Temperature-dependent regulation of the ribosomal small-subunit protein S21 in the cyanobacterium Anabaena variabilis M3.

AUTOR(ES)

Sato, N

RESUMO

The rpsU gene, which encodes the ribosomal small-subunit protein S21 in Anabaena, is not a part of the macromolecular-synthesis operon as in most enterobacteria but rather is located downstream of the rbpA1 gene, which encodes an RNA-binding protein. Two types of transcripts were detected for this gene cluster. The level of the major rbpA1-rpsU transcript was about 10 times higher at 22 degrees C than at 38 degrees C, whereas the minor monocistronic rpsU transcript was more abundant at the higher temperature. The level of the S21 protein in relation to total protein was three times lower at 38 degrees C than at 22 degrees C. Analysis of isolated ribosomes indicated that S21 was present at an equimolar ratio with regard to other ribosomal proteins at 22 degrees C but that its level decreased with temperature. Conversely, the relative abundance of S5 increased with temperature. A decrease in the level of S21 at high temperature was also found in Synechocystis, in which rpsU is located downstream of the rrn operon. These results suggest that S21 is involved in the adaptation to changes in temperature in cyanobacteria.

Documentos Relacionados

• A family of cold-regulated RNA-binding protein genes in the cyanobacterium Anabaena variabilis M3.
• High-Density Microarray of Small-Subunit Ribosomal DNA Probes
• Involvement of the 5'-untranslated region in cold-regulated expression of the rbpA1 gene in the cyanobacterium Anabaena variabilis M3.
• A novel small-subunit ribosomal protein of yeast mitochondria that interacts functionally with an mRNA-specific translational activator.
• Temperature-dependent splicing of β-globin pre-mRNA