CFAP53

CFAP53 (CCDC11) is a centriolar satellite and microtubule-associated protein that operates at several stages of ciliogenesis and cell division, and its loss-of-function causes autosomal recessive laterality defects (PMID:22577226, PMID:26538025). As a centriolar satellite component it physically associates with core satellite proteins and is required for organizing them, and its depletion blocks both primary and motile ciliogenesis (PMID:26538025). CFAP53 shows cilia-type-specific deployment: it localizes to basal bodies/centriolar satellites at the base of node (9+0) cilia, where it facilitates axonemal transport of the dynein docking factor TTC25 and outer dynein arms, whereas in tracheal (9+2) cilia it distributes along the axoneme and stabilizes dynein binding to microtubules (PMID:25504577, PMID:33347437). Consistent with these roles, CFAP53 is specifically required for rotational motility of Kupffer's vesicle cilia, and its loss randomizes asymmetric gene expression to produce heterotaxy (PMID:25504577, PMID:26531781). At the level of axonemal architecture, CFAP53 promotes microtubule doublet B-tubule assembly by relieving steric hindrance at the A-tubule surface and stabilizing B-tubule docking [PMID:bio_10.1101_2025.08.03.668368]. Beyond cilia, CFAP53 is required for cytokinesis, localizing to the contractile ring alongside RhoA and regulating total RhoA protein levels (PMID:39479942); it is essential for sperm flagellum biogenesis, localizing to the manchette and sperm tail (PMID:34124066); and it facilitates zygotic MTOC formation by enabling γ-tubulin recruitment to the centrosome, with maternal or paternal loss arresting embryos at the first cell cycle (PMID:35980365).

1. 2012 Medium

   Established that CFAP53/CCDC11 loss-of-function is a genetic cause of human laterality defects, linking the gene to left-right axis determination before any molecular mechanism was known.

   Evidence Homozygosity mapping in a consanguineous family with protein analysis in patient fibroblasts

   PMID:22577226

   Open questions at the time

   • No subcellular localization or molecular partner identified
   • Mechanism connecting truncation to laterality defect unresolved
2. 2015 High

   Defined CFAP53 as a centriolar satellite protein required for ciliogenesis, providing the first subcellular and interaction context for its function.

   Evidence Reciprocal Co-IP with satellite proteins, immunofluorescence, and loss-of-function in human tracheal cells, Xenopus, and zebrafish

   PMID:26538025

   Open questions at the time

   • Which axonemal cargoes depend on satellite function not yet defined
   • Distinction between primary and motile cilia roles not mechanistically separated
3. 2015 High

   Showed cilia-type-specific localization (axonemal in respiratory cilia, basal-body restricted in the laterality organ) explaining why loss preferentially impairs Kupffer's vesicle motility and produces heterotaxy.

   Evidence Tissue immunofluorescence, high-speed cilia motility imaging, CRISPR/Cas9 zebrafish mutants, and in situ hybridization for asymmetric markers

   PMID:25504577 PMID:26531781

   Open questions at the time

   • Molecular basis of differential localization between cilia types unknown
   • Did not identify the transported axonemal components
4. 2017 Medium

   Placed CFAP53 downstream of the ciliogenic transcription factor FoxJ1 and documented its centriolar and actin-cytoskeleton localization, positioning it within the left-right patterning program.

   Evidence Immunofluorescence in patient cells plus gain- and loss-of-function epistasis in Xenopus

   PMID:28621423

   Open questions at the time

   • Functional significance of actin-cytoskeleton localization unresolved
   • Mechanism of FoxJ1-dependent regulation not defined
5. 2020 High

   Resolved the cilia-type-specific mechanism: CFAP53 transports TTC25 and outer dynein arms into node cilia via its basal pool while stabilizing dynein-microtubule binding along 9+2 axonemes.

   Evidence Cfap53 knockout mouse with reciprocal Co-IP (dyneins, TTC25, microtubules), immunofluorescence, TEM, and cilia beat analysis

   PMID:33347437

   Open questions at the time

   • Direct transport machinery linking CFAP53 to TTC25/dynein delivery not identified
   • Structural basis of dynein-microtubule stabilization unknown
6. 2021 High

   Extended CFAP53 function to sperm flagellum biogenesis, demonstrating an axoneme-assembly role distinct from its centriolar satellite activity.

   Evidence Cfap53 knockout mouse with manchette/sperm-tail immunofluorescence, Co-IP of interacting proteins, and fertility assays

   PMID:34124066

   Open questions at the time

   • Identities and roles of the manchette partners not fully characterized
   • Whether flagellar defect uses the same dynein-transport mechanism as node cilia unclear
7. 2022 High

   Revealed a non-ciliary role in zygotic MTOC assembly, showing CFAP53 enables γ-tubulin recruitment to the centrosome and is required maternally and paternally for the first cell cycle.

   Evidence Zebrafish maternal/paternal mutants with live imaging and γ-tubulin colocalization studies

   PMID:35980365

   Open questions at the time

   • Mechanism by which CFAP53 recruits γ-tubulin unresolved
   • Whether centriolar satellite function underlies the MTOC role not established
8. 2024 High

   Identified a cytokinesis requirement, with CFAP53 at the contractile ring regulating RhoA protein levels, providing an alternative route to laterality defects via multiciliation in LRO cells.

   Evidence Xenopus morpholino depletion with contractile-ring immunofluorescence, RhoA Western quantification, Co-IP, and division assays

   PMID:39479942

   Open questions at the time

   • Whether CFAP53 directly binds RhoA or acts indirectly not resolved
   • Mechanism by which RhoA levels are controlled unknown
9. 2025 High

   Demonstrated biochemical sufficiency of CFAP53 to build microtubule doublet B-tubules, defining a direct structural role in axoneme architecture.

   Evidence In vitro reconstitution with recombinant FAP53 and tubulin, molecular dynamics simulations, HeLa co-expression with CFAP20, and C. elegans neuronal overexpression (preprint)

   PMID:bio_10.1101_2025.08.03.668368

   Open questions at the time

   • Preprint, not yet peer-reviewed
   • Relationship between B-tubule nucleation and dynein-transport roles in vivo not integrated
10. 2025 Low

    Expanded the disease allelic spectrum by identifying splicing and predicted interaction-disrupting CFAP53 mutations in patients.

    Evidence Whole-exome sequencing, minigene splicing assay, and in silico CFAP53–TTC25 interaction prediction

    PMID:39969775

    Open questions at the time

    • TTC25 interaction disruption is in silico only with no protein-level validation
    • Functional consequence of the variants not tested in cells

• How CFAP53's distinct activities—centriolar satellite organization, axonemal dynein transport, B-tubule nucleation, RhoA-dependent cytokinesis, and γ-tubulin recruitment—are coordinated by a single protein remains unresolved.
• No structural model unifying microtubule binding, dynein interaction, and B-tubule docking
• Domain mapping of the multiple interaction surfaces not reported
• Direct versus indirect nature of RhoA and γ-tubulin regulation undetermined