Dopamine Transporter Endocytic Trafficking in Striatal Dopaminergic Neurons: Differential Dependence on Dynamin and the Actin Cytoskeleton
| Autor: | Sijia Wu, Karl D. Bellve, Haley E. Melikian, Clive Standley, Luke R. Gabriel, Patrick J. Kearney, Kevin E. Fogarty |
|---|---|
| Rok vydání: | 2013 |
| Předmět: |
Dynamins
Male media_common.quotation_subject Endocytic cycle Endocytic recycling Biology Mice Cell Line Tumor parasitic diseases mental disorders Animals Humans Internalization Lipid raft Cytoskeleton media_common Dopamine transporter Dynamin Dopamine Plasma Membrane Transport Proteins Dopaminergic Neurons General Neuroscience Dopaminergic food and beverages Articles Actin cytoskeleton Corpus Striatum Endocytosis Cell biology Protein Transport nervous system biology.protein Neuroscience |
| Zdroj: | The Journal of Neuroscience. 33:17836-17846 |
| ISSN: | 1529-2401 0270-6474 |
| Popis: | Dopaminergic signaling profoundly impacts rewarding behaviors, movement, and executive function. The presynaptic dopamine (DA) transporter (DAT) recaptures released DA, thereby limiting synaptic DA availability and maintaining dopaminergic tone. DAT constitutively internalizes and PKC activation rapidly accelerates DAT endocytosis, resulting in DAT surface loss. Longstanding evidence supports PKC-stimulated DAT trafficking in heterologous expression studies. However, PKC-stimulated DAT internalization is not readily observed in cultured dopaminergic neurons. Moreover, conflicting reports implicate both classic and nonclassic endocytic mechanisms mediating DAT trafficking. Prior DAT trafficking studies relied primarily upon chronic gene disruption and dominant-negative protein expression, or were performed in cell lines and cultured neurons, yielding results difficult to translate to adult dopaminergic neurons. Here, we use newly described dynamin inhibitors to test whether constitutive and PKC-stimulated DAT internalization are dynamin-dependent in adult dopaminergic neurons.Ex vivobiotinylation studies in mouse striatal slices demonstrate that acute PKC activation drives native DAT surface loss, and that surface DAT surprisingly partitions between endocytic-willing and endocytic-resistant populations. Acute dynamin inhibition reveals that constitutive DAT internalization is dynamin-independent, whereas PKC-stimulated DAT internalization is dynamin-dependent. Moreover, total internal reflection fluorescence microscopy experiments demonstrate that constitutive DAT internalization occurs equivalently from lipid raft and nonraft microdomains, whereas PKC-stimulated DAT internalization arises exclusively from lipid rafts. Finally, DAT endocytic recycling relies on a dynamin-dependent mechanism that acts in concert with the actin cytoskeleton. These studies are the first comprehensive investigation of native DAT trafficking inex vivoadult neurons, and reveal that DAT surface dynamics are governed by complex multimodal mechanisms. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|