Pathway Human Homo sapiens

Cargo trafficking to the periciliary membrane

R-HSA-5620920 in Reactome release 97: under Assembly of the 9+0 primary cilium, with 71 genes placed in it by the mapping files and 4 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-5620920 (mouse), R-RNO-5620920 (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-5620920.6
Class: Pathway
Species: Homo sapiens (human)
Inferred: no: a curated human pathway
Disease pathway: no
Released: 2014-12-11
Last updated: 2016-12-21
Events inside: 6, counted from the record

Proteomic studies suggest that the cilium is home to approximately a thousand proteins, and has a unique protein and lipid make up relative to the bulk cytoplasm and plasma membrane (Pazour et al, 2005; Ishikawa et al, 2012; Ostrowoski et al, 2002; reviewed in Emmer et al, 2010; Rohatgi and Snell, 2010). In addition, the cilium is a dynamic structure, and the axoneme is continually being remodeled by addition and removal of tubulin at the distal tip (Marshall and Rosenbaum, 2001; Stephens, 1997; Song et al, 2001). As a result, the function and structure of this organelle relies on the directed trafficking of protein and vesicles to the cilium. Small GTPases of the RAS, RAB, ARF and ARL families are involved in cytoskeletal organization and membrane traffic and are required to regulate the traffic from the Golgi and the trans-Golgi network to the cilium (reviewed in Deretic, 2013; Li et al, 2012). ARF4 is a Golgi-resident GTPase that acts in conjunction with a ciliary-targeting complex consisting of the ARF-GAP ASAP1, RAB11A, the RAB11 effector FIP3 and the RAB8A guanine nucleotide exchange factor RAB3IP/RABIN8 to target cargo bearing a putative C-terminal VxPx targeting motif to the cilium. A well-studied example of this system involves the trafficking of rhodopsin to the retinal rod photoreceptors, a specialized form of the cilium (reviewed in Deretic, 2013). ARL3, ARL13B and ARL6 are all small ARF-like GTPases with assorted roles in ciliary trafficking and maintenance. Studies in C. elegans suggest that ARL3 and ARL13B have opposing roles in maintaining the stability of the anterograde IFT trains in the cilium (Li et al, 2010). In addition, both ARL3 and ARL13B have roles in facilitating the traffic of subsets of ciliary cargo to the cilium. Myristoylated cargo such as peripheral membrane protein Nephrocystin-3 (NPHP3) is targeted to the cilium in a UNC119- and ARL3-dependent manner, while ARL13B is required for the PDE6-dependent ciliary localization of INPP5E (Wright et al, 2011; Humbert et al, 2012; reviewed in Li et al, 2012). ARL6 was also identified as BBS3, a gene that when mutated gives rise to the ciliopathy Bardet-Biedl syndrome (BBS). ARL6 acts upstream of a complex of 8 other BBS-associated proteins known as the BBSome. ARL6 and the BBSome are required for the ciliary targeting of proteins including the melanin concentrating hormone receptor (MCHR) and the somatostatin receptor (SSTR3), among others (Nachury et al, 2007; Loktev et al, 2008; Jin et al, 2010; Zhang et al, 2011). Both the BBSome and ARL6 may continue to be associated with cargo inside the cilium, as they are observed to undergo typical IFT movements along the axoneme (Fan et al, 2004; Lechtreck et al, 2009; reviewed in Li et al, 2012).

Literature Reactome attaches

Proteomic analysis of a eukaryotic ciliumJ. Cell Biol., 2005, vol. 170, p. 103-13PubMed 15998802
Proteomic analysis of mammalian primary ciliaCurr. Biol., 2012, vol. 22, p. 414-9PubMed 22326026
A proteomic analysis of human cilia: identification of novel componentsMol. Cell Proteomics, 2002, vol. 1, p. 451-65PubMed 12169685
Molecular mechanisms of protein and lipid targeting to ciliary membranesJ. Cell. Sci., 2010, vol. 123, p. 529-36PubMed 20145001
The ciliary membraneCurr. Opin. Cell Biol., 2010, vol. 22, p. 541-6PubMed 20399632
Intraflagellar transport balances continuous turnover of outer doublet microtubules: implications for flagellar length controlJ. Cell Biol., 2001, vol. 155, p. 405-14PubMed 11684707
Synthesis and turnover of embryonic sea urchin ciliary proteins during selective inhibition of tubulin synthesis and assemblyMol. Biol. Cell, 1997, vol. 8, p. 2187-98PubMed 9362062

Reactome's record lists 14 orthologous events, R-MMU-5620920 (Mus musculus), R-RNO-5620920 (Rattus norvegicus) among the species this site serves, and 12 in species this site opens no page for.

