RT Journal Article
SR Electronic
T1 Intricate regulation of ribosome biogenesis genes in response to mTORC1 signaling
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2021.01.04.425249
DO 10.1101/2021.01.04.425249
A1 Sanjay Kumar
A1 Muneera Mashkoor
A1 Priya Balamurugan
A1 Anne Grove
YR 2021
UL http://biorxiv.org/content/early/2021/01/04/2021.01.04.425249.abstract
AB Genes encoding ribosomal proteins are repressed in response to inhibition of mTORC1. In Saccharomyces cerevisiae, this involves dissociation of the activator Ifh1p in a process that depends on Utp22p, a protein that also functions in pre-rRNA processing. Ifh1p has a paralog, Crf1p, which can mediate mTORC1 inhibition by acting as a repressor. Ifh1p and Crf1p derive from a common ancestor, which may have acted as both an activator and a repressor. We report here that UTP22 and RRP7, which encodes another pre-rRNA processing factor, are controlled by mTORC1; both gene promoters are bound by Ifh1p, which dissociates on mTORC1 inhibition. Notably, Crf1p acts as an activator as evidenced by reduced expression in a crf1Δ strain. By contrast, Crf1p is required to repress expression of HMO1, which encodes a cofactor involved in communicating mTORC1 activity to target genes. Our data therefore indicate that Crf1p exhibits the dual repressor/activator functions of the Ifh1p-Crf1p ancestor.Competing Interest StatementThe authors have declared no competing interest.