title: Regulation of the divalent metal ion transporter via membrane budding.
abstract: The release of extracellular vesicles (EVs) is important for both normal physiology and disease. However, a basic understanding of the targeting of EV cargoes, composition and mechanism of release is lacking. Here we present evidence that the divalent metal ion transporter (DMT1) is unexpectedly regulated through release in EVs. This process involves the Nedd4-2 ubiquitin ligase, and the adaptor proteins Arrdc1 and Arrdc4 via different budding mechanisms. We show that mouse gut explants release endogenous DMT1 in EVs. Although we observed no change in the relative amount of DMT1 released in EVs from gut explants in Arrdc1 or Arrdc4 deficient mice, the extent of EVs released was significantly reduced indicating an adaptor role in biogenesis. Furthermore, using Arrdc1 or Arrdc4 knockout mouse embryonic fibroblasts, we show that both Arrdc1 and Arrdc4 are non-redundant positive regulators of EV release. Our results suggest that DMT1 release from the plasma membrane into EVs may represent a novel mechanism for the maintenance of iron homeostasis, which may also be important for the regulation of other membrane proteins.
authors.affiliation: Centre for Cancer Biology, University of South Australia , Adelaide, South Australia , Australia.
authors.forename: KimberlyD
authors.initials: K
authors.lastname: Mackenzie
authors.affiliation: Centre for Cancer Biology, University of South Australia , Adelaide, South Australia , Australia.
authors.forename: Natalie J
authors.initials: NJ
authors.lastname: Foot
authors.affiliation: Department of Biochemistry, La Trobe Institute for Molecular Science, La Trobe University , Melbourne, Victoria , Australia.
authors.forename: Sushma
authors.initials: S
authors.lastname: Anand
authors.affiliation: Centre for Cancer Biology, University of South Australia , Adelaide, South Australia , Australia.
authors.forename: Hazel E
authors.initials: HE
authors.lastname: Dalton
authors.affiliation: Institute for Molecular Bioscience, The University of Queensland , St Lucia, Queensland , Australia.
authors.forename: Natasha
authors.initials: N
authors.lastname: Chaudhary
authors.affiliation: Institute for Molecular Bioscience, The University of Queensland , St Lucia, Queensland , Australia.
authors.forename: Brett M
authors.initials: BM
authors.lastname: Collins
authors.affiliation: Department of Biochemistry, La Trobe Institute for Molecular Science, La Trobe University , Melbourne, Victoria , Australia.
authors.forename: Suresh
authors.initials: S
authors.lastname: Mathivanan
authors.affiliation: Centre for Cancer Biology, University of South Australia , Adelaide, South Australia , Australia.
authors.forename: Sharad
authors.initials: S
authors.lastname: Kumar
keywords: Arrdc; DMT1; extracellular vesicles; ubiquitin ligases; ubiquitination