specific targeting of a plasmodesmal protein affecting cell-to-cell communication影响细胞间通讯plasmodesmal蛋白的特定目标.pdfVIP

PLoS BIOLOGY Specific Targeting of a Plasmodesmal Protein Affecting Cell-to-Cell Communication 1 1¤ 2,3 1 1* Carole L. Thomas , Emmanuelle M. Bayer , Christophe Ritzenthaler , Lourdes Fernandez-Calvino , Andrew J. Maule ´ 1 John Innes Centre, Norwich Research Park, Colney, Norwich, United Kingdom, 2 Institut de Biologie Moleculaire des Plantes du CNRS (UPR2357), Strasbourg, France, ´ 3 Universite Louis Pasteur (Strasbourg 1), Strasbourg, France Plasmodesmata provide the cytoplasmic conduits for cell-to-cell communication throughout plant tissues and participate in a diverse set of non–cell-autonomous functions. Despite their central role in growth and development and defence, resolving their modus operandi remains a major challenge in plant biology. Features of protein sequences and/or structure that determine protein targeting to plasmodesmata were previously unknown. We identify here a novel family of plasmodesmata-located proteins (called PDLP1) whose members have the features of type I membrane receptor-like proteins. We focus our studies on the first identified type member (namely At5g43980, or PDLP1a) and show that, following its altered expression, it is effective in modulating cell-to-cell trafficking. PDLP1a is targeted to plasmodesmata via the secretory pathway in a Brefeldin A–sensitive and COPII-dependent manner, and resides at plasmodesmata with its C-terminus in th