title: Multiple intracellular locations of Lon protease in Arabidopsis: evidence for the localization of AtLon4 to chloroplasts.
abstract: Arabidopsis contains four Lon protease-like proteins (AtLon1-AtLon4), predicted to be localized in different cellular organelles, including mitochondria, peroxisomes and plastids. A notable question is whether Lon is present in chloroplasts, since it is absent from cyanobacteria and thus appears to have been lost during the evolution of photosynthetic organisms. Based on in vivo transient assays, we found that AtLon4 is dually targeted to both mitochondria and chloroplasts. Furthermore, immunoblot analysis localized AtLon4 to the thylakoids. Thus, in spite of its absence from basal photosynthetic organisms, our results suggest the presence of Lon in plant plastids.
authors.affiliation: Agricultural Research Organization, Volcani Center, Bet Dagan 50250, Israel.
authors.forename: Oren
authors.initials: O
authors.lastname: Ostersetzer
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Kato
authors.forename: Zach
authors.initials: Z
authors.lastname: Adam
authors.forename: Wataru
authors.initials: W
authors.lastname: Sakamoto
mesh_terms: D017360:Arabidopsis / Q000166:cytology* / Q000201:enzymology*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D002736:Chloroplasts / Q000201:enzymology* / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism; D049070:Protease La / Q000378:metabolism*; D021381:Protein Transport; D012697:Serine Endopeptidases / Q000378:metabolism*; D020524:Thylakoids / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D012697:Serine Endopeptidases; C523311:Lon4 protein, Arabidopsis; D049070:Protease La