The rna2 mutation of yeast affects the processing of actin mRNA as well as ribosomal protein mRNAs

Abstract

The temperature sensitive rna2 mutation of Saccharomyces cerevisiae causes a rapid and dramatic decrease in the abundance of most ribosomal protein mRNAs [6, 14]. We and others have recently shown that the processing of ribosomal protein mRNAs is defective at the nonpermissive temperature, suggesting that inefficient mRNA processing might be responsible for the decline in ribosomal protein mRNA levels [2, 4, 8, 11]. Actin is the only known intron-containing non-ribosomal protein yeast nuclear gene [5, 10]. We show here that the processing of actin mRNA is also defective at the nonpermissive temperature in rna2-containing strains. The observation supports the notion that all intron-containing genes are affected in a similar fashion by the rna2 mutation.