DIFFERENTIAL REGULATION OF THE MURINE RIBOSOMAL-PROTEIN L26 GENE IN MACROPHAGE ACTIVATION

In mouse RAW 264.7 macrophages, the gene for ribosomal protein L26 is positively regulated by silica. In order to study L26 gene expression a near full-length cDNA for mouse L26 was isolated and characterized. Sequence analysis revealed that mouse L26 is a 145 amino acid protein highly homologous to other vertebrate L26 proteins. The treatment of R AW 264.7 cells with the inflammatory mediators LPS and IFN gamma induc ed the expression of L26 mRNA but the patterns of expression obtained differed markedly hem silica. On the contrary, TNF alpha acted as a do wn-regulator of L26 gene. Our results suggest that the synthesis of ri bosomal components in response to macrophage activators is inducer-spe cific. Mouse genomic DNA analysis revealed the presence of multiple (1 0-12) sequences related to the L26 gene.