T1277C (F426S) single nucleotide mutation in human SLC22A9 in osteoporosis patient attenuates transport properties of estrone sulfate conjugate

초록

The organic anion transporters (OATs) play an important role for movement of anionic compounds in cells. Among OATs, human SLC22A9 transports estrone sulfate with high affinity. The present study, the single nucleotide polymorphism (SNP) in the coding regions of SLC22A9 was screened using GC-clamped PCR and denaturing gradient gel electrophoresis in each fifty healthy controls and osteoporosis patients. Six SNPs were found on the SLC22A9 gene from Korean women with/without osteoporosis. The SNPs were located as follows: two SNPs in the patients group (A645G and T1277C), three SNPs in the control group (G1449T, C1467T and C1487T) and one SNP in both groups (G767A). The G767A, T1277C and C1487T SNPs result in an amino acid substitution, arginine to glutamine (R256Q), phenylalanine to serine (F426S) and proline to leucine (P496L), respectively. The Km and Vmax values of the wild type and three mutants were 8.8, 8.9, 9.8 and 12.7 uM, and 2.0, 2.0, 2.1 and 1.6 pmol/oocyte/h, respectively. In conclusion, the SLC22A9 variant F426S is causing inter-individual variation that is leading to the differences in transport of the estrone sulfate conjugate and, therefore, this could be used as a marker for certain disease including osteoporosis.