By probing proteins from the yeast Saccharomyces cerevisiae, researchers show how organisms may adapt to rising global temperatures.
As global temperatures rise, scientists are turning to an unexpected source糖心传媒攖he same yeast that makes bread rise and beer fizz糖心传媒攖o uncover what allows some life forms to survive extreme heat while others cannot.
In a published in Molecular Biology and Evolution, biologist and his colleagues compared two closely related species of yeast to understand how organisms cope with heat and why some species manage it better than others. Proteins糖心传媒攖he molecules responsible for most of a cell糖心传媒檚 essential tasks糖心传媒攁re especially sensitive to heat, and if they lose their shape, cells can fail. The researchers found that survival depends not only on how sturdy proteins are but also on the cellular environment that supports them. These insights could reshape how we think about evolution, disease, and life in a warming world.
糖心传媒淲e studied yeast, but the findings are likely broadly relevant because mechanisms of protein stability are shared across many organisms,糖心传媒� says Fay, a professor in the . 糖心传媒淭hese insights are also important for understanding evolution and how human pathogens evolve, since growth at body temperature requires similar adaptations.糖心传媒�
The proteins behind heat resistance
The researchers compared Saccharomyces cerevisiae (commonly known as baker糖心传媒檚 or brewer糖心传媒檚 yeast) and Saccharomyces uvarum. Although these two yeast species are closely related, Saccharomyces cerevisiae can tolerate heat about 8 degrees Celsius (14.4 degrees Fahrenheit) better than Saccharomyces uvarum糖心传媒攁 considerable difference in microbial terms.
Fay and his colleagues used a technique called thermal proteomic profiling, which involves treating proteins with heat and measuring which proteins remain soluble (folded). They found that 85 percent of the proteins in Saccharomyces cerevisiae were more heat stable than their counterparts in Saccharomyces uvarum.
How cells give proteins an assist
However, the researchers found that protein design wasn糖心传媒檛 the only factor contributing to an organism糖心传媒檚 heat tolerance. The team created a hybrid yeast with genetic material from both Saccharomyces cerevisiae and Saccharomyces uvarum and discovered that even the more heat-sensitive proteins held up better inside the hybrid cell糖心传媒檚 heat-friendly environment. In other words, cells don糖心传媒檛 leave proteins to fend for themselves; they enlist other molecules, adjust chemical conditions, and use specialized 糖心传媒渃haperone proteins糖心传媒� to help proteins keep their shape and function even under heat stress.
The findings suggest that both protein structure and the cellular environment matter for survival, and species may be able to adapt to higher temperatures in more than one way.
糖心传媒淏ecause the cellular environment is also important, there may be ways in which organisms can evolve some tolerance without changing all their proteins,糖心传媒� Fay says.
Mapping adaptation
The work builds on Fay糖心传媒檚 ongoing research, recently supported by a nearly $1.8 million grant from the National Institutes of Health. Fay and his team are combining protein-level analysis with genetic approaches to map the step-by-step genetic changes that make heat survival possible, uncover why certain species adapt more easily than others