Our research

Receptor-like protein kinases and reactive oxygen species

We are interested in how receptor-like protein kinases (RLKs) are intricately involved in signaling through reactive oxygen species (ROS). Plant genomes encode a large number of RLKs which monitor the extracellular space for signals from other cells and tissues but also for signals from the environment. RLKs participate in coordinating and orchestrating plant development, hormone signaling, responses to abiotic stimuli and also recognition of pathogenic and beneficial microbes. We concentrate on the cysteine-rich RLKs (CRKs) and together with the ERA-PG consortium “PROSIG” we have created a comprehensive knockout collection for all CRKs.

We are now dissecting the protein complexes containing CRKs and analyze the dynamics of the interactions. CRKs interact with a number of plasma membrane-localized proteins which are involved in various aspects of signaling including ion transport, cell wall remodeling, vesicle transport, pathogen recognition, ROS signaling and response to abiotic stress. The CRK2 protein complexes are highly dynamic and change upon signal perception. Investigation of substrate proteins for CRKs has allowed us to determine the effects of phosphorylation by CRKs on the respective targets.

The CRKs are one of the largest groups of RLKs in plants. However, their expansions are to a large extant lineage-specific. This poses a severe challenge for translational approaches rooted in the model plant Arabidopsis thaliana. We use the CRKs as a model to understand gene family expansions in plants. In the most general sense we are asking why many gene families in higher plants have expanded considerably compared to animals and other organisms. The CRKs are closely related to plasmodesmata-localized proteins (PDLPs) and a group os secreted proteins, the cysteine-rich receptor-like secreted proteins (CRRSPs). Using this large phylogenetic group of proteins we can use evolutionary analysis to obtain further clues about their biochemical roles and identify conserved versus specialized functions of those proteins in different plants.

We are supported by the University of Helsinki, the Doctoral Programme in Plant Science (DPPS) and the Academy of Finland. We are also a member of the Centre of Excellence in the Molecular Biology of Primary Producers (funded by the Academy of Finland) and the Viikki Plant Science Centre (ViPS). We are also collaborating with a large number of groups all over the world.