UniProt: Q8I7G4 (TTC30_CAEEL) · WormBase: WBGene00001117 / F54C1.5 · Gene: dyf-1
("abnormal dye filling protein 1"). Member of the CAEEL_CILIOPATHY / IFT flagship
project (anterograde IFT-B).
Automated deep research did not complete for this gene. just deep-research-falcon worm dyf-1
--fallback perplexity-lite ran but both providers failed: falcon (Edison) timed out
after 600 s ("Verbose Edison response has no answer. Status: in progress"), and the
perplexity-lite fallback returned HTTP 401 – insufficient_quota ("You exceeded your current
quota"). No -deep-research-*.md file was generated, and none was fabricated. This review is
therefore grounded directly in the UniProt entry, the GOA table, and the cached primary
publications (PMID:16049494, PMID:28479320, PMID:22922713, PMID:17761526, PMID:15916950), with
every supporting_text verbatim-verified against those cached publications.
DYF-1 is a ~656-aa tetratricopeptide-repeat (TPR) protein (9 TPR repeats; TTC30/DYF-1/fleer
family; ortholog of human TTC30A/TTC30B and the algal/ciliate IFT70/FAP259) that is a subunit
of intraflagellar transport (IFT) complex B (IFT-B). It is expressed specifically in ciliated
sensory neurons and localizes to the ciliary base (basal body), the axoneme (axonemal
microtubules), and undergoes IFT along the cilium. Its best-defined role is as an obligatory
activator/adaptor for the homodimeric kinesin-2 motor OSM-3 (KIF17 ortholog): DYF-1 is
specifically required for OSM-3 to dock onto and move IFT particles. In dyf-1 mutants OSM-3
is inactive, IFT particles are carried by heterotrimeric kinesin-II alone, the distal singlet
segments of the amphid/phasmid cilia are not built, and the animals are dye-filling defective
(Dyf). DYF-1/IFT70 is also required for tubulin polyglutamylation of the ciliary axoneme in
sensory neurons.
The defining C. elegans finding (Ou et al. 2005, Nature): the amphid/phasmid channel cilia are
built by two anterograde IFT motors — heterotrimeric kinesin-II (builds the middle doublet
segment) and homodimeric OSM-3 (extends the distal singlet segment) — which normally move the
same IFT particles cooperatively. DYF-1 is the factor that couples OSM-3 to the IFT train:
The same study established DYF-1's ciliary localization and IFT behavior (basis of the
axonemal-microtubule / cilium IDA localization annotations). UniProt FUNCTION synthesizes:
"Specifically required for the kinesin osm-3 to dock onto and move the IFT particles which
contain these precursors." [file:worm/dyf-1/dyf-1-uniprot.txt].
DYF-1 is a bona fide IFT complex B subunit, identified biochemically by mass spectrometry:
- UniProt SUBUNIT: "Component of the IFT complex B composed of at least che-2, che-13, dyf-1,
dyf-3, dyf-6, dyf-11, dyf-13, ift-20, ift-74, ift-81, ifta-2, osm-1, osm-5 and osm-6."
[file:worm/dyf-1/dyf-1-uniprot.txt]; ComplexPortal CPX-1290 (IFT complex B).
- Yi et al. 2017 (Curr Biol) identified DYF-1 in IFT-B by mass spectrometry and showed IFT-B is
required for ciliary entry of the retrograde motor dynein-2:
PMID:28479320. This is the NAS source (ComplexPortal)
for the cilium / IFT particle B / intraciliary transport / cilium-assembly annotations.
As an IFT-B subunit DYF-1 localizes to the ciliary basal body (docking/loading zone) — IDA
localization to GO:0036064 ciliary basal body is from PMID:22922713 (a C. elegans IFT study).
The DYF-1/fleer family is required for cilia tubulin polyglutamylation, shown in zebrafish and
confirmed directly in C. elegans dyf-1:
- PMID:17761526
- PMID:17761526
- Loss is accompanied by B-tubule ultrastructural defects PMID:17761526.
Note: the GOA protein polyglutamylation (GO:0018095) IMP annotation is attributed to
PMID:16049494 (Ou 2005), whose abstract is entirely about IFT-motor coordination and does not
itself mention polyglutamylation; the function is definitively established for dyf-1 in
PMID:17761526. Treated as a real but non-core (downstream) role; supporting text drawn from
PMID:17761526.
Molecular mechanism of OSM-3 activation (MF-dark / ontology gap). DYF-1 is genetically
required for OSM-3 to dock onto and move IFT particles, but the biochemical activity is
undefined: does DYF-1 bind OSM-3 directly, relieve OSM-3 autoinhibition, or bridge OSM-3 to
the IFT-B core? No GO molecular-function term expresses "kinesin-2 docking/activation factor";
the only informative MF available is intraciliary transport particle B binding (GO:0120170),
which captures IFT-B membership, not the OSM-3-activation activity.
Provenance: PMID:16049494 — establishes requirement, never a
biochemical activity/interaction.
Cause vs consequence of the polyglutamylation defect. Whether DYF-1/IFT70 promotes tubulin
polyglutamylation directly (e.g. by IFT-dependent delivery of a TTLL glutamylase or its
substrate) or indirectly (as a downstream consequence of the B-tubule/axoneme structural
defect) is unresolved. The zebrafish study frames flr as a "novel modulator of tubulin
polyglutamylation" PMID:17761526 without a molecular mechanism, and did not distinguish
these possibilities.
protein localization to plasma membrane (GO:0072659) evidence. The basis of this IMP
annotation (cited to PMID:16049494, abstract-only in our cache) cannot be verified from the
available text; the abstract concerns IFT-motor coordination, not membrane-protein
localization. Which ciliary/plasma-membrane cargo protein (if any) mislocalizes in dyf-1 is
not established from the accessible evidence.