Affinage

CCDC93

Coiled-coil domain-containing protein 93 · UniProt Q567U6

Length
631 aa
Mass
73.2 kDa
Annotated
2026-06-09
31 papers in source corpus 19 papers cited in narrative 17 extracted findings
Cross-family judge vs UniProt: Affinage preferred faithfulness: 7/7 claims corpus-supported (100%)

Mechanistic narrative

Synthesis pass · prose summary of the discoveries below

CCDC93 is a core scaffolding subunit of the endosomal CCC (COMMD/CCDC22/CCDC93) complex that directs the recycling of internalized plasma membrane proteins back to the cell surface and prevents their lysosomal degradation (PMID:25355947, PMID:28892079). Together with CCDC22, it forms the structural scaffold that bridges the stable COMMD1-10 core to the Retriever subcomplex (VPS35L/VPS26C/VPS29) and the effector DENND10, assembling the larger Commander complex (PMID:38062209, PMID:37397996, PMID:37333304, PMID:38459129); complex integrity depends reciprocally on COMMD proteins, whose loss destabilizes CCDC93 and CCDC22 (PMID:29545368, PMID:33262129). CCDC93 is recruited to early endosomes through its carboxyl-terminal interaction with the WASH subunit FAM21, coupling cargo sorting to actin polymerization (PMID:25355947). Mechanistically, the complex maintains endosomal phosphatidylinositol-3-phosphate homeostasis by controlling phosphorylation and endosomal recruitment of the PI(3)P phosphatase MTMR2; its loss elevates PI(3)P, drives excess WASH-dependent F-actin, and traps internalized receptors (PMID:31537807). Acting with the cargo adaptor SNX17, the complex recycles α5β1 integrin, LDLR, ATP7A/B, and Notch2 along with over a hundred surface proteins bearing ΦxNPxY/F sorting motifs (PMID:28892079, PMID:26965651, PMID:26553930, PMID:40601774), and CCDC93 also engages the PROPPIN protein WIPI2 to support a distinct β1-integrin recycling route [PMID:bio_10.1101_2025.10.08.681146]. CCDC93 thereby supports physiological copper excretion, LDL clearance, and Notch signaling (PMID:25355947, PMID:26965651, PMID:26553930), and in macrophages the complex is required for phagosome maturation and bacterial clearance (PMID:41473320). Loss-of-function mutations in CCDC93 cause Ritscher-Schinzel syndrome by disrupting Commander assembly and reducing surface presentation of SNX17 cargoes, phenocopied in mouse models displaying proteinuria, skeletal, and neurological defects (PMID:40601774).

Mechanistic history

Synthesis pass · year-by-year structured walk · 14 steps
  1. 2014 High

    Established CCDC93 as a constituent of the CCC complex and defined how it is targeted to endosomes, answering what molecular machine it belongs to and how that machine localizes.

    Evidence Reciprocal Co-IP, siRNA depletion, and copper homeostasis readouts mapping the CCDC93 C-terminal interaction with FAM21

    PMID:25355947

    Open questions at the time
    • Did not resolve atomic architecture of CCDC93 within the complex
    • Cargo repertoire beyond ATP7A not yet defined
  2. 2015 High

    Showed the CCC complex governs surface recycling of signaling receptors, extending its role from a single transporter to broad receptor homeostasis.

    Evidence siRNA depletion, Notch2 localization and reporter assays, conditional Commd9 knockout mice

    PMID:26553930

    Open questions at the time
    • Direct CCDC93 contribution distinct from other subunits not isolated
    • Sorting-motif requirement on Notch2 not defined
  3. 2016 High

    Demonstrated in vivo that CCC-dependent recycling controls LDLR surface levels and plasma lipid handling, linking the complex to systemic physiology.

    Evidence Liver-specific knockout mice, CRISPR somatic editing, LDL uptake and LDLR localization assays

    PMID:26965651

    Open questions at the time
    • CCDC93-specific knockout not used here
    • Mechanism of LDLR retrieval step unresolved
  4. 2017 High

    Defined the CCC complex as the lysosomal-degradation-protecting partner of SNX17 and Retriever, establishing the scope of cargo it recycles.

    Evidence Quantitative cell-surface proteomics, Co-IP, and loss-of-function recycling assays across >120 cargoes

    PMID:28892079

    Open questions at the time
    • How CCDC93 physically couples to SNX17/Retriever not yet structurally resolved
    • Selectivity rules for cargo unclear
  5. 2018 High

    Showed CCC complex integrity is interdependent, with COMMD proteins required to stabilize CCDC93 and CCDC22, clarifying assembly hierarchy.

