Société Française de Biochimie et Biologie Moléculaire

Guillaume Hummel - Février 2019

IBMP-Metabolism and trafficking of RNA within the plant cell-Strasbourg Plant RNases T2, but not Dicer-like proteins, are major players of tRNA-derived fragments biogenesis Nucleic Acids Res. 2019 Jan 25;47(2):941-952-doi: 10.1093/nar/gky1156 PMID:30462257*Megel, C., *Hummel, G., Lalande, S., Ubrig, E., Cognat, V., Morelle, G., Salinas-Giegé, T., Duchêne, A. M. & Maréchal-Drouard, L. *co-first authors


Guillaume Hummel, 25 years old, obtained a Master's degree in Plant Biotechnologies and Molecular Biology (2016, Life Sciences Faculty, Strasbourg University). He is currently doing a PhD under the supervision of Laurence Drouard (IBMP (CNRS), Strasbourg University) which aims at figuring out new transfer RNA (tRNA) related mechanisms responsible for plant cell homeostasis. On the one hand, his work investigates at the genetic and epigenetic levels the expression, regulation and functions of some tandemly repeated nuclear tRNA genes in Arabidopsis thaliana. On the other hand, he is also actively studying the biogenesis and functions of tRNAs-derived fragments (tRFs) in Arabidopsis thaliana. In this way, his recent results describe RNases T2 as predominant actors of tRFs biogenesis upon development, ageing and stress adaptation, cutting the trendy debate on the molecular actors responsible for their biogenesis in well-studied model organisms. These important data led to the selected publication entitled “Plant RNases T2, but not Dicer-like proteins, are major players of tRNA-derived fragments biogenesis” and published in the Nucleic Acids Research journal on October 29th, 2018.


Guillaume Hummel
Institut de biologie moléculaire des plantes (IBMP),
“Metabolism and trafficking of RNA within the plant cell” team,
12 rue du Général Zimmer,
67084 Strasbourg cedex,


RNA fragments deriving from tRNAs (tRFs) exist in all branches of life and the repertoire of their biological functions regularly increases. Paradoxically, their biogenesis remains unclear. The human RNase A, Angiogenin, and the yeast RNase T2, Rny1p, generate long tRFs after cleavage in the anticodon region. The production of short tRFs after cleavage in the D or T regions is still enigmatic. Here, we show that the Arabidopsis Dicer-like proteins, DCL1-4, do not play a major role in the production of tRFs. Rather, we demonstrate that the Arabidopsis RNases T2, called RNS, are key players of both long and short tRFs biogenesis. Arabidopsis RNS show specific expression profiles. In particular, RNS1 and RNS3 are mainly found in the outer tissues of senescing seeds where they are the main endoribonucleases responsible of tRNA cleavage activity for tRFs production. In plants grown under phosphate starvation conditions, the induction of RNS1 is correlated with the accumulation of specific tRFs. Beyond plants, we also provide evidence that short tRFs can be produced by the yeast Rny1p and that, in vitro, human RNase T2 is also able to generate long and short tRFs. Our data suggest an evolutionary conserved feature of these enzymes in eukaryotes.