Regulation of the divalent metal ion transporter DMT1 and iron homeostasis by a ubiquitin-dependent mechanism involving Ndfips and WWP2

Foot, Natalie; Dalton, Hazel; Shearwin-Whyatt, Linda M.; Dorstyn, Loretta; Tan, Seong‐Seng; Yang, Baoli; Kumar, Sharad

doi:10.1182/blood-2008-04-150953

Cited by 121 publications

(116 citation statements)

References 41 publications

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“…This means that for redox cycling to occur, back-oxidation would have to be quicker then the rate of ligand release, which is unlikely considering the rate of aquation of cobalt complexes is in the order of 10 6 s Ϫ1 (20). To determine whether Co II is released following reduction by intracellular reductants we carried out a fluorescence quenching assay (21). The acetomethoxy derivate of calcein (calcein-AM) is non fluorescent and can be transported through the cellular membranes, where intracellular esterases remove the acetomethoxy groups resulting in a strong green fluorescence.…”

Section: Resultsmentioning

confidence: 99%

Cellular Up-regulation of Nedd4 Family Interacting Protein 1 (Ndfip1) using Low Levels of Bioactive Cobalt Complexes

Schieber

Howitt

Putz

et al. 2011

Journal of Biological Chemistry

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The delivery of metal ions using cell membrane-permeable metal complexes represents a method for activating cellular pathways. Here, we report the synthesis and characterization of new [ Transition metals are essential for many important chemical processes in biological systems. Most of these metal-related processes occur by interactions with nucleic acids and proteins. Within the cell, metal ions can stabilize, destabilize, or modulate DNA and proteins by introducing conformational changes and by creating centers of activity. Although the use of metals as structural elements within the cell is well known, emerging evidence now recasts metals as signaling molecules able to activate critical cellular pathways. For example, metals such as iron, copper, and cobalt can produce reactive oxygen species that lead to the activation of redox-sensitive transcription factors including NF-B, AP-1, and p53. Metals have also been suggested to affect the upstream regulatory components of the MAP kinase and the PI3K/Akt/mTor pathway (1, 2). Thus the levels and regulation of metals in a cell can have a direct role on cell function and survival.Metal ions such as Co II and Fe II can stimulate the expression of the neuroprotective protein Nedd4 family interacting protein 1 (Ndfip1) 4 in the brain (3). Ndfip1 is a transmembrane protein that is localized to the Golgi and post-Golgi vesicles such as endosomes (4, 5). Ndfip1 functions as an adaptor protein for the Nedd4 family of ubiquitin ligases that target proteins for both degradation and trafficking (4). The metal-induced up-regulation of Ndfip1 results in the activation of the ubiquitin proteasome pathway. Ndfip1 recognizes and interacts with divalent metal transporter 1 (DMT1), this recruits the E3 ligase Nedd4 -2 resulting in degradation of DMT1, preventing iron overload within the cell (3). Other targets for Ndfip1 have also been identified, including the transcription factor JunB that is regulated by Ndfip1 in association with the E3 ligase Itch (6). In the adult brain, Ndfip1 is endogenously present in cortical neurons at low levels, however it is up-regulated in a subset of neurons upon activation by injury or stress (7). Importantly, this up-regulation of Ndfip1 has been shown to be neuroprotective, and neurons with up-regulated Ndfip1 do not undergo apoptosis.Whereas high levels of exogenous Co II and Fe II are toxic to cells, our previous results show they also stimulate Ndfip1 via still unknown mechanisms. Barring the effects of metal toxicity, this finding introduces an opportunity to harness the capacity of metal ions to up-regulate Ndfip1 for neuroprotective purposes. In the present study, we investigate the utility of nontoxic metal complexes for controlled intracellular delivery of cobalt to stimulate Ndfip1 expression. This was based on the premise that the reactivity of metal ions can be modulated by the formation of coordination complexes, with a complexed 4 The abbreviations used are: Ndfip1, Nedd4 family interacting protein 1; DMT1, divalent metal transporte...

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Section: Resultsmentioning

confidence: 99%

Cellular Up-regulation of Nedd4 Family Interacting Protein 1 (Ndfip1) using Low Levels of Bioactive Cobalt Complexes

Schieber

Howitt

Putz

et al. 2011

Journal of Biological Chemistry

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“…dNdfip may facilitate E3 access to Notch, as it interacts with both dNedd4 and Su(dx) and colocalizes with Notch in wing discs and in S2 cells stably 29 Indeed we have observed such a role for dNdfip in the promotion of ubiquitination of Malvolio, 30 the ortholog of the known Ndfip-regulated iron transporter DMT1 (our unpublished observations). 20 Another possible regulatory mode of action for dNdfip may include the direct activation of Nedd4 family E3s, as has been observed for Ndfip2 that promotes the auto-activation of several E3s, including Itch. 19 Furthermore, Ndfip2 promotes the ubiquitination of the PY-containing substrates c-Jun and JunB, as well as the non-PY-containing substrate Endophilin A1.…”

