MORC3

UniProt ID: Q14149
Organism: Homo sapiens
Review Status: COMPLETE
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Gene Description

MORC3/NXP2 is a nuclear matrix and PML nuclear body-associated MORC-family GHKL/HATPase protein with a CW-type zinc finger that reads methylated H3K4. It functions as a SUMO-regulated chromatin/PML-body scaffold and ATPase involved in intrinsic antiviral restriction, chromatin-associated repression, recruitment/maintenance of nuclear restriction factors, and negative regulation of interferon-beta programs.

Existing Annotations Review

GO Term Evidence Action Reason
GO:0005634 nucleus
IBA
GO_REF:0000033
ACCEPT
Summary: MORC3 is a nuclear/nuclear-matrix protein and PML nuclear body component.
Reason: Nuclear localization is strongly supported, although more specific PML body and nuclear matrix terms should also be retained.
Supporting Evidence:
file:human/MORC3/MORC3-deep-research-falcon.md
**SUMO biology and PML nuclear bodies (PML-NBs/ND10).** MORC3 is a **SUMOylated** nuclear matrix/PML nuclear body client protein. It associates with PML nuclear bodies through **SUMO–SIM interactions** (SUMO on one partner and a SUMO-interacting motif on the other), specifically reported as a SUMO–SIM interaction with **PML isoform I** (sloan2016morc3acomponent pages 3-5, sloan2016morc3acomponent pages 13-15). PML nuclear bodies are SUMO-enriched subnuclear condensates and hubs for intrinsic immunity, DNA damage response, transcription regulation, and other nuclear processes; MORC3 is one of the SUMO-linked client proteins integrated into these assemblies (sloan2016morc3acomponent pages 3-5).
file:human/MORC3/MORC3-deep-research-falcon.md
MORC3 is consistently characterized as a **nuclear matrix protein** that localizes to **PML nuclear bodies**. In immunofluorescence microscopy, MORC3 colocalizes with the PML-NB component Sp100 in punctate nuclear structures (sloan2016morc3acomponent media 84630a9e). During infection with HSV-1 lacking ICP0, MORC3 is recruited to sites associated with incoming viral genomes (identified by ICP4 foci), consistent with a role in intrinsic restriction at early stages of infection (sloan2016morc3acomponent media 5b6c97c8).
file:human/MORC3/MORC3-deep-research-falcon.md
Mechanistically, the association with PML-NBs is reported to occur via **SUMO–SIM interaction** with PML.I, and PML-NB localization/recruitment functions require a **functional ATPase domain** (sloan2016morc3acomponent pages 3-5, sloan2016morc3acomponent pages 13-15).
GO:0140002 histone H3K4me3 reader activity
IBA
GO_REF:0000033
ACCEPT
Summary: The MORC3 CW-type zinc finger is reported to bind methylated H3K4.
Reason: Histone H3K4me3 reader activity is consistent with the CW-domain evidence and chromatin-associated function.
Supporting Evidence:
file:human/MORC3/MORC3-deep-research-falcon.md
**Domain architecture and biochemical capabilities.** MORC3 is described as containing three conserved modules: (i) a **GHKL/HATPase-like ATPase domain** (a “GHL ATPase”/GHKL-type ATPase in the MORC family), (ii) a **CW-type zinc finger** reported to bind **methylated H3K4**, and (iii) a **coiled-coil** region implicated in dimerization/oligomerization (sloan2016morc3acomponent pages 3-5). These features fit the concept of MORC proteins as **chromatin-associated ATPases** that integrate ATPase-driven conformational changes with chromatin recognition (via CW) and multivalent interactions (via coiled-coil) to regulate nuclear substructures and transcriptional states (sloan2016morc3acomponent pages 3-5).
GO:0140374 antiviral innate immune response
IBA
GO_REF:0000033
ACCEPT
Summary: MORC3 contributes to intrinsic antiviral restriction, including PML-body-associated restriction of HSV-1 and HCMV.
Reason: Antiviral innate immune response is a supported major function of MORC3.
Supporting Evidence:
file:human/MORC3/MORC3-deep-research-falcon.md
| PML nuclear bodies / viral restriction | Human MORC3 (NXP2) is a SUMOylated nuclear-matrix protein that localizes to PML nuclear bodies via SUMO-SIM interactions with PML.I; its ATPase domain is required for PML-NB localization and for recruiting Sp100/p53. During HSV-1 infection, MORC3 is recruited to incoming viral genomes and promotes recruitment of intrinsic restriction factors (Sp100, hDaxx, PML, γH2AX). HSV-1 ICP0 counteracts this by degrading MORC3. MORC3 also restricts HCMV, although influenza studies indicate virus-specific proviral effects in other contexts. (sloan2016morc3acomponent pages 3-5, sloan2016morc3acomponent pages 13-15, sloan2016morc3acomponent media 84630a9e) | SILAC/MS proteomics, colocalization microscopy, HSV-1 and HCMV plaque assays, shRNA knockdown, viral protein immunoblotting | MORC3 abundance decreased ~5.6-fold during HSV-1 infection in proteomics; MORC3 depletion caused a marked increase in plaque formation efficiency of ICP0-null HSV-1 and increased HCMV plaque formation; MORC3 colocalizes with PML-NB markers in punctate nuclear structures. (sloan2016morc3acomponent pages 3-5, sloan2016morc3acomponent pages 13-15, sloan2016morc3acomponent media 84630a9e) | Sloan et al., *J Virol* (Oct 2016), DOI: 10.1128/JVI.00621-16, https://doi.org/10.1128/JVI.00621-16 |
file:human/MORC3/MORC3-deep-research-falcon.md
A notable mechanistic finding is that MORC3 depletion reduced recruitment of multiple factors (Sp100, hDaxx, PML, γH2AX) to viral genomes, implying MORC3 participates in building/maintaining a restrictive chromatin environment at incoming HSV-1 genomes (sloan2016morc3acomponent pages 3-5).
GO:0016605 PML body
IBA
GO_REF:0000033
ACCEPT
Summary: MORC3 localizes to PML nuclear bodies through SUMO/SIM-dependent interactions and helps recruit restriction factors there.
Reason: PML body localization is one of the best-supported cellular component annotations for MORC3.
Supporting Evidence:
file:human/MORC3/MORC3-deep-research-falcon.md
**SUMO biology and PML nuclear bodies (PML-NBs/ND10).** MORC3 is a **SUMOylated** nuclear matrix/PML nuclear body client protein. It associates with PML nuclear bodies through **SUMO–SIM interactions** (SUMO on one partner and a SUMO-interacting motif on the other), specifically reported as a SUMO–SIM interaction with **PML isoform I** (sloan2016morc3acomponent pages 3-5, sloan2016morc3acomponent pages 13-15). PML nuclear bodies are SUMO-enriched subnuclear condensates and hubs for intrinsic immunity, DNA damage response, transcription regulation, and other nuclear processes; MORC3 is one of the SUMO-linked client proteins integrated into these assemblies (sloan2016morc3acomponent pages 3-5).
file:human/MORC3/MORC3-deep-research-falcon.md
MORC3 is consistently characterized as a **nuclear matrix protein** that localizes to **PML nuclear bodies**. In immunofluorescence microscopy, MORC3 colocalizes with the PML-NB component Sp100 in punctate nuclear structures (sloan2016morc3acomponent media 84630a9e). During infection with HSV-1 lacking ICP0, MORC3 is recruited to sites associated with incoming viral genomes (identified by ICP4 foci), consistent with a role in intrinsic restriction at early stages of infection (sloan2016morc3acomponent media 5b6c97c8).
file:human/MORC3/MORC3-deep-research-falcon.md
Mechanistically, the association with PML-NBs is reported to occur via **SUMO–SIM interaction** with PML.I, and PML-NB localization/recruitment functions require a **functional ATPase domain** (sloan2016morc3acomponent pages 3-5, sloan2016morc3acomponent pages 13-15).
GO:0006325 chromatin organization
IEA
GO_REF:0000108
ACCEPT
Summary: MORC3 is a chromatin-associated ATPase/scaffold implicated in epigenetic repression and chromatin organization.
Reason: Chromatin organization is supported by conserved MORC3 mechanism and by MORC3-mediated repression of viral/foreign DNA and interferon programs.
Supporting Evidence:
file:human/MORC3/MORC3-deep-research-falcon.md
**Domain architecture and biochemical capabilities.** MORC3 is described as containing three conserved modules: (i) a **GHKL/HATPase-like ATPase domain** (a “GHL ATPase”/GHKL-type ATPase in the MORC family), (ii) a **CW-type zinc finger** reported to bind **methylated H3K4**, and (iii) a **coiled-coil** region implicated in dimerization/oligomerization (sloan2016morc3acomponent pages 3-5). These features fit the concept of MORC proteins as **chromatin-associated ATPases** that integrate ATPase-driven conformational changes with chromatin recognition (via CW) and multivalent interactions (via coiled-coil) to regulate nuclear substructures and transcriptional states (sloan2016morc3acomponent pages 3-5).
file:human/MORC3/MORC3-deep-research-falcon.md
| Epigenetic silencing / chromatin regulation | MORC3 is a GHKL ATPase with CW zinc finger and coiled-coil domains; ATP binding/hydrolysis and SUMOylation enable interaction with DAXX and promote histone H3.3 deposition at retroelement loci, supporting H3K9me3 heterochromatin and silencing. Although shown directly in mouse ES cells, the mechanism is highly relevant to human MORC3 because the same domain architecture/function is conserved. (groh2021morc3silencesendogenous pages 10-11, groh2021morc3silencesendogenous pages 1-2, groh2020morc3silencesendogenous pages 10-13) | Genome-wide sgRNA screen, knockout/rescue mutants, ChIP-seq, ChIP-MS/IP-MS, ATAC-seq, H3.3 ChIP-qPCR, RT-qPCR | 2,737 reproducible Morc3 ChIP peaks; Morc3 loss increased chromatin accessibility at 444 peaks and decreased it at 10 peaks; ChIP-MS identified 489 Morc3-associated proteins; ATPase-cycle mutants failed to rescue ERV silencing. (groh2020morc3silencesendogenous pages 7-10, groh2021morc3silencesendogenous pages 1-2, groh2020morc3silencesendogenous pages 10-13) | Groh et al., *Nat Commun* (Oct 2021), DOI: 10.1038/s41467-021-26288-7, https://doi.org/10.1038/s41467-021-26288-7 |
GO:0002376 immune system process
IEA
GO_REF:0000043
MODIFY
Summary: MORC3 has immune functions, but the evidence supports the more specific antiviral innate immune response and interferon-beta regulatory terms.
