DNAAF1 (AGAP009594) is the Anopheles gambiae ortholog of human DNAAF1 (formerly LRRC50) and Chlamydomonas ODA7. It is a cytoplasmic leucine-rich repeat protein that functions as a dynein arm assembly factor, required for the preassembly of both outer dynein arm (ODA) and inner dynein arm (IDA) complexes in the cytoplasm before their transport into the ciliary/flagellar axoneme. The protein operates as part of a chaperone complex with the AAA+ ATPases RUVBL1/RUVBL2 (Pontin/Reptin) and couples dynein assembly to intraflagellar transport via interaction with IFT88. Loss of function in orthologs across zebrafish, human, and Chlamydomonas results in absence of both ODA and IDA from axonemes, immotile cilia/flagella, and primary ciliary dyskinesia. In Anopheles gambiae, DNAAF1 is predicted to be essential for sperm flagellar motility and potentially chordotonal organ function. All GO annotations are inferred from orthologs by sequence similarity or phylogenetic inference.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0070840 dynein complex binding | ISS GO_REF:0000024 | ACCEPT | Summary: Correct annotation. DNAAF1/LRRC50/ODA7 binds dynein complexes as its core molecular function. The Chlamydomonas ortholog ODA7 interacts with both outer row dynein and I1 inner row dynein. This binding is required for cytoplasmic preassembly of dynein arm complexes. Supporting Evidence: PMID:17194703 Oda7 participates in a previously uncharacterized structural link between inner and outer row dyneins file:ANOGA/DNAAF1/DNAAF1-deep-research-bioreason-sft.md The BioReason report identifies IPR050576 (Ciliary and flagellar integrity-associated protein family) covering the entire protein, consistent with ciliary function |
| GO:0070840 dynein complex binding | IBA GO_REF:0000033 | ACCEPT | Summary: Redundant with the ISS annotation above. Both correctly capture the core molecular function of dynein complex binding. Supporting Evidence: PMID:17194703 Oda7 participates in a previously uncharacterized structural link between inner and outer row dyneins |
| GO:0007368 determination of left/right symmetry | IBA GO_REF:0000033 | KEEP AS NON CORE | Summary: This annotation reflects the role of DNAAF1 in left-right axis determination, which depends on motile cilia at the embryonic node. DNAAF1 mutations in humans cause situs inversus and congenital heart defects through loss of nodal ciliary motility. However, determination of left/right symmetry is a vertebrate-specific process involving nodal cilia, and its applicability to Anopheles gambiae is questionable since insects do not use nodal cilia for left-right patterning. This IBA annotation may be an over-extension of vertebrate biology to an insect. Reason: Left-right symmetry determination via nodal cilia is a vertebrate mechanism. While the IBA annotation from phylogenetic inference is technically valid, this process is unlikely to occur in Anopheles gambiae which does not have vertebrate-style nodal cilia. Kept as non-core rather than removed because the phylogenetic inference is methodologically sound even if the biological relevance to this species is uncertain. Supporting Evidence: PMID:29228333 DNAAF1-RUVBL1 biochemical and genetic interactions have a novel functional role in symmetry breaking and cardiac development |
| GO:0035082 axoneme assembly | IBA GO_REF:0000033 | ACCEPT | Summary: Correct and core annotation. DNAAF1 is directly required for axoneme assembly through its role in preassembling dynein arm complexes in the cytoplasm. Loss of DNAAF1 orthologs results in axonemes lacking both outer and inner dynein arms. Supporting Evidence: PMID:19944400 combined defect involving assembly of the ODAs and IDAs |
