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TORC1 phosphorylates and inhibits the ribosome preservation factor Stm1 to activate dormant ribosomes

ABSTRACT: Target of rapamycin complex 1 (TORC1) promotes biogenesis and inhibits degradation of ribosomes in response to nutrient availability. To ensure a basal supply of ribosomes, cells preserve a small pool of dormant ribosomes under nutrient-limited conditions. The regulation of dormant ribosomes is poorly characterized. Here, we show that upon inhibition of TORC1 by rapamycin or nitrogen starvation, Stm1 (suppressor of target of Myb protein 1) forms non-translating, dormant 80S ribosomes. Furthermore, Stm1-bound 80S ribosomes are protected from proteasomal degradation. Upon re-feeding, TORC1 directly phosphorylates and inhibits Stm1, thereby reactivating translation. Finally, SERBP1 (SERPINE1 mRNA binding protein), a mammalian ortholog of Stm1, forms dormant 80S ribosomes upon mTORC1 inhibition in mammalian cells. Thus, TORC1 regulates ribosomal dormancy in an evolutionarily conserved manner via a ribosome preservation factor.

INSTRUMENT(S): Orbitrap Fusion Lumos

ORGANISM(S): Homo Sapiens (human) Saccharomyces Cerevisiae (baker's Yeast)

SUBMITTER: Danilo Ritz

LAB HEAD: Alexander Schmidt

PROVIDER: PXD037117 | Pride | 2023-01-19

REPOSITORIES: Pride

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			Action	DRS
	001_Pilot_3ul.raw	Raw
	001_Pilot_3ul__F068277_.mzid.gz	Mzid
	001_Pilot_3ul__F068277_.mzid_001_Pilot_3ul__F068277_.MGF	Mzid
	001_ss_036_PO4_D22.raw	Raw
	001_ss_036_PO4_D22__F068242_.mzid.gz	Mzid

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