Characterization of a ribosomal p40 homologue gene showing the same pattern of expression as the elongation factor-1α in Arabidopsis thaliana

A genomic clone encoding a ribosomal p40 protein homologue was isolated from an Arabidopsis thaliana genomic library. The deduced amino acid sequence shows high homology with other ribosomal p40 proteins. The structural features of nucleic acid and protein sequences indicate that the Arabidopsis clone (A-p40) is likely a ribosomal associated p40 protein. A single copy of this gene seems to be present in the Arabidopsis genome, however, genes encoding related proteins may be present. The expression of the A-p40 gene was studied in comparison with the expression of the translation elongation factor EF-1α. Both genes show the same pattern of expression in all the tissues studied, as well as during the cell culture cycle. The linkage of both ribosomal proteins to the cytoskeleton is discussed. It is concluded that A-p40 is regulated in a similar way as EF-1α, and that the expression is linked to cycling cells.