Research in the focus

Unravelling the nuclear manipulation by geminiviruses

In cooperation with the Plant Stress Center, Shanghai, China, the Junior Research Group VirusInteract will start a new research project:

Geminiviruses constitute a large and economically important group of single-stranded (ss) DNA plant viruses with circular genomes, causal agents of devastating crop diseases worldwide. Geminiviral replication occurs in the nucleus and uses the plant DNA replication machinery; the geminiviral genome forms minichromosomes and is subjected to epigenetic modifications, which seem to play an important role in the outcome of geminivirus-plant interactions; viral encapsidation also takes place in the nucleus. It is obvious that the nucleus is the most important subcellular compartment for geminiviral invasion; spatial information regarding the subnuclear distribution of virus-related processes, however, is lacking. Interestingly, geminiviral infection and/or expression of specific viral proteins induce characteristic changes in nuclear architecture, e.g. upon combined expression of Abutilon mosaic virus transport proteins, MP and NSP, inner nuclear envelope-derived vesicles invaginate into nuclei, but also appear associated with the nuclear surface. Additionally, changes in the localization of nuclear markers in geminivirus-infected cells also reflect an alteration of nuclear organization. These observations suggest that a concerted action of plant viral replication and shuttling/movement proteins leads to the re-organization of nuclear and membrane domains, which might be essential for viral replication, evasion of plant anti-viral mechanisms, and trafficking. Thus, the objectives of this proposal are i) to gain insight into the nuclear reorganization and manipulation by geminiviruses; ii) to define the nuclear interactome of geminiviruses; and iii) to identify nuclear targets of viral manipulation. Nuclear import, subversion, and export are essential for the establishment of the viral infection; a deep understanding of how these processes occur would pave the way for the design of efficient anti-viral strategies. Because strategies aimed at impairing the viral co-option of the nucleus would potentially impact viral replication, they would minimize the appearance.

The Sino-German Project is funded by the Deutsche Forschungsgemeinschaft (DFG).