Recognizing Plant Cell authors: Marie-Christin Baune

Marie-Christin Baune, first author of The Arabidopsis Plastidial Glucose-6-phosphate Transporter GPT1 is Dually Targeted to Peroxisomes via the Endoplasmic Reticulum

Current Position: Post-doctoral researcher at German Institute of Food Technology

Education: BSc and MSc in Plant Biotechnology from Leibniz University Hannover; PhD in Molecular Plant Biology from University Münster

Non-scientific Interests: cycling, hiking, sewing, and reading

Brief bio: I am a PhD graduate from University Münster, and the research presented in this paper was a part of my thesis work in the lab of Prof. Dr. Antje von Schaewen. I was always drawn by metabolism reactions and biochemistry, but I am totally against animal testing. Thus, studying the fascinating metabolism of plants enabled to follow my interests without conflict. For my PhD I aimed to better understand the role of the oxidative pentose-phosphate pathway (OPPP) enzymes in peroxisomes of Arabidopsis thaliana including potential translocators for substrate exchange. Here, we show that the plastidial Glucose-6-Phosphate/Phosphate Translocator 1 (GPT1) can be recruited to peroxisome membranes via the ER, most likely in a redox-dependent manner. Even with uncleaved transit peptide the protein is capable of exchanging OPPP substrate versus product, completing the oxidative part of the OPPP to deliver NADPH in peroxisomes. Peroxisomal loss of GPT1 is lethal and can’t be rescued by GPT2, showing 81% sequence identity but strict plastidial targeting. The potential implications of this finding and probable targeting regulation mechanisms are discussed in the paper.