • Mechanism linking ASGR1 endocytosis to INSIG1 induction not fully resolved
    • Relative contributions of synthesis vs secretion vs uptake not quantified
  4. 2021 High

    Receptor profiling identified ASGR1 as an ACE2-independent SARS-CoV-2 entry receptor, revealing a non-canonical viral-tropism function.

    Evidence Screen of 5054 membrane proteins, S-protein binding, pseudovirus/live-virus entry in vitro and in vivo with antibody blockade

    PMID:34837059

    Open questions at the time
    • Structural basis of spike-ASGR1 binding not defined
    • Physiological relevance versus ACE2 in vivo not quantified
  5. 2022 High

    A single integrated study defined the core ASGR1 lipid-lowering pathway: glycoprotein clearance blockade → lysosomal amino-acid depletion → mTORC1 inhibition/AMPK activation → LXRα stabilization and SREBP1 suppression → cholesterol efflux.

    Evidence Asgr1-KO mice, anti-ASGR1 neutralizing antibody, AMPK and BRCA1/BARD1 pathway rescue, in vivo/in vitro lipid measurements

    PMID:35922515

    Open questions at the time
    • Direct glycoprotein cargo whose clearance limits lysosomal amino acids not enumerated
    • Whether BRCA1/BARD1 directly ubiquitinate LXRα versus indirect regulation unresolved
  6. 2023 Medium

    Identifying ASGR1-ATF5 binding and NF-κB activation defined a function in innate immune cell differentiation distinct from lipid metabolism.

    Evidence Co-IP (ASGR1-ATF5), KD/OE in THP-1 and BMDMs, RNA-seq, ASGR1-knockdown mouse LPS sepsis model

    PMID:36621538

    Open questions at the time
    • Single lab
    • How a hepatic lectin signals to NF-κB/ATF5 mechanistically unclear
    • Co-IP not reciprocally validated for directness
  7. 2024 High

    ASGR1 was shown to directly clear the ER-stress mediator GP73, linking its endocytic activity to protection from ER-stress-driven liver injury.

    Evidence Reciprocal Co-IP, ASGR1 KO/OE in acetaminophen and CCl4 injury models, GP73 neutralizing antibody rescue

    PMID:38459023

    Open questions at the time
    • Glycan determinant on GP73 recognized by ASGR1 not defined
    • Quantitative contribution of GP73 clearance to total ASGR1 cargo unknown
  8. 2024 Medium

    Bidirectional genetic manipulation extended the lipid phenotype to ANGPTL3/8, LPL, LDLR and CYP7A1, and identified PON2 as an interactor that degrades ASGR1, while KO improved hepatic insulin sensitivity — broadening ASGR1's metabolic regulatory scope.

    Evidence Asgr1/ApoE double-KO and overexpression mice; IP-MS identification of PON2; HFD-fed KO mice and HepG2 insulin signaling assays

    PMID:38310881 PMID:39055948 PMID:39387120

    Open questions at the time
    • PON2-driven degradation route (proteasomal vs lysosomal) not defined
    • Insulin sensitivity mechanism downstream of ASGR1 loss unresolved
    • Liver-specific PI3K-AKT enhancement mechanism unknown
  9. 2024 Medium

    ASGR1 deficiency was linked to a NOXs-ROS-PANoptosis-like cell death axis, indicating a hepatoprotective role under acute inflammatory challenge.

    Evidence ASGR1-KO mice (LPS/D-Gal), primary hepatocytes, ROS/NOX inhibitors, proteomics, electron microscopy

    PMID:41443470

    Open questions at the time
    • Single lab
    • Direct molecular link between ASGR1 and NOX/ROS regulation undefined
    • Apparent conflict with protective roles elsewhere not reconciled
  10. 2025 Medium

    ASGR1 was shown to cooperate with DC-SIGN and TMEM106B to route a spike mutant into an ACE2-independent endosomal entry pathway resistant to a neutralizing antibody, refining the combinatorial receptor model.

    Evidence Pseudovirus entry assays with single and combinatorial ASGR1/DC-SIGN/TMEM106B expression, imdevimab neutralization

    PMID:39791910

    Open questions at the time
    • Single lab pseudovirus system
    • In vivo relevance of the ASGR1/DC-SIGN/TMEM106B combination not tested
    • Mechanism of endosomal routing unresolved
  11. 2026 Medium

    Pharmacological targeting via the polyketide enterocin showed that direct ASGR1 binding and degradation activates the AMPK-LXRα cholesterol efflux program, validating ASGR1 as a druggable lipid-lowering target.

