Cloning and Regulation of Schizosaccharomyces pombe Gene Encoding Ribosomal Protein L11

The cDNA encoding ribosomal protein was identified from a cDNA library of Schizosaccharomyces pombe. The nucleotide sequence of the 548 bp cDNA clone reveals an open reading frame, which encodes a putative protein of 166 amino acids with a molecular mass of 18.3 kDa. The amino acid sequence of the S. pombe L11 protein is highly homologous with those of rat and fruit, while it is clearly less similar to those of prokaryotic counterparts. The 1,044 bp upstream sequence, and the region encoding N-terminal 7 amino acids of the genomic DNA were fused into the promoterless β-galactosidase gene of the shuttle vector YEp357 in order to generate the fusion plasmid pHY L11. Synthesis of β-galactosidase from the fusion plasmid varied according to the growth curve. It decreased significantly in the growth-arrested yeast cells that were treated with aluminum chloride and mercuric chloride. However, it was enhanced by treatments with cadmium chloride (2.5 μM), zinc chloride (2.5 μM), and hydrogen peroxide (0.5 mM). This indicates that the expression of the L11 gene could be induced by oxidative stress.