Abstract
The Arabidopsis ankyrin-repeat containing protein 2A (AKR2A) was shown to be an essential molecular chaperone for the peroxisomal membranebound ascorbate peroxidase 3 (APX3), because the biogenesis of APX3 depends on the function of AKR2A in plant cells. AKR2A binds specifically to a sequence in APX3 that is made up of a transmembrane domain followed by a few positively charged amino acid residues; this sequence is named as AKR2Abinding sequence or ABS. Interestingly, a sequence in the chloroplast outer envelope protein 7 (OEP7) shares similar features to ABS and is able to bind specifically to AKR2A, suggesting a possibility that proteins with a sequence similar to ABS could bind to AKR2A and they are all likely ligand proteins of AKR2A. This hypothesis was supported by analyzing 5 additional proteins that contain sequences similar to ABS using the yeast two-hybrid technique. A preliminary survey in the Arabidopsis genome indicates that there are at least 500 genes encoding proteins that contain sequences similar to ABS, which raises interesting questions: Are these proteins AKR2A's ligand proteins and does AKR2A play a critical role in the biogenesis of these proteins in plants?
Original language | English |
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Pages (from-to) | 1520-1522 |
Number of pages | 3 |
Journal | Plant Signaling and Behavior |
Volume | 5 |
Issue number | 11 |
DOIs | |
State | Published - Nov 2010 |
Keywords
- Arabidopsis
- Membrane protein
- Molecular chaperone
- Protein targeting
- Transmembrane domain