tailieunhanh - Báo cáo khoa học: Arabidopsis ATPase family gene 1-like protein 1 is a calmodulin-binding AAA+-ATPase with a dual localization in chloroplasts and mitochondria

Members of the AAA+ -ATPase superfamily (ATPases associated with vari-ous cellular activities) are found in all kingdoms of life and they are involved in very diverse cellular processes, including protein degradation, membrane fusion or cell division. | ễFEBS Journal Arabidopsis ATPase family gene 1-like protein 1 is a calmodulin-binding AAA -ATPase with a dual localization in chloroplasts and mitochondria Johanna Bussemer1 Fatima Chigri1 2 and Ute C. Vothknecht1 2 1 Department of Biology I LMU Munich Planegg-Martinsried Germany 2 Center for Integrated Protein Science Munich at the Department of Biology of the LMU Munich Planegg-Martinsried Germany Keywords AAA -ATPase calcium-signaling calmodulin chloroplasts plant mitochondria Correspondence U. Vothknecht Department of Biology 1 GroBhaderner Strasse 2-4 D-82152 Planegg-Martinsried Germany Fax 49 89 2180 74661 Tel 49 89 2180 74660 E-mail vothknecht@ Website http personen professuren vothknecht Received 31 March 2009 revised 13 May 2009 accepted 14 May 2009 doi Members of the AAA -ATPase superfamily ATPases associated with various cellular activities are found in all kingdoms of life and they are involved in very diverse cellular processes including protein degradation membrane fusion or cell division. The Arabidopsis genome encodes approximately 140 different proteins that are putative members of this superfamily although the exact function of most of these proteins remains unknown. Using affinity chromatography on calmodulin-agarose with chloroplast proteins we purified a 50 kDa protein encoded by AT4G30490 with similarity to the ATPase family gene 1 protein from yeast. Structural analysis showed that the protein possesses a single AAA-domain characteristic for members of the AAA -ATPase superfamily and that this contains all features specific to proteins of the ATPase family gene 1-like subfamily. In vitro pull-down as well as cross-linking assays corroborate calcium-dependent binding of the protein to calmodulin. The calmodulin binding domain could be located to a region of 20 amino acids within the AAA-domain in close proximity to the Walker A motif. Our analysis further showed that