A geminivirus replication protein interacts with a protein kinase and a motor protein that display different expression patterns during plant development and infection.
The geminivirus protein AL1 initiates viral DNA replication, regulates its own expression, and induces plant gene transcription. To better understand how AL1 interacts with host proteins during these processes, we used yeast two-hybrid library screening and a baculovirus protein interaction system to identify plant proteins that interact with AL1. These studies identified a Ser/Thr kinase, a kinesin, and histone H3 as AL1 partners. The kinase is autophosphorylated and can phosphorylate common kinase substrates in vitro. The kinesin is phosphorylated in insect cells by a cyclin-dependent kinase. Immunostaining of Nicotiana benthamiana and Arabidopsis showed that kinase protein levels and subcellular location are regulated during plant development and geminivirus infection. By contrast, the kinesin is ubiquitous even though it is associated with the spindle apparatus in mitotic cells. Together, our results establish that AL1 interacts with host proteins involved in plant cell division and development. Possible functions of these host factors in healthy and geminivirus-infected plants are discussed.
Kong
Ling-Jie
LJ
Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC 27695-7622, USA.
Hanley-Bowdoin
Linda
L
D000818:Animals; D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development / Q000821:virology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D001692:Biological Transport / Q000502:physiology; D004279:DNA, Viral / Q000235:genetics; D017791:Geminiviridae / Q000235:genetics / Q000254:growth & development; D018507:Gene Expression Regulation, Developmental; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D006657:Histones / Q000378:metabolism; D017403:In Situ Hybridization; D016547:Kinesins / Q000235:genetics / Q000378:metabolism*; D008868:Microtubule Proteins / Q000378:metabolism; D008938:Mitosis / Q000235:genetics / Q000502:physiology; D008969:Molecular Sequence Data; D010766:Phosphorylation; D011485:Protein Binding; D025941:Protein Interaction Mapping; D011494:Protein Kinases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D014026:Nicotiana / Q000821:virology; D020798:Two-Hybrid System Techniques; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism*
D029681:Arabidopsis Proteins; D004279:DNA, Viral; C469253:GRIMP protein, Arabidopsis; D006657:Histones; D008868:Microtubule Proteins; D014764:Viral Proteins; C080288:replication protein AL1, Begomovirus; D011494:Protein Kinases; C469254:GRIK protein, Arabidopsis; D017346:Protein Serine-Threonine Kinases; D016547:Kinesins