Use of a Yeast tRNase Killer Toxin to Diagnose Kti12 Motifs Required for tRNA Modification by Elongator

Toxins

Michael J. R. Stark¹  Gyung-Tae Kim²  Sang Eun Jun²  Alexander Hammermeister³  Wael Abdel-Fattah³  Raffael Schaffrath⁴  Constance Mehlgarten⁴  Melanie Wagner⁴  Karin D. Breunig⁴  Heike Prochaska⁴  Rościsław Krutyhołowa⁵  Sebastian Glatt⁵ 

[1] Centre for Gene Regulation & Expression, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK;Department of Molecular Biotechnology, Dong-A University, Busan 604-714, Korea;Institut für Biologie, FG Mikrobiologie, Universität Kassel, Heirich-Plett-Str. 40, 34132 Kassel, Germany;Institut für Biologie, Martin Luther Universität Halle-Wittenberg, Weinbergweg 10, 06120 Halle/Saale, Germany;Max Planck Research Group at the Malopolska Centre of Biotechnology, Jagiellonian University, 31-007 Krakow, Poland;

关键词: zymocin;    ribotoxin;    tRNase;    Kti12;    Elongator complex;    tRNA anticodon modification;   

DOI  :  10.3390/toxins9090272

来源: DOAJ

【 摘 要 】

Saccharomyces cerevisiae cells are killed by zymocin, a tRNase ribotoxin complex from Kluyveromyces lactis, which cleaves anticodons and inhibits protein synthesis. Zymocin’s action requires specific chemical modification of uridine bases in the anticodon wobble position (U34) by the Elongator complex (Elp1-Elp6). Hence, loss of anticodon modification in mutants lacking Elongator or related KTI (K. lactis Toxin Insensitive) genes protects against tRNA cleavage and confers resistance to the toxin. Here, we show that zymocin can be used as a tool to genetically analyse KTI12, a gene previously shown to code for an Elongator partner protein. From a kti12 mutant pool of zymocin survivors, we identify motifs in Kti12 that are functionally directly coupled to Elongator activity. In addition, shared requirement of U34 modifications for nonsense and missense tRNA suppression (SUP4; SOE1) strongly suggests that Kti12 and Elongator cooperate to assure proper tRNA functioning. We show that the Kti12 motifs are conserved in plant ortholog DRL1/ELO4 from Arabidopsis thaliana and seem to be involved in binding of cofactors (e.g., nucleotides, calmodulin). Elongator interaction defects triggered by mutations in these motifs correlate with phenotypes typical for loss of U34 modification. Thus, tRNA modification by Elongator appears to require physical contact with Kti12, and our preliminary data suggest that metabolic signals may affect proper communication between them.

【 授权许可】

Unknown