2023-06-27 ワシントン大学セントルイス校
◆この発見は、環境中でRNAがどれくらいの期間存在するかに制限を与える重要な要素となります。また、鉄の豊富な土壌や堆積物におけるRNA分解についての既存の仮定を覆すものです。これにより、DNAとRNAの相対的な量の解釈やウイルスや農薬の研究、そして生命の起源の探求などにおいて、RNA分解のメカニズムと時間軸の理解が重要とされます。
<関連情報>
- https://engineering.wustl.edu/news/2023/New-pathway-discovered-for-RNA-degradation-in-iron-rich-environments.html
- https://pubs.acs.org/doi/10.1021/acs.est.3c01407
鉱物-水界面におけるRNA加水分解 RNA Hydrolysis at Mineral–Water Interfaces
Ke Zhang, Kun-Pu Ho, Anamika Chatterjee, Grace Park, Zhiyao Li, Jeffrey G. Catalano, and Kimberly M. Parker
Environmental Science & Technology Published:May 22, 2023
DOI:https://doi.org/10.1021/acs.est.3c01407
Abstract
As an essential biomolecule for life, RNA is ubiquitous across environmental systems where it plays a central role in biogeochemical processes and emerging technologies. The persistence of RNA in soils and sediments is thought to be limited by enzymatic or microbial degradation, which occurs on timescales that are orders of magnitude faster than known abiotic pathways. Herein, we unveil a previously unreported abiotic pathway by which RNA rapidly hydrolyzes on the timescale of hours upon adsorption to iron (oxyhydr)oxide minerals such as goethite (α-FeOOH). The hydrolysis products were consistent with iron present in the minerals acting as a Lewis acid to accelerate sequence-independent hydrolysis of phosphodiester bonds comprising the RNA backbone. In contrast to acid- or base-catalyzed RNA hydrolysis in solution, mineral-catalyzed hydrolysis was fastest at circumneutral pH, which allowed for both sufficient RNA adsorption and hydroxide concentration. In addition to goethite, we observed that RNA hydrolysis was also catalyzed by hematite (α-Fe2O3) but not by aluminum-containing minerals (e.g., montmorillonite). Given the extensive adsorption of nucleic acids to environmental surfaces, we anticipate previously overlooked mineral-catalyzed hydrolysis of RNA may be prevalent particularly in iron-rich soils and sediments, which must be considered across biogeochemical applications of nucleic acid analysis in environmental systems.