| GO:0060271 cilium assembly | ISS GO_REF:0000024 | KEEP AS NON CORE | Summary: Appropriate annotation. DNAAF1 contributes to cilium assembly by enabling the cytoplasmic preassembly of dynein arm complexes that are then transported into the cilium. However, the more specific term GO:0035082 (axoneme assembly) better captures the precise step at which DNAAF1 acts. DNAAF1 is not involved in ciliogenesis per se (basal body formation, transition zone assembly) but specifically in the assembly of dynein arms that are components of the axoneme. Reason: While cilium assembly is technically correct, DNAAF1 specifically acts at the level of axoneme assembly (dynein arm preassembly). The more specific term GO:0035082 is the core annotation. Cilium assembly is retained as non-core because it is not incorrect, just less precise. Supporting Evidence: PMID:19944405 support a key role for LRRC50, a member of the leucine-rich-repeat superfamily, in cytoplasmic preassembly of dynein arms |
| GO:0005930 axoneme | IBA GO_REF:0000033 | KEEP AS NON CORE | Summary: The Chlamydomonas ortholog ODA7 is found associated with the axoneme where it forms a structural link between inner and outer dynein arms. However, DNAAF1 primarily functions in the cytoplasm as an assembly factor. The axonemal localization may reflect the final destination of assembled dynein complexes rather than the primary site of DNAAF1 activity. Reason: DNAAF1 primarily functions in the cytoplasm during dynein arm preassembly. Some axonemal association is documented for the Chlamydomonas ortholog ODA7, but the primary functional site is cytoplasmic. Kept as non-core. Supporting Evidence: PMID:17194703 Oda7 participates in a previously uncharacterized structural link between inner and outer row dyneins |
| GO:0005930 axoneme | ISS GO_REF:0000024 | KEEP AS NON CORE | Summary: Consistent with the IBA annotation above. DNAAF1/ODA7 has been found associated with the axoneme in Chlamydomonas. Reason: The primary site of activity is the cytoplasm, but axonemal localization is documented for the ortholog. Kept as non-core. Supporting Evidence: PMID:17194703 Oda7 participates in a previously uncharacterized structural link between inner and outer row dyneins |
| GO:0005929 cilium | IEA GO_REF:0000044 | KEEP AS NON CORE | Summary: Consistent with the axoneme localization. The cilium is the parent structure containing the axoneme. LRRC50 has been localized to the ciliary structure in zebrafish and human cells. Reason: Correct but less specific than the axoneme annotation. The primary functional site is the cytoplasm. Supporting Evidence: PMID:18385425 Subcellular distribution of human LRRC50-EGFP in MDCK and HEK293T cells is diffusely cytoplasmic and concentrated at the mitotic spindle poles and cilium |
| GO:0005737 cytoplasm | ISS PMID:18385425 LRRC50, a Conserved Ciliary Protein Implicated in Polycystic... | NEW | Summary: DNAAF1 primarily functions in the cytoplasm where it assembles dynein arm complexes before their transport into the cilium. Human LRRC50-EGFP shows diffuse cytoplasmic distribution. This is the primary site of DNAAF1 activity as a dynein arm assembly factor. Reason: The cytoplasmic localization is well-supported and represents the primary functional site of DNAAF1, where dynein arm preassembly occurs. This annotation is important because it distinguishes the assembly site (cytoplasm) from the destination (axoneme/cilium). Supporting Evidence: PMID:18385425 Subcellular distribution of human LRRC50-EGFP in MDCK and HEK293T cells is diffusely cytoplasmic and concentrated at the mitotic spindle poles and cilium |
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Download this section (compressed HTML)Q: Does DNAAF1 in Anopheles gambiae function specifically in sperm flagellar dynein assembly, and does its loss cause male sterility in mosquitoes?
Q: Is the IBA annotation for left-right symmetry determination biologically relevant in insects, or is this a vertebrate-specific function that should not be transferred to Anopheles?
Experiment: CRISPR knockout of AGAP009594 (DNAAF1) in Anopheles gambiae to assess effects on sperm flagellar motility and male fertility.
Experiment: Transmission electron microscopy of sperm flagella in DNAAF1 knockdown mosquitoes to determine whether outer and inner dynein arms are absent from the axoneme, as observed in vertebrate orthologs.
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