Expression data from fission yeast deletion mutant of Klf1, a C2H2 zinc finger-transcription factor, in G0 and VE phases

Fission yeast Schizosaccharomyces pombe is a model for studying cellular quiescence. Shifting to medium without a nitrogen-source induces proliferative cells to enter long-term G0 quiescence. Klf1 is a Kruppel-like transcription factor with a 7-amino acid-spaced C2H2-type zinc finger motif. The deletion mutant klf1 normally divides in vegetative medium, but proliferation is not restored after long-term G0 quiescence. Cell biologic, transcriptomic, and metabolomic analyses revealed a unique phenotype of the klf1 mutant in quiescence. Mutant cells had diminished transcripts related to signaling molecules for switching to differentiation. In contrast, proliferative metabolites for cell-wall assembly and antioxidants significantly increased. Further, the size of the klf1 cells is markedly increased during quiescence due to the aberrant accumulation of calcofluor-positive chitin-like materials beneath the cell wall. After 4 weeks quiescence, the ability for reversible proliferation is lost, but energy metabolism is maintained. Klf1 thus plays a role in G0 phase longevity through enhancing the differentiation signal and suppressing metabolism for growth. If Klf1 is lost, S. pombe fails to maintain a constant cell size during quiescence.

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