DRC1 is a structural subunit of the nexin-dynein regulatory complex (N-DRC), which couples neighboring axonemal doublets and coordinates dynein-driven bending. The integrated core combines scaffold activity, axoneme assembly and regulation of cilium movement. Its structural contribution does not imply autonomous dynein ATPase or motor activity. The source guide provides original-paper links, specific assay locations and access limits.
PMID:23354437(https://pubmed.ncbi.nlm.nih.gov/23354437/) combines human respiratory cilia with algal DRC1/pf3 experiments. Human cilia lose N-DRC links and associated GAS8/LRRC48 signal, show reduced bending amplitude and altered beating, yet retain DNALI1/CCDC39 and apparently normal gross dynein arms. Algal mutants lose selected inner-arm components and the associated calmodulin/spoke complex. The human result is not wholesale motor-arm loss, and the algal result is positive assembly evidence rather than merely a nonspecific motility phenotype.
PMID:34169321(https://pubmed.ncbi.nlm.nih.gov/34169321/) supports human male infertility with abnormal sperm flagella and a mouse structural-stability phenotype. Mouse spermatid axonemes initially assemble and subsequently become disorganized; mature sperm have severe N-DRC, radial-spoke and dynein defects. Respiratory cilia retain the gross 9+2, radial-spoke and dynein arrangements despite abnormal length and beating. These observations explain why the consequences of DRC1 loss depend on cell type and developmental stage.
PMID:37258679(https://pubmed.ncbi.nlm.nih.gov/37258679/) resolves detailed N-DRC scaffold architecture in algae and identifies the corresponding human components in respiratory ALI axonemes using cryo-EM density and predicted homologous subcomplexes. Human Supplementary Table 3 lists DRC1/Q96MC2 and DRC2, DRC3, DRC4 and DRC5. Its explicit uncertainty about human IDAe docking is retained. It neither contradicts the conserved assembly contribution nor establishes every human contact at the same resolution as the algal structure.
The existing three axonemal-dynein-assembly assertions are retained with these limits. Structural participation and the original selective algal assembly phenotype support the conserved role; preserved gross human arms do not establish a target-specific loss of that contribution. Complex membership is a different question: the N-DRC scaffold belongs to the axonemal nexin link, not to the force-generating dynein motor complex. The InterPro-derived membership assertion is therefore refined accordingly.
The controlled HA-DRC1/Flag-DRC2, DRC3, DRC4 and DRC5 co-immunoprecipitations in PMID:34169321 support positive association. Each exact human partner is independently identified as an axonemal N-DRC component in the 2023 structural inventory. Their cytoskeletal class supports refinement to cytoskeletal protein binding. This classification does not require a new physiological-pathway claim, nor does it imply purified direct contact or assign scaffold activity to each individual pair.
The original main Methods and genuine supplementary document do not authenticate the species or sequence of the transfected ORFs. HEK293T host identity is not construct identity. The preserved UniProt-curated human partner assertions are evaluated at gene level with that assay limitation; no sequence or isoform is substituted into the source records. The current target-paper IntAct query returned no records, so no unobserved clone identifiers are invented.
The official human Q96MC2 record contains one displayed 740-residue product and no alternative-products block. Clinical truncation variants and engineered mouse alleles are not additional natural isoforms. Available co-IP Methods and primer tables do not establish exact identity to that displayed sequence.
Human respiratory-axoneme placement and human/mouse flagellar evidence support the axonemal core location. HPA metadata additionally report nucleoplasm and primary-cilium transition-zone staining in cultured human cells with one antibody. Those metadata were read without independent image scoring. Broad cilium annotations are retained so an exclusive motile-axoneme replacement does not erase a distinct ciliary context; HPA staining is not assigned an unmeasured structural function.
The mouse Q3USS3 cytosol IDA is traceable to PMID:27914912(https://pubmed.ncbi.nlm.nih.gov/27914912/), but the target-specific localization experiment could not be recovered. The complete abstract does not expose it. Human cytosol transfer remains undecided without alleging a donor error or claiming that DRC1 cannot enter cytosol.
The PTHR21625 alignment reproduces the complete human 740-residue sequence. Four literal IBDs at PTN000492844 join a 19-node path to the human DRC1 leaf; the common ancestor spans DRC1 and DRC2. Donor count and legitimate target experimental grounding are not failures. The separately read original PMID:20876659(https://pmc.ncbi.nlm.nih.gov/articles/PMC2951471/) provides endogenous-locus tagging, fractionation and flagellar propulsion evidence for trypanosome CMF70/Q384U1 on the DRC2 branch. Bovine Q32KY1 identity is preserved without inventing a bovine assay account. Matching ARBA conditions and current InterPro mappings are assessed individually, rather than treated as proof independent of their underlying sources.
All 23 imported assertions retain their source dictionaries and qualifiers: 17 are accepted, five are refined and one remains undecided. No new annotation is proposed. The scaffold molecular function summarizes independent structural evidence even though the imported source set contains no identical molecular-function assertion; that absence alone is not a reason to manufacture a new row.
Genuine configured research-provider attempts failed at authentication and quota checks; no provider report was produced. The assessment uses the cited primary originals, independently read reserved-source consultation, official records and manual source reconciliation. Existing publication caches and their access flags are unchanged. The 2010 donor cache remains abstract-only despite separate original recovery, while the 2017 donor experiment remains unavailable. One short source excerpt appears once in the core; these notes add no quotations.