Reason: Use antiviral innate immune response rather than the broad parent immune system process.
Proposed replacements: antiviral innate immune response
Supporting Evidence:
file:human/MORC3/MORC3-deep-research-falcon.md
| PML nuclear bodies / viral restriction | Human MORC3 (NXP2) is a SUMOylated nuclear-matrix protein that localizes to PML nuclear bodies via SUMO-SIM interactions with PML.I; its ATPase domain is required for PML-NB localization and for recruiting Sp100/p53. During HSV-1 infection, MORC3 is recruited to incoming viral genomes and promotes recruitment of intrinsic restriction factors (Sp100, hDaxx, PML, γH2AX). HSV-1 ICP0 counteracts this by degrading MORC3. MORC3 also restricts HCMV, although influenza studies indicate virus-specific proviral effects in other contexts. (sloan2016morc3acomponent pages 3-5, sloan2016morc3acomponent pages 13-15, sloan2016morc3acomponent media 84630a9e) | SILAC/MS proteomics, colocalization microscopy, HSV-1 and HCMV plaque assays, shRNA knockdown, viral protein immunoblotting | MORC3 abundance decreased ~5.6-fold during HSV-1 infection in proteomics; MORC3 depletion caused a marked increase in plaque formation efficiency of ICP0-null HSV-1 and increased HCMV plaque formation; MORC3 colocalizes with PML-NB markers in punctate nuclear structures. (sloan2016morc3acomponent pages 3-5, sloan2016morc3acomponent pages 13-15, sloan2016morc3acomponent media 84630a9e) | Sloan et al., *J Virol* (Oct 2016), DOI: 10.1128/JVI.00621-16, https://doi.org/10.1128/JVI.00621-16 |
file:human/MORC3/MORC3-deep-research-falcon.md
A notable mechanistic finding is that MORC3 depletion reduced recruitment of multiple factors (Sp100, hDaxx, PML, γH2AX) to viral genomes, implying MORC3 participates in building/maintaining a restrictive chromatin environment at incoming HSV-1 genomes (sloan2016morc3acomponent pages 3-5).
GO:0003723 RNA binding
IEA
GO_REF:0000043
REMOVE
Summary: The curated MORC3 literature supports ATPase, CW histone-reader, chromatin/PML-body scaffold, and antiviral restriction roles, not direct RNA binding.
Reason: This electronically inferred RNA-binding annotation is not supported by the gene-specific functional synthesis.
Supporting Evidence:
file:human/MORC3/MORC3-deep-research-falcon.md
**Domain architecture and biochemical capabilities.** MORC3 is described as containing three conserved modules: (i) a **GHKL/HATPase-like ATPase domain** (a “GHL ATPase”/GHKL-type ATPase in the MORC family), (ii) a **CW-type zinc finger** reported to bind **methylated H3K4**, and (iii) a **coiled-coil** region implicated in dimerization/oligomerization (sloan2016morc3acomponent pages 3-5). These features fit the concept of MORC proteins as **chromatin-associated ATPases** that integrate ATPase-driven conformational changes with chromatin recognition (via CW) and multivalent interactions (via coiled-coil) to regulate nuclear substructures and transcriptional states (sloan2016morc3acomponent pages 3-5).
GO:0005654 nucleoplasm
IEA
GO_REF:0000120
MODIFY
Summary: MORC3 is nuclear, but the more specific supported locations are PML bodies and nuclear matrix/chromatin-associated nuclear structures.
Reason: Use PML body and nuclear matrix instead of broad nucleoplasm when curating MORC3 localization.
Proposed replacements: PML body nuclear matrix
Supporting Evidence:
file:human/MORC3/MORC3-deep-research-falcon.md
**SUMO biology and PML nuclear bodies (PML-NBs/ND10).** MORC3 is a **SUMOylated** nuclear matrix/PML nuclear body client protein. It associates with PML nuclear bodies through **SUMO–SIM interactions** (SUMO on one partner and a SUMO-interacting motif on the other), specifically reported as a SUMO–SIM interaction with **PML isoform I** (sloan2016morc3acomponent pages 3-5, sloan2016morc3acomponent pages 13-15). PML nuclear bodies are SUMO-enriched subnuclear condensates and hubs for intrinsic immunity, DNA damage response, transcription regulation, and other nuclear processes; MORC3 is one of the SUMO-linked client proteins integrated into these assemblies (sloan2016morc3acomponent pages 3-5).
file:human/MORC3/MORC3-deep-research-falcon.md
MORC3 is consistently characterized as a **nuclear matrix protein** that localizes to **PML nuclear bodies**. In immunofluorescence microscopy, MORC3 colocalizes with the PML-NB component Sp100 in punctate nuclear structures (sloan2016morc3acomponent media 84630a9e). During infection with HSV-1 lacking ICP0, MORC3 is recruited to sites associated with incoming viral genomes (identified by ICP4 foci), consistent with a role in intrinsic restriction at early stages of infection (sloan2016morc3acomponent media 5b6c97c8).
file:human/MORC3/MORC3-deep-research-falcon.md
Mechanistically, the association with PML-NBs is reported to occur via **SUMO–SIM interaction** with PML.I, and PML-NB localization/recruitment functions require a **functional ATPase domain** (sloan2016morc3acomponent pages 3-5, sloan2016morc3acomponent pages 13-15).
GO:0005694 chromosome
IEA
GO_REF:0000044
MODIFY
Summary: MORC3 is chromatin-associated, but chromosome is a broad location for this evidence.
Reason: Use chromatin to represent the supported chromosome-associated localization/function more precisely.
Proposed replacements: chromatin
Supporting Evidence:
file:human/MORC3/MORC3-deep-research-falcon.md
**Domain architecture and biochemical capabilities.** MORC3 is described as containing three conserved modules: (i) a **GHKL/HATPase-like ATPase domain** (a “GHL ATPase”/GHKL-type ATPase in the MORC family), (ii) a **CW-type zinc finger** reported to bind **methylated H3K4**, and (iii) a **coiled-coil** region implicated in dimerization/oligomerization (sloan2016morc3acomponent pages 3-5). These features fit the concept of MORC proteins as **chromatin-associated ATPases** that integrate ATPase-driven conformational changes with chromatin recognition (via CW) and multivalent interactions (via coiled-coil) to regulate nuclear substructures and transcriptional states (sloan2016morc3acomponent pages 3-5).
file:human/MORC3/MORC3-deep-research-falcon.md
| Epigenetic silencing / chromatin regulation | MORC3 is a GHKL ATPase with CW zinc finger and coiled-coil domains; ATP binding/hydrolysis and SUMOylation enable interaction with DAXX and promote histone H3.3 deposition at retroelement loci, supporting H3K9me3 heterochromatin and silencing. Although shown directly in mouse ES cells, the mechanism is highly relevant to human MORC3 because the same domain architecture/function is conserved. (groh2021morc3silencesendogenous pages 10-11, groh2021morc3silencesendogenous pages 1-2, groh2020morc3silencesendogenous pages 10-13) | Genome-wide sgRNA screen, knockout/rescue mutants, ChIP-seq, ChIP-MS/IP-MS, ATAC-seq, H3.3 ChIP-qPCR, RT-qPCR | 2,737 reproducible Morc3 ChIP peaks; Morc3 loss increased chromatin accessibility at 444 peaks and decreased it at 10 peaks; ChIP-MS identified 489 Morc3-associated proteins; ATPase-cycle mutants failed to rescue ERV silencing. (groh2020morc3silencesendogenous pages 7-10, groh2021morc3silencesendogenous pages 1-2, groh2020morc3silencesendogenous pages 10-13) | Groh et al., *Nat Commun* (Oct 2021), DOI: 10.1038/s41467-021-26288-7, https://doi.org/10.1038/s41467-021-26288-7 |
GO:0008270 zinc ion binding
IEA
GO_REF:0000120
ACCEPT
Summary: MORC3 contains a CW-type zinc finger domain.
Reason: Zinc ion binding is supported by the CW zinc-finger domain architecture.
Supporting Evidence:
file:human/MORC3/MORC3-deep-research-falcon.md
**Domain architecture and biochemical capabilities.** MORC3 is described as containing three conserved modules: (i) a **GHKL/HATPase-like ATPase domain** (a “GHL ATPase”/GHKL-type ATPase in the MORC family), (ii) a **CW-type zinc finger** reported to bind **methylated H3K4**, and (iii) a **coiled-coil** region implicated in dimerization/oligomerization (sloan2016morc3acomponent pages 3-5). These features fit the concept of MORC proteins as **chromatin-associated ATPases** that integrate ATPase-driven conformational changes with chromatin recognition (via CW) and multivalent interactions (via coiled-coil) to regulate nuclear substructures and transcriptional states (sloan2016morc3acomponent pages 3-5).
GO:0016363 nuclear matrix
IEA
GO_REF:0000044
ACCEPT
Summary: MORC3/NXP2 is consistently characterized as a nuclear matrix protein.
Reason: Nuclear matrix localization is supported by the literature synthesis.
Supporting Evidence:
file:human/MORC3/MORC3-deep-research-falcon.md
MORC3 is consistently characterized as a **nuclear matrix protein** that localizes to **PML nuclear bodies**. In immunofluorescence microscopy, MORC3 colocalizes with the PML-NB component Sp100 in punctate nuclear structures (sloan2016morc3acomponent media 84630a9e). During infection with HSV-1 lacking ICP0, MORC3 is recruited to sites associated with incoming viral genomes (identified by ICP4 foci), consistent with a role in intrinsic restriction at early stages of infection (sloan2016morc3acomponent media 5b6c97c8).
GO:0016605 PML body
IEA
GO_REF:0000120
ACCEPT
Summary: MORC3 localizes to PML nuclear bodies through SUMO/SIM-dependent interactions and helps recruit restriction factors there.
Reason: PML body localization is one of the best-supported cellular component annotations for MORC3.
Supporting Evidence:
file:human/MORC3/MORC3-deep-research-falcon.md
**SUMO biology and PML nuclear bodies (PML-NBs/ND10).** MORC3 is a **SUMOylated** nuclear matrix/PML nuclear body client protein. It associates with PML nuclear bodies through **SUMO–SIM interactions** (SUMO on one partner and a SUMO-interacting motif on the other), specifically reported as a SUMO–SIM interaction with **PML isoform I** (sloan2016morc3acomponent pages 3-5, sloan2016morc3acomponent pages 13-15). PML nuclear bodies are SUMO-enriched subnuclear condensates and hubs for intrinsic immunity, DNA damage response, transcription regulation, and other nuclear processes; MORC3 is one of the SUMO-linked client proteins integrated into these assemblies (sloan2016morc3acomponent pages 3-5).
file:human/MORC3/MORC3-deep-research-falcon.md
