Stephane Bentolila

Dr. Bentolila’s research is aimed at understanding the nuclear control of plant organelle gene expression. Once free-living prokaryotic organisms, the ancestors of mitochondria and chloroplasts were taken up as endosymbionts first by the ancestral cells of eukaryotes and later on by the ancestral cells of the green lineage of eukaryotes. As a result, gene expression and more specifically RNA metabolism in plant organelles is complex and combines bacterial-like traits with novel features that evolved in the host cell. These complex RNA processes are regulated by families of nucleus-encoded RNA-binding proteins.

One model of mitochondrial gene expression under nucleus control concerns pollen development and was extensively studied by Dr. Bentolila when he joined the Hanson lab as a postdoctoral associate. Cytoplasmic male sterility (CMS) is a phenotypic trait encoded by the mitochondrion which results in the inability of the plant to produce viable pollen. Natural suppressors of CMS called restorers of fertility (Rf) are found in the nucleus and have the ability to restore the production of pollen to plants carrying the deleterious mitochondrial CMS associated gene. Cloning of the first Rf gene identified it as a member of the pentatricopeptide repeat (PPR) proteins, a family of helical-repeat RNA-binding proteins, particularly prevalent in plants.

Recently, Dr. Bentolila has focused on RNA editing, a process that modifies cytidines encoded by genomic DNAs to uridines in plant organelle transcripts. A combinatorial approach involving quantitative genetics, biochemistry and genomics allowed identification of several components of the editosome, the editing machinery responsible for the modification of C to U on organelle transcripts. Pentatricopeptide repeat-containing proteins serve as recognition factors for the proper C to undergo editing. However, additional proteins are needed in the editing complex, and Dr. Bentolila’s work has been instrumental in identifying three additional protein families whose members are present in editing complexes in chloroplasts and/or mitochondria. Integration of next generation sequencing technology in the current research has facilitated the characterization of these new families of plant editing factors. Ultimately, the goal of this research is to reconstitute the plant editosome in vitro, which could pave the way for future genetic engineering of RNAs in plants and other organisms, technology which could benefit the biotechnology industry and society.

Journal Publications

• Gipson, A.B., Hanson, M.R., & Bentolila, S. (2022). The RanBP2 zinc finger domains of chloroplast RNA editing factor OZ1 are required for protein-protein interactions and conversion of C to U. The Plant Journal.109: 215-226.
• Bentolila, S., Gipson, A.B., Kehl, A.J., Hamm, L.N., Hayes, M.L., Mulligan, R.M., &Hanson, M.R. (2021). A RanBP2-type zinc finger protein functions in intron splicing in Arabidopsis mitochondria and is involved in the biogenesis of respiratory complex I. Nucleic Acids Research. 49:3490-3506.
• Gipson, A.B., Giloteaux, L., Hanson, M.R., & Bentolila, S. (2020). Arabidopsis RanBP2-Type Zinc Finger Proteins Related to Chloroplast RNA Editing Factor OZ1. Plants. 9:307.
• Diaz, M. F., Bentolila, S., Hayes, M. L., Hanson, M. R., & Mulligan, R. M. (2017). A protein with an unusually short PPR domain, MEF8, affects editing at over 60 Arabidopsis mitochondrial C targets of RNA editing. The Plant Journal. 92:638-649.
• Shi, X., Hanson, M. R., & Bentolila, S. (2017). Functional diversity of Arabidopsis organelle-localized RNA-recognition motif-containing proteins. Wiley Interdisciplinary Reviews (WIREs): RNA. 8:e1420.
• Shi, X., Castandet, B., Germain, A., Hanson, M. R., & Bentolila, S. (2017). ORRM5, an RNA recognition motif-containing protein, has a unique effect on mitochondrial RNA editing. JXB: Journal of Experimental Botany. 68:2833-2847.
• Hackett, J. B., Shi, X., Kobylarz, A. T., Lucas, M. K., Wessendorf, R. L., Hines, K. M., Bentolila, S., Hanson, M. R., & Lu, Y. (2017). An Organelle RNA Recognition Motif Protein Is Required for Photosystem II Subunit psbF Transcript Editing. Plant Physiology. 173:2278-2293.
• Shi, X., Germain, A., Hanson, M. R., & Bentolila, S. (2016). RNA recognition motif-containing protein ORRM4 broadly affects mitochondrial RNA editing and impacts plant development and flowering. Plant Physiology. 170:294-309.
• Sun, T., Bentolila, S., & Hanson, M. R. (2016). The unexpected diversity of plant organelle RNA editosomes. Trends in Plant Science. 21:962-973.
• Shi, X., Bentolila, S., & Hanson, M. R. (2016). Organelle RNA recognition motif-containing (ORRM) proteins are plastid and mitochondrial editing factors in Arabidopsis. Plant Signaling & Behavior. 11: e1167299.

Presentations and Activities

• Exploration of the involvement of the RanBP2 zinc finger domain in plant organelle RNA processing. Penn State Plant Biology Symposium - RNA Biology. May 2022. University Park, PA.
• Investigating OZ2, a protein related to the plastid editing factor OZ1. 11th International Conference for Plant and Mitochondrial Biology. March 2019. Israel Science Foundation. Ein Gedi, Israel.
• Mitochondrial relevant area session: An unusual PPR-PLS protein controlling the editing extent of over 10% of the mitochondrial editome. 10th International Conference for Plant Mitochondrial Biology. May 2017. Hangzhou, China.
• The Organelle RNA Editing Apparatus. Gordon Research Conference: Chloroplast Biotechnology, Session on Transcription and RNA Metabolism in Plastids. January 2017. Gordon Research Conferences, USDA, Bayer, Wiley, NSF, et al.. Ventura, CA.
• Unraveling the complexity of plant RNA editing machinery. Plant Biology Seminar, Cornell University. November 2016. Cornell University.
• More than PPR Proteins: The Complexity of Plant RNA Editosomes. Gordon Research Conference. June 2016. Mount Snow, USA.