    Evidence Liver-specific Commd knockout mice, targeted proteomics, CRISPR Ccdc22 deletion, western blotting

    PMID:29545368

    Open questions at the time
    • Order of complex assembly not defined
    • Whether CCDC93 has roles outside the assembled complex unknown
  6. 2019 High

    Provided the lipid-level mechanism by which the complex acts, linking CCDC93/CCC to MTMR2-controlled endosomal PI(3)P and WASH-dependent actin.

    Evidence siRNA depletion with PI(3)P biosensors, F-actin quantification, and MTMR2 phosphorylation/recruitment assays

    PMID:31537807

    Open questions at the time
    • Direct enzymatic relationship between CCDC93 and MTMR2 not established
    • Kinase responsible for MTMR2 phosphorylation not identified
  7. 2020 Medium

    Connected human genetic variation in CCDC93 to LDL handling, showing CCDC93 dosage and stability directly tune LDLR surface levels.

    Evidence Population genetics with mouse overexpression and cellular ablation, LDLR surface and LDL uptake assays

    PMID:31630160

    Open questions at the time
    • Single-lab functional validation
    • Mechanism by which p.Pro228Leu stabilizes protein not resolved
  8. 2021 Medium

    Confirmed across multiple COMMD genes that the assembled complex including CCDC93 drives hepatic ATP7B recycling and copper excretion.

    Evidence Tissue-specific COMMD knockout mice, biochemical CCC integrity analysis, copper measurements

    PMID:33262129

    Open questions at the time
    • CCDC93-specific deletion not tested
    • Single lab
  9. 2023 High

    Resolved the structural basis of CCDC93's scaffolding role, showing it bridges the COMMD core to Retriever and that cancer mutations break this coupling.

    Evidence Cryo-EM of Retriever, AlphaFold modeling, biochemical pulldowns, proteomics, disease-variant mutagenesis

    PMID:37333304 PMID:37397996 PMID:38062209

    Open questions at the time
    • Conformational dynamics during cargo handoff not captured
    • Membrane-bound state not resolved
  10. 2024 High

    Determined the endogenous Commander architecture, placing CCDC22-CCDC93 as the scaffold linking the COMMD core to DENND10 and Retriever effector module.

    Evidence Cryo-EM of endogenous human Commander with MS-based composition validation

    PMID:38459129

    Open questions at the time
    • Function of DENND10 module within recycling not defined
    • Dynamics of submodule engagement unresolved
  11. 2024 Medium

    Revealed a vascular and mitochondrial requirement for CCDC93 in vivo, indicating phenotypes beyond cargo recycling and that the gene is developmentally essential.

    Evidence CRISPR Ccdc93 knockout mice (homozygous lethal), wire myography, RNA-Seq, plasma fatty acid and mitochondrial protein analysis

    PMID:39250516

    Open questions at the time
    • Mechanistic link between recycling defects and mitochondrial dysfunction unclear
    • Single lab
  12. 2025 High

    Established CCDC93 as a Ritscher-Schinzel syndrome gene, mechanistically tying disease to disrupted Commander assembly and loss of SNX17-motif cargo at the surface.

    Evidence Patient mutation interactome analysis, cell-surface proteomics, CCDC93-deficient mouse models, cargo motif analysis

    PMID:40601774

    Open questions at the time
    • Tissue-specific basis of individual RSS features not dissected
    • Relationship to vascular/mitochondrial phenotypes not integrated
  13. 2025 Medium

    Identified WIPI2 as a CCDC93 partner defining a pathway-selective recycling route, refining how distinct cargo classes are sorted.

    Evidence Co-IP, FSSS-motif mutagenesis, and selective cargo trafficking assays (β1-integrin vs EGFR/GLUT1) (preprint)

    PMID:bio_10.1101_2025.10.08.681146

    Open questions at the time
    • Preprint, not peer-reviewed
    • Structural basis of WIPI2-CCDC93 interface not resolved
  14. 2025 Medium

    Extended CCC function to innate immunity, showing the complex is required for phagosome maturation and bacterial clearance via PI(3)P control.