MORC3 is consistently characterized as a **nuclear matrix protein** that localizes to **PML nuclear bodies**. In immunofluorescence microscopy, MORC3 colocalizes with the PML-NB component Sp100 in punctate nuclear structures (sloan2016morc3acomponent media 84630a9e). During infection with HSV-1 lacking ICP0, MORC3 is recruited to sites associated with incoming viral genomes (identified by ICP4 foci), consistent with a role in intrinsic restriction at early stages of infection (sloan2016morc3acomponent media 5b6c97c8).
file:human/MORC3/MORC3-deep-research-falcon.md
Mechanistically, the association with PML-NBs is reported to occur via **SUMO–SIM interaction** with PML.I, and PML-NB localization/recruitment functions require a **functional ATPase domain** (sloan2016morc3acomponent pages 3-5, sloan2016morc3acomponent pages 13-15).
GO:0016887 ATP hydrolysis activity
IEA
GO_REF:0000002
ACCEPT
Summary: MORC3 is a MORC-family GHKL/HATPase ATPase, and ATPase activity is required for PML-body localization/recruitment functions.
Reason: ATP hydrolysis activity is a core molecular feature of MORC3.
Supporting Evidence:
file:human/MORC3/MORC3-deep-research-falcon.md
**Domain architecture and biochemical capabilities.** MORC3 is described as containing three conserved modules: (i) a **GHKL/HATPase-like ATPase domain** (a “GHL ATPase”/GHKL-type ATPase in the MORC family), (ii) a **CW-type zinc finger** reported to bind **methylated H3K4**, and (iii) a **coiled-coil** region implicated in dimerization/oligomerization (sloan2016morc3acomponent pages 3-5). These features fit the concept of MORC proteins as **chromatin-associated ATPases** that integrate ATPase-driven conformational changes with chromatin recognition (via CW) and multivalent interactions (via coiled-coil) to regulate nuclear substructures and transcriptional states (sloan2016morc3acomponent pages 3-5).
file:human/MORC3/MORC3-deep-research-falcon.md
Mechanistically, the association with PML-NBs is reported to occur via **SUMO–SIM interaction** with PML.I, and PML-NB localization/recruitment functions require a **functional ATPase domain** (sloan2016morc3acomponent pages 3-5, sloan2016morc3acomponent pages 13-15).
GO:0045087 innate immune response
IEA
GO_REF:0000043
MODIFY
Summary: MORC3 participates in innate immunity, but the evidence is specifically antiviral restriction and interferon regulation.
Reason: Use antiviral innate immune response for the supported immune role.
Proposed replacements: antiviral innate immune response
Supporting Evidence:
file:human/MORC3/MORC3-deep-research-falcon.md
| PML nuclear bodies / viral restriction | Human MORC3 (NXP2) is a SUMOylated nuclear-matrix protein that localizes to PML nuclear bodies via SUMO-SIM interactions with PML.I; its ATPase domain is required for PML-NB localization and for recruiting Sp100/p53. During HSV-1 infection, MORC3 is recruited to incoming viral genomes and promotes recruitment of intrinsic restriction factors (Sp100, hDaxx, PML, γH2AX). HSV-1 ICP0 counteracts this by degrading MORC3. MORC3 also restricts HCMV, although influenza studies indicate virus-specific proviral effects in other contexts. (sloan2016morc3acomponent pages 3-5, sloan2016morc3acomponent pages 13-15, sloan2016morc3acomponent media 84630a9e) | SILAC/MS proteomics, colocalization microscopy, HSV-1 and HCMV plaque assays, shRNA knockdown, viral protein immunoblotting | MORC3 abundance decreased ~5.6-fold during HSV-1 infection in proteomics; MORC3 depletion caused a marked increase in plaque formation efficiency of ICP0-null HSV-1 and increased HCMV plaque formation; MORC3 colocalizes with PML-NB markers in punctate nuclear structures. (sloan2016morc3acomponent pages 3-5, sloan2016morc3acomponent pages 13-15, sloan2016morc3acomponent media 84630a9e) | Sloan et al., *J Virol* (Oct 2016), DOI: 10.1128/JVI.00621-16, https://doi.org/10.1128/JVI.00621-16 |
file:human/MORC3/MORC3-deep-research-falcon.md
A notable mechanistic finding is that MORC3 depletion reduced recruitment of multiple factors (Sp100, hDaxx, PML, γH2AX) to viral genomes, implying MORC3 participates in building/maintaining a restrictive chromatin environment at incoming HSV-1 genomes (sloan2016morc3acomponent pages 3-5).
GO:0046872 metal ion binding
IEA
GO_REF:0000043
MODIFY
Summary: MORC3 metal binding is specifically attributable to its CW-type zinc finger.
Reason: Use zinc ion binding rather than generic metal ion binding.
Proposed replacements: zinc ion binding
Supporting Evidence:
file:human/MORC3/MORC3-deep-research-falcon.md
**Domain architecture and biochemical capabilities.** MORC3 is described as containing three conserved modules: (i) a **GHKL/HATPase-like ATPase domain** (a “GHL ATPase”/GHKL-type ATPase in the MORC family), (ii) a **CW-type zinc finger** reported to bind **methylated H3K4**, and (iii) a **coiled-coil** region implicated in dimerization/oligomerization (sloan2016morc3acomponent pages 3-5). These features fit the concept of MORC proteins as **chromatin-associated ATPases** that integrate ATPase-driven conformational changes with chromatin recognition (via CW) and multivalent interactions (via coiled-coil) to regulate nuclear substructures and transcriptional states (sloan2016morc3acomponent pages 3-5).
GO:0140002 histone H3K4me3 reader activity
IEA
GO_REF:0000117
ACCEPT
Summary: The MORC3 CW-type zinc finger is reported to bind methylated H3K4.
Reason: Histone H3K4me3 reader activity is consistent with the CW-domain evidence and chromatin-associated function.
Supporting Evidence:
file:human/MORC3/MORC3-deep-research-falcon.md
**Domain architecture and biochemical capabilities.** MORC3 is described as containing three conserved modules: (i) a **GHKL/HATPase-like ATPase domain** (a “GHL ATPase”/GHKL-type ATPase in the MORC family), (ii) a **CW-type zinc finger** reported to bind **methylated H3K4**, and (iii) a **coiled-coil** region implicated in dimerization/oligomerization (sloan2016morc3acomponent pages 3-5). These features fit the concept of MORC proteins as **chromatin-associated ATPases** that integrate ATPase-driven conformational changes with chromatin recognition (via CW) and multivalent interactions (via coiled-coil) to regulate nuclear substructures and transcriptional states (sloan2016morc3acomponent pages 3-5).
GO:0005515 protein binding
IPI
PMID:26496610
A human interactome in three quantitative dimensions organiz...
MARK AS OVER ANNOTATED
Summary: MORC3 has many protein partners in PML body, SUMO, chromatin, and interactome datasets, but generic protein binding is not informative.
Reason: The actionable biology is better represented by protein-macromolecule adaptor activity, PML body localization, chromatin organization, and antiviral restriction.
Supporting Evidence:
file:human/MORC3/MORC3-deep-research-falcon.md
**SUMO biology and PML nuclear bodies (PML-NBs/ND10).** MORC3 is a **SUMOylated** nuclear matrix/PML nuclear body client protein. It associates with PML nuclear bodies through **SUMO–SIM interactions** (SUMO on one partner and a SUMO-interacting motif on the other), specifically reported as a SUMO–SIM interaction with **PML isoform I** (sloan2016morc3acomponent pages 3-5, sloan2016morc3acomponent pages 13-15). PML nuclear bodies are SUMO-enriched subnuclear condensates and hubs for intrinsic immunity, DNA damage response, transcription regulation, and other nuclear processes; MORC3 is one of the SUMO-linked client proteins integrated into these assemblies (sloan2016morc3acomponent pages 3-5).
file:human/MORC3/MORC3-deep-research-falcon.md
A notable mechanistic finding is that MORC3 depletion reduced recruitment of multiple factors (Sp100, hDaxx, PML, γH2AX) to viral genomes, implying MORC3 participates in building/maintaining a restrictive chromatin environment at incoming HSV-1 genomes (sloan2016morc3acomponent pages 3-5).
GO:0005515 protein binding
IPI
PMID:27173435
An organelle-specific protein landscape identifies novel dis...
MARK AS OVER ANNOTATED
Summary: MORC3 has many protein partners in PML body, SUMO, chromatin, and interactome datasets, but generic protein binding is not informative.
Reason: The actionable biology is better represented by protein-macromolecule adaptor activity, PML body localization, chromatin organization, and antiviral restriction.
Supporting Evidence:
file:human/MORC3/MORC3-deep-research-falcon.md
**SUMO biology and PML nuclear bodies (PML-NBs/ND10).** MORC3 is a **SUMOylated** nuclear matrix/PML nuclear body client protein. It associates with PML nuclear bodies through **SUMO–SIM interactions** (SUMO on one partner and a SUMO-interacting motif on the other), specifically reported as a SUMO–SIM interaction with **PML isoform I** (sloan2016morc3acomponent pages 3-5, sloan2016morc3acomponent pages 13-15). PML nuclear bodies are SUMO-enriched subnuclear condensates and hubs for intrinsic immunity, DNA damage response, transcription regulation, and other nuclear processes; MORC3 is one of the SUMO-linked client proteins integrated into these assemblies (sloan2016morc3acomponent pages 3-5).
file:human/MORC3/MORC3-deep-research-falcon.md
A notable mechanistic finding is that MORC3 depletion reduced recruitment of multiple factors (Sp100, hDaxx, PML, γH2AX) to viral genomes, implying MORC3 participates in building/maintaining a restrictive chromatin environment at incoming HSV-1 genomes (sloan2016morc3acomponent pages 3-5).
GO:0005515 protein binding
IPI
PMID:32296183
A reference map of the human binary protein interactome.
MARK AS OVER ANNOTATED
Summary: MORC3 has many protein partners in PML body, SUMO, chromatin, and interactome datasets, but generic protein binding is not informative.
