Poster abstracts
Poster number 53 submitted by Theodore Lemuel Joseph Mathuram
Identification of human homologue of mtDNA encoded retrograde signaling molecule, mmu-mito-ncR805
T. L. Mathuram (Department of Biochemistry, University at Buffalo, NY, USA), Y. Perry (Department of Surgery, University at Buffalo, NY, USA), A. Blumental-Perry (Department of Biochemistry, University at Buffalo, NY, USA)
Abstract:
We previously discovered mtDNA-encoded small ncRNA, mmu-mito-ncR805 (1), which increases in Alveolar Epithelial Type II (AETII) during the stress of smoking (SS). Recovery from SS characterizes by distribution of mmu-mito-ncR805 to the nucleus. Redistribution helps to preserve mitochondrial bioenergetics. Mmu-mito-ncR-805 maps to the D-loop of the mtDNA at the beginning of light strand promoter (LSP). Its sequence is not conserved between mouse and human. Nevertheless, identification of human homologue is important because mitochondrial stress and malfunction drives multiple human pathologies. The goal of this study was to identify human homologue of mmu-mito-ncR805 based on genomic location, kinetics and function during stress. Existing databases that contained transcripts originating from the D-loop of human mitochondrial genome were re-analyzed and 4 potential transcripts were identified. Their presence in the relevant human cell lines was confirmed via Northern blot analysis. RNA probes were designed to exclude cross-reactivity to Nuclear Mitochondrial DNA (NUMTS). Mitochondrial origin of the transcripts was further confirmed by their absence in cells with inhibited mitochondrial transcription (2). Mitochondria specific ~260 bp transcript (hsa-mito-ncR-D-loop-805) that originate from the transcription initiation site of human D-loop was further analyzed, and found to increase in its levels during SS. hsa-mito-ncR-D-loop-805 demonstrated dotted pattern throughout the cell, with dots juxtaposed, but not overlapping with mitochondrial protein Tom20. The dots became smaller, and some nuclear localization was detectable during recovery from SS. We therefore identified hsa-mito-ncR-D-loop-805 as a candidate to be a human homologue of mmu-mito-ncR805 retrograde signaling molecule. Our current research is validating hsa-mito-ncR-D-loop-805 levels, kinetics and retrograde signaling function in primary human AETII cells.
References:
1. Blumental-Perry A, Jobava R, Bederman I, Degar AJ, Kenche H, Guan BJ, Pandit K, Perry NA, Molyneaux ND, Wu J, Prendergas E, Ye ZW, Zhang J, Nelson CE, Ahangari F, Krokowski D, Guttentag SH, Linden PA, Townsend DM, Miron A, Kang MJ, Kaminski N, Perry Y, Hatzoglou M. Retrograde signaling by a mtDNA-encoded non-coding RNA preserves mitochondrial bioenergetics. Commun Biol. 2020 Oct 30;3(1):626. doi: 10.1038/s42003-020-01322-4. PMID: 33127975; PMCID: PMC7603330.
2. Gear AR. Rhodamine 6G. A potent inhibitor of mitochondrial oxidative phosphorylation. J Biol Chem. 1974 Jun 10;249(11):3628-37. PMID: 4275428.
Keywords: mmu-mito-ncR805, mtDNA-encoded small ncRNA, retrograde signaling molecule