Research

The cysteine-rich receptor-like kinases (CRKs)

The CRKs and the related cysteine-rich receptor-like proteins (CRPs) are groups of receptor-proteins that have undergone drastic expansion in higher plants. We are analyzing the biochemical and physiological roles of the CRKs as well as their molecular function. The work was initiated in the ERA-PG consortium "PROSIG". The consortium has created a comprehensive knockout collection for all CRKs. Now, on this foundation we are busy understanding the molecular biology and biochemistry of the CRKs.

Gene family expansion in plants

We are interested in the underlying reasons for 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. With this idea in mind we are trying to understand the evolution of CRKs and CRPs and whether we can use evolutionary analysis to get clues about their biochemical roles.

Ligand and receptor biology

We use a secreted protein, GRIM REAPER (GRI), and its receptor as model system to investigate the molecular biology of peptide ligands and receptors. GRI is processed by proteases and the resulting peptide is perceived by a receptor-like kinase. GRI is an interesting protein that can induce cell death but also seems to play roles in various developmental aspects.

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.

The cysteine-rich receptor-like protein kinases (CRKs) and the related cysteine-rich receptor-like proteins (CRPs) are groups of receptor-proteins that have undergone drastic expansion in higher plants. We are analyzing the biochemical and physiological roles of the CRKs as well as their molecular function. We are collaborating with several other groups in the ERA-PG consortium "PROSIG" and have created a comprehensive knockout collection for all CRKs.

The CRKs are an intriguing family of receptor proteins. Their striking extracellular domain with conserved cysteine repeats is unique to higher plants. Their biochemical role and the signals that are preceived by the CRKs are currently not known. Starting from the characterization of a crk T-DNA insertion collection and the transcriptional regulation of the CRKs we are now addressing the molecular biology of these receptors. Using several parallel approaches we are currently in process of identifying interacting proteins and substrates for the CRKs as well as creating tools for understanding the role of the conserved cysteines in the extracellular domain.

Publications:

Bourdais G, Burdiak P, Gauthier A, Nitsch L, Salojärvi J, Rayapuram C, Idänheimo N, Hunter K, Kimura S, Merilo E, Vaattovaara A, Oracz K, Kaufholdt D, Pallon A, Anggoro DT, Glów D, Lowe J, Zhou J, Mohammadi O, Puukko T, Albert A, Lang H, Ernst D, Kollist H, Brosché M, Durner J, Borst JW, Collinge D, Karpiński S, Lyngkjær M, Robatzek S, Wrzaczek M*, Kangasjärvi J. 2015. Large-scale phenomics identifies primary and fine-tuning roles for CRKs in responses related to oxidative stress. PLoS Genetics 11(7): e1005373.

Idänheimo N, Gauthier A, Salojärvi J, Siligato R, Brosché M, Kollist H, Mähönen AP, Kangasjärvi J, Wrzaczek M*. 2014. The Arabidopsis thaliana Cysteine-rich Receptor-like Kinases CRK6 and CRK7 protect against apoplastic oxidative stress. Biochem Biophys Res Comm 445(2): 457-462.

Wrzaczek M, Brosché M, Salojärvi J, Kangasjärvi S, Idänheimo N, Mersmann S, Robatzek S, Karpinski S, Karpinska B, Kangasjärvi J. 2010. Transcriptional regulation of the CRK/DUF26 group of Receptor-like protein kinases by ozone and plant hormones in Arabidopsis. BMC Plant Biology 10: 95.

We are interested in the underlying reasons for 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. With this idea in mind we are trying to understand the evolution of CRKs and CRPs and whether we can use evolutionary analysis to get clues about their biochemical roles.

We are also attempting to find models that can describe gene family expansion events in plants which can help to understand plant evolution.

This work is an intensive collaboration with Dr. Jarkko Salojärvi but also Dr. Ari Löytynoja (University of Helsinki, Finland) and Dr. Stefan Wrzaczek (Vienna University of Technology, Austria).

Publications:

Bourdais G, Burdiak P, Gauthier A, Nitsch L, Salojärvi J, Rayapuram C, Idänheimo N, Hunter K, Kimura S, Merilo E, Vaattovaara A, Oracz K, Kaufholdt D, Pallon A, Anggoro DT, Glów D, Lowe J, Zhou J, Mohammadi O, Puukko T, Albert A, Lang H, Ernst D, Kollist H, Brosché M, Durner J, Borst JW, Collinge D, Karpiński S, Lyngkjær M, Robatzek S, Wrzaczek M*, Kangasjärvi J. 2015. Large-scale phenomics identifies primary and fine-tuning roles for CRKs in responses related to oxidative stress. PLoS Genetics 11(7): e1005373.

Jaspers P, Overmyer K, Wrzaczek M, Vainonen JP, Blomster T, Reddy R, Salojärvi J, Kangasjärvi J. 2010. The RST and PARP-like domain containing SRO protein family: analysis of protein structure, function and conservation in land plants. BMC Genomics 11: 170.

We use a secreted protein, GRIM REAPER (GRI), and its receptor as model system to investigate the molecular biology of peptide ligands and receptors. GRI is processed by proteases and the resulting peptide is perceived by a receptor-like kinase. GRI is an interesting protein that can induce cell death but also seems to play roles in various developmental aspects. We are currently aiming to understand the mechanism through which the enzymatically inactive receptor-like protein kinase that perceives GRI functions. We are also identifying novel secreted peptides for further characterization.

This work is a collaboration with Prof. Frank Van Breusegem (VIB Ghent, Belgium), Prof. Kris Gevaert (VIB Ghent, Belgium) and Dr. Hannele Tuominen (UPSC Umeå, Sweden). We also collaborate with Prof. Ykä Helariutta, Dr. Ari-Pekka Mähönen and Prof. Jaakko Kangasjärvi at the University of Helsinki, Finland.

Publications:

Wrzaczek M*, Vainonen JP, Stael S, Tsiatsiani L, Help-Rinta-Rahko H, Gauthier A, Kaufholdt D, Bollhöner B, Lamminmäki A, Staes A, Gevaert K, Tuominen H, Van Breusegem F, Helariutta Y, Kangasjärvi J. 2015. GRIM REAPER peptide binds to receptor kinase PRK5 to trigger cell death in Arabidopsis. EMBO J 34(1): 55-66.

Wrzaczek M, Brosché M, Kollist H, Kangasjärvi J. 2009. Arabidopsis GRI is involved in the regulation of cell death induced by extracellular ROS. Proc Natl Acad Sci USA 106(13): 5412-5417.

Wrzaczek M, Brosché M, Kangasjärvi J. 2009. Scorched earth strategy: Grim Reaper saves the plant. Plant Signaling & Behavior 4(7):1-3.