The use of the yeast model for the study of the molecular and cellular effects of the pathogenic base substitutions in human mitochondrial tRNA genes has recently been validated by the finding that the suppressing factors identified in yeast (the mitochondrial protein elongation factor EF-Tu and the cognate aminoacyl-tRNA synthetase) have suppressing activities also in human cells. In this paper we report a detailed analysis of the cross-suppressing activities of valyl- and leucyl-tRNA synthetases on different tRNA mutants. Glycerol growth, respiration, Northern analysis consistently show that similar suppressing effects can be obtained by these two yeast synthetases and by the orthologous human enzymes. As a whole the present data indicate that the suppression by mt aa-RS is probably not related to the enzyme activities per se. and may be due to a stabilizing chaperon-like effect of the synthetase molecules on the tRNA structure altered by the mutations. (C) 2010 Elsevier B.V. All rights reserved.
Aminoacyl-tRNA synthetases are multivalent suppressors of defects due to human equivalent mutations in yeast mt tRNA genes / Montanari, Arianna; DE LUCA, Cristina; Frontali, Laura; Francisci, Silvia. - In: BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH. - ISSN 0167-4889. - 1803:9(2010), pp. 1050-1057. [10.1016/j.bbamcr.2010.05.003]
Aminoacyl-tRNA synthetases are multivalent suppressors of defects due to human equivalent mutations in yeast mt tRNA genes
MONTANARI, Arianna;DE LUCA, CRISTINA;FRONTALI, Laura;FRANCISCI, Silvia
2010
Abstract
The use of the yeast model for the study of the molecular and cellular effects of the pathogenic base substitutions in human mitochondrial tRNA genes has recently been validated by the finding that the suppressing factors identified in yeast (the mitochondrial protein elongation factor EF-Tu and the cognate aminoacyl-tRNA synthetase) have suppressing activities also in human cells. In this paper we report a detailed analysis of the cross-suppressing activities of valyl- and leucyl-tRNA synthetases on different tRNA mutants. Glycerol growth, respiration, Northern analysis consistently show that similar suppressing effects can be obtained by these two yeast synthetases and by the orthologous human enzymes. As a whole the present data indicate that the suppression by mt aa-RS is probably not related to the enzyme activities per se. and may be due to a stabilizing chaperon-like effect of the synthetase molecules on the tRNA structure altered by the mutations. (C) 2010 Elsevier B.V. All rights reserved.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.