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Available structures
PDBOrtholog search: PDBe RCSB
AliasesPREX1, P-REX1, phosphatidylinositol-3,4,5-trisphosphate dependent Rac exchange factor 1
External IDsOMIM: 606905 MGI: 3040696 HomoloGene: 10821 GeneCards: PREX1
Gene location (Human)
Chromosome 20 (human)
Chr.Chromosome 20 (human)[1]
Chromosome 20 (human)
Genomic location for PREX1
Genomic location for PREX1
Band20q13.13Start48,624,252 bp[1]
End48,827,999 bp[1]
RNA expression pattern
PBB GE PREX1 gnf1h08616 at fs.png
More reference expression data
RefSeq (mRNA)



RefSeq (protein)



Location (UCSC)Chr 20: 48.62 – 48.83 MbChr 2: 166.57 – 166.71 Mb
PubMed search[3][4]
View/Edit HumanView/Edit Mouse

Phosphatidylinositol 3,4,5-trisphosphate-dependent Rac exchanger 1 protein is a protein that in humans is encoded by the PREX1 gene.[5][6][7][8]


The protein encoded by this gene acts as a guanine nucleotide exchange factor for the RHO family of small GTP-binding proteins (RACs). It has been shown to bind to and activate RAC1 by exchanging bound GDP for free GTP. The encoded protein, which is found mainly in the cytoplasm, is activated by phosphatidylinositol-3,4,5-trisphosphate and the beta-gamma subunits of heterotrimeric G proteins.[8]

Clinical significance[edit]

The protein has been implicated in the spread of melanoma skin cancer.[9]


  1. ^ a b c GRCh38: Ensembl release 89: ENSG00000124126 - Ensembl, May 2017
  2. ^ a b c GRCm38: Ensembl release 89: ENSMUSG00000039621 - Ensembl, May 2017
  3. ^ "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  4. ^ "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  5. ^ Welch HC, Coadwell WJ, Ellson CD, Ferguson GJ, Andrews SR, Erdjument-Bromage H, Tempst P, Hawkins PT, Stephens LR (Apr 2002). "P-Rex1, a PtdIns(3,4,5)P3- and Gbetagamma-regulated guanine-nucleotide exchange factor for Rac". Cell. 108 (6): 809–21. doi:10.1016/S0092-8674(02)00663-3. PMID 11955434.
  6. ^ Hill K, Krugmann S, Andrews SR, Coadwell WJ, Finan P, Welch HC, Hawkins PT, Stephens LR (Feb 2005). "Regulation of P-Rex1 by phosphatidylinositol (3,4,5)-trisphosphate and Gbetagamma subunits". J Biol Chem. 280 (6): 4166–73. doi:10.1074/jbc.M411262200. PMID 15545267.
  7. ^ Mayeenuddin LH, Garrison JC (Jan 2006). "Phosphorylation of P-Rex1 by the cyclic AMP-dependent protein kinase inhibits the phosphatidylinositiol (3,4,5)-trisphosphate and Gbetagamma-mediated regulation of its activity". J Biol Chem. 281 (4): 1921–8. doi:10.1074/jbc.M506035200. PMID 16301320.
  8. ^ a b "Entrez Gene: PREX1 phosphatidylinositol 3,4,5-trisphosphate-dependent RAC exchanger 1".
  9. ^ Lindsay CR, Lawn S, Campbell AD, et al. (2011). "P-Rex1 is required for efficient melanoblast migration and melanoma metastasis". Nature Communications. 2: 555. doi:10.1038/ncomms1560. PMC 3400057. PMID 22109529. Lay summaryCancer Research UK.

Further reading[edit]