Characterization of plant eukaryotic translation initiation factor 6 (eIF6) genes: The essential role in embryogenesis and their differential expression in Arabidopsis and rice

• Published in: Biochemical and biophysical research communications Vol. 397; no. 4; pp. 673 - 678
• Main Authors: Kato, Yuki, Konishi, Mineko, Shigyo, Mikao, Yoneyama, Tadakatsu, Yanagisawa, Shuichi
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 09-07-2010
• Subjects: Ammonia induction; Arabidopsis; Arabidopsis - embryology; Arabidopsis - genetics; eIF6; Eukaryotic Initiation Factors - genetics; Eukaryotic Initiation Factors - physiology; Gene Expression Regulation, Plant; Genes, Plant - physiology; Introns - genetics; Nitrogen response; Oryza - embryology; Oryza - genetics; Ribosome biogenesis; Rice; RT; MSX; Ribosome biogenesis; Arabidopsis; Nitrogen response; eIF6; Ammonia induction; Rice
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2010.06.001

Eukaryotic translation initiation factor 6 (eIF6) is an essential component of ribosome biogenesis. In our present study, we characterize plant eIF6 genes for the first time. Although a single gene encodes eIF6 in yeast and animals, two genes were found to encode proteins homologous to animal and yeast eIF6 in
Arabidopsis and rice, denoted At
-eIF6;1 and At
-eIF6;2, and O
s-eIF6;1 and Os
-eIF6;2, respectively
. Analysis of the yeast
eif6 (
tif6) mutant suggested that plant eIF6, at least in the case of At-eIF6;1, can complement the essential function of eIF6 in yeast. Evidence for the essential role of eIF6 in plants was also provided by the embryonic-lethal phenotype of the
at-
eif6;1 mutant. In contrast, At
-eIF6;2 appears not to be essential due to its very low expression level and the normal growth phenotype of the
eif6;2 mutants. Consistent with the putative role of plant eIF6 in ribosome biogenesis,
At-eIF6;1 is predominately expressed in tissues where cell division actively proceeds under the control of intronic
cis-regulatory elements. On the other hand, both O
s-eIF6;1 and Os
-eIF6;2 are probably active genes because they are expressed at significant expression levels. Interestingly, the supply of ammonium nitrate as a plant nutrient was found to induce specifically the expression of Os-
eIF6;2. Our present findings indicate that the eIF6 genes have differently evolved in plant and animal kingdoms and also in distinct plant species.