eLife assessment
This important study provides evidence for CPC-3 mediating induction of the transcription factor CPC-1 in starved Neurospora cells, with CPC-1-mediated recruitment of Gcn5 and acetylation of the FRQ promoter counteracting the function of histone deacetylase HDA1, which in turn maintains high occupancy of the transcription factor WCC and attendant circadian rhythm of FRQ expression. The findings are significant in showing how the well-established pathways for circadian rhythm centered on FRQ gene expression and cross-pathway control centered on CPC-1 induction are integrated to maintain rhythmic cell growth in the face of amino acid limitation. However, the evidence for these claims is incomplete in certain respects and additional statistical analyses and experimental evidence are needed to better support the claims of rhythmic CPC-1 binding at FRQ, of the role of GCN-5 in rhythmic FRQ transcription in starvation conditions, and of rhythmic transcription of CPC-1-regulated amino acid biosynthetic genes.