title: Subcellular localization and putative role of VPS13A/chorein in dopaminergic neuronal cells.
abstract: Chorea-acanthocytosis (ChAc) is a rare hereditary neurodegenerative disorder caused by loss of function mutations in the vacuolar protein sorting 13 homolog A (VPS13A) gene encoding chorein. Although a deficiency in chorein function leads to apoptosis of striatal neurons in ChAc model mouse, its detailed subcellular localization and physiological role remain unclear. In this study, we produced two anti-chorein polyclonal antibodies and examined the intracellular localization of endogenous chorein in neuronal cells. Immunocytochemically, chorein was observed in the termini of extended neurites and partially colocalized with synaptotagmin I in differentiated PC12 cells. Subcellular localization analysis by sucrose density gradient fractionation showed that chorein and synaptotagmin I were located in dense-core vesicles (DCVs), which contain dopamine. In addition, PC12 cells stably expressing carboxyterminal fragment of chorein increased K(+)-induced dopamine release. Taken together, these results suggest that chorein is involved in exocytosis of DCV.
authors.affiliation: Department of Biochemistry and Genetics, Kagoshima University Graduate School of Medical and Dental Sciences, Sakuragaoka, Kagoshima, Japan.
authors.forename: Takehiro
authors.initials: T
authors.lastname: Hayashi
authors.forename: Michiko
authors.initials: M
authors.lastname: Kishida
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Nishizawa
authors.forename: Mikio
authors.initials: M
authors.lastname: Iijima
authors.forename: Chihaya
authors.initials: C
authors.lastname: Koriyama
authors.forename: Masayuki
authors.initials: M
authors.lastname: Nakamura
authors.forename: Akira
authors.initials: A
authors.lastname: Sano
authors.forename: Shosei
authors.initials: S
authors.lastname: Kishida
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D059290:Dopaminergic Neurons / Q000378:metabolism*; D005089:Exocytosis; D006801:Humans; D051379:Mice; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism; D054546:Neuroacanthocytosis / Q000235:genetics; D016716:PC12 Cells; D051381:Rats; D022142:Secretory Vesicles / Q000378:metabolism*; D050863:Synaptotagmin I / Q000378:metabolism; D033921:Vesicular Transport Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D009419:Nerve Tissue Proteins; D050863:Synaptotagmin I; C429654:VPS13A protein, human; D033921:Vesicular Transport Proteins; C497828:Vps13a protein, mouse