    Evidence Direct enterocin-ASGR1 binding, proteasomal vs lysosomal inhibitor experiments, AMPK/LXRα/ABCA1-G8 assays, ASGR1-KO and HFD mouse models

    PMID:41580117

    Open questions at the time
    • Enterocin specificity for ASGR1 versus off-targets not fully excluded
    • Proteasomal degradation route differs from canonical lysosomal turnover and is unexplained

Open questions

Synthesis pass · forward-looking unresolved questions
  • The molecular link between glycoprotein endocytosis at the plasma membrane and the intracellular signaling cascade (lysosomal amino acid sensing, AMPK, INSIG1, NF-κB/ATF5) remains the central unresolved question.
  • No structural model of the ASGR1 receptor-ligand or signaling interface
  • The complete repertoire of physiological glycoprotein cargoes is undefined
  • How a single endocytic receptor coordinates lipid, immune, and antiviral outputs mechanistically is unknown

Mechanism profile

Synthesis pass · controlled-vocabulary classification · explore literature graph →
Molecular activity
GO:0001618 virus receptor activity 2 GO:0038024 cargo receptor activity 2 GO:0008289 lipid binding 1
Localization
GO:0005764 lysosome 2 GO:0005886 plasma membrane 2
Pathway
R-HSA-1430728 Metabolism 4 R-HSA-1643685 Disease 2 R-HSA-5653656 Vesicle-mediated transport 2 R-HSA-168256 Immune System 1

