SLC23A1 activity and human genetic variation.
(a) Distribution of SLC23A1 in kidney
nephron segments by Serial Analysis of Gene Expression (SAGE) libraries
containing expression data from microdissected glomeruli and six different
nephron segments; values are expressed as tags per million. (b)
Effect of SLC23A1 SNPs on ascorbate transport. Xenopus
laevis oocytes were microinjected with the following
SLC23A1 cRNAs: common type; sham injected; human deletion
construct; and SNPs A652G (rs34521685), G790A (rs33972313), A772G (rs35817838),
and C180T (rs6886922). (c) Population prevalences of
SLC23A1 polymorphisms. Shown are averaged minor allelic
frequencies of SLC23A1 genotypes in African (n
= 48), American African (n = 438), and white
(n = 1,874) individuals, using pooled genotype
data. (d) Modeled effects of SLC23A1
polymorphisms on plasma ascorbate concentrations in humans. Values in healthy
young women for common type SLC23A1 are measured and calculated
fasting steady-state plasma ascorbate concentrations. For women with SNPs,
values are calculated from wild-type data comparisons to transport data in panel
b. Reprinted with permission of the American Society for
Clinical Investigations, from Corpe C.P., Tu H., Eck P., Wang J.,
Faulhaber-Walter R., Schnermann J., Margolis S., Padayatty S., Sun H., Wang Y.,
Nussbaum R.L., Espey, M.G., and Levine, M. Vitamin C transporter Slc23a1 links
renal reabsorption, vitamin C tissue accumulation, and perinatal survival in
mice. April 1:120(4). Copyright 2010
(17).