Post-transcriptional regulation of ura4⁺ gene expression by glucose in Schizosaccharomyces pombe

Glucose-inducible gene expression is a fundamental cellular response for optimal cell growth, but identities of glucose-inducible genes and its regulatory mechanism remain largely elusive in Schizosaccharomyces pombe. Here we report that ura4⁺, encoding orotidine monophosphate decarboxylase (OMPdecase), shows glucose-inducible expression regulated at post-transcriptional level. The ura4⁺ mRNA level was rapidly decreased by ∼50% within 20 min after glucose depletion and it was readily recovered upon glucose-readdition within 1 h. Glucose at above 2% similarly raised the transcript level of ura4⁺, while low concentration (0.1%) was not effective. Interestingly, control of mRNA turnover would be the main regulatory step of the glucose-dependent expression of ura4⁺. Moreover, stress-activated MAPK (SAPK) pathway was partially responsible for the glucose-regulated expression of ura4⁺ and rrg1⁺, another example of glucose-dependent mRNA stability control in S. pombe. These results suggest that the SAPK pathway might participate in the glucose-dependent regulation of ura4⁺ and rrg1⁺ mRNA stabilities.