Evidence

Reading pass · 14 per-paper findings extracted from the source corpus
Year Finding Method Journal Conf PMIDs
2022 ASGR1 deficiency decreases lipid levels by stabilizing LXRα: loss of ASGR1 blocks endocytosis and lysosomal degradation of glycoproteins, reduces lysosomal amino-acid levels, inhibits mTORC1 and activates AMPK. AMPK then (1) increases LXRα by decreasing its ubiquitin ligases BRCA1/BARD1, and (2) suppresses SREBP1. LXRα upregulates ABCA1 and ABCG5/G8, promoting cholesterol transport to HDL and excretion to bile/faeces. Anti-ASGR1 neutralizing antibody recapitulates this effect and shows synergy with atorvastatin or ezetimibe. Asgr1-knockout mouse model, anti-ASGR1 neutralizing antibody treatment, Western blot, pathway rescue experiments (AMPK inhibition, BRCA1/BARD1 modulation), in vitro and in vivo cholesterol/lipid measurements Nature High 35922515
2021 ASGR1 deficiency reduces VLDL/LDL secretion and increases uptake via decreased expression of MTTP and PCSK9 (SREBP targets), linked to increased INSIG1 that traps SREBPs in the ER and prevents their nuclear translocation. INSIG1 knockdown independently reversed ASGR1-deficient lipid phenotypes, establishing an ASGR1/INSIG1/SREBP axis in lipid homeostasis. Asgr1-knockout mice, INSIG1 overexpression and knockdown in multiple cell/animal models, SREBP nuclear fractionation, apolipoprotein B secretion assay, LDL uptake assay JCI insight High 34622799
2024 ASGR1 binds the ER-stress mediator GP73 and facilitates its lysosomal degradation. ASGR1 depletion increases circulating GP73, which then interacts with BIP to activate ER stress, leading to liver injury. Neutralization of GP73 attenuates ASGR1 deficiency-induced liver injury. Co-IP (ASGR1–GP73 interaction), ASGR1 KO and overexpression mouse models (acetaminophen-induced acute and CCl4-induced chronic injury), GP73 neutralizing antibody, Western blot for ER stress markers Nature communications High 38459023
2021 ASGR1 and KREMEN1 are sufficient for ACE2-independent SARS-CoV-2 entry in vitro and in vivo; they were identified by screening 5054 human membrane proteins for interaction with the SARS-CoV-2 spike (S) protein. SARS-CoV-2 uses distinct ACE2/ASGR1/KREMEN1 (ASK) receptor combinations to enter different cell types. Genomic receptor profiling screen (5054 membrane proteins), S-protein binding assays, pseudovirus and live-virus entry assays in vitro and in vivo, neutralizing antibody blockade in human lung organoids Cell research High 34837059
2024 ASGR1 deficiency reduces VLDL production by inhibiting MTTP and ANGPTL3/ANGPTL8, increases LPL activity, increases LDL uptake via elevated LDLR, and promotes cholesterol efflux through upregulation of LXRα, ABCA1, ABCG5, and CYP7A1. Conversely, ASGR1 overexpression augments VLDL production and reduces fecal cholesterol. Confirmed in both KO and overexpression mouse models on ApoE background. Asgr1/ApoE double-KO mice, ASGR1-overexpressing ApoE mice, Western diet feeding, VLDL production assay, LPL activity assay, fecal cholesterol measurement, hepatic gene expression analysis Arteriosclerosis, thrombosis, and vascular biology High 39387120
2021 ASGR1 deficiency in pigs reduces hepatic de novo cholesterol synthesis by downregulating HMGCR and increases cholesterol clearance by upregulating LDLR, together lowering non-HDL-C. CRISPR/Cas9-generated ASGR1-deficient pigs on atherogenic diet show lower non-HDL-C and less atherosclerotic lesions. CRISPR/Cas9-generated ASGR1-deficient pigs, atherogenic diet feeding, hepatic transcriptome analysis, in vivo cholesterol metabolism tracing PLoS genetics High 34762653