Reason: The actionable biology is better represented by protein-macromolecule adaptor activity, PML body localization, chromatin organization, and antiviral restriction.
Supporting Evidence:
file:human/MORC3/MORC3-deep-research-falcon.md
**SUMO biology and PML nuclear bodies (PML-NBs/ND10).** MORC3 is a **SUMOylated** nuclear matrix/PML nuclear body client protein. It associates with PML nuclear bodies through **SUMO–SIM interactions** (SUMO on one partner and a SUMO-interacting motif on the other), specifically reported as a SUMO–SIM interaction with **PML isoform I** (sloan2016morc3acomponent pages 3-5, sloan2016morc3acomponent pages 13-15). PML nuclear bodies are SUMO-enriched subnuclear condensates and hubs for intrinsic immunity, DNA damage response, transcription regulation, and other nuclear processes; MORC3 is one of the SUMO-linked client proteins integrated into these assemblies (sloan2016morc3acomponent pages 3-5).
file:human/MORC3/MORC3-deep-research-falcon.md
A notable mechanistic finding is that MORC3 depletion reduced recruitment of multiple factors (Sp100, hDaxx, PML, γH2AX) to viral genomes, implying MORC3 participates in building/maintaining a restrictive chromatin environment at incoming HSV-1 genomes (sloan2016morc3acomponent pages 3-5).
GO:0005515 protein binding
IPI
PMID:33961781
Dual proteome-scale networks reveal cell-specific remodeling...
MARK AS OVER ANNOTATED
Summary: MORC3 has many protein partners in PML body, SUMO, chromatin, and interactome datasets, but generic protein binding is not informative.
Reason: The actionable biology is better represented by protein-macromolecule adaptor activity, PML body localization, chromatin organization, and antiviral restriction.
Supporting Evidence:
file:human/MORC3/MORC3-deep-research-falcon.md
**SUMO biology and PML nuclear bodies (PML-NBs/ND10).** MORC3 is a **SUMOylated** nuclear matrix/PML nuclear body client protein. It associates with PML nuclear bodies through **SUMO–SIM interactions** (SUMO on one partner and a SUMO-interacting motif on the other), specifically reported as a SUMO–SIM interaction with **PML isoform I** (sloan2016morc3acomponent pages 3-5, sloan2016morc3acomponent pages 13-15). PML nuclear bodies are SUMO-enriched subnuclear condensates and hubs for intrinsic immunity, DNA damage response, transcription regulation, and other nuclear processes; MORC3 is one of the SUMO-linked client proteins integrated into these assemblies (sloan2016morc3acomponent pages 3-5).
file:human/MORC3/MORC3-deep-research-falcon.md
A notable mechanistic finding is that MORC3 depletion reduced recruitment of multiple factors (Sp100, hDaxx, PML, γH2AX) to viral genomes, implying MORC3 participates in building/maintaining a restrictive chromatin environment at incoming HSV-1 genomes (sloan2016morc3acomponent pages 3-5).
GO:0005515 protein binding
IPI
PMID:35271311
OpenCell: Endogenous tagging for the cartography of human ce...
MARK AS OVER ANNOTATED
Summary: MORC3 has many protein partners in PML body, SUMO, chromatin, and interactome datasets, but generic protein binding is not informative.
Reason: The actionable biology is better represented by protein-macromolecule adaptor activity, PML body localization, chromatin organization, and antiviral restriction.
Supporting Evidence:
file:human/MORC3/MORC3-deep-research-falcon.md
**SUMO biology and PML nuclear bodies (PML-NBs/ND10).** MORC3 is a **SUMOylated** nuclear matrix/PML nuclear body client protein. It associates with PML nuclear bodies through **SUMO–SIM interactions** (SUMO on one partner and a SUMO-interacting motif on the other), specifically reported as a SUMO–SIM interaction with **PML isoform I** (sloan2016morc3acomponent pages 3-5, sloan2016morc3acomponent pages 13-15). PML nuclear bodies are SUMO-enriched subnuclear condensates and hubs for intrinsic immunity, DNA damage response, transcription regulation, and other nuclear processes; MORC3 is one of the SUMO-linked client proteins integrated into these assemblies (sloan2016morc3acomponent pages 3-5).
file:human/MORC3/MORC3-deep-research-falcon.md
A notable mechanistic finding is that MORC3 depletion reduced recruitment of multiple factors (Sp100, hDaxx, PML, γH2AX) to viral genomes, implying MORC3 participates in building/maintaining a restrictive chromatin environment at incoming HSV-1 genomes (sloan2016morc3acomponent pages 3-5).
GO:0005515 protein binding
IPI
PMID:35914814
Chr21 protein-protein interactions: enrichment in proteins i...
MARK AS OVER ANNOTATED
Summary: MORC3 has many protein partners in PML body, SUMO, chromatin, and interactome datasets, but generic protein binding is not informative.
Reason: The actionable biology is better represented by protein-macromolecule adaptor activity, PML body localization, chromatin organization, and antiviral restriction.
Supporting Evidence:
file:human/MORC3/MORC3-deep-research-falcon.md
**SUMO biology and PML nuclear bodies (PML-NBs/ND10).** MORC3 is a **SUMOylated** nuclear matrix/PML nuclear body client protein. It associates with PML nuclear bodies through **SUMO–SIM interactions** (SUMO on one partner and a SUMO-interacting motif on the other), specifically reported as a SUMO–SIM interaction with **PML isoform I** (sloan2016morc3acomponent pages 3-5, sloan2016morc3acomponent pages 13-15). PML nuclear bodies are SUMO-enriched subnuclear condensates and hubs for intrinsic immunity, DNA damage response, transcription regulation, and other nuclear processes; MORC3 is one of the SUMO-linked client proteins integrated into these assemblies (sloan2016morc3acomponent pages 3-5).
file:human/MORC3/MORC3-deep-research-falcon.md
A notable mechanistic finding is that MORC3 depletion reduced recruitment of multiple factors (Sp100, hDaxx, PML, γH2AX) to viral genomes, implying MORC3 participates in building/maintaining a restrictive chromatin environment at incoming HSV-1 genomes (sloan2016morc3acomponent pages 3-5).
GO:0005515 protein binding
IPI
PMID:40205054
Multimodal cell maps as a foundation for structural and func...
MARK AS OVER ANNOTATED
Summary: MORC3 has many protein partners in PML body, SUMO, chromatin, and interactome datasets, but generic protein binding is not informative.
Reason: The actionable biology is better represented by protein-macromolecule adaptor activity, PML body localization, chromatin organization, and antiviral restriction.
Supporting Evidence:
file:human/MORC3/MORC3-deep-research-falcon.md
**SUMO biology and PML nuclear bodies (PML-NBs/ND10).** MORC3 is a **SUMOylated** nuclear matrix/PML nuclear body client protein. It associates with PML nuclear bodies through **SUMO–SIM interactions** (SUMO on one partner and a SUMO-interacting motif on the other), specifically reported as a SUMO–SIM interaction with **PML isoform I** (sloan2016morc3acomponent pages 3-5, sloan2016morc3acomponent pages 13-15). PML nuclear bodies are SUMO-enriched subnuclear condensates and hubs for intrinsic immunity, DNA damage response, transcription regulation, and other nuclear processes; MORC3 is one of the SUMO-linked client proteins integrated into these assemblies (sloan2016morc3acomponent pages 3-5).
file:human/MORC3/MORC3-deep-research-falcon.md
A notable mechanistic finding is that MORC3 depletion reduced recruitment of multiple factors (Sp100, hDaxx, PML, γH2AX) to viral genomes, implying MORC3 participates in building/maintaining a restrictive chromatin environment at incoming HSV-1 genomes (sloan2016morc3acomponent pages 3-5).
GO:0005634 nucleus
IEA
GO_REF:0000107
ACCEPT
Summary: MORC3 is a nuclear/nuclear-matrix protein and PML nuclear body component.
Reason: Nuclear localization is strongly supported, although more specific PML body and nuclear matrix terms should also be retained.
Supporting Evidence:
file:human/MORC3/MORC3-deep-research-falcon.md
**SUMO biology and PML nuclear bodies (PML-NBs/ND10).** MORC3 is a **SUMOylated** nuclear matrix/PML nuclear body client protein. It associates with PML nuclear bodies through **SUMO–SIM interactions** (SUMO on one partner and a SUMO-interacting motif on the other), specifically reported as a SUMO–SIM interaction with **PML isoform I** (sloan2016morc3acomponent pages 3-5, sloan2016morc3acomponent pages 13-15). PML nuclear bodies are SUMO-enriched subnuclear condensates and hubs for intrinsic immunity, DNA damage response, transcription regulation, and other nuclear processes; MORC3 is one of the SUMO-linked client proteins integrated into these assemblies (sloan2016morc3acomponent pages 3-5).
file:human/MORC3/MORC3-deep-research-falcon.md
MORC3 is consistently characterized as a **nuclear matrix protein** that localizes to **PML nuclear bodies**. In immunofluorescence microscopy, MORC3 colocalizes with the PML-NB component Sp100 in punctate nuclear structures (sloan2016morc3acomponent media 84630a9e). During infection with HSV-1 lacking ICP0, MORC3 is recruited to sites associated with incoming viral genomes (identified by ICP4 foci), consistent with a role in intrinsic restriction at early stages of infection (sloan2016morc3acomponent media 5b6c97c8).
file:human/MORC3/MORC3-deep-research-falcon.md
Mechanistically, the association with PML-NBs is reported to occur via **SUMO–SIM interaction** with PML.I, and PML-NB localization/recruitment functions require a **functional ATPase domain** (sloan2016morc3acomponent pages 3-5, sloan2016morc3acomponent pages 13-15).
GO:0005654 nucleoplasm
IDA
GO_REF:0000052
MODIFY
Summary: MORC3 is nuclear, but the more specific supported locations are PML bodies and nuclear matrix/chromatin-associated nuclear structures.
Reason: Use PML body and nuclear matrix instead of broad nucleoplasm when curating MORC3 localization.
Proposed replacements: PML body nuclear matrix
Supporting Evidence:
file:human/MORC3/MORC3-deep-research-falcon.md
