A Functional Chaperone Triad on the Yeast Ribosome
Overview
Affiliations
The chaperones RAC (ribosome-associated complex), consisting of Ssz1p and zuotin, and Ssb1/2p are associated with ribosomes of yeast. Ssb1/2p was previously shown to form a crosslink product to polypeptides trapped in ribosome-nascent chain complexes (RNCs) in vitro. Here we show that an efficient crosslink of the nascent chain to Ssb1/2p depends on the presence of functional RAC. The crosslink to Ssb1/2p was significantly diminished if (i) RAC was removed from RNCs: a process reversed by addition of purified RAC; (ii) RAC carried a mutation in the J-domain of zuotin, leading to its inactivation in vivo; (iii) RAC's Ssz1p subunit was absent because RNCs were generated in a Deltassz1-derived translation extract. In vivo the same specific set of growth defects caused by the absence of any of the three chaperones was also displayed by a Deltassb1/2Deltassz1Deltazuo1 strain. The combination of in vitro and in vivo data supports a model in which Ssb1/2p, Ssz1p, and zuotin act in concert on nascent chains while they are being synthesized.
Oxidative protein folding in the intermembrane space of human mitochondria.
Zarges C, Riemer J FEBS Open Bio. 2024; 14(10):1610-1626.
PMID: 38867508 PMC: 11452306. DOI: 10.1002/2211-5463.13839.
The ribosome-associated chaperone Zuo1 controls translation upon TORC1 inhibition.
Black A, Williams T, Soubigou F, Joshua I, Zhou H, Lamoliatte F EMBO J. 2023; 42(24):e113240.
PMID: 37984430 PMC: 10711665. DOI: 10.15252/embj.2022113240.
Prions in Microbes: The Least in the Most.
Son M, Han S, Lee S J Microbiol. 2023; 61(10):881-889.
PMID: 37668956 DOI: 10.1007/s12275-023-00070-4.
Yeast Chaperone Hsp70-Ssb Modulates a Variety of Protein-Based Heritable Elements.
Jay-Garcia L, Cornell J, Howie R, Faber Q, Salas A, Chernova T Int J Mol Sci. 2023; 24(10).
PMID: 37240005 PMC: 10218661. DOI: 10.3390/ijms24108660.
Structural inventory of cotranslational protein folding by the eukaryotic RAC complex.
Kisonaite M, Wild K, Lapouge K, Valentin Gese G, Kellner N, Hurt E Nat Struct Mol Biol. 2023; 30(5):670-677.
PMID: 37081320 PMC: 10191838. DOI: 10.1038/s41594-023-00973-1.