title: [Subcellular localization of ataxin-3 and its effect on the morphology of cytoplasmic organoids].
abstract: OBJECTIVE
  To explore the subcellular localization of ataxin-3 and the effect of polyglutamine (polyQ) expansion mutation on the morphology of mitochondrion, golgi apparatus and endoplasmic reticulum.
  
  
  METHODS
  Transient transfection was employed to build cell models expressing wild-type or mutant ataxin-3 proteins. Indirect immunofluorescence was applied to identify markers of organelle membrane. The results were observed under a laser scanning confocal microscope.
  
  
  RESULTS
  No co-localization was observed for ataxin-3 protein and mitochondrial marker TOM20, but the percentage of cells with mitochondrial fragmentation has increased in cells expressing mutant ataxin-3 (P<0.05). No co-localization was observed for ataxin-3 protein and golgi marker GM130, and mutant ataxin-3 did not cause golgi fragmentation. Wide type and polyQ-expanded ataxin-3 both showed partial co-localization with ER marker calnexin. The latter showed more overlap with calnexin, and the overlapping signals were mostly located in the places where aggregates were situated.
  
  
  CONCLUSIONS
  PolyQ-expanded ataxin-3 protein may indirectly affect the integrity of mitochondria, but may cause no effect on the structure and functions of golgi apparatus. Endoplasmic reticulum may be another place where extended ataxin-3 protein can induce cytotoxicity in addition to the nucleus.
authors.affiliation: Department of Neurology, the Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, P.R.China. tjg168@aliyun.com.
authors.forename: Feifei
authors.initials: F
authors.lastname: Wei
authors.forename: Han
authors.initials: H
authors.lastname: Xiao
authors.forename: Zhiping
authors.initials: Z
authors.lastname: Hu
authors.forename: Hainan
authors.initials: H
authors.lastname: Zhang
authors.forename: Chunyu
authors.initials: C
authors.lastname: Wang
authors.forename: Heping
authors.initials: H
authors.lastname: Dai
authors.forename: Jianguang
authors.initials: J
authors.lastname: Tang
mesh_terms: D000067699:Ataxin-3; D003593:Cytoplasm / Q000235:genetics / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000235:genetics / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D017827:Machado-Joseph Disease / Q000235:genetics / Q000378:metabolism*; D008928:Mitochondria / Q000235:genetics / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D021381:Protein Transport; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins; D012097:Repressor Proteins; C092341:ATXN3 protein, human; D000067699:Ataxin-3