Välkommen till UPSC (1. The Carbon Concentrating Mechanism (CCM) in green algae

1. The Carbon Concentrating Mechanism (CCM) in green algae - Göran Samuelsson

Personnel:
Göran Samuelsson, PhD, Professor
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PhD student: Stefan Burén, Linda Renberg, Tatiana Shutova

Light microscopie picture of Chlamydomonas reinhardtii.

2. Intracellular transport
3. Cell division

Objectives

1. In this project we are mainly working with the green alga Chlamydomonas reinhardtii as a molecular model system. We are now mainly focusing on the function of a lumenal carbonic anhydrase (Cah3) associated with PSII that was discovered by us a few years ago, Karlsson et al 1(998). The location of Cah3 at or close to the PSII reaction centre, together with functional differences of PSII activity in a Cah3 less mutant, gives us reason to believe that it is functioning in the splitting of water and production of molecular oxygen (Villarejo et al ). Our objective is therefore to try to describe both the structure and function of this CA in the water splitting process. We are using both biophysical, biochemical and molecular techniques in our research. In addition we are also trying to describe the interaction between the CA and the 33kDa manganese stabilizing protein.

An electron microscopie photo of a transsection of a cell of C. reinhardtii.

2. This is a newly initiated project with the aim to study transport of nuclear-encoded proteins into the chloroplast. The work is done mainly using Arabidopsis thaliana. In this project we are using molecular/cellular techniques in combination with proteomics.

3. We have recently been able to identify a gene in A. thaliana that is homologous to a gene in Mouse and Human and involved in regulation of cell division. We are now trying to resolve the function of its gene product in plants. This is also a newly initiated project.

Selected publications:

Karlsson, J., Clarke,A.K., Chen,Z., Hugghins,S.Y., Park,S.I., Husic,D., Moroney, J.V. and Samuelsson, G.. A novel a-type carbonic anhydrase associated with the thylakoid membrane in Chlamydomonas reinhardtii is required for growth at ambient CO₂. EMBO Journal 17, .

Moroney, J.V., Bartlett S.G and Samuelsson. G. Carbonic anhydrases in plants and algae. Plant Cell and Environment 24, 141-153.

Villarejo, A., Shutova, T, Moskvin, O, Forssen, M., Klimov, V.V. and Samuelsson G. . A Photosystem II associated carbonic anhydrase regulates the efficiency of photosynthetic oxygen evolution. EMBO Journal 21, .