Albrecht von Arnim, Ph. D.
Department of Biochemistry, Cellular and Molecular Biology
Phone: (865) 974-6206
Walter Life Science M407
The past ten years have witnessed a renaissance in our appreciation for the role of RNA in gene regulation. Protein synthesis (translation) in particular remains poorly understood, although translational control affords a rapid means to amplify changes in gene activity that occur at the level of transcription.
We are using the reference plant Arabidopsis thaliana because of the excellent genetic resources available in this species. A reporter gene system was developed to monitor the translation status of specific genes in response to external signals, such as the light environment. We are combining this tool with mutations affecting individual translation initiation factors in an effort to assign specific functions to these proteins in translational control. Our data exemplify that generic initiation factors can contribute to the sequence-specific regulation of translational efficiency. Specifically, we implicated the H subunit of the largest initiation factor, eIF3, in the control of translation by upstream open reading frames, a type of regulatory device present in the 5’ leader of many mRNAs. Furthermore, we have learned how to use the toolkit of genomics, such as microarrays and bioinformatics, to survey the translation status of the entire set of cellular mRNAs. Experiments such as these are poised to reveal systematically which mRNAs are bundled together into regulons of translational control.
This work is helping us to understand how plants respond to their environment, has implications for the mechanisms of translational control in eukaryotes in general, and it may lead to novel ways to manipulate gene expression in the context of biotechnology.
Independently, we are engaged in developing biosensor technology for monitoring specific cellular events, in particular protein-protein interactions. To this end, we are harnessing a biophysical phenomenon, termed bioluminescence resonance energy transfer (BRET), which allows one to measure directly whether and when two proteins associate with each other in a living organism in real time. These and other related biosensors can yield direct and immediate insights into the mechanisms of life in plants and animals.
Roy, B., Vaughn, J.N., Kim, B.H., Zhou, F., Gilchrist, M.A., and von Arnim, A.G. (2010) The h subunit of eIF3 promotes reinitiation competence during translation of mRNAs harboring upstream open reading frames. RNA. 16:748-61.
Li, J.F., Park, E., von Arnim A.G., and Nebenführ, A. (2009) The FAST technique: a simplified Agrobacterium-based transformation method for transient gene expression analysis in seedlings of Arabidopsis and other plant species. PlantMethods. 5:6.
Kim, B.H. and von Arnim, A.G.. (2009) FIERY1 regulates light-mediated repression of cell elongation and flowering time via its 3'(2'),5'-bisphosphate nucleotidase activity. Plant J. 58:208-19.
Stahle, M.I., Kuehlich, J., Staron, L., von Arnim, A.G., and Golz JF. (2009) YABBYs and the transcriptional corepressors LEUNIG and LEUNIG_HOMOLOG maintain leaf polarity and meristem activity in Arabidopsis. Plant Cell. 21:3105-18.
Li, J.-F., Park, E., von Arnim, A.G. and Nebenführ, A. (2009). Fast Agrobacterium-mediated seedling transformation in Arabidopsis and other plant species. Plant Methods 5:6.
Woo, J.C. and von Arnim, A.G. (2008) Mutational optimization of the coelenterazine-dependent luciferase from Renilla. Plant Methods. 4:23.
Kim, B.H., and von Arnim, A.G. (2008). FIERY1 regulates light-mediated repression of cell elongation and flowering time via its 3’(2’),5’-bisphosphate nucleotidase activity. Plant Journal 58:208-19.