    Evidence BMDM loss-of-function, phagosomal PI(3)P imaging, phagosome-lysosome fusion and bacterial clearance assays (preprint)

    PMID:41473320

    Open questions at the time
    • Preprint, not peer-reviewed
    • Whether CCDC93 acts identically on phagosomes and endosomes unverified

Open questions

Synthesis pass · forward-looking unresolved questions
  • How the broader CCDC93-dependent phenotypes (vascular tone, mitochondrial homeostasis, lysosomal secretion) mechanistically derive from endosomal recycling defects remains unresolved.
  • No unifying model connecting recycling defects to mitochondrial/vascular phenotypes
  • Cargo-by-cargo selectivity rules of the complex not fully defined
  • Membrane-engaged structural state of CCDC93 not captured

Mechanism profile

Synthesis pass · controlled-vocabulary classification · explore literature graph →
Molecular activity
GO:0005198 structural molecule activity 3 GO:0060090 molecular adaptor activity 2
Localization
GO:0005768 endosome 2 GO:0031410 cytoplasmic vesicle 1
Pathway
R-HSA-5653656 Vesicle-mediated transport 4 R-HSA-9609507 Protein localization 2
Complex memberships
CCC complexCommander complexRetriever-CCC complex

Evidence

Reading pass · 17 per-paper findings extracted from the source corpus
Year Finding Method Journal Conf PMIDs
2014 CCDC93, together with CCDC22 and C16orf62, forms the CCC (COMMD/CCDC22/CCDC93) complex that localizes to early endosomes and interacts with the WASH complex to regulate endosomal trafficking of the copper transporter ATP7A; the carboxyl-terminal end of CCDC93 interacts with FAM21 (a WASH complex subunit) to recruit the CCC complex to endosomes. Co-immunoprecipitation, protein depletion (siRNA knockdown), endosomal localization assays, copper homeostasis functional readouts Molecular biology of the cell High 25355947
2017 CCDC93 is a core subunit of the CCC complex (CCDC93, CCDC22, COMMD proteins), which associates with the cargo adaptor SNX17 and the Retriever complex to form a larger assembly that prevents lysosomal degradation and promotes cell surface recycling of α5β1 integrin and over 120 other cell surface proteins. Quantitative proteomics, Co-immunoprecipitation, cell surface proteomics, loss-of-function depletion with cargo recycling readouts Nature cell biology High 28892079
2016 The CCC complex (including CCDC93) is required for endosomal sorting and recycling of LDLR back to the cell surface; depletion of CCC components leads to LDLR mislocalization and decreased LDL uptake. Liver-specific knockout mice, CRISPR/Cas9 somatic gene editing, plasma LDL measurements, LDLR localization assays, LDL uptake assays Nature communications High 26965651
2015 The CCC complex (including CCDC93) controls Notch receptor recycling to the cell surface; disruption of the CCC complex causes intracellular accumulation of Notch2 and reduced Notch signaling. siRNA depletion of CCC components, Notch2 localization assays, Notch signaling reporter assays, conditional Commd9 knockout mice The Journal of cell biology High 26553930
2019 The CCC complex (including CCDC93) maintains normal endosomal levels of phosphatidylinositol-3-phosphate (PI(3)P) by regulating the phosphorylation and endosomal recruitment of the PI(3)P phosphatase MTMR2; CCC depletion elevates endosomal PI(3)P, leading to enhanced WASH recruitment, excess endosomal F-actin, and trapping of internalized receptors. siRNA depletion of CCC components, PI(3)P biosensor imaging, F-actin quantification, MTMR2 phosphorylation and localization assays, receptor recycling assays Nature communications High 31537807
2023 Cryo-EM structure of the Retriever complex was determined, and biochemical, cellular, and proteomic analyses revealed the structural organization of the entire Retriever-CCC complex; CCDC93 (along with CCDC22) scaffolds the CCC and Retriever subcomplexes together; cancer-associated mutations disrupt complex formation and impair membrane protein homeostasis. Cryogenic electron microscopy, AlphaFold structural predictions, biochemical pulldowns, cellular and proteomic analyses, mutagenesis of disease variants Nature structural & molecular biology High 37333304 37397996 38062209
2024 Cryo-EM structure of the endogenous human Commander complex shows that CCDC22 and CCDC93 act as a scaffold bridging the stable COMMD1-10 core and the effector module containing DENND10 and Retriever (VPS26C, VPS29, VPS35L); key interaction interfaces between these submodules were identified. Cryogenic electron microscopy, mass spectrometry-based proteomics, structural analysis of endogenous complex Nature structural & molecular biology High 38459129
