A Hereditary Enteropathy Caused by Mutations in the SLCO2A1 Gene, Encoding a Prostaglandin Transporter
Fig 3
Genetic and functional analyses of SLCO2A1 gene mutations.
(A) RT-PCR and sequencing analysis of SLCO2A1 mRNA with homozygous c.940+1G>A mutation. A splicing mutation form (deletion of the whole exon 7) of SLCO2A1 mRNA was expressed in the biopsy specimen from the affected siblings with the homozygous c.940+1G>A mutation (patients 6 and 7). PBMCs denotes peripheral blood mononuclear cells. (B) The mutant SLCO2A1 protein shows loss-of-function for PGE2 transport. Data represent means ± SD (n = 3). Statistical analyses were performed using a repeated-measures Dunnett’s multiple-comparison test. *p < 0.0001. (C) Immunohistochemical and immunofluorescence staining using antibodies against SLCO2A1 and VE-cadherin reveals that SLCO2A1 is expressed on the cellular membrane of vascular endothelial cells in the small intestinal mucosa in the control subject, but is not detected in the affected individuals. (D) The truncated form of the SLCO2A1 protein shows altered intracellular localization. Expression vectors for GFP-SLCO2A1 and GFP-ΔSLCO2A1 fusion proteins were transfected into HEK293 cells. GFP-SLCO2A1 protein is localized on the cellular membrane (arrows), while GFP-ΔSLCO2A1 accumulates in the cytosol.