Section: Discussionmentioning

confidence: 99%

“…[15][16][17] Ndfip1 and 2 localize to Golgi, late endosomes and other vesicles and function as adapters and activators to facilitate the ubiquitination and regulation of a number of substrates. 15,[17][18][19][20][21] Here, we report on the Drosophila Nedd4 family interacting protein (dNdfip) homolog, and reveal that it is a novel regulator of Notch signaling.…”

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confidence: 99%

Drosophila Ndfip is a novel regulator of Notch signaling

et al. 2010

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“…Cell staining was conducted as described using 1 : 500 rabbit a-zNEDD1 5 and 1 : 500 mouse a-g-tubulin, (GTU-88, Sigma, St. Louis, MO, USA) and images obtained using a confocal microscope as described. 43 For immunoprecipitation, 1 Â 10 6 HEK293T cells were lysed and immunoprecipitated as previously described, 44 using 1 ml of antibodies to zNEDD1 or a-g-tubulin.…”

Section: Methodsmentioning

confidence: 99%

“…Embryos stained with a-acetylated tubulin were photographed on a confocal microscope as described. 43 Whole-mount immunohistochemistry for HuC. Embryos were fixed in 4%PFA/PBS overnight followed by several washes in PBST.…”

Section: Methodsmentioning

confidence: 99%

An essential function for the centrosomal protein NEDD1 in zebrafish development

et al. 2010

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The centrosome is the primary microtubule organising centre of the cell. It is composed of many proteins, some of which make up the core of the centrosome, whereas others are used for specific functions. Although the cellular roles of many centrosomal proteins are well defined, much less is known about their functions and the role of the centrosome in development. In this study we investigated the function of NEDD1, a critical component of the centrosome essential for microtubule nucleation, in zebrafish (Danio rerio) development. The zebrafish homologue of NEDD1 (zNEDD1) was cloned and found to have a similar localisation and function to mammalian NEDD1. We show that zNEDD1 is essential for survival, as a high level of knockdown was embryonic lethal. Partial knockdown of zNEDD1 caused abnormalities including an increase in mitotic and apoptotic cells. Pronounced phenotypic defects were seen in the brain, with a lack of defined brain structures, incomplete neural tube formation and a disorganisation of neurons. In addition, we show that a reduction in zNEDD1 resulted in the loss of c-tubulin at the centrosome. Our data thus demonstrate that zNEDD1 is critical for the recruitment of c-tubulin to the centrosome, and is essential for the proper development of zebrafish. The centrosome is the major microtubule organising centre (MTOC) of cells and serves as a centralised location for controlling many cellular processes. The centrosomal protein neural precursor cell expressed developmentally downregulated gene 1 (NEDD1), 1 functions in the centrosomal and mitotic-spindle recruitment of the g-tubulin ring complex (g-TuRC). This complex is required for the nucleation of microtubules, correct formation of the mitotic spindle and hence progression of the cell cycle. 2,3 Because of this, depletion of NEDD1 from mammalian cells results in dispersion of the MTOC, impaired centrosomal and chromatin nucleation of microtubules, mitotic chaos and cell-cycle arrest. [2][3][4] Given the centrosomal localisation and function of NEDD1, and its dynamic expression during mouse embryogenesis, 5 it is expected that this protein has an important role during development. However, because of the early embryonic lethality of mouse knockouts of centrosomal proteins, including g-tubulin, it has not been possible to study the function of these proteins in later stages of development in this organism. 6,7 Zebrafish (Danio rerio) posses many benefits for developmental studies including the conservation of genes involved in cell growth and proliferation, 8 the rapid maturation of translucent embryos 9 and the ability to specifically deplete proteins of interest. 10 Although there has been much work analysing the cell cycle in zebrafish, 11 there has been limited analysis of the centrosome in this species. Therefore, this system was chosen as a model to study the role of NEDD1 during development. In addition, NEDD1 homologues have been described in Drosophila, Xenopus and Arabidopsis. [12][13][14] Despite the consistent centrosomal localisation o...

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Regulation of the divalent metal ion transporter DMT1 and iron homeostasis by a ubiquitin-dependent mechanism involving Ndfips and WWP2

Cited by 121 publications

References 41 publications

Cellular Up-regulation of Nedd4 Family Interacting Protein 1 (Ndfip1) using Low Levels of Bioactive Cobalt Complexes

Cellular Up-regulation of Nedd4 Family Interacting Protein 1 (Ndfip1) using Low Levels of Bioactive Cobalt Complexes

Drosophila Ndfip is a novel regulator of Notch signaling

An essential function for the centrosomal protein NEDD1 in zebrafish development

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