2013 CCDC93 (along with CCDC22 and related proteins) contains a divergent N-terminal calponin homology (NN-CH)-like domain adjoined to C-terminal heptad repeats predicted to form a coiled-coil, defining a novel protein family sharing evolutionary ancestry with NDC80/NUF2 kinetochore components. Computational profile-to-profile comparisons, structure modeling Bioinformatics (Oxford, England) Low 24257188
2018 COMMD protein deficiency destabilizes the core of the CCC complex (CCDC22 and CCDC93 protein levels are reduced), and CCDC22 deletion by CRISPR/Cas9 likewise destabilizes the complete CCC complex, demonstrating that the integrity of COMMD proteins is required for CCC complex stability. Liver-specific Commd knockout mice, quantitative targeted proteomics, CRISPR/Cas9 somatic Ccdc22 deletion, western blotting of complex components Circulation research High 29545368
2020 A coding variant in CCDC93 (p.Pro228Leu) increases CCDC93 protein stability; overexpression of CCDC93 in mice decreases plasma LDL-c, while CCDC93 ablation reduces LDLR cell surface levels and LDL uptake. Population genetics combined with functional cell-based assays (overexpression in mice, CCDC93 ablation), LDLR surface level and LDL uptake assays European heart journal Medium 31630160
2021 Deficiency of any of three COMMD genes (Commd1, Commd6, or Commd9) destabilizes the entire CCC complex including CCDC93, and the CCC complex regulates ATP7B endosomal recycling and copper excretion in hepatocytes. Enterocyte- and hepatocyte-specific COMMD knockout mice, biochemical analysis of CCC complex integrity, copper level measurements Disease models & mechanisms Medium 33262129
2025 The CCC complex (including CCDC93) is essential for phagosome maturation in macrophages; CCC deficiency impairs phagosome-lysosome fusion, leads to excessive PI(3)P accumulation on phagosome membranes, and reduces bacterial clearance. Bone marrow-derived macrophage (BMDM) loss-of-function, PI(3)P imaging, phagosome-lysosome fusion assays, bacterial clearance assays bioRxiv : the preprint server for biologypreprint Medium 41473320
2025 CCDC93 interacts with WIPI2 (a PROPPIN protein) as part of the CROP2 complex (Retriever-PROPPIN complex), which is required for endosomal exit of β1-Integrin but not for CROP (Retromer-WIPI1)-dependent cargos such as EGFR or GLUT1; WIPI2 uses an FSSS motif to integrate into the Retriever complex via interaction with CCDC93. Co-immunoprecipitation, cargo trafficking assays (β1-Integrin, EGFR, GLUT1), mutagenesis of FSSS motif, loss-of-function depletion bioRxivpreprint Medium bio_10.1101_2025.10.08.681146
2025 Mutations in CCDC93 cause Ritscher-Schinzel syndrome (RSS) by disrupting Commander complex assembly, leading to reduced cell surface presentation of integral membrane proteins containing SNX17-recognized ΦxNPxY/F sorting motifs; mouse models of CCDC93 deficiency replicate RSS phenotypes including proteinuria, skeletal malformation, and neurological impairment. Interactome analysis of patient mutations, cell surface proteomics, mouse models of CCDC93 deficiency, motif analysis of cargo proteins Science translational medicine High 40601774
2025 CCDC22 mutations (p.E208K and p.P172R) that impair CCC complex assembly do so by disrupting a conserved interaction surface required for CCDC22-COMMD4 binding, demonstrating that COMMD binding to CCDC22 is required for CCC complex integrity; CCDC93 remains part of the complex that is disrupted by these mutations. Mutagenesis of CCDC22, co-immunoprecipitation of CCC complex components including CCDC93, patient mutation characterization BMC medical genomics Medium 40448120
2024 Heterozygous Ccdc93 deletion in mice (homozygous deletion is embryonic lethal by day 10.5) results in elevated systolic blood pressure, impaired acetylcholine-induced arterial relaxation, enhanced phenylephrine-induced contraction, elevated plasma free fatty acids, and aortic mitochondrial dysfunction with aberrant Parkin and Nix expression. CRISPR/Cas9 Ccdc93 knockout mice, wire myography, RNA-Seq transcriptome analysis, plasma fatty acid measurements, western blotting for mitochondrial proteins PLoS genetics Medium 39250516
2025 Loss of COMMD3 (a CCC complex component) increases release of lysosomal proteins through extracellular vesicles, leading to impaired delivery to endolysosomes and lysosomal dysfunction; COMMD3 was identified as a modifier of lysosomal glucocerebrosidase (GCase) activity through a genome-wide CRISPR interference screen. Pooled genome-wide CRISPRi screen, extracellular vesicle proteomics, lysosomal function assays Science (New York, N.Y.) Medium 40209002