2011 ASGR1 on porcine liver sinusoidal endothelial cells mediates binding and phagocytosis of human platelets. siRNA knockdown of ASGR1 reduced its protein by ~20%, correlating with a 21% decrease in human platelet binding. Anti-ASGR1 antibodies and the ASGR1 substrate asialofetuin inhibited platelet binding in a dose-dependent manner. siRNA knockdown, anti-ASGR1 inhibition assay, substrate competition with asialofetuin, flow cytometry, quantitative PCR, immunoblot, confocal microscopy Xenotransplantation Medium 21848542
2023 ASGR1 promotes monocyte-to-macrophage differentiation by upregulating CD68, F4/80, and CD86. Mechanistically, ASGR1 increases ATF5 expression by promoting phosphorylation of NF-κB and IKBα. ASGR1 physically interacts with ATF5 (demonstrated by co-IP). ASGR1 knockdown in mice suppressed inflammatory monocytes and macrophages in liver and improved survival in LPS-induced sepsis. ASGR1 knockdown/overexpression in THP-1 cells and BMDMs, flow cytometry, RNA-seq, co-IP (ASGR1–ATF5), Western blot (NF-κB and IKBα phosphorylation), ASGR1-knockdown mouse LPS sepsis model Life sciences Medium 36621538
2024 Paraoxonase-2 (PON2) interacts with ASGR1 and promotes its degradation in a dose-dependent manner, as identified by immunoprecipitation combined with mass spectrometry (IP-MS). PON2-mediated ASGR1 degradation reduced lipid levels in mice. IP-MS (immunoprecipitation + mass spectrometry), dose-dependent co-expression experiments, lipid level measurement in mice iScience Medium 39055948
2025 ASGR1 (lectin) and DC-SIGN, acting jointly with TMEM106B, allow ACE2-independent entry of SARS-CoV-2 spike mutant E484D. ASGR1 alone or TMEM106B alone was insufficient; the combination directed viral entry to an ACE2-independent, TMEM106B-dependent endosomal pathway that is not inhibited by the neutralizing antibody imdevimab. S protein-pseudotyped particle entry assays, cell lines with single and combinatorial expression of ASGR1/DC-SIGN/TMEM106B, imdevimab neutralization assay Journal of virology Medium 39791910
2024 ASGR1 deficiency improved hepatic insulin sensitivity in HFD-fed mice, evidenced by enhanced PI3K-AKT insulin signaling in liver (but not muscle or adipose tissue), reduced hepatic gluconeogenesis and glycogenolysis. ASGR1−/− HepG2 cells showed enhanced insulin signal transduction, and transcriptome analysis showed enrichment in PI3K-AKT signaling. ASGR1-KO mice fed HFD, ASGR1−/− HepG2 cells, insulin tolerance tests, insulin signaling pathway assays (phospho-AKT), transcriptome analysis, glucose/glycogen metabolism assays Diabetes & metabolism journal Medium 38310881
2024 ASGR1 deficiency in ALI exacerbates liver injury via the NOXs-ROS-PANoptosis-like axis: ASGR1 KO hepatocytes show elevated ROS and reduced mitochondrial membrane potential under LPS/D-Gal challenge, activating apoptosis (BAX/BCL-2, cleaved caspase-8) and necroptosis (p-RIPK1, p-RIPK3, p-MLKL). Inhibiting NOXs or scavenging ROS reversed these effects. ASGR1-KO mice (LPS/D-Gal ALI model), primary hepatocyte KO/overexpression, cell death inhibitors, ROS inhibitor NAC and NOXs inhibitor DPI, electron microscopy, proteomics, Western blot Life sciences Medium 41443470
2026 The natural polyketide enterocin directly binds ASGR1 and promotes its proteasomal (not lysosomal) degradation, leading to AMPKα activation and LXRα-mediated upregulation of cholesterol efflux transporters (ABCA1/G1/G5/G8) in liver cells and in HFD-fed mice. Direct binding assay (enterocin–ASGR1), proteasomal vs. lysosomal inhibitor experiments, AMPKα/LXRα/ABCA1/G1/G5/G8 protein/RNA assays, ASGR1 KO and HFD mouse models Metabolism: clinical and experimental Medium 41580117
2000 The mouse ASGR1 gene comprises eight coding exons; a minimal 600 bp proximal upstream region exhibits hepatic-specific promoter activity in HepG2 cells, establishing the basis for liver-restricted expression of this receptor. Gene sequencing, exon mapping, promoter-reporter assay in HepG2 cells Gene Low 10675034

