title: Differential Targeting of SLC30A10/ZnT10 Heterodimers to Endolysosomal Compartments Modulates EGF-Induced MEK/ERK1/2 Activity.
abstract: The solute carrier 30A (SLC30A) family of zinc exporters transports zinc into the lumen of intracellular organelles in order to prevent zinc toxicity. We reported that formation of tyrosine dimers is required for ZnT3 (zinc transporter 3) zinc transport activity and targeting to synaptic-like microvesicles (SLMVs) in PC12 cells and the formation of ZnT3/ZnT10 heterodimers. Here, we focused on ZnT10 to determine the role of heterodimerization in the sorting of ZnTs in the endolysosomal pathway. Using cell fractionation, immunoprecipitation and immunofluorescence approaches, we found that ZnT10 resides in transferrin receptor and Rab5-positive endosomes and forms covalent heterodimers and oligomers with ZnT2, ZnT3 and ZnT4. The interaction of ZnT10 with ZnT3, mediated by dityrosine bonds, was unable to target ZnT10 into SLMVs in vitro or into synaptic vesicles isolated from mouse brain in vivo. However, ZnT3/ZnT10 heterodimers regulate epidermal growth factor receptor (EGF-R) signaling by increasing the phosphorylation of mitogen-activated protein kinase kinase (MEK) and extracellular signal-regulated kinase (ERK1/2), but not EGF-R, C-Raf or Akt phosphorylation in response to EGF. Further, mutation of tyrosine 4 in ZnT10 reduced ZnT3/ZnT10 dityrosine-mediated heterodimerization and zinc transport, as well as MEK and ERK1/2 phosphorylation, which were also reduced by the zinc chelator TPEN. Phosphorylation of these kinases is likely to occur in the cytosol as no differences in phosphorylation were observed in membrane fractions of control and ZnT3/ZnT10-expressing cells. We propose that ZnT10 plays a role in signal transduction, which is mediated by homo and heterodimerization with other ZnTs.
authors.affiliation: The Department of Nutrition, Food and Exercise Sciences, Florida State University, Tallahassee, FL, USA.
authors.forename: Yitong
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: The Department of Nutrition, Food and Exercise Sciences, Florida State University, Tallahassee, FL, USA.|Department of Dietetics and Nutrition, University of Arkansas for Medical Sciences, Little Rock, AR, USA.
authors.forename: Rafaela G
authors.initials: RG
authors.lastname: Feresin
authors.affiliation: Exosomes Lab, Metabolomics Unit, CIC bioGUNE, CIBErehd, Derio, IKERBASQUE, Basque Foundation for Science, Bilbao, Spain.
authors.forename: Juan M
authors.initials: JM
authors.lastname: Falcon-Perez
authors.affiliation: The Department of Nutrition, Food and Exercise Sciences, Florida State University, Tallahassee, FL, USA.|Department of Medicine, Division of Cardiology, Emory University, Atlanta, GA, USA.
authors.forename: Gloria
authors.initials: G
authors.lastname: Salazar
mesh_terms: D000818:Animals; D027682:Cation Transport Proteins / Q000378:metabolism*; D011992:Endosomes / Q000378:metabolism*; D004815:Epidermal Growth Factor / Q000378:metabolism; D066246:ErbB Receptors / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D020930:MAP Kinase Kinase Kinases / Q000378:metabolism; D020935:MAP Kinase Signaling System; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D016716:PC12 Cells; D055503:Protein Multimerization; D021381:Protein Transport; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D051381:Rats; D013572:Synaptic Vesicles / Q000378:metabolism
chemical_list: D027682:Cation Transport Proteins; C498299:SLC30A1 protein, human; D004815:Epidermal Growth Factor; D066246:ErbB Receptors; D051057:Proto-Oncogene Proteins c-akt; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020930:MAP Kinase Kinase Kinases
keywords: ERK; SLC30A10; ZnT10; ZnT2; ZnT3; ZnT4; endosomes; lysosomes; synaptic vesicles; zinc