Reactome ContentService, this pathway's record · Reactome v97 · read 2026-10-01 ET · Reactome pathway browser"Cargo trafficking to the periciliary membrane". Reactome, release 97, https://reactome.org/PathwayBrowser/#/R-HSA-5620920 with StableID: R-HSA-5620920.6 (accessed 2026-10-01 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 71 genes in this human pathway; showing 1 to 71, in pages of 100, sorted by symbol for reading. The order carries no ranking.

Genes Reactome places in this human pathway, page 1 of 1
Gene	Authority id	Mapping file id	Evidence codes
GeneARF4	AuthorityHGNC:655	Mapping file id378 NCBI file	EvidenceIEA, TAS
GeneARL13B	AuthorityHGNC:25419	Mapping file id200894 NCBI file	EvidenceTAS
GeneARL3	AuthorityHGNC:694	Mapping file id403 NCBI file	EvidenceTAS
GeneARL6	AuthorityHGNC:13210	Mapping file id84100 NCBI file	EvidenceTAS
GeneASAP1	AuthorityHGNC:2720	Mapping file id50807 NCBI file	EvidenceIEA, TAS
GeneATAT1	AuthorityHGNC:21186	Mapping file id79969 NCBI file	EvidenceTAS
GeneBBIP1	AuthorityHGNC:28093	Mapping file id92482 NCBI file	EvidenceTAS
GeneBBS1	AuthorityHGNC:966	Mapping file id582 NCBI file	EvidenceTAS
GeneBBS10	AuthorityHGNC:26291	Mapping file id79738 NCBI file	EvidenceTAS
GeneBBS12	AuthorityHGNC:26648	Mapping file id166379 NCBI file	EvidenceTAS
GeneBBS2	AuthorityHGNC:967	Mapping file id583 NCBI file	EvidenceTAS
GeneBBS4	AuthorityHGNC:969	Mapping file id585 NCBI file	EvidenceTAS
GeneBBS5	AuthorityHGNC:970	Mapping file id129880 NCBI file	EvidenceTAS
GeneBBS7	AuthorityHGNC:18758	Mapping file id55212 NCBI file	EvidenceTAS
GeneBBS9	AuthorityHGNC:30000	Mapping file id27241 NCBI file	EvidenceTAS
GeneCCT2	AuthorityHGNC:1615	Mapping file id10576 NCBI file	EvidenceTAS
GeneCCT3	AuthorityHGNC:1616	Mapping file id7203 NCBI file	EvidenceTAS
GeneCCT4	AuthorityHGNC:1617	Mapping file id10575 NCBI file	EvidenceTAS
GeneCCT5	AuthorityHGNC:1618	Mapping file id22948 NCBI file	EvidenceTAS
GeneCCT8	AuthorityHGNC:1623	Mapping file id10694 NCBI file	EvidenceTAS
GeneCNGA2	AuthorityHGNC:2149	Mapping file id1260 NCBI file	EvidenceIEA, TAS
GeneCNGA4	AuthorityHGNC:2152	Mapping file id1262 NCBI file	EvidenceIEA, TAS
GeneCNGB1	AuthorityHGNC:2151	Mapping file id1258 NCBI file	EvidenceIEA, TAS
GeneCYS1	AuthorityHGNC:18525	Mapping file id192668 NCBI file	EvidenceTAS
GeneEXOC1	AuthorityHGNC:30380	Mapping file id55763 NCBI file	EvidenceTAS
GeneEXOC2	AuthorityHGNC:24968	Mapping file id55770 NCBI file	EvidenceTAS
GeneEXOC3	AuthorityHGNC:30378	Mapping file id11336 NCBI file	EvidenceTAS
GeneEXOC4	AuthorityHGNC:30389	Mapping file id60412 NCBI file	EvidenceTAS
GeneEXOC5	AuthorityHGNC:10696	Mapping file id10640 NCBI file	EvidenceTAS
GeneEXOC6	AuthorityHGNC:23196	Mapping file id54536 NCBI file	EvidenceTAS
GeneEXOC7	AuthorityHGNC:23214	Mapping file id23265 NCBI file	EvidenceTAS
GeneEXOC8	AuthorityHGNC:24659	Mapping file id149371 NCBI file	EvidenceTAS
GeneGBF1	AuthorityHGNC:4181	Mapping file id8729 NCBI file	EvidenceTAS
