Function of microtubules in intercellular transport of plant virus RNA.
Cell-to-cell progression of tobacco mosaic virus (TMV) infection in plants depends on virus-encoded movement protein (MP). Here we show that a conserved sequence motif in tobamovirus MPs shares similarity with a region in tubulins that is proposed to mediate lateral contacts between microtubule protofilaments. Point mutations in this motif confer temperature sensitivity to microtubule association and viral-RNA intercellular-transport functions of the protein, indicating that MP-interacting microtubules are functionally involved in the transport of vRNA to plasmodesmata. Moreover, we show that MP interacts with microtubule-nucleation sites. Together, our results indicate that MP may mimic tubulin assembly surfaces to propel vRNA transport by a dynamic process that is driven by microtubule polymerization.
Boyko
V
V
Friedrich Miescher-Institute, Maulbeerstrasse 66, CH-4058 Basel, Switzerland.
Ferralli
J
J
Ashby
J
J
Schellenbaum
P
P
Heinlein
M
M
D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000818:Animals; D001692:Biological Transport; D019556:COS Cells; D002522:Chlorocebus aethiops; D017124:Conserved Sequence; D049452:Green Fluorescent Proteins; D007424:Intracellular Fluid / Q000378:metabolism; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D008870:Microtubules / Q000378:metabolism / Q000502:physiology*; D008969:Molecular Sequence Data; D053830:Plant Viral Movement Proteins; D010947:Plants, Toxic; D012367:RNA, Viral / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D013696:Temperature; D014026:Nicotiana; D014027:Tobacco Mosaic Virus / Q000235:genetics*; D014404:Tubulin / Q000235:genetics; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism*
D008164:Luminescent Proteins; D053830:Plant Viral Movement Proteins; D012367:RNA, Viral; D014404:Tubulin; D014764:Viral Proteins; D049452:Green Fluorescent Proteins