Differential expression of genes encoding the hypusine-containing translation initiation factor, eIF-5A, in tobacco.
Two Nicotiana plumbaginifolia cDNA clones, NeIF-5A1 and NeIF-5A2, encoding eukaryotic translation initiation factor eIF-5A (formerly called eIF-4D) were cloned by heterologous screening with Dictyostelium and human eIF-5A probes. eIF-5A is the only protein known to contain a unique amino acid modification, hypusine. Comparison of the Nicotiana deduced amino acid sequences with those of other eIF-5A polypeptides reveals conservation throughout the coding sequence, especially in the region of the hypusine residue. Transcript analysis reveals that NeIF-5A1 is preferentially expressed in photosynthetic tissues, while NeIF-5A2 is constitutively expressed in all plant tissues examined. A polyclonal antibody was raised against NeIF-5A1 overexpressed in E. coli. NeIF-5A1 antiserum crossreacts with an 18 kDa polypeptide doublet in all tobacco tissues examined. At least one polypeptide of ca. 18 kDa from a diversity of higher and lower plants crossreacts with NeIF-5A1 antiserum.
Chamot
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Institute of Plant Physiology, University of Berne, Switzerland.
Kuhlemeier
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D000595:Amino Acid Sequence; D015152:Blotting, Northern; D015153:Blotting, Western; D003001:Cloning, Molecular; D040061:Eukaryotic Initiation Factor-5; D015870:Gene Expression; D008239:Lysine / Q000031:analogs & derivatives / Q000235:genetics; D008969:Molecular Sequence Data; D010448:Peptide Initiation Factors / Q000737:chemistry / Q000235:genetics*; D010947:Plants, Toxic; D016415:Sequence Alignment; D014026:Nicotiana / Q000235:genetics*
D040061:Eukaryotic Initiation Factor-5; D010448:Peptide Initiation Factors; C100028:hypusine; D008239:Lysine