Ubiquitin-related modifiers of Arabidopsis thaliana influence root development.
Ubiquitins are small peptides that allow for posttranslational modification of proteins. Ubiquitin-related modifier (URM) proteins belong to the class of ubiquitin-like proteins. A primary function of URM proteins has been shown to be the sulfur transfer reaction leading to thiolation of tRNAs, a process that is important for accurate and effective protein translation. Recent analyses revealed that the Arabidopsis genome codes for two URM proteins, URM11 and URM12, which both are active in the tRNA thiolation process. Here, we show that URM11 and URM12 have overlapping expression patterns and are required for tRNA thiolation. The characterization of urm11 and urm12 mutants reveals that the lack of tRNA thiolation induces changes in general root architecture by influencing the rate of lateral root formation. In addition, they synergistically influence root hair cell growth. During the sulfur transfer reaction, URM proteins of different organisms interact with a thiouridylase, a protein-protein interaction that also takes place in Arabidopsis, since URM11 and URM12 interact with the Arabidopsis thiouridylase ROL5. Hence, the sulfur transfer reaction is conserved between distantly related species such as yeast, humans, and plants, and in Arabidopsis has an impact on root development.
Institute of Plant Biology, University of Zürich, Zürich, Switzerland.
Florian
F
John
Institute of Plant Biology, University of Zürich, Zürich, Switzerland.
Matthias
M
Philipp
Institute of Plant Biology, University of Zürich, Zürich, Switzerland.
Ruth-Maria
RM
Leiber
Institute of Plant Biology, University of Zürich, Zürich, Switzerland.
Sanae
S
Errafi
Institute of Plant Biology, University of Zürich, Zürich, Switzerland.
Christoph
C
Ringli
D017360:Arabidopsis / Q000254:growth & development* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000378:metabolism*; D018076:DNA, Complementary / Q000235:genetics; D020869:Gene Expression Profiling; D008856:Microscopy, Fluorescence; D018517:Plant Roots / Q000254:growth & development* / Q000378:metabolism; D012343:RNA, Transfer / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D025841:Small Ubiquitin-Related Modifier Proteins / Q000378:metabolism*; D013457:Sulfur Compounds / Q000378:metabolism*; D013466:Sulfurtransferases / Q000378:metabolism; D020798:Two-Hybrid System Techniques
D029681:Arabidopsis Proteins; D018076:DNA, Complementary; D025841:Small Ubiquitin-Related Modifier Proteins; D013457:Sulfur Compounds; C000591699:URM11 protein, Arabidopsis; C000591700:URM12 protein, Arabidopsis; D012343:RNA, Transfer; D013466:Sulfurtransferases; C024550:thiouridine-tRNA sulfurtransferase