Pathway Human Homo sapiens

Tight junction interactions

R-HSA-420029 in Reactome release 97: under Cell-cell junction organization, with 31 genes placed in it by the mapping files and 0 child pathways in the hierarchy.

The same number in the other species

Reactome writes the mouse and rat events it infers from a human pathway under the human number with the species token. A door opens only where that species' own list in this release holds the id: R-MMU-420029 (mouse), R-RNO-420029 (rat). Whether the event was inferred from this one is what the record says.

The record
The genes
Parents and children

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This page reads the pathway's record from its source while you read the rest; with scripts off the card stays at its loading line. Reload with scripts on to see it, or open the source's own page from the link in the card.

01The record

Reactome's own record of this pathway

What this tells you

The pathway list, the hierarchy and the genes on this page are read from the files Reactome publishes for Reactome release 97, built into this site on 2026-09-09: the pathway list, the hierarchy relationship file and the two gene mapping files. The record card is the one live read, Reactome's own record of this pathway.

Reactome's download page describes the mapping files: Mapping files link the source database identifier to the lowest level pathway diagram or subset of the pathway, all levels of the pathway hierarchy or database identifier to all reactions. [R13] The gene list here is the all-levels mapping of NCBI Gene ids, filled from the all-levels mapping of Ensembl ids where the NCBI file has no row for a gene; each row names which file it came from by the shape of its source id. Each row carries the evidence codes the file writes for it, as written and unranked, and both where the file writes both; no page of Reactome's documentation the survey read defines the codes, so this page does not expand them. A gene id the identity files do not name is kept as the source's own id with no door rather than turned into a symbol.

On citing what a search finds, Reactome says: It should be remembered that while we strive to contain the most current and accurate data, Reactome should not be used in citations where other primary sources of information are available. [R12] The record card prints the literature Reactome attaches to a curated pathway for that reason. The data are public domain: All data in the Reactome database and files derived from that data are licensed under the Creative Commons Public Domain Dedication (CC0). User may copy, modify, and distribute these data, even for commercial purposes, without asking for permission. Attribution is encouraged but not required. [R10] The pathway illustrations are licensed apart, under CC BY 4.0, and none is shown here.

A gene on this list is one Reactome places in this pathway in this release, and that is all the row says: it does not say the gene is expressed in a tissue or associated with a disease, which are the other two explorers' questions, read from other sources. Reactome's papers of record are [R01] [R02].

[R01] Ragueneau E, Gong C, Sinquin P, Sevilla C, Beavers D, Grentner A, et al. (2026). The Reactome Knowledgebase 2026. Nucleic Acids Research 54:D673-D681. PMID 41251150, doi 10.1093/nar/gkaf1223.
[R02] Milacic M, Beavers D, Conley P, Gong C, Gillespie M, Griss J, et al. (2024). The Reactome Pathway Knowledgebase 2024. Nucleic Acids Research 52:D672-D678. PMID 37941124, doi 10.1093/nar/gkad1025.
[R10] Reactome, reactome.org. License Agreement. https://reactome.org/license, read 2026-09-09.
[R12] Reactome, reactome.org. Citing us. https://reactome.org/cite, read 2026-09-09.
[R13] Reactome, reactome.org. Download. https://reactome.org/download-data, read 2026-09-09.

Stable id: R-HSA-420029.3
Class: Pathway
Species: Homo sapiens (human)
Inferred: no: a curated human pathway
Disease pathway: no
Released: 2009-09-30
Last updated: 2022-04-07
Events inside: 3, counted from the record

Tight junctions (TJs) are the most apical component of the epithelial junctional complex forming a belt-like structure at the cellular junction. When visualized by freeze-fracture electron microscopy they appear as a branched network of intramembrane strands that correspond to the sites of direct membrane contacts and that are composed of the integral membrane claudin proteins. The TJs act as a primary barrier to the diffusion of solutes through the paracellular space (barrier function) (Tsukita et al., 2001). They also prevent the intermixing of intramembrane proteins and lipids and thus create a boundary between the apical and the basolateral membrane domains of polarized epithelial cells (fence function) (Tsukita et al., 2001). Interestingly, the fence function seems not to depend on TJ strands (Umeda et al., 2006). Recents evidence indicates that the TJs also participate in signal transduction mechanisms which regulate cell proliferation and morphogenesis (Matter and Balda, 2003; Matter and Balda, 2007). This module describes the major molecular interactions responsible for the formation of TJ strands and for the rectruitment of the PAR-3-PKC-PAR-6 and CRB3-Pals1-PATJ complexes that function in tight junction formation (Ebnet, 2008).

Literature Reactome attaches

Organization of multiprotein complexes at cell-cell junctionsHistochem Cell Biol, 2008, vol. 130, p. 1-20PubMed 18365233
Signalling to and from tight junctionsNat Rev Mol Cell Biol, 2003, vol. 4, p. 225-36PubMed 12612641
Epithelial tight junctions, gene expression and nucleo-junctional interplayJ Cell Sci, 2007, vol. 120, p. 1505-11PubMed 17452622
Multifunctional strands in tight junctionsNat Rev Mol Cell Biol, 2001, vol. 2, p. 285-93PubMed 11283726
ZO-1 and ZO-2 independently determine where claudins are polymerized in tight-junction strand formationCell, 2006, vol. 126, p. 741-54PubMed 16923393

Reactome's record lists 7 orthologous events, R-MMU-420029 (Mus musculus), R-RNO-420029 (Rattus norvegicus) among the species this site serves, and 5 in species this site opens no page for.

Reactome ContentService, this pathway's record · Reactome v97 · read 2026-10-05 ET · Reactome pathway browser"Tight junction interactions". Reactome, release 97, https://reactome.org/PathwayBrowser/#/R-HSA-420029 with StableID: R-HSA-420029.3 (accessed 2026-10-05 ET). Reactome version 97 (CC0).