**SUMO biology and PML nuclear bodies (PML-NBs/ND10).** MORC3 is a **SUMOylated** nuclear matrix/PML nuclear body client protein. It associates with PML nuclear bodies through **SUMO–SIM interactions** (SUMO on one partner and a SUMO-interacting motif on the other), specifically reported as a SUMO–SIM interaction with **PML isoform I** (sloan2016morc3acomponent pages 3-5, sloan2016morc3acomponent pages 13-15). PML nuclear bodies are SUMO-enriched subnuclear condensates and hubs for intrinsic immunity, DNA damage response, transcription regulation, and other nuclear processes; MORC3 is one of the SUMO-linked client proteins integrated into these assemblies (sloan2016morc3acomponent pages 3-5).
file:human/MORC3/MORC3-deep-research-falcon.md
MORC3 is consistently characterized as a **nuclear matrix protein** that localizes to **PML nuclear bodies**. In immunofluorescence microscopy, MORC3 colocalizes with the PML-NB component Sp100 in punctate nuclear structures (sloan2016morc3acomponent media 84630a9e). During infection with HSV-1 lacking ICP0, MORC3 is recruited to sites associated with incoming viral genomes (identified by ICP4 foci), consistent with a role in intrinsic restriction at early stages of infection (sloan2016morc3acomponent media 5b6c97c8).
file:human/MORC3/MORC3-deep-research-falcon.md
Mechanistically, the association with PML-NBs is reported to occur via **SUMO–SIM interaction** with PML.I, and PML-NB localization/recruitment functions require a **functional ATPase domain** (sloan2016morc3acomponent pages 3-5, sloan2016morc3acomponent pages 13-15).
GO:0140002 histone H3K4me3 reader activity
IDA
PMID:26933034
Family-wide Characterization of Histone Binding Abilities of...
ACCEPT
Summary: The MORC3 CW-type zinc finger is reported to bind methylated H3K4.
Reason: Histone H3K4me3 reader activity is consistent with the CW-domain evidence and chromatin-associated function.
Supporting Evidence:
file:human/MORC3/MORC3-deep-research-falcon.md
**Domain architecture and biochemical capabilities.** MORC3 is described as containing three conserved modules: (i) a **GHKL/HATPase-like ATPase domain** (a “GHL ATPase”/GHKL-type ATPase in the MORC family), (ii) a **CW-type zinc finger** reported to bind **methylated H3K4**, and (iii) a **coiled-coil** region implicated in dimerization/oligomerization (sloan2016morc3acomponent pages 3-5). These features fit the concept of MORC proteins as **chromatin-associated ATPases** that integrate ATPase-driven conformational changes with chromatin recognition (via CW) and multivalent interactions (via coiled-coil) to regulate nuclear substructures and transcriptional states (sloan2016morc3acomponent pages 3-5).
GO:0000122 negative regulation of transcription by RNA polymerase II
IDA
PMID:34759314
Self-guarding of MORC3 enables virulence factor-triggered im...
ACCEPT
Summary: MORC3 contributes to repression of transcriptional programs, including IFNB1/interferon-linked gene regulation and foreign DNA silencing.
Reason: Negative regulation of RNA polymerase II transcription is consistent with the MORC3 chromatin repression evidence.
Supporting Evidence:
file:human/MORC3/MORC3-deep-research-falcon.md
**Intrinsic immunity and interferon pathway modulation.** In OSCC/HNSCC models, MORC3 knockdown upregulated interferon-associated genes and increased STAT1 and PD-L1, suggesting MORC3 suppresses interferon-driven transcriptional programs in this context (fu2024genomewideanalysisreveals pages 3-7). In myositis/cancer-associated myositis literature, MORC3 is described as an antiviral factor and a repressor of IFNB1 (patasova2023geneticinfluencesin pages 6-8). Together, these suggest MORC3 contributes to a chromatin-based brake on interferon gene expression, with context-dependent consequences (antiviral restriction in fibroblast/hepatocyte models vs immune evasion phenotypes in cancer).
file:human/MORC3/MORC3-deep-research-falcon.md
| Epigenetic silencing / chromatin regulation | MORC3 is a GHKL ATPase with CW zinc finger and coiled-coil domains; ATP binding/hydrolysis and SUMOylation enable interaction with DAXX and promote histone H3.3 deposition at retroelement loci, supporting H3K9me3 heterochromatin and silencing. Although shown directly in mouse ES cells, the mechanism is highly relevant to human MORC3 because the same domain architecture/function is conserved. (groh2021morc3silencesendogenous pages 10-11, groh2021morc3silencesendogenous pages 1-2, groh2020morc3silencesendogenous pages 10-13) | Genome-wide sgRNA screen, knockout/rescue mutants, ChIP-seq, ChIP-MS/IP-MS, ATAC-seq, H3.3 ChIP-qPCR, RT-qPCR | 2,737 reproducible Morc3 ChIP peaks; Morc3 loss increased chromatin accessibility at 444 peaks and decreased it at 10 peaks; ChIP-MS identified 489 Morc3-associated proteins; ATPase-cycle mutants failed to rescue ERV silencing. (groh2020morc3silencesendogenous pages 7-10, groh2021morc3silencesendogenous pages 1-2, groh2020morc3silencesendogenous pages 10-13) | Groh et al., *Nat Commun* (Oct 2021), DOI: 10.1038/s41467-021-26288-7, https://doi.org/10.1038/s41467-021-26288-7 |
GO:0000785 chromatin
IDA
PMID:34759314
Self-guarding of MORC3 enables virulence factor-triggered im...
ACCEPT
Summary: MORC3 is a chromatin-associated ATPase/scaffold with roles in repressive chromatin states.
Reason: Chromatin localization/function is supported by the mechanistic synthesis.
Supporting Evidence:
file:human/MORC3/MORC3-deep-research-falcon.md
**Domain architecture and biochemical capabilities.** MORC3 is described as containing three conserved modules: (i) a **GHKL/HATPase-like ATPase domain** (a “GHL ATPase”/GHKL-type ATPase in the MORC family), (ii) a **CW-type zinc finger** reported to bind **methylated H3K4**, and (iii) a **coiled-coil** region implicated in dimerization/oligomerization (sloan2016morc3acomponent pages 3-5). These features fit the concept of MORC proteins as **chromatin-associated ATPases** that integrate ATPase-driven conformational changes with chromatin recognition (via CW) and multivalent interactions (via coiled-coil) to regulate nuclear substructures and transcriptional states (sloan2016morc3acomponent pages 3-5).
file:human/MORC3/MORC3-deep-research-falcon.md
| Epigenetic silencing / chromatin regulation | MORC3 is a GHKL ATPase with CW zinc finger and coiled-coil domains; ATP binding/hydrolysis and SUMOylation enable interaction with DAXX and promote histone H3.3 deposition at retroelement loci, supporting H3K9me3 heterochromatin and silencing. Although shown directly in mouse ES cells, the mechanism is highly relevant to human MORC3 because the same domain architecture/function is conserved. (groh2021morc3silencesendogenous pages 10-11, groh2021morc3silencesendogenous pages 1-2, groh2020morc3silencesendogenous pages 10-13) | Genome-wide sgRNA screen, knockout/rescue mutants, ChIP-seq, ChIP-MS/IP-MS, ATAC-seq, H3.3 ChIP-qPCR, RT-qPCR | 2,737 reproducible Morc3 ChIP peaks; Morc3 loss increased chromatin accessibility at 444 peaks and decreased it at 10 peaks; ChIP-MS identified 489 Morc3-associated proteins; ATPase-cycle mutants failed to rescue ERV silencing. (groh2020morc3silencesendogenous pages 7-10, groh2021morc3silencesendogenous pages 1-2, groh2020morc3silencesendogenous pages 10-13) | Groh et al., *Nat Commun* (Oct 2021), DOI: 10.1038/s41467-021-26288-7, https://doi.org/10.1038/s41467-021-26288-7 |
GO:0003677 DNA binding
IDA
PMID:34759314
Self-guarding of MORC3 enables virulence factor-triggered im...
MARK AS OVER ANNOTATED
Summary: MORC3 regulates chromatin/DNA elements, but available synthesized evidence supports chromatin association and MRE regulation rather than a clearly separable direct DNA-binding MF.
Reason: Curate the supported chromatin and transcription-regulatory roles instead of broad DNA binding unless direct DNA-binding evidence is reviewed in detail.
Supporting Evidence:
file:human/MORC3/MORC3-deep-research-falcon.md
**Intrinsic immunity and interferon pathway modulation.** In OSCC/HNSCC models, MORC3 knockdown upregulated interferon-associated genes and increased STAT1 and PD-L1, suggesting MORC3 suppresses interferon-driven transcriptional programs in this context (fu2024genomewideanalysisreveals pages 3-7). In myositis/cancer-associated myositis literature, MORC3 is described as an antiviral factor and a repressor of IFNB1 (patasova2023geneticinfluencesin pages 6-8). Together, these suggest MORC3 contributes to a chromatin-based brake on interferon gene expression, with context-dependent consequences (antiviral restriction in fibroblast/hepatocyte models vs immune evasion phenotypes in cancer).
file:human/MORC3/MORC3-deep-research-falcon.md
| Epigenetic silencing / chromatin regulation | MORC3 is a GHKL ATPase with CW zinc finger and coiled-coil domains; ATP binding/hydrolysis and SUMOylation enable interaction with DAXX and promote histone H3.3 deposition at retroelement loci, supporting H3K9me3 heterochromatin and silencing. Although shown directly in mouse ES cells, the mechanism is highly relevant to human MORC3 because the same domain architecture/function is conserved. (groh2021morc3silencesendogenous pages 10-11, groh2021morc3silencesendogenous pages 1-2, groh2020morc3silencesendogenous pages 10-13) | Genome-wide sgRNA screen, knockout/rescue mutants, ChIP-seq, ChIP-MS/IP-MS, ATAC-seq, H3.3 ChIP-qPCR, RT-qPCR | 2,737 reproducible Morc3 ChIP peaks; Morc3 loss increased chromatin accessibility at 444 peaks and decreased it at 10 peaks; ChIP-MS identified 489 Morc3-associated proteins; ATPase-cycle mutants failed to rescue ERV silencing. (groh2020morc3silencesendogenous pages 7-10, groh2021morc3silencesendogenous pages 1-2, groh2020morc3silencesendogenous pages 10-13) | Groh et al., *Nat Commun* (Oct 2021), DOI: 10.1038/s41467-021-26288-7, https://doi.org/10.1038/s41467-021-26288-7 |
GO:0016605 PML body
IDA
PMID:27440897
MORC3, a Component of PML Nuclear Bodies, Has a Role in Rest...
ACCEPT
Summary: MORC3 localizes to PML nuclear bodies through SUMO/SIM-dependent interactions and helps recruit restriction factors there.
Reason: PML body localization is one of the best-supported cellular component annotations for MORC3.
