AG Thomas Merkle

Nuclear transport of proteins and its role in plant development

Nuclear Transport

Nuclear import of proteins into the cell nucleus is known very well. We are mainly interested in proteins that are also actively exported from the nucleus. Nuclear transport of proteins is regulated by specific nuclear import and nuclear export receptors.

The balance between import and export rates results in a steady state localization of a given protein that can be influenced and changed. This phenomenon is termed nucleo-cytoplasmic partitioning that is exploited as a regulatory mechanism for different signalling pathways in eukaryotic cells.

We are working on specific transcription factors and RNA-binding proteins, which are subject to nuclear export. We examine in detail their functions and the role of nucleo-cytoplasmic partitioning of these proteins for signalling and development, using the model plant Arabidopsis thaliana.


microRNAs: endogenous regulators of gene expression and tools for functional genomics


MicroRNAs (miRNAs) are a group of small non-coding RNAs (ncRNAs) that play very important roles in the endogenous fine-tuning of gene expression, mainly on the post-transcriptional level.

In co-operation with bioinformatics groups, we predicted many novel mRNA targets for miRNAs of the model plant Arabidopsis thaliana. Currently, we are analyzing the endogenous functions of novel selected miRNA targets.

In addition, we are using artificial miRNAs that are designed to specifically target single mRNAs or multiple related mRNAs to generate plants that show synthetic down-regulation of specific gene functions. This method is used as a very effective means for functional genomics approaches.