tailieunhanh - Báo cáo khoa học: The amyloplast proteome of potato tuber

Potato (Solanum tuberosum) is the fourth largest crop worldwide in yield, and cv. Kuras is the major starch potato of northern Europe. Storage starch is packed densely in tuber amyloplasts, which become starch gran-ules. Amyloplasts of soil-grown mini-tubers and agar-grown micro-tubers of cv. | ỊFEBS Journal The amyloplast proteome of potato tuber Allan Stensballe1 z Simon Hald1 z Guy Bauw1 Andreas Blennow2 and Karen G. Welinder1 1 Department of Biotechnology Chemistry and EnvironmentalEngineering Aalborg University Denmark 2 Department of Plant Biology Faculty of Life Sciences University of Copenhagen Denmark Keywords amyloplast protein import starch biosynthesis starch granule transit peptides twin-arginine Tat motif Correspondence K. G. Welinder Department of Biotechnology Chemistry and Environmental Engineering Aalborg University Sohngaardsholmsvej49 DK-9000 Aalborg Denmark Fax 45 9814 1808 Tel 45 9940 8467 E-mail kgw@ These authors contributed equally to this work Received 7 December 2007 revised 23 January 2008 accepted 11 February 2008 doi Potato Solanum tuberosum is the fourth largest crop worldwide in yield and cv. Kuras is the major starch potato of northern Europe. Storage starch is packed densely in tuber amyloplasts which become starch granules. Amyloplasts of soil-grown mini-tubers and agar-grown micro-tubers of cv. Kuras were purified. The mini-tuber amyloplast preparation was enriched 10-20-fold and the micro-tuber amyloplast approximately fivefold over comparative total protein extracts. Proteins separated by SDS-PAGE were digested with trypsin analysed by mass spectrometry and identified by MASCOT software searches against an in-house potato protein database and the NCBI non-redundant plant database. The differential growth conditions for mini- and micro-tubers gave rise to rather different protein profiles but the major starch granule-bound proteins were identical for both and dominated by granule-bound starch synthase I starch synthase II and a-glucan water dikinase. Soluble proteins were dominated by starch phosphorylase L-1 other large proteins of the classes starch and sucrose metabolism pentose phosphate pathway glycolysis amino acid metabolism and other proteins such as plastid .