Poster abstracts

Poster number 107 submitted by Noa Perry

Nuclear Level of mtDNA Encoded Non-Coding RNA Regulates Mitochondrial Bioenergetics

Noa A. Perry (Department of Biochemistry, University at Buffalo, State University of New York, Buffalo, NY, United States), Chien-Wen Chen (Department of Genetics and Genome Sciences, School of Medicine, Case Western Reserve University, Cleveland, OH, United States), Yafei Su (Department of Biomedical Engineering, University at Buffalo, State University of New York, Buffalo, NY, United States), Maria Hatzoglou (Department of Genetics and Genome Sciences, School of Medicine, Case Western Reserve University, Cleveland, OH, United States), Yun Wu (Department of Biomedical Engineering, University at Buffalo, State University of New York, Buffalo, NY, United States), Anna Blumental-Perry (Department of Biochemistry, University at Buffalo, State University of New York, Buffalo, NY, United States)

Abstract:
We recently identified a cellular pathway that regulates mitochondrial energy metabolism. The pathway involves the translocation to the nucleus of mito-ncR-LDL805 (mitochondrial non-coding RNA Light stand D-Loop 805), a small ncRNA transcribed by the mitochondrial genome. This ncRNA is highly conserved among mammals, suggesting a function in the regulation of expression of nuclear genes encoding regulators of mitochondrial function. The presence in the nucleus correlates with an increase in the expression of nuclear genes encoding regulators of mitochondrial function and energy metabolism. To investigate the causality between increased levels of mito-ncR-LDL805 and bioenergetics, we enhanced the nuclear expression of mito-ncR-LDL805, by placing the mito-ncR-LDL805 sequence between two small nucleolar RNA genes of pWZ1-vector (Sno-vector). Nuclear overexpression using this construct increased mitochondrial bioenergetics and promoted cell proliferation. We extended our analysis and compared transcriptomic changes induced by delivering enhanced nuclear levels of mito-ncR-LDL805 to MLE12 cells. We found that mito-ncR-LDL805 induces massive transcriptional reprogramming, including upregulation of multiple ETC subunits, Krebs’s cycle limiting step enzymes Idh1, sterols and fatty acid metabolism, as well as transcripts participating in multiple pathways involving PiP3K and AKT1, and extracellular matrix. We further used the Sno-vector system and tagged mmu-mito-ncR-LDL805 at the 3’ end with Mango2 (M2) aptamer (a 24-nt nontoxic fluorogenic RNA aptamer that binds the cell-permeable biotin-conjugated fluorogen Thiazole Orange (TO)1-desthio-biotin). The fusion Sno-mito-ncR-LDL805-M2 transcript is expressed and functional in MLE12 cells. We are using this system to identify mito-ncR-LDL805 interacting nuclear partners, which will help us understand the molecular mechanism of its nuclear function.

References:
SnoVectors for nuclear expression of RNA
Q.-F. Yin, S-B Hu, et al. Nucleic Acids Research, 2015, Vol. 43, No. 1 e5
Blumental-Perry, A., Jobava, R. et al. (2020) Retrograde signaling by a mtDNA-encoded non-coding RNA preserves mitochondrial bioenergetics. Commun Biol 3, 626
Mathuram, T. L., Townsend, D. M., et al. (2022) A Synthetic Small RNA Homologous to the D-Loop Transcript of mtDNA Enhances Mitochondrial Bioenergetics. Front Physiol 13, 772313

Keywords: Mitochondria to nucleus signaling, Small mito-ncRNAs, Nuclear retention via Sno-Vectors