Supporting Evidence:
file:human/MORC3/MORC3-deep-research-falcon.md
**SUMO biology and PML nuclear bodies (PML-NBs/ND10).** MORC3 is a **SUMOylated** nuclear matrix/PML nuclear body client protein. It associates with PML nuclear bodies through **SUMO–SIM interactions** (SUMO on one partner and a SUMO-interacting motif on the other), specifically reported as a SUMO–SIM interaction with **PML isoform I** (sloan2016morc3acomponent pages 3-5, sloan2016morc3acomponent pages 13-15). PML nuclear bodies are SUMO-enriched subnuclear condensates and hubs for intrinsic immunity, DNA damage response, transcription regulation, and other nuclear processes; MORC3 is one of the SUMO-linked client proteins integrated into these assemblies (sloan2016morc3acomponent pages 3-5).
file:human/MORC3/MORC3-deep-research-falcon.md
MORC3 is consistently characterized as a **nuclear matrix protein** that localizes to **PML nuclear bodies**. In immunofluorescence microscopy, MORC3 colocalizes with the PML-NB component Sp100 in punctate nuclear structures (sloan2016morc3acomponent media 84630a9e). During infection with HSV-1 lacking ICP0, MORC3 is recruited to sites associated with incoming viral genomes (identified by ICP4 foci), consistent with a role in intrinsic restriction at early stages of infection (sloan2016morc3acomponent media 5b6c97c8).
file:human/MORC3/MORC3-deep-research-falcon.md
Mechanistically, the association with PML-NBs is reported to occur via **SUMO–SIM interaction** with PML.I, and PML-NB localization/recruitment functions require a **functional ATPase domain** (sloan2016morc3acomponent pages 3-5, sloan2016morc3acomponent pages 13-15).
GO:0030674 protein-macromolecule adaptor activity
IDA
PMID:27440897
MORC3, a Component of PML Nuclear Bodies, Has a Role in Rest...
ACCEPT
Summary: MORC3 functions as a SUMO-regulated scaffold/adaptor for PML-body and viral-genome-associated restriction factors.
Reason: Protein-macromolecule adaptor activity is supported by MORC3-dependent recruitment of PML, Sp100, hDaxx, gamma-H2AX, p53, and related nuclear factors.
Supporting Evidence:
file:human/MORC3/MORC3-deep-research-falcon.md
A notable mechanistic finding is that MORC3 depletion reduced recruitment of multiple factors (Sp100, hDaxx, PML, γH2AX) to viral genomes, implying MORC3 participates in building/maintaining a restrictive chromatin environment at incoming HSV-1 genomes (sloan2016morc3acomponent pages 3-5).
file:human/MORC3/MORC3-deep-research-falcon.md
| PML nuclear bodies / viral restriction | Human MORC3 (NXP2) is a SUMOylated nuclear-matrix protein that localizes to PML nuclear bodies via SUMO-SIM interactions with PML.I; its ATPase domain is required for PML-NB localization and for recruiting Sp100/p53. During HSV-1 infection, MORC3 is recruited to incoming viral genomes and promotes recruitment of intrinsic restriction factors (Sp100, hDaxx, PML, γH2AX). HSV-1 ICP0 counteracts this by degrading MORC3. MORC3 also restricts HCMV, although influenza studies indicate virus-specific proviral effects in other contexts. (sloan2016morc3acomponent pages 3-5, sloan2016morc3acomponent pages 13-15, sloan2016morc3acomponent media 84630a9e) | SILAC/MS proteomics, colocalization microscopy, HSV-1 and HCMV plaque assays, shRNA knockdown, viral protein immunoblotting | MORC3 abundance decreased ~5.6-fold during HSV-1 infection in proteomics; MORC3 depletion caused a marked increase in plaque formation efficiency of ICP0-null HSV-1 and increased HCMV plaque formation; MORC3 colocalizes with PML-NB markers in punctate nuclear structures. (sloan2016morc3acomponent pages 3-5, sloan2016morc3acomponent pages 13-15, sloan2016morc3acomponent media 84630a9e) | Sloan et al., *J Virol* (Oct 2016), DOI: 10.1128/JVI.00621-16, https://doi.org/10.1128/JVI.00621-16 |
GO:0032688 negative regulation of interferon-beta production
IDA
PMID:34759314
Self-guarding of MORC3 enables virulence factor-triggered im...
ACCEPT
Summary: Loss or degradation of MORC3 derepresses IFNB1/interferon programs, supporting a negative regulatory role.
Reason: Negative regulation of interferon-beta production is directly aligned with MORC3-mediated IFNB1 repression.
Supporting Evidence:
file:human/MORC3/MORC3-deep-research-falcon.md
**Intrinsic immunity and interferon pathway modulation.** In OSCC/HNSCC models, MORC3 knockdown upregulated interferon-associated genes and increased STAT1 and PD-L1, suggesting MORC3 suppresses interferon-driven transcriptional programs in this context (fu2024genomewideanalysisreveals pages 3-7). In myositis/cancer-associated myositis literature, MORC3 is described as an antiviral factor and a repressor of IFNB1 (patasova2023geneticinfluencesin pages 6-8). Together, these suggest MORC3 contributes to a chromatin-based brake on interferon gene expression, with context-dependent consequences (antiviral restriction in fibroblast/hepatocyte models vs immune evasion phenotypes in cancer).
GO:0140374 antiviral innate immune response
IDA
PMID:27440897
MORC3, a Component of PML Nuclear Bodies, Has a Role in Rest...
ACCEPT
Summary: MORC3 contributes to intrinsic antiviral restriction, including PML-body-associated restriction of HSV-1 and HCMV.
Reason: Antiviral innate immune response is a supported major function of MORC3.
Supporting Evidence:
file:human/MORC3/MORC3-deep-research-falcon.md
| PML nuclear bodies / viral restriction | Human MORC3 (NXP2) is a SUMOylated nuclear-matrix protein that localizes to PML nuclear bodies via SUMO-SIM interactions with PML.I; its ATPase domain is required for PML-NB localization and for recruiting Sp100/p53. During HSV-1 infection, MORC3 is recruited to incoming viral genomes and promotes recruitment of intrinsic restriction factors (Sp100, hDaxx, PML, γH2AX). HSV-1 ICP0 counteracts this by degrading MORC3. MORC3 also restricts HCMV, although influenza studies indicate virus-specific proviral effects in other contexts. (sloan2016morc3acomponent pages 3-5, sloan2016morc3acomponent pages 13-15, sloan2016morc3acomponent media 84630a9e) | SILAC/MS proteomics, colocalization microscopy, HSV-1 and HCMV plaque assays, shRNA knockdown, viral protein immunoblotting | MORC3 abundance decreased ~5.6-fold during HSV-1 infection in proteomics; MORC3 depletion caused a marked increase in plaque formation efficiency of ICP0-null HSV-1 and increased HCMV plaque formation; MORC3 colocalizes with PML-NB markers in punctate nuclear structures. (sloan2016morc3acomponent pages 3-5, sloan2016morc3acomponent pages 13-15, sloan2016morc3acomponent media 84630a9e) | Sloan et al., *J Virol* (Oct 2016), DOI: 10.1128/JVI.00621-16, https://doi.org/10.1128/JVI.00621-16 |
file:human/MORC3/MORC3-deep-research-falcon.md
A notable mechanistic finding is that MORC3 depletion reduced recruitment of multiple factors (Sp100, hDaxx, PML, γH2AX) to viral genomes, implying MORC3 participates in building/maintaining a restrictive chromatin environment at incoming HSV-1 genomes (sloan2016morc3acomponent pages 3-5).
GO:2000774 positive regulation of cellular senescence
IDA
PMID:17332504
Dynamic regulation of p53 subnuclear localization and senesc...
KEEP AS NON CORE
Summary: MORC3 can activate p53 and induce cellular senescence in fibroblast models.
Reason: The p53/senescence phenotype is supported but is a downstream context-specific outcome of MORC3 PML-body localization and scaffold activity rather than the core conserved function.
Supporting Evidence:
PMID:17332504
Dynamic regulation of p53 subnuclear localization and senescence by MORC3.
file:human/MORC3/MORC3-deep-research-falcon.md
| PML nuclear bodies / viral restriction | Human MORC3 (NXP2) is a SUMOylated nuclear-matrix protein that localizes to PML nuclear bodies via SUMO-SIM interactions with PML.I; its ATPase domain is required for PML-NB localization and for recruiting Sp100/p53. During HSV-1 infection, MORC3 is recruited to incoming viral genomes and promotes recruitment of intrinsic restriction factors (Sp100, hDaxx, PML, γH2AX). HSV-1 ICP0 counteracts this by degrading MORC3. MORC3 also restricts HCMV, although influenza studies indicate virus-specific proviral effects in other contexts. (sloan2016morc3acomponent pages 3-5, sloan2016morc3acomponent pages 13-15, sloan2016morc3acomponent media 84630a9e) | SILAC/MS proteomics, colocalization microscopy, HSV-1 and HCMV plaque assays, shRNA knockdown, viral protein immunoblotting | MORC3 abundance decreased ~5.6-fold during HSV-1 infection in proteomics; MORC3 depletion caused a marked increase in plaque formation efficiency of ICP0-null HSV-1 and increased HCMV plaque formation; MORC3 colocalizes with PML-NB markers in punctate nuclear structures. (sloan2016morc3acomponent pages 3-5, sloan2016morc3acomponent pages 13-15, sloan2016morc3acomponent media 84630a9e) | Sloan et al., *J Virol* (Oct 2016), DOI: 10.1128/JVI.00621-16, https://doi.org/10.1128/JVI.00621-16 |
GO:0006468 protein phosphorylation
IDA
PMID:17332504
Dynamic regulation of p53 subnuclear localization and senesc...
REMOVE
Summary: MORC3 is a GHKL ATPase, not a protein kinase; the p53 study states that genotoxic stress-induced p53 phosphorylation still occurs in Morc3-deficient fibroblasts.
Reason: This annotation misattributes phosphorylation catalysis to MORC3. MORC3 regulates p53 localization/activity downstream of phosphorylation through PML nuclear bodies.
Supporting Evidence:
PMID:17332504
phosphorylation and stabilization of p53 but barely increased its
PMID:17332504
Dynamic regulation of p53 subnuclear localization and senescence by MORC3.
file:human/MORC3/MORC3-deep-research-falcon.md
