Zinc plays fundamental and diverse roles in cells yet excess free zinc is associated with metal cytotoxicity. To balance these opposing effects, cells have evolved universal mechanisms controlling cytoplasmic metal concentration. Cells accomplish this goal by zinc extrusion into the extracellular space, chelation by cytosolic chaperones, or sequestration within intracellular compartments. This last mechanism is the less explored process and it constitutes the main focus of our proposal. Zinc plays fundamental roles in synaptic physiology as well as in acute and chronic pathological conditions, ranging from excitotoxicity to the formation of amyloid aggregates characteristic of neurodegenerative diseases. Despite these fundamental roles of zinc, our understanding of the contribution of intracellular compartment in metal sequestration and homoeostasis is limited. In neurons, organellar zinc is stored in synaptic vesicles (SVs) by the activity of a synaptic vesicle specific zinc transporter, ZnT3. We have isolated and characterized by proteomics a ZnT3- enriched vesicle population. In these vesicles, we have identified ~ 140 molecular targets, several of which either up- or down-regulate vesicular endosomal zinc stores. These molecules provide a unique set of tools to assess the role of intracellular organelles, en particular endosomes and SV, in normal and pathological metal homeostasis. Our studies suggest that ZnT3 transport function are regulated by the nature of the compartment in which the ZnT3 transporter resides. Consistent with this notion, we have identified three targeting mechanisms that control ZnT3 subcellular localization that have the potential to regulate ZnT3 zinc transport function. In this proposal, we will specifically explore these novel regulatory paradigms testing the hypothesis that endosome-specific zinc transporter interactions regulate zinc transporter activity and resistance to metal-induced cytotoxicity.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM077569-04
Application #
7599255
Study Section
Neurotoxicology and Alcohol Study Section (NAL)
Program Officer
Anderson, Vernon
Project Start
2006-04-01
Project End
2011-03-31
Budget Start
2009-04-01
Budget End
2011-03-31
Support Year
4
Fiscal Year
2009
Total Cost
$278,815
Indirect Cost
Name
Emory University
Department
Anatomy/Cell Biology
Type
Schools of Medicine
DUNS #
066469933
City
Atlanta
State
GA
Country
United States
Zip Code
30322
Monis, William J; Faundez, Victor; Pazour, Gregory J (2017) BLOC-1 is required for selective membrane protein trafficking from endosomes to primary cilia. J Cell Biol 216:2131-2150
Devergnas, Annaelle; Chen, Erdong; Ma, Yuxian et al. (2016) Anatomical localization of Cav3.1 calcium channels and electrophysiological effects of T-type calcium channel blockade in the motor thalamus of MPTP-treated monkeys. J Neurophysiol 115:470-85
Delevoye, Cédric; Heiligenstein, Xavier; Ripoll, Léa et al. (2016) BLOC-1 Brings Together the Actin and Microtubule Cytoskeletons to Generate Recycling Endosomes. Curr Biol 26:1-13
Gokhale, Avanti; Hartwig, Cortnie; Freeman, Amanda H et al. (2016) The Proteome of BLOC-1 Genetic Defects Identifies the Arp2/3 Actin Polymerization Complex to Function Downstream of the Schizophrenia Susceptibility Factor Dysbindin at the Synapse. J Neurosci 36:12393-12411
Gokhale, Avanti; Ryder, Pearl V; Zlatic, Stephanie A et al. (2016) Identification of the Interactome of a Palmitoylated Membrane Protein, Phosphatidylinositol 4-Kinase Type II Alpha. Methods Mol Biol 1376:35-42
Arnold, Miranda; Cross, Rebecca; Singleton, Kaela S et al. (2016) The Endosome Localized Arf-GAP AGAP1 Modulates Dendritic Spine Morphology Downstream of the Neurodevelopmental Disorder Factor Dysbindin. Front Cell Neurosci 10:218
Gokhale, Avanti; Vrailas-Mortimer, Alysia; Larimore, Jennifer et al. (2015) Neuronal copper homeostasis susceptibility by genetic defects in dysbindin, a schizophrenia susceptibility factor. Hum Mol Genet 24:5512-23
Gokhale, Avanti; Mullin, Ariana P; Zlatic, Stephanie A et al. (2015) The N-ethylmaleimide-sensitive factor and dysbindin interact to modulate synaptic plasticity. J Neurosci 35:7643-53
Mullin, Ariana P; Sadanandappa, Madhumala K; Ma, Wenpei et al. (2015) Gene dosage in the dysbindin schizophrenia susceptibility network differentially affect synaptic function and plasticity. J Neurosci 35:325-38
Marzolo, María-Paz; Faundez, Victor; Galli, Thierry (2015) EMBO workshop al fin del mundo: a meeting on membrane trafficking and its implication for polarity and diseases. Biol Cell 107:245-8

Showing the most recent 10 out of 40 publications