RT Journal Article SR Electronic T1 The TGB1 Movement Protein of Potato virus X Reorganizes Actin and Endomembranes into the X-Body, a Viral Replication Factory JF Plant Physiology JO Plant Physiol. FD American Society of Plant Biologists SP 1359 OP 1370 DO 10.1104/pp.111.189605 VO 158 IS 3 A1 Tilsner, Jens A1 Linnik, Olga A1 Wright, Kathryn M. A1 Bell, Karen A1 Roberts, Alison G. A1 Lacomme, Christophe A1 Santa Cruz, Simon A1 Oparka, Karl J. YR 2012 UL http://www.plantphysiol.org/content/158/3/1359.abstract AB Potato virus X (PVX) requires three virally encoded proteins, the triple gene block (TGB), for movement between cells. TGB1 is a multifunctional protein that suppresses host gene silencing and moves from cell to cell through plasmodesmata, while TGB2 and TGB3 are membrane-spanning proteins associated with endoplasmic reticulum-derived granular vesicles. Here, we show that TGB1 organizes the PVX “X-body,” a virally induced inclusion structure, by remodeling host actin and endomembranes (endoplasmic reticulum and Golgi). Within the X-body, TGB1 forms helically arranged aggregates surrounded by a reservoir of the recruited host endomembranes. The TGB2/3 proteins reside in granular vesicles within this reservoir, in the same region as nonencapsidated viral RNA, while encapsidated virions accumulate at the outer (cytoplasmic) face of the X-body, which comprises a highly organized virus “factory.” TGB1 is both necessary and sufficient to remodel host actin and endomembranes and to recruit TGB2/3 to the X-body, thus emerging as the central orchestrator of the X-body. Our results indicate that the actin/endomembrane-reorganizing properties of TGB1 function to compartmentalize the viral gene products of PVX infection.