**Domain architecture and biochemical capabilities.** MORC3 is described as containing three conserved modules: (i) a **GHKL/HATPase-like ATPase domain** (a “GHL ATPase”/GHKL-type ATPase in the MORC family), (ii) a **CW-type zinc finger** reported to bind **methylated H3K4**, and (iii) a **coiled-coil** region implicated in dimerization/oligomerization (sloan2016morc3acomponent pages 3-5). These features fit the concept of MORC proteins as **chromatin-associated ATPases** that integrate ATPase-driven conformational changes with chromatin recognition (via CW) and multivalent interactions (via coiled-coil) to regulate nuclear substructures and transcriptional states (sloan2016morc3acomponent pages 3-5).
GO:0016605 PML body
IDA
PMID:17332504
Dynamic regulation of p53 subnuclear localization and senesc...
ACCEPT
Summary: MORC3 localizes to PML nuclear bodies through SUMO/SIM-dependent interactions and helps recruit restriction factors there.
Reason: PML body localization is one of the best-supported cellular component annotations for MORC3.
Supporting Evidence:
file:human/MORC3/MORC3-deep-research-falcon.md
**SUMO biology and PML nuclear bodies (PML-NBs/ND10).** MORC3 is a **SUMOylated** nuclear matrix/PML nuclear body client protein. It associates with PML nuclear bodies through **SUMO–SIM interactions** (SUMO on one partner and a SUMO-interacting motif on the other), specifically reported as a SUMO–SIM interaction with **PML isoform I** (sloan2016morc3acomponent pages 3-5, sloan2016morc3acomponent pages 13-15). PML nuclear bodies are SUMO-enriched subnuclear condensates and hubs for intrinsic immunity, DNA damage response, transcription regulation, and other nuclear processes; MORC3 is one of the SUMO-linked client proteins integrated into these assemblies (sloan2016morc3acomponent pages 3-5).
file:human/MORC3/MORC3-deep-research-falcon.md
MORC3 is consistently characterized as a **nuclear matrix protein** that localizes to **PML nuclear bodies**. In immunofluorescence microscopy, MORC3 colocalizes with the PML-NB component Sp100 in punctate nuclear structures (sloan2016morc3acomponent media 84630a9e). During infection with HSV-1 lacking ICP0, MORC3 is recruited to sites associated with incoming viral genomes (identified by ICP4 foci), consistent with a role in intrinsic restriction at early stages of infection (sloan2016morc3acomponent media 5b6c97c8).
file:human/MORC3/MORC3-deep-research-falcon.md
Mechanistically, the association with PML-NBs is reported to occur via **SUMO–SIM interaction** with PML.I, and PML-NB localization/recruitment functions require a **functional ATPase domain** (sloan2016morc3acomponent pages 3-5, sloan2016morc3acomponent pages 13-15).
GO:0018105 peptidyl-serine phosphorylation
IDA
PMID:17332504
Dynamic regulation of p53 subnuclear localization and senesc...
REMOVE
Summary: MORC3 is not a serine/threonine kinase, and the p53 paper supports a localization/activity role rather than peptidyl-serine phosphorylation by MORC3.
Reason: The annotation incorrectly converts a p53 phosphorylation phenotype into MORC3 kinase activity.
Supporting Evidence:
PMID:17332504
phosphorylation and stabilization of p53 but barely increased its
PMID:17332504
Dynamic regulation of p53 subnuclear localization and senescence by MORC3.
file:human/MORC3/MORC3-deep-research-falcon.md
**Domain architecture and biochemical capabilities.** MORC3 is described as containing three conserved modules: (i) a **GHKL/HATPase-like ATPase domain** (a “GHL ATPase”/GHKL-type ATPase in the MORC family), (ii) a **CW-type zinc finger** reported to bind **methylated H3K4**, and (iii) a **coiled-coil** region implicated in dimerization/oligomerization (sloan2016morc3acomponent pages 3-5). These features fit the concept of MORC proteins as **chromatin-associated ATPases** that integrate ATPase-driven conformational changes with chromatin recognition (via CW) and multivalent interactions (via coiled-coil) to regulate nuclear substructures and transcriptional states (sloan2016morc3acomponent pages 3-5).
GO:0048147 negative regulation of fibroblast proliferation
IDA
PMID:17332504
Dynamic regulation of p53 subnuclear localization and senesc...
KEEP AS NON CORE
Summary: MORC3-dependent p53 activation and cellular senescence in fibroblast models imply reduced fibroblast proliferation.
Reason: This is a supported context-specific p53/senescence phenotype rather than a core MORC3 molecular function.
Supporting Evidence:
PMID:17332504
Dynamic regulation of p53 subnuclear localization and senescence by MORC3.
file:human/MORC3/MORC3-deep-research-falcon.md
| PML nuclear bodies / viral restriction | Human MORC3 (NXP2) is a SUMOylated nuclear-matrix protein that localizes to PML nuclear bodies via SUMO-SIM interactions with PML.I; its ATPase domain is required for PML-NB localization and for recruiting Sp100/p53. During HSV-1 infection, MORC3 is recruited to incoming viral genomes and promotes recruitment of intrinsic restriction factors (Sp100, hDaxx, PML, γH2AX). HSV-1 ICP0 counteracts this by degrading MORC3. MORC3 also restricts HCMV, although influenza studies indicate virus-specific proviral effects in other contexts. (sloan2016morc3acomponent pages 3-5, sloan2016morc3acomponent pages 13-15, sloan2016morc3acomponent media 84630a9e) | SILAC/MS proteomics, colocalization microscopy, HSV-1 and HCMV plaque assays, shRNA knockdown, viral protein immunoblotting | MORC3 abundance decreased ~5.6-fold during HSV-1 infection in proteomics; MORC3 depletion caused a marked increase in plaque formation efficiency of ICP0-null HSV-1 and increased HCMV plaque formation; MORC3 colocalizes with PML-NB markers in punctate nuclear structures. (sloan2016morc3acomponent pages 3-5, sloan2016morc3acomponent pages 13-15, sloan2016morc3acomponent media 84630a9e) | Sloan et al., *J Virol* (Oct 2016), DOI: 10.1128/JVI.00621-16, https://doi.org/10.1128/JVI.00621-16 |
GO:0050821 protein stabilization
IDA
PMID:17332504
Dynamic regulation of p53 subnuclear localization and senesc...
REMOVE
Summary: The p53 study indicates that genotoxic stress-induced p53 stabilization still occurs in Morc3-deficient fibroblasts; MORC3 instead affects p53 localization and transcriptional activity.
Reason: Protein stabilization is not the supported MORC3 activity from this evidence.
Supporting Evidence:
PMID:17332504
phosphorylation and stabilization of p53 but barely increased its
PMID:17332504
Dynamic regulation of p53 subnuclear localization and senescence by MORC3.
GO:0051457 maintenance of protein location in nucleus
IDA
PMID:17332504
Dynamic regulation of p53 subnuclear localization and senesc...
KEEP AS NON CORE
Summary: MORC3 helps recruit/maintain p53, Sp100, and viral-genome-associated restriction factors in nuclear PML-body contexts.
Reason: Maintenance of nuclear protein location is supported as a scaffold/localization role, but is secondary to the core PML-body chromatin-adaptor function.
Supporting Evidence:
PMID:17332504
Dynamic regulation of p53 subnuclear localization and senescence by MORC3.
file:human/MORC3/MORC3-deep-research-falcon.md
| PML nuclear bodies / viral restriction | Human MORC3 (NXP2) is a SUMOylated nuclear-matrix protein that localizes to PML nuclear bodies via SUMO-SIM interactions with PML.I; its ATPase domain is required for PML-NB localization and for recruiting Sp100/p53. During HSV-1 infection, MORC3 is recruited to incoming viral genomes and promotes recruitment of intrinsic restriction factors (Sp100, hDaxx, PML, γH2AX). HSV-1 ICP0 counteracts this by degrading MORC3. MORC3 also restricts HCMV, although influenza studies indicate virus-specific proviral effects in other contexts. (sloan2016morc3acomponent pages 3-5, sloan2016morc3acomponent pages 13-15, sloan2016morc3acomponent media 84630a9e) | SILAC/MS proteomics, colocalization microscopy, HSV-1 and HCMV plaque assays, shRNA knockdown, viral protein immunoblotting | MORC3 abundance decreased ~5.6-fold during HSV-1 infection in proteomics; MORC3 depletion caused a marked increase in plaque formation efficiency of ICP0-null HSV-1 and increased HCMV plaque formation; MORC3 colocalizes with PML-NB markers in punctate nuclear structures. (sloan2016morc3acomponent pages 3-5, sloan2016morc3acomponent pages 13-15, sloan2016morc3acomponent media 84630a9e) | Sloan et al., *J Virol* (Oct 2016), DOI: 10.1128/JVI.00621-16, https://doi.org/10.1128/JVI.00621-16 |
GO:0051457 maintenance of protein location in nucleus
IMP
PMID:17332504
Dynamic regulation of p53 subnuclear localization and senesc...
KEEP AS NON CORE
Summary: MORC3 helps recruit/maintain p53, Sp100, and viral-genome-associated restriction factors in nuclear PML-body contexts.
Reason: Maintenance of nuclear protein location is supported as a scaffold/localization role, but is secondary to the core PML-body chromatin-adaptor function.
Supporting Evidence:
PMID:17332504
Dynamic regulation of p53 subnuclear localization and senescence by MORC3.
file:human/MORC3/MORC3-deep-research-falcon.md
| PML nuclear bodies / viral restriction | Human MORC3 (NXP2) is a SUMOylated nuclear-matrix protein that localizes to PML nuclear bodies via SUMO-SIM interactions with PML.I; its ATPase domain is required for PML-NB localization and for recruiting Sp100/p53. During HSV-1 infection, MORC3 is recruited to incoming viral genomes and promotes recruitment of intrinsic restriction factors (Sp100, hDaxx, PML, γH2AX). HSV-1 ICP0 counteracts this by degrading MORC3. MORC3 also restricts HCMV, although influenza studies indicate virus-specific proviral effects in other contexts. (sloan2016morc3acomponent pages 3-5, sloan2016morc3acomponent pages 13-15, sloan2016morc3acomponent media 84630a9e) | SILAC/MS proteomics, colocalization microscopy, HSV-1 and HCMV plaque assays, shRNA knockdown, viral protein immunoblotting | MORC3 abundance decreased ~5.6-fold during HSV-1 infection in proteomics; MORC3 depletion caused a marked increase in plaque formation efficiency of ICP0-null HSV-1 and increased HCMV plaque formation; MORC3 colocalizes with PML-NB markers in punctate nuclear structures. (sloan2016morc3acomponent pages 3-5, sloan2016morc3acomponent pages 13-15, sloan2016morc3acomponent media 84630a9e) | Sloan et al., *J Virol* (Oct 2016), DOI: 10.1128/JVI.00621-16, https://doi.org/10.1128/JVI.00621-16 |

