Back to Search
Start Over
Non-canonical transit peptide for import into the chloroplast.
- Source :
-
The Journal of biological chemistry [J Biol Chem] 2002 Dec 06; Vol. 277 (49), pp. 47770-8. Date of Electronic Publication: 2002 Oct 03. - Publication Year :
- 2002
-
Abstract
- The large majority of plastid proteins are nuclear-encoded and, thus, must be imported within these organelles. Unlike most of the outer envelope proteins, targeting of proteins to all other plastid compartments (inner envelope membrane, stroma, and thylakoid) is strictly dependent on the presence of a cleavable transit sequence in the precursor N-terminal region. In this paper, we describe the identification of a new envelope protein component (ceQORH) and demonstrate that its subcellular localization is limited to the inner membrane of the chloroplast envelope. Immunopurification, microsequencing of the natural envelope protein and cloning of the corresponding full-length cDNA demonstrated that this protein is not processed in the N-terminal region during its targeting to the inner envelope membrane. Transient expression experiments in plant cells were performed with truncated forms of the ceQORH protein fused to the green fluorescent protein. These experiments suggest that neither the N-terminal nor the C-terminal are essential for chloroplastic localization of the ceQORH protein. These observations are discussed in the frame of the endosymbiotic theory of chloroplast evolution and suggest that a domain of the ceQORH bacterial ancestor may have evolved so as to exclude the general requirement of an N-terminal plastid transit sequence.
- Subjects :
- Amino Acid Sequence
Arabidopsis metabolism
Base Sequence
Biological Transport
Blotting, Western
Cell Membrane metabolism
Cloning, Molecular
DNA, Complementary metabolism
Detergents pharmacology
Electrophoresis, Polyacrylamide Gel
Escherichia coli metabolism
Gene Library
Genes, Reporter
Green Fluorescent Proteins
Luminescent Proteins metabolism
Microscopy, Fluorescence
Models, Biological
Models, Molecular
Molecular Sequence Data
Oxidation-Reduction
Plasmids metabolism
Plastids chemistry
Protein Binding
Protein Structure, Tertiary
Recombinant Fusion Proteins metabolism
Sequence Homology, Amino Acid
Spinacia oleracea metabolism
Time Factors
Nicotiana metabolism
Chloroplasts metabolism
Membrane Proteins chemistry
Membrane Proteins metabolism
Peptides chemistry
Subjects
Details
- Language :
- English
- ISSN :
- 0021-9258
- Volume :
- 277
- Issue :
- 49
- Database :
- MEDLINE
- Journal :
- The Journal of biological chemistry
- Publication Type :
- Academic Journal
- Accession number :
- 12368288
- Full Text :
- https://doi.org/10.1074/jbc.M207477200