Selection for Protein Kinetic Stability Connects Denaturation Temperatures to Organismal Temperatures and Provides Clues to Archaean Life Romero Romero, María Luisa Risso, Valeria Alejandra Martínez Rodríguez, Sergio Gaucher, Eric A. Ibarra Molero, Beatriz Sánchez Ruiz, José Manuel The relationship between the denaturation temperatures of proteins (Tm values) and the living temperatures of their host organisms (environmental temperatures: TENV values) is poorly understood. Since different proteins in the same organism may show widely different Tm’s, no simple universal relationship between Tm and TENV should hold, other than Tm TENV. Yet, when analyzing a set of homologous proteins from different hosts, Tm’s are oftentimes found to correlate with TENV’s but this correlation is shifted upward on the Tm axis. Supporting this trend, we recently reported Tm’s for resurrected Precambrian thioredoxins that mirror a proposed environmental cooling over long geological time, while remaining a shocking ~50°C above the proposed ancestral ocean temperatures. Here, we show that natural selection for protein kinetic stability (denaturation rate) can produce a Tm$TENV correlation with a large upward shift in Tm. A model for protein stability evolution suggests a link between the Tm shift and the in vivo lifetime of a protein and, more specifically, allows us to estimate ancestral environmental temperatures from experimental denaturation rates for resurrected Precambrian thioredoxins. The TENV values thus obtained match the proposed ancestral ocean cooling, support comparatively high Archaean temperatures, and are consistent with a recent proposal for the environmental temperature (above 75°C) that hosted the last universal common ancestor. More generally, this work provides a framework for understanding how features of protein stability reflect the environmental temperatures of the host organisms. 2024-01-19T09:25:24Z 2024-01-19T09:25:24Z 2016-06-02 info:eu-repo/semantics/article Romero-Romero ML, Risso VA, Martinez- Rodriguez S, Gaucher EA, Ibarra-Molero B, Sanchez-Ruiz JM (2016) Selection for Protein Kinetic Stability Connects Denaturation Temperatures to Organismal Temperatures and Provides Clues to Archaean Life. PLoS ONE 11(6): e0156657. doi:10.1371/journal.pone.0156657 https://hdl.handle.net/10481/86942 10.1371/journal.pone.0156657 eng This work was supported by Feder Funds, Grants BIO2012-34937, BIO2015-66426-R and CSD2009-00088 (JMSR) from the Spanish Ministry of Economy and Competitiveness, Grant CVI-12483 (JMSR) from the "Junta de Andalucía", Grant P09- CVI-5073 (BIM) from the “Junta de Andalucía”, DuPont Young Professor Award (EAG) and Grants NNX13AI08G & NNX13AI10G (EAG) from NASA Exobiology. http://creativecommons.org/licenses/by-nc-nd/4.0/ info:eu-repo/semantics/openAccess Creative Commons Attribution-NonCommercial-NoDerivs 3.0 License Attribution-NonCommercial-NoDerivatives 4.0 Internacional Public Library of Science