Reading this pathway's record from Reactome (the pathway record).Still reading. A first read of a pathway can take a while; this page waits up to 35 seconds for it, and its scripts then bring in the panel, or a line saying what did not arrive.

02The genes

Genes Reactome places in this human pathway

The mapping files place 31 genes in this human pathway; showing 1 to 31, in pages of 100, sorted by symbol for reading. The order carries no ranking. 1 of the rows shown carries an id the identity file does not name, kept as the source wrote it.

Genes Reactome places in this human pathway, page 1 of 1
Gene	Authority id	Mapping file id	Evidence codes
GeneCLDN1	AuthorityHGNC:2032	Mapping file id9076 NCBI file	EvidenceIEA
GeneCLDN10	AuthorityHGNC:2033	Mapping file id9071 NCBI file	EvidenceIEA
GeneCLDN11	AuthorityHGNC:8514	Mapping file id5010 NCBI file	EvidenceIEA
GeneCLDN12	AuthorityHGNC:2034	Mapping file id9069 NCBI file	EvidenceIEA
GeneCLDN14	AuthorityHGNC:2035	Mapping file id23562 NCBI file	EvidenceIEA
GeneCLDN15	AuthorityHGNC:2036	Mapping file id24146 NCBI file	EvidenceIEA
GeneCLDN16	AuthorityHGNC:2037	Mapping file id10686 NCBI file	EvidenceIEA
GeneCLDN17	AuthorityHGNC:2038	Mapping file id26285 NCBI file	EvidenceIEA
GeneCLDN18	AuthorityHGNC:2039	Mapping file id51208 NCBI file	EvidenceIEA
GeneCLDN19	AuthorityHGNC:2040	Mapping file id149461 NCBI file	EvidenceIEA
GeneCLDN2	AuthorityHGNC:2041	Mapping file id9075 NCBI file	EvidenceIEA
GeneCLDN20	AuthorityHGNC:2042	Mapping file id49861 NCBI file	EvidenceIEA
GeneCLDN22	AuthorityHGNC:2044	Mapping file id53842 NCBI file	EvidenceIEA
GeneCLDN23	AuthorityHGNC:17591	Mapping file id137075 NCBI file	EvidenceIEA
GeneCLDN3	AuthorityHGNC:2045	Mapping file id1365 NCBI file	EvidenceIEA
GeneCLDN4	AuthorityHGNC:2046	Mapping file id1364 NCBI file	EvidenceIEA
GeneCLDN5	AuthorityHGNC:2047	Mapping file id7122 NCBI file	EvidenceIEA
GeneCLDN6	AuthorityHGNC:2048	Mapping file id9074 NCBI file	EvidenceIEA
GeneCLDN7	AuthorityHGNC:2049	Mapping file id1366 NCBI file	EvidenceIEA
GeneCLDN8	AuthorityHGNC:2050	Mapping file id9073 NCBI file	EvidenceIEA
GeneCLDN9	AuthorityHGNC:2051	Mapping file id9080 NCBI file	EvidenceIEA
GeneCRB3	AuthorityHGNC:20237	Mapping file id92359 NCBI file	EvidenceTAS
GeneF11R	AuthorityHGNC:14685	Mapping file id50848 NCBI file	EvidenceTAS
GenePALS1	AuthorityHGNC:18669	Mapping file id64398 NCBI file	EvidenceTAS
GenePARD3	AuthorityHGNC:16051	Mapping file id56288 NCBI file	EvidenceTAS
GenePARD6A	AuthorityHGNC:15943	Mapping file id50855 NCBI file	EvidenceTAS
GenePARD6B	AuthorityHGNC:16245	Mapping file id84612 NCBI file	EvidenceTAS
GenePARD6G	AuthorityHGNC:16076	Mapping file id84552 NCBI file	EvidenceTAS
GenePATJ	AuthorityHGNC:28881	Mapping file id10207 NCBI file	EvidenceTAS
GenePRKCI	AuthorityHGNC:9404	Mapping file id5584 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id43740570 NCBI file	EvidenceTAS

Evidence codes on this page: IEA, TAS, as the mapping file writes them; a row carrying two was written twice by the file, once under each. The mapping file id says which file placed the gene: an NCBI Gene id from NCBI2Reactome_All_Levels.txt, an Ensembl gene id from Ensembl2Reactome_All_Levels.txt. The two files can disagree about a code, so a row's codes are the one file's view. Measured by this site's build over this release on 2026-09-09: of the 138,908 human pathway-gene pairs both files place, 207 (0.149 per cent, over 47 genes) carry TAS in the Ensembl file where the NCBI rows carry IEA alone.

Reactome mapping files, the human rows for this pathway · Reactome release 97 · read 2026-09-09 · Reactome downloads"NCBI2Reactome_All_Levels.txt" and "Ensembl2Reactome_All_Levels.txt", Reactome, release 97, https://reactome.org/download-data/ (date of access 2026-09-09). Data CC0; attribution encouraged.

03The hierarchy

Parents and children in this release's hierarchy

Parents

Cell-cell junction organizationR-HSA-421270301 genes

Children

None: no pathway of this release's list names this one as a parent.

Reactome's hierarchy is a graph rather than a tree: a pathway can sit under more than one parent, and the gene counts are each pathway's own placements at every level under it, so a parent's count is not the sum of its children's.

Reactome, the human pathway list and hierarchy relationship file · Reactome release 97 · read 2026-09-09 · Reactome downloads"ReactomePathways.txt" and "ReactomePathwaysRelation.txt", Reactome, release 97, https://reactome.org/download-data/ (date of access 2026-09-09). Data CC0; attribution encouraged.