The transit peptide of a chloroplast thylakoid membrane protein is functionally equivalent to a stromal-targeting sequence
| Autor: | A C Vasconcelos, J M Hand, Anthony R. Cashmore, Les J. Szabo |
|---|---|
| Rok vydání: | 1989 |
| Předmět: |
Chlorophyll
Chloroplasts Time Factors Photosystem II Protein subunit Recombinant Fusion Proteins Ribulose-Bisphosphate Carboxylase Photosynthetic Reaction Center Complex Proteins Light-Harvesting Protein Complexes Biology Cell Fractionation General Biochemistry Genetics and Molecular Biology Transit Peptide Cloning Molecular Protein Precursors Molecular Biology Plant Proteins Plants Medicinal General Immunology and Microbiology General Neuroscience Binding protein fungi food and beverages Photosystem II Protein Complex Biological Transport Fabaceae Intracellular Membranes Fusion protein Cell biology Chloroplast Biochemistry Thylakoid Electrophoresis Polyacrylamide Gel Peptides Chloroplast thylakoid membrane Plasmids Research Article |
| Zdroj: | Scopus-Elsevier |
| ISSN: | 0261-4189 |
| Popis: | The role of transit peptides in intraorganellar targeting has been studied for a chlorophyll a/b binding (CAB) polypeptide of photosystem II (PSII) and the small subunit of ribulose-1,5-bisphosphate carboxylase (RBCS) from Pisum sativum (pea). These studies have involved in vitro import of fusion proteins into isolated pea chloroplasts. Fusion of the CAB transit peptide to RBCS mediates import to the stroma, as evidenced by assembly of RBCS with chloroplast-synthesized large subunit (RBCL) to form holoenzyme. Similarly, fusion of the RBCS transit peptide to the mature CAB polypeptide mediates import and results in integration of the processed CAB protein into the thylakoid membrane. Correct integration was indicated by association with PSII and assembly with chlorophyll to form the light-harvesting chlorophyll a/b protein complex (LHCII). We interpret these results as evidence that the CAB transit peptide is functionally equivalent to a stromal-targeting sequence and that intraorganellar sorting of the CAB protein must be determined by sequences residing within the mature protein. Our results and those of others suggest that import and integration of CAB polypeptides into the thylakoid proceeds via the stroma. |
| Databáze: | OpenAIRE |
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