Source papers

Stage 0 corpus · 41 papers · ranked by NIH iCite citations
Year Title Journal Citations PMID
2021 Receptome profiling identifies KREMEN1 and ASGR1 as alternative functional receptors of SARS-CoV-2. Cell research 150 34837059
2022 Inhibition of ASGR1 decreases lipid levels by promoting cholesterol excretion. Nature 135 35922515
2016 Variant ASGR1 Associated with a Reduced Risk of Coronary Artery Disease. The New England journal of medicine 133 27192541
2020 ASGR1 and Its Enigmatic Relative, CLEC10A. International journal of molecular sciences 57 32650396
2012 ASGR1 and ASGR2, the Genes that Encode the Asialoglycoprotein Receptor (Ashwell Receptor), Are Expressed in Peripheral Blood Monocytes and Show Interindividual Differences in Transcript Profile. Molecular biology international 57 22919488
2023 ASGR1 promotes liver injury in sepsis by modulating monocyte-to-macrophage differentiation via NF-κB/ATF5 pathway. Life sciences 47 36621538
2011 ASGR1 expressed by porcine enriched liver sinusoidal endothelial cells mediates human platelet phagocytosis in vitro. Xenotransplantation 46 21848542
2024 Deficiency of ASGR1 promotes liver injury by increasing GP73-mediated hepatic endoplasmic reticulum stress. Nature communications 43 38459023
2021 Hypomorphic ASGR1 modulates lipid homeostasis via INSIG1-mediated SREBP signaling suppression. JCI insight 35 34622799
2021 Deficiency of ASGR1 in pigs recapitulates reduced risk factor for cardiovascular disease in humans. PLoS genetics 34 34762653
2020 Common gene variants in ASGR1 gene locus associate with reduced cardiovascular risk in absence of pleiotropic effects. Atherosclerosis 16 32679274
2024 ASGR1 Deficiency Inhibits Atherosclerosis in Western Diet-Fed ApoE Mice by Regulating Lipoprotein Metabolism and Promoting Cholesterol Efflux. Arteriosclerosis, thrombosis, and vascular biology 14 39387120
2022 Hepatocellular carcinoma risk-stratification based on ASGR1 in circulating epithelial cells for cancer interception. Frontiers in molecular biosciences 13 36518850
2023 Genetically mimicked effects of ASGR1 inhibitors on all-cause mortality and health outcomes: a drug-target Mendelian randomization study and a phenome-wide association study. BMC medicine 11 37400795
1990 Assignment of Amog (adhesion molecule on glia) gene to mouse chromosome 11 near Zfp-3 and Asgr-1,2 and to human chromosome 17. Somatic cell and molecular genetics 11 1699290
2024 Deficiency of ASGR1 Alleviates Diet-Induced Systemic Insulin Resistance via Improved Hepatic Insulin Sensitivity. Diabetes & metabolism journal 10 38310881
2024 ASGR1 deficiency diverts lipids toward adipose tissue but results in liver damage during obesity. Cardiovascular diabetology 9 38281933
2024 ASGR1 deficiency improves atherosclerosis but alters liver metabolism in ApoE-/- mice. Cardiovascular diabetology 8 39616371
2019 ASGR1 but not FOXM1 expression decreases in the peripheral blood mononuclear cells of diabetic atherosclerotic patients. Journal of diabetes and its complications 8 31202960
2000 Organization of the mouse ASGR1 gene encoding the major subunit of the hepatic asialoglycoprotein receptor. Gene 8 10675034
2024 Beyond conventional treatment: ASGR1 Leading the new era of hypercholesterolemia management. Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie 7 39316974
2024 The serum soluble ASGR1 concentration is elevated in patients with coronary artery disease and is associated with inflammatory markers. Lipids in health and disease 5 38539180
2023 Correlation between serum soluble ASGR1 concentration and low-density lipoprotein cholesterol levels: a cross-sectional study. Lipids in health and disease 5 37667265
2025 Host cell lectins ASGR1 and DC-SIGN jointly with TMEM106B confer ACE2 independence and imdevimab resistance to SARS-CoV-2 pseudovirus with spike mutation E484D. Journal of virology 4 39791910
2025 Discovery of ASGR1 and HMGCR dual-target inhibitors based on supervised learning, molecular docking, molecular dynamics simulations, and biological evaluation. Bioorganic chemistry 3 40080975
2025 Forsythoside B and Its Derivatives as Novel ASGR1 Inhibitors for Enhanced Cholesterol Efflux. Chemistry & biodiversity 2 40768748
2022 SARS-CoV-2-correlated ASGR1 is a novel potential marker for the treatment and identification of multiple human cancers. American journal of translational research 2 36628237
2016 ASGR1 - a new target for lowering non-HDL cholesterol. Global cardiology science & practice 2 29043262
2026 Natural polyketide enterocin inhibits ASGR1 to enhance cholesterol efflux and regulate hepatic lipid metabolism. Metabolism: clinical and experimental 1 41580117
2025 ASGR1 inhibitors, inflammation, and heart failure: A Mendelian randomization analysis. Lipids 1 40391737
2025 A High-Throughput Cell-Based Luciferase Reporter Assay for Identifying Inhibitors of ASGR1. International journal of molecular sciences 1 40429734
2024 Rapid depletion of "catch-and-release" anti-ASGR1 antibody in vivo. mAbs 1 39051531
2024 ASGR1 is a promising target for lipid reduction in pigs with PON2 as its inhibitor. iScience 1 39055948
2017 Generation of an ASGR1 homozygous mutant human embryonic stem cell line WAe001-A-6 using CRISPR/Cas9. Stem cell research 1 28952928
2026 Serum soluble ASGR1 concentration is elevated in patients with metabolic dysfunction-associated steatotic liver disease and is associated with adiponectin. BMJ open diabetes research & care 0 41592894
2026 Fisetin-loaded nanoparticles as a novel approach for cholesterol regulation in hypercholesterolemia: targeting the ASGR1-mediated mTORC1/AMPK pathway. Journal of nanobiotechnology 0 41761201
2026 Elevated ASGR1 as a Potential Diagnostic Biomarker for Coronary Artery Disease and Predictor of Adverse Outcomes in Hypertensive Patients. FASEB journal : official publication of the Federation of American Societies for Experimental Biology 0 42048115
2026 Quantitative Analysis of Protein-Receptor Binding Using Solid-State Nanopores: Accurate Measurement of Dissociation Constants for KREMEN1 and ASGR1 with SARS-CoV-2 Spike RBD Protein. The journal of physical chemistry. B 0 42144848
2026 In vivo base editing of Asgr1 reduces blood lipids in mice. Molecular therapy : the journal of the American Society of Gene Therapy 0 42198846
2025 Role and mechanism of ASGR1 in acute liver injury. Life sciences 0 41443470
2022 Generation of a human iPSC line CIBi010-A with a reporter for ASGR1 using CRISPR/Cas9. Stem cell research 0 35561459

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