Effect of SUMO-1 on mitochondria subcellular localization of alpha-synuclein and its degradation via ubiquitin-proteasome system.
- Author:
Tao CHEN
1
;
Xiao-ping LIAO
;
Guo-qiang WEN
;
Zhi-gang NONG
;
Feng OUYANG
;
Yi-dong DENG
;
Min GUO
;
Hui-ling WU
;
Peng ZHOU
Author Information
- Publication Type:Journal Article
- MeSH: Blotting, Western; Cell Line; Humans; Mitochondria; metabolism; Proteasome Endopeptidase Complex; metabolism; SUMO-1 Protein; metabolism; Ubiquitin; metabolism; alpha-Synuclein; metabolism
- From: Chinese Journal of Medical Genetics 2010;27(3):267-271
- CountryChina
- Language:Chinese
-
Abstract:
OBJECTIVETo investigate the effect of sumoylation of alpha-synuclein by SUMO-1 on the mitochondria subcellular localization of alpha-synuclein and its degradation via ubiquitin-proteasome system.
METHODSPrimers of wild-type, A53T pathogenic mutant and K96R mutant of human alpha-synuclein were designed to amplify the corresponding cDNAs without stop codon. The cDNAs were cloned into pGEM T-easy vector, analyzed by using enzyme mapping and DNA sequencing, and subcloned into pEGFP-N1 vector. The recombinant plasmids of pEGFP-alpha-synuclein-WT, pEGFP-alpha-synuclein-A53T and pEGFP-alpha-synuclein-K96R were transfected into HEK293 cells by lipofectamine method. The expression of the alpha-synuclein protein was measured by immunofluorescence and confocal microscope. Then mitochondria staining as well as immunofluorescence were utilized to investigate the effect of wild-type, A53T mutant and sumoylation of alpha-synuclein on mitochondria subcellular localization of alpha-synuclein. The effect of sumoylation of alpha-synuclein on its degradation via the ubiquitin-proteasome system in the cells was assayed by Western-blot.
RESULTSThe enzyme mapping suggested that the eukaryotic expression plasmids for human wild-type, A53T and K96R mutants of the alpha-synuclein gene were constructed successfully. By immunofluorescence and confocal microscope, it was observed that alpha-synuclein-WT and alpha-synuclein-A53T proteins aggregated in cytoplasm, and alpha-synuclein-K96R protein aggregation was decreased in cytoplasm of cultured cells. The alpha-synuclein proteins of wild-type, A53T and K96R mutants were co-localized with mitochondria. Western-blot analysis revealed that both wild-type and A53T mutant affected the amount of the ubiquitinated proteins.
CONCLUSIONNeither overexpression of wild-type and A53T pathogenic mutant alpha-synuclein, nor sumoylation of alpha-synuclein, affected the subcellular localization in the mitochondria. However, overexpression of wild-type and A53T mutant alpha-synuclein affected the amount of the ubiquitinated proteins.
