The role of the N-terminal domain of chloroplast targeting peptides in organellar protein import and miss-sorting.
We have analysed 385 mitochondrial and 567 chloroplastic signal sequences of proteins found in the organellar proteomes of Arabidopsis thaliana. Despite overall similarities, the first 16 residues of transit peptides differ remarkably. To test the hypothesis that the N-terminally truncated transit peptides would redirect chloroplastic precursor proteins to mitochondria, we studied import of the N-terminal deletion mutants of ELIP, PetC and Lhcb2.1. The results show that the deletion mutants were neither imported into chloroplasts nor miss-targeted to mitochondria in vitro and in vivo, showing that the entire transit peptide is necessary for correct targeting as well as miss-sorting.
Bhushan
Shashi
S
Department of Biochemistry and Biophysics, Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-106 91 Stockholm, Sweden.
Kuhn
Claus
C
Berglund
Anna-Karin
AK
Roth
Christian
C
Glaser
Elzbieta
E
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000378:metabolism; D002736:Chloroplasts / Q000378:metabolism*; D008928:Mitochondria / Q000378:metabolism*; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D010455:Peptides / Q000737:chemistry* / Q000378:metabolism*; D018515:Plant Leaves / Q000166:cytology; D010940:Plant Proteins / Q000737:chemistry; D030821:Plants, Genetically Modified; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D020543:Proteome / Q000737:chemistry; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000378:metabolism; D020539:Sequence Analysis, Protein; D014026:Nicotiana / Q000166:cytology
D010455:Peptides; D010940:Plant Proteins; D020543:Proteome; D011993:Recombinant Fusion Proteins