Core Functions

MORC3 is a MORC-family GHKL/HATPase chromatin-associated ATPase. Its ATPase cycle works with its CW zinc-finger chromatin-reader module and SUMOylation to support repressive chromatin organization at foreign or deleterious DNA templates.

Supporting Evidence:
  • file:human/MORC3/MORC3-deep-research-falcon.md
    **Domain architecture and biochemical capabilities.** MORC3 is described as containing three conserved modules: (i) a **GHKL/HATPase-like ATPase domain** (a “GHL ATPase”/GHKL-type ATPase in the MORC family), (ii) a **CW-type zinc finger** reported to bind **methylated H3K4**, and (iii) a **coiled-coil** region implicated in dimerization/oligomerization (sloan2016morc3acomponent pages 3-5). These features fit the concept of MORC proteins as **chromatin-associated ATPases** that integrate ATPase-driven conformational changes with chromatin recognition (via CW) and multivalent interactions (via coiled-coil) to regulate nuclear substructures and transcriptional states (sloan2016morc3acomponent pages 3-5).
  • file:human/MORC3/MORC3-deep-research-falcon.md
    | Epigenetic silencing / chromatin regulation | MORC3 is a GHKL ATPase with CW zinc finger and coiled-coil domains; ATP binding/hydrolysis and SUMOylation enable interaction with DAXX and promote histone H3.3 deposition at retroelement loci, supporting H3K9me3 heterochromatin and silencing. Although shown directly in mouse ES cells, the mechanism is highly relevant to human MORC3 because the same domain architecture/function is conserved. (groh2021morc3silencesendogenous pages 10-11, groh2021morc3silencesendogenous pages 1-2, groh2020morc3silencesendogenous pages 10-13) | Genome-wide sgRNA screen, knockout/rescue mutants, ChIP-seq, ChIP-MS/IP-MS, ATAC-seq, H3.3 ChIP-qPCR, RT-qPCR | 2,737 reproducible Morc3 ChIP peaks; Morc3 loss increased chromatin accessibility at 444 peaks and decreased it at 10 peaks; ChIP-MS identified 489 Morc3-associated proteins; ATPase-cycle mutants failed to rescue ERV silencing. (groh2020morc3silencesendogenous pages 7-10, groh2021morc3silencesendogenous pages 1-2, groh2020morc3silencesendogenous pages 10-13) | Groh et al., *Nat Commun* (Oct 2021), DOI: 10.1038/s41467-021-26288-7, https://doi.org/10.1038/s41467-021-26288-7 |

The MORC3 CW-type zinc finger recognizes methylated H3K4, connecting MORC3 to chromatin-reader activity in nuclear chromatin contexts.

Directly Involved In:
Cellular Locations:
Supporting Evidence:
  • file:human/MORC3/MORC3-deep-research-falcon.md
    **Domain architecture and biochemical capabilities.** MORC3 is described as containing three conserved modules: (i) a **GHKL/HATPase-like ATPase domain** (a “GHL ATPase”/GHKL-type ATPase in the MORC family), (ii) a **CW-type zinc finger** reported to bind **methylated H3K4**, and (iii) a **coiled-coil** region implicated in dimerization/oligomerization (sloan2016morc3acomponent pages 3-5). These features fit the concept of MORC proteins as **chromatin-associated ATPases** that integrate ATPase-driven conformational changes with chromatin recognition (via CW) and multivalent interactions (via coiled-coil) to regulate nuclear substructures and transcriptional states (sloan2016morc3acomponent pages 3-5).

MORC3 acts as a SUMO-regulated PML-body scaffold/adaptor that recruits and maintains nuclear restriction factors at PML bodies and incoming viral genomes, contributing to antiviral restriction and interferon-beta regulatory programs.

Supporting Evidence:
  • file:human/MORC3/MORC3-deep-research-falcon.md
    **SUMO biology and PML nuclear bodies (PML-NBs/ND10).** MORC3 is a **SUMOylated** nuclear matrix/PML nuclear body client protein. It associates with PML nuclear bodies through **SUMO–SIM interactions** (SUMO on one partner and a SUMO-interacting motif on the other), specifically reported as a SUMO–SIM interaction with **PML isoform I** (sloan2016morc3acomponent pages 3-5, sloan2016morc3acomponent pages 13-15). PML nuclear bodies are SUMO-enriched subnuclear condensates and hubs for intrinsic immunity, DNA damage response, transcription regulation, and other nuclear processes; MORC3 is one of the SUMO-linked client proteins integrated into these assemblies (sloan2016morc3acomponent pages 3-5).
  • file:human/MORC3/MORC3-deep-research-falcon.md
    | PML nuclear bodies / viral restriction | Human MORC3 (NXP2) is a SUMOylated nuclear-matrix protein that localizes to PML nuclear bodies via SUMO-SIM interactions with PML.I; its ATPase domain is required for PML-NB localization and for recruiting Sp100/p53. During HSV-1 infection, MORC3 is recruited to incoming viral genomes and promotes recruitment of intrinsic restriction factors (Sp100, hDaxx, PML, γH2AX). HSV-1 ICP0 counteracts this by degrading MORC3. MORC3 also restricts HCMV, although influenza studies indicate virus-specific proviral effects in other contexts. (sloan2016morc3acomponent pages 3-5, sloan2016morc3acomponent pages 13-15, sloan2016morc3acomponent media 84630a9e) | SILAC/MS proteomics, colocalization microscopy, HSV-1 and HCMV plaque assays, shRNA knockdown, viral protein immunoblotting | MORC3 abundance decreased ~5.6-fold during HSV-1 infection in proteomics; MORC3 depletion caused a marked increase in plaque formation efficiency of ICP0-null HSV-1 and increased HCMV plaque formation; MORC3 colocalizes with PML-NB markers in punctate nuclear structures. (sloan2016morc3acomponent pages 3-5, sloan2016morc3acomponent pages 13-15, sloan2016morc3acomponent media 84630a9e) | Sloan et al., *J Virol* (Oct 2016), DOI: 10.1128/JVI.00621-16, https://doi.org/10.1128/JVI.00621-16 |
  • file:human/MORC3/MORC3-deep-research-falcon.md
    **Intrinsic immunity and interferon pathway modulation.** In OSCC/HNSCC models, MORC3 knockdown upregulated interferon-associated genes and increased STAT1 and PD-L1, suggesting MORC3 suppresses interferon-driven transcriptional programs in this context (fu2024genomewideanalysisreveals pages 3-7). In myositis/cancer-associated myositis literature, MORC3 is described as an antiviral factor and a repressor of IFNB1 (patasova2023geneticinfluencesin pages 6-8). Together, these suggest MORC3 contributes to a chromatin-based brake on interferon gene expression, with context-dependent consequences (antiviral restriction in fibroblast/hepatocyte models vs immune evasion phenotypes in cancer).

References

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Suggested Questions for Experts

Q: Which MORC3 activities in human cells require the ATPase domain, the CW H3K4me3-reader domain, SUMOylation/SIM interactions, or combinations of these modules?

Q: Does MORC3 directly bind specific DNA elements such as the IFNB1-adjacent MRE, or is repression mediated through chromatin-associated partner proteins?

Suggested Experiments

Experiment: Rescue MORC3 knockout human cells with ATPase-dead, CW-domain, SUMOylation-defective, and SIM-interaction mutants, then measure PML-body localization, restriction-factor recruitment, IFNB1/MRE repression, and HSV-1/HCMV restriction.

Hypothesis: MORC3 antiviral and interferon-repressive functions require separable ATPase, chromatin-reader, and SUMO/PML-body interaction modules.

Experiment: Perform CUT&RUN/CUT&Tag or ChIP-seq for endogenous MORC3 together with DNA-binding-deficient and partner-recruitment mutants at IFNB1/MRE, viral episomes, and retroelement loci.

Hypothesis: MORC3 occupies repressed chromatin templates through a partner-dependent chromatin scaffold mechanism rather than generic sequence-independent DNA binding.

Deep Research

Falcon

(MORC3-deep-research-falcon.md)

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