Pathway Human Homo sapiens

PPARA activates gene expression

R-HSA-1989781 in Reactome release 97: under Regulation of lipid metabolism by PPARalpha, with 117 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; neither of the other two lists holds it. Whether the event was inferred from this one is what the record says.

The record
The genes
Parents and children

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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-1989781.6
Class: Pathway
Species: Homo sapiens (human)
Inferred: no: a curated human pathway
Disease pathway: no
Released: 2011-12-06
Last updated: 2021-09-15
Events inside: 41, counted from the record

The set of genes regulated by PPAR-alpha is not fully known in humans, however many examples have been found in mice. Genes directly activated by PPAR-alpha contain peroxisome proliferator receptor elements (PPREs) in their promoters and include:

1) genes involved in fatty acid oxidation and ketogenesis (Acox1, Cyp4a, Acadm, Hmgcs2);

2) genes involved in fatty acid transport (Cd36, , Slc27a1, Fabp1, Cpt1a, Cpt2);

3) genes involved in producing fatty acids and very low density lipoproteins (Me1, Scd1);

4) genes encoding apolipoproteins (Apoa1, Apoa2, Apoa5);

5) genes involved in triglyceride clearance ( Angptl4);

6) genes involved in glycerol metabolism (Gpd1 in mouse);

7) genes involved in glucose metabolism (Pdk4);

8) genes involved in peroxisome proliferation (Pex11a);

9) genes involved in lipid storage (Plin, Adfp).

Many other genes are known to be regulated by PPAR-alpha but whether their regulation is direct or indirect remains to be found. These genes include: ACACA, FAS, SREBP1, FADS1, DGAT1, ABCA1, PLTP, ABCB4, UGT2B4, SULT2A1, Pnpla2, Acsl1, Slc27a4, many Acot genes, and others (reviewed in Rakhshandehroo et al. 2010).

Literature Reactome attaches

Peroxisome proliferator activated receptors and lipoprotein metabolismPPAR Res, 2008, vol. 2008, p. 132960PubMed 18288277
Peroxisome proliferator-activated receptor alpha target genesCell Mol Life Sci, 2004, vol. 61, p. 393-416PubMed 14999402

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 117 genes in this human pathway; showing 101 to 117, in pages of 100, sorted by symbol for reading. The order carries no ranking.

Genes Reactome places in this human pathway, page 2 of 2
Gene	Authority id	Mapping file id	Evidence codes
GeneRXRA	AuthorityHGNC:10477	Mapping file id6256 NCBI file	EvidenceIEA, TAS
GeneRXRB	AuthorityHGNC:10478	Mapping file id6257 NCBI file	EvidenceTAS
GeneSLC27A1	AuthorityHGNC:10995	Mapping file id376497 NCBI file	EvidenceTAS
GeneSMARCD3	AuthorityHGNC:11108	Mapping file id6604 NCBI file	EvidenceIEA, TAS
GeneSP1	AuthorityHGNC:11205	Mapping file id6667 NCBI file	EvidenceTAS
GeneSREBF1	AuthorityHGNC:11289	Mapping file id6720 NCBI file	EvidenceTAS
GeneSREBF2	AuthorityHGNC:11290	Mapping file id6721 NCBI file	EvidenceTAS
GeneSULT2A1	AuthorityHGNC:11458	Mapping file id6822 NCBI file	EvidenceTAS
GeneTBL1X	AuthorityHGNC:11585	Mapping file id6907 NCBI file	EvidenceIEA, TAS
GeneTBL1XR1	AuthorityHGNC:29529	Mapping file id79718 NCBI file	EvidenceIEA, TAS
GeneTGS1	AuthorityHGNC:17843	Mapping file id96764 NCBI file	EvidenceIEA, TAS
GeneTHRAP3	AuthorityHGNC:22964	Mapping file id9967 NCBI file	EvidenceTAS
GeneTIAM2	AuthorityHGNC:11806	Mapping file id26230 NCBI file	EvidenceTAS
GeneTNFRSF21	AuthorityHGNC:13469	Mapping file id27242 NCBI file	EvidenceTAS
GeneTRIB3	AuthorityHGNC:16228	Mapping file id57761 NCBI file	EvidenceTAS
GeneTXNRD1	AuthorityHGNC:12437	Mapping file id7296 NCBI file	EvidenceTAS
GeneUGT1A9	AuthorityHGNC:12541	Mapping file id54600 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

Regulation of lipid metabolism by PPARalphaR-HSA-400206119 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.