Source papers

Stage 0 corpus · 31 papers · ranked by NIH iCite citations
Year Title Journal Citations PMID
2017 Retriever is a multiprotein complex for retromer-independent endosomal cargo recycling. Nature cell biology 282 28892079
2014 COMMD1 is linked to the WASH complex and regulates endosomal trafficking of the copper transporter ATP7A. Molecular biology of the cell 186 25355947
2016 CCC- and WASH-mediated endosomal sorting of LDLR is required for normal clearance of circulating LDL. Nature communications 165 26965651
2019 Towards a molecular understanding of endosomal trafficking by Retromer and Retriever. Traffic (Copenhagen, Denmark) 148 30993794
2018 Endosomal receptor trafficking: Retromer and beyond. Traffic (Copenhagen, Denmark) 142 29667289
2018 The COMMD Family Regulates Plasma LDL Levels and Attenuates Atherosclerosis Through Stabilizing the CCC Complex in Endosomal LDLR Trafficking. Circulation research 107 29545368
2019 Endosomal PI(3)P regulation by the COMMD/CCDC22/CCDC93 (CCC) complex controls membrane protein recycling. Nature communications 97 31537807
2015 Endosomal sorting of Notch receptors through COMMD9-dependent pathways modulates Notch signaling. The Journal of cell biology 54 26553930
2023 Structural organization of the retriever-CCC endosomal recycling complex. Nature structural & molecular biology 38 38062209
2013 A divergent calponin homology (NN-CH) domain defines a novel family: implications for evolution of ciliary IFT complex B proteins. Bioinformatics (Oxford, England) 37 24257188
2024 Structure and interactions of the endogenous human Commander complex. Nature structural & molecular biology 35 38459129
2021 Regulation of murine copper homeostasis by members of the COMMD protein family. Disease models & mechanisms 33 33262129
2020 A common variant in CCDC93 protects against myocardial infarction and cardiovascular mortality by regulating endosomal trafficking of low-density lipoprotein receptor. European heart journal 19 31630160
2019 COMMD10-Guided Phagolysosomal Maturation Promotes Clearance of Staphylococcus aureus in Macrophages. iScience 19 30959277
2021 Commander Complex-A Multifaceted Operator in Intracellular Signaling and Cargo. Cells 17 34943955
2015 Genetic variation associates with susceptibility for cigarette smoke-induced neutrophilia in mice. American journal of physiology. Lung cellular and molecular physiology 17 25637605
2022 Integrating genome-wide association study with RNA-seq revealed DBI as a good candidate gene for intramuscular fat content in Beijing black pigs. Animal genetics 14 36305366
2019 Ancestral reconstruction of protein interaction networks. PLoS computational biology 13 31658251
2017 Novel regulators of plasma lipid levels. Current opinion in lipidology 8 28333714
2025 Commander complex regulates lysosomal function and is implicated in Parkinson's disease risk. Science (New York, N.Y.) 7 40209002
2023 COMMD3-Mediated Endosomal Trafficking of HER2 Inhibits the Progression of Ovarian Carcinoma. Molecular cancer research : MCR 5 36445330
2020 Data mining for traffic information. Traffic (Copenhagen, Denmark) 4 31596015
2020 Integrative Analysis of MicroRNAs and mRNAs in LPS-Induced Macrophage Inflammation Based on Adipose Tissue Stem Cell Therapy. Inflammation 4 32955644
2025 Phenotypic screens for SIRPA expression reveal RAB21 as a general regulator of macrophage surface identity. Cell reports 2 40580479
2025 Ritscher-Schinzel syndrome can be characterized as an endosomal recyclinopathy. Science translational medicine 2 40601774
2025 CCDC22 mutations that impair COMMD binding cause attenuated 3C/Ritscher-Schinzel syndrome. BMC medical genomics 1 40448120
2024 Genetic variation in CCDC93 is associated with elevated central systolic blood pressure, impaired arterial relaxation, and mitochondrial dysfunction. PLoS genetics 1 39250516
2023 Structural Organization of the Retriever-CCC Endosomal Recycling Complex. bioRxiv : the preprint server for biology 1 37333304
2023 Structural Organization of the Retriever-CCC Endosomal Recycling Complex. Research square 1 37397996
2025 Serum proteomic profiling during the periovulatory period identifies preliminary candidate biomarkers of oocyte maturation in deslorelin-induced ovulation in dogs. PeerJ 0 41112769
2025 The CCC complex directs phagosomal maturation and bactericidal activity in macrophages through PI(3)P regulation. bioRxiv : the preprint server for biology 0 41473320

Missed literature

Know a paper Affinage missed for CCDC93? Flag it for the maintainers and the community.

No submissions yet.