Mouse anti-Human SLC11A2 monoclonal antibody, clone 5D7

Divalent metal ion transporter 1 (DMT1; also known as SLC11A2) can transport several metals including Fe and Cu in mammalian systems. We set out to determine whether Malvolio (Mvl), the Drosophila melanogaster orthologue of DMT1, can also transport Cu. Overexpression of Mvl caused Cu accumulation in Drosophila S2 cultured cells and conversely dsRNAi knockdown of endogenous Mvl reduced cellular Cu levels. Cell viability under Cu limiting conditions was reduced following dsRNAi knockdown. A homozygous viable Mvl loss-of-function mutant (Mvl(97f)) was sensitive to excess Cu and female Mvl(97f) flies were also sensitive to Cu limitation. An MtnA-EYFP reporter was used as a proxy measure of Cu distribution within Mvl(97f/+) larvae. Under basal conditions Cu levels were reduced in the anterior midgut and proventriculus relative to control larvae. These results demonstrate Mvl is a functional Cu transporter and that despite partial functional redundancy with the Ctr1 proteins, Cu uptake through this pathway is necessary for optimal viability at the cellular and organismal levels.

Background: Iron-refractory iron deficiency anaemia (IRIDA) is a rare disorder which was linked to mutations in two genes (SLC11A2 and TMPRSS6). Common polymorphisms within these genes were associated with serum iron levels. We identified a family of Serbian origin with asymptomatic non-consanguineous parents with three of four children presenting with IRIDA not responding to oral but to intravenous iron supplementation. After excluding all known causes responsible for iron deficiency anaemia we searched for mutations in SLC11A2 and TMPRSS6 that could explain the severe anaemia in these children. Methodology/Results: We sequenced the exons and exon-intron boundaries of SLC11A2 and TMPRSS6 in all six family members. Thereby, we found seven known and fairly common SNPs, but no new mutation. We then genotyped these seven SNPs in the population-based SAPHIR study (n = 1,726) and performed genetic association analysis on iron and ferritin levels. Only two SNPs, which were top-hits from recent GWAS on iron and ferritin, exhibited an effect on iron and ferritin levels in SAPHIR. Six SAPHIR participants carrying the same TMPRSS6 genotypes and haplotype-pairs as one anaemic son showed lower ferritin and iron levels than the average. One individual exhibiting the joint SLC11A2/TMPRSS6 profile of the anaemic son had iron and ferritin levels lying below the 5(th) percentile of the population's iron and ferritin level distribution. We then checked the genotype constellations in the Nijmegen Biomedical Study (n = 1,832), but the profile of the anaemic son did not occur in this population. Conclusions: We cannot exclude a gene-gene interaction between SLC11A2 and TMPRSS6, but we can also not confirm it. As in this case candidate gene sequencing did not reveal causative rare mutations, the samples will be subjected to whole exome sequencing.