Targeting of thylakoid proteins by the delta pH-driven twin-arginine translocation pathway requires a specific signal in the hydrophobic domain in conjunction with the twin-arginine motif
| Autor: | Erik G. Bogsch, Wayne R. Edwards, Peter J. Hynds, Susanne Brink, Colin Robinson |
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| Rok vydání: | 1998 |
| Předmět: |
Signal peptide
Targeting signal Molecular Sequence Data Biophysics Arabidopsis Biology Protein Sorting Signals medicine.disease_cause Arginine Chloroplast Sec-independent Biochemistry Twin-arginine translocation pathway Structural Biology Protein targeting Genetics medicine Amino Acid Sequence Molecular Biology Peroxisomal targeting signal Peptide sequence chemistry.chemical_classification Protein transport Membrane Proteins Biological Transport Cell Biology Hydrogen-Ion Concentration Amino acid chemistry Membrane protein Mutagenesis Thylakoid |
| Zdroj: | FEBS letters. 434(3) |
| ISSN: | 0014-5793 |
| Popis: | Superficially similar cleavable targeting signals specify whether lumenal proteins are transported across the thylakoid membrane by a Sec- or delta pH-dependent pathway. A twin-arginine motif is essential but not sufficient to direct delta pH-dependent targeting; here we show that a second determinant is located in the hydrophobic region. A highly hydrophobic amino acid is found either two or three residues C-terminal to the twin-arginine in all known transfer peptides for the delta pH-dependent system, and substitution of this residue in the 23-kDa (23K) peptide markedly inhibits translocation. Further, whereas the insertion of twin-arginine in a Sec-dependent precursor does not permit efficient delta pH-dependent targeting, the simultaneous presence of a leucine at the +3 position (relative to the RR) enables the peptide to function as efficiently as an authentic transfer peptide. RRNVL, RRAAL and RRALA within a Sec targeting signal all support efficient delta pH-dependent targeting, RRNVA is less effective and RRNAA/RRNAG are totally ineffective. We conclude that the core signal for this pathway is a twin-arginine together with an adjacent hydrophobic determinant. |
| Databáze: | OpenAIRE |
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