GeneHDAC6	AuthorityHGNC:14064	Mapping file id10013 NCBI file	EvidenceTAS
GeneINPP5E	AuthorityHGNC:21474	Mapping file id56623 NCBI file	EvidenceTAS
GeneLZTFL1	AuthorityHGNC:6741	Mapping file id54585 NCBI file	EvidenceTAS
GeneMCHR1	AuthorityHGNC:4479	Mapping file id2847 NCBI file	EvidenceTAS
GeneMKKS	AuthorityHGNC:7108	Mapping file id8195 NCBI file	EvidenceTAS
GeneNPHP3	AuthorityHGNC:7907	Mapping file id27031 NCBI file	EvidenceTAS
GenePDE6D	AuthorityHGNC:8788	Mapping file id5147 NCBI file	EvidenceTAS
GenePKD1	AuthorityHGNC:9008	Mapping file id5310 NCBI file	EvidenceIEA, TAS
GenePKD2	AuthorityHGNC:9009	Mapping file id5311 NCBI file	EvidenceIEA, TAS
GeneRAB11A	AuthorityHGNC:9760	Mapping file id8766 NCBI file	EvidenceTAS
GeneRAB11FIP3	AuthorityHGNC:17224	Mapping file id9727 NCBI file	EvidenceTAS
GeneRAB3IP	AuthorityHGNC:16508	Mapping file id117177 NCBI file	EvidenceTAS
GeneRAB8A	AuthorityHGNC:7007	Mapping file id4218 NCBI file	EvidenceTAS
GeneRHO	AuthorityHGNC:10012	Mapping file id6010 NCBI file	EvidenceIEA, TAS
GeneRP2	AuthorityHGNC:10274	Mapping file id6102 NCBI file	EvidenceTAS
GeneSMO	AuthorityHGNC:11119	Mapping file id6608 NCBI file	EvidenceTAS
GeneSSTR3	AuthorityHGNC:11332	Mapping file id6753 NCBI file	EvidenceTAS
GeneTCP1	AuthorityHGNC:11655	Mapping file id6950 NCBI file	EvidenceTAS
GeneTTC8	AuthorityHGNC:20087	Mapping file id123016 NCBI file	EvidenceTAS
GeneTUBA1A	AuthorityHGNC:20766	Mapping file id7846 NCBI file	EvidenceTAS
GeneTUBA1B	AuthorityHGNC:18809	Mapping file id10376 NCBI file	EvidenceTAS
GeneTUBA1C	AuthorityHGNC:20768	Mapping file id84790 NCBI file	EvidenceTAS
GeneTUBA3C	AuthorityHGNC:12408	Mapping file id7278 NCBI file	EvidenceTAS
GeneTUBA3D	AuthorityHGNC:24071	Mapping file id113457 NCBI file	EvidenceTAS
GeneTUBA3E	AuthorityHGNC:20765	Mapping file id112714 NCBI file	EvidenceTAS
GeneTUBA4A	AuthorityHGNC:12407	Mapping file id7277 NCBI file	EvidenceTAS
GeneTUBA8	AuthorityHGNC:12410	Mapping file id51807 NCBI file	EvidenceTAS
GeneTUBAL3	AuthorityHGNC:23534	Mapping file id79861 NCBI file	EvidenceTAS
GeneTUBB1	AuthorityHGNC:16257	Mapping file id81027 NCBI file	EvidenceTAS
GeneTUBB2A	AuthorityHGNC:12412	Mapping file id7280 NCBI file	EvidenceTAS
GeneTUBB2B	AuthorityHGNC:30829	Mapping file id347733 NCBI file	EvidenceTAS
GeneTUBB3	AuthorityHGNC:20772	Mapping file id10381 NCBI file	EvidenceTAS
GeneTUBB4A	AuthorityHGNC:20774	Mapping file id10382 NCBI file	EvidenceTAS
GeneTUBB4B	AuthorityHGNC:20771	Mapping file id10383 NCBI file	EvidenceTAS
GeneTUBB6	AuthorityHGNC:20776	Mapping file id84617 NCBI file	EvidenceTAS
GeneTUBB8	AuthorityHGNC:20773	Mapping file id347688 NCBI file	EvidenceTAS
GeneTUBB8B	AuthorityHGNC:24983	Mapping file id260334 NCBI file	EvidenceTAS
GeneUNC119B	AuthorityHGNC:16488	Mapping file id84747 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

Assembly of the 9+0 primary ciliumR-HSA-9975921201 genes

Children

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.