CLDN14 review notes

Biological synthesis

CLDN14 is a structural claudin of epithelial tight junctions. Its membrane strands restrict paracellular permeability, and its C-terminal motif recognizes PDZ domains. Human deafness genetics establishes clinical relevance, while mechanistic studies distinguish inner-ear barrier organization from regulated renal claudin composition. One structural molecular-function core covers the performed junctional work. No new annotation is proposed.

The older renal study uses mouse CLDN14 with human CLDN16 and CLDN19. Membrane two-hybrid and extract coimmunoprecipitation show self-association and CLDN16 association under those conditions; transepithelial measurements show reduced cation permeability. This is not a purified human CLDN14 binding or ion-channel assay PMID:22373575. The newer study resolves CLDN14-containing strands, copolymerization with CLDN19 and replacement of CLDN16. In a septuple-claudin knockout MDCKII background, CLDN14 expression restores a restrictive barrier. These observations establish structural participation in assembly. The actual supplement describes synthetic tagged CLDN14 constructs but does not specify their species or accession, so host-cell identity is not used to claim human transgene identity PMID:41325524.

The two studies probe different geometries and expression contexts. The 2012 association model is retained as an actual observation rather than declared false because the 2025 study resolves a different strand arrangement. Native mouse renal observations support changing claudin composition; the tested dynamin perturbation does not exclude every endocytic mechanism. A barrier that restricts permeability is not assigned the selective paracellular channel activity term merely because it regulates flux. Current structural descendants contain no appropriate barrier-specific molecular-function child.

Selected original cochlear Methods and Results distinguish mouse cDNA-derived GFP constructs from endogenous mouse, rat and guinea-pig localization. CLDN14 occupies an apical junctional subdomain and forms parallel strands in COS-7 cells. The native partner across the opposing cell membrane was unresolved; CLDN14 did not recruit the tested catenins in that model PMID:17130295. Human deafness and mouse-loss phenotypes contextualize this structural role without generating additional developmental or hearing-process assertions [PMID:11163249; PMID:12913076]. The authentic 2005 variant abstract reports distinct assembly defects for V85D and G101R, but its full Methods were not recovered PMID:15880785.

Original annotations and source-specific decisions

All 35 original annotation objects remain in their original order, including their evidence, qualifiers, supporting entities and reference identifiers. All eight original reference identity/title pairs remain. No alternative-products list was seeded; the review does not invent one or treat transcript variants as independently tested proteins. The final decisions are eight ACCEPT, 22 MODIFY and five KEEP_AS_NON_CORE.

The three HuRI partner assertions—MAL, CTXN3 and PLLP—have nine exact positive human records across validated, array and prey-pooling two-hybrid configurations. They remain supported, non-core associations under the project policy. A generic term's limited information is not a reason to remove an actual positive interaction. These records do not establish native tissue encounters or transfer a partner's function to CLDN14 PMID:32296183.

Twenty holdup assertions are refined to PDZ-domain binding. All 61 exact records test the CLDN14 terminal peptide, residues 230–239, against identified partner PDZ fragments. The assay uses a biotin-linked peptide and domain preparations of different purification levels; it does not test every full-length protein pair in its native context. Each review retains the specific partner and assayed domain ranges. The refinement follows the actual PDZ-binding definition and target fragment evidence, not a blanket claim that all screen partners are physiological scaffolds PMID:36115835.

The original human localization supplement identifies CLDN14 NM_012130/AAG60052 as ER/PM in HEK293T cells. The ER observation is retained as non-core overexpression localization, while plasma membrane is a core structural compartment. Actual Figure 4 and the exact supplement row were independently inspected PMID:16780588.

The PAINT plasma membrane and tight-junction assertions retain their curated inherited interpretation. Current experimental descendant records and target evidence corroborate those compartments; historical IBD placement, alignment and tree reconstruction were not performed. A short donor list or target self-inclusion is not treated as a failure. Q9Z0S3 is mouse Cldn14. O88552 is mouse Cldn2, a genuine claudin-family donor, not an incorrectly identified ortholog. The latter has direct junctional, calcium-independent adhesion and self-association annotations. Its adhesion paper remains abstract-only; its self-assembly study was read in full selected Methods/Results. Calcium-independent adhesion remains non-core because an equivalent target-specific calcium-dependence assay was not established. Calcium-sensitive expression regulation is a separate phenomenon [PMID:10508613; PMID:10562289].

Assembly citation correction

The original TAS assembly assertion cites PMID:7644498. All five authentic original journal page images, pages 7819–7823, were read, including Methods, Results, Discussion and figures. The paper assays YAP WW-domain recognition of WBP proline-rich ligands. It does not assay CLDN14 or tight-junction assembly. This MISCITED assessment is based on the actual complete original article, not its title or abstract. The original source object is preserved rather than silently redirected.

Independent CLDN14 strand formation supports a MODIFY proposal to bicellular tight junction assembly, GO:0070830 [PMID:17130295; PMID:41325524]. The protein itself polymerizes and contributes the sealing structure. The actual term definition and parents were checked; GO:0070830 is not claimed to be a descendant of the original GO:0065003. Same-role human CLDN1 and CLDN3 carry experimental and inherited assembly assertions, while CLDN19 has no exact current match. Comparator presence is corroboration, not the basis for the proposal. The authenticated GO-CAM index has no target match. This is a replacement of an existing assertion, not a NEW process added from necessity alone.

Evidence and access

The compact source index records actual source identifiers, hashes, locators, interaction features, experimental donor premises and ontology checks. It is provenance, not an independent experiment; file citations carry no self-quoted supporting text. Raw primary responses, complete interaction exports, donor pages and retrieval failures remain in the isolated research packet. Primary quotations are limited to one short barrier-assay anchor in the review, with no repeated quote inventory in this index or notes.

Existing main publication and PANTHER cache bytes are preserved. Genuine new normal caches are selected only for absent paths, with alternative fetched versions retained separately. External full-page access does not rewrite an abstract-only cache. The source index distinguishes cached availability from actual external reading, particularly the complete original 1995 paper and selected original 2006 text. Closed or challenged publisher responses are recorded as failures, not treated as full text.

The genuine default Falcon attempt timed out after 90 seconds. Its actual Perplexity-lite fallback returned HTTP 401 quota failure. No provider-labelled report was manufactured; manual primary research and independent bounded consultations supplied the review. Project completion still requires publication, review and merge.