Iron-responsive miR-485-3p regulates cellular iron homeostasis by targeting ferroportin.

Published

Journal Article

Ferroportin (FPN) is the only known cellular iron exporter in mammalian cells and plays a critical role in the maintenance of both cellular and systemic iron balance. During iron deprivation, the translation of FPN is repressed by iron regulatory proteins (IRPs), which bind to the 5' untranslated region (UTR), to reduce iron export and preserve cellular iron. Here, we report a novel iron-responsive mechanism for the post-transcriptional regulation of FPN, mediated by miR-485-3p, which is induced during iron deficiency and represses FPN expression by directly targeting the FPN 3'UTR. The overexpression of miR-485-3p represses FPN expression and leads to increased cellular ferritin levels, consistent with increased cellular iron. Conversely, both inhibition of miR-485-3p activity and mutation of the miR-485-3p target sites on the FPN 3'UTR are able to relieve FPN repression and lead to decreased cellular iron levels. Together, these findings support a model that includes both IRPs and microRNAs as iron-responsive post-transcriptional regulators of FPN. The involvement of microRNA in the iron-responsive regulation of FPN offers additional stability and fine-tuning of iron homeostasis within different cellular contexts. MiR-485-3p-mediated repression of FPN may also offer a novel potential therapeutic mechanism for circumventing hepcidin-resistant mechanisms responsible for some iron overload diseases.

Full Text

Duke Authors

Cited Authors

  • Sangokoya, C; Doss, JF; Chi, J-T

Published Date

  • April 2013

Published In

Volume / Issue

  • 9 / 4

Start / End Page

  • e1003408 -

PubMed ID

  • 23593016

Pubmed Central ID

  • 23593016

Electronic International Standard Serial Number (EISSN)

  • 1553-7404

Digital Object Identifier (DOI)

  • 10.1371/journal.pgen.1003408

Language

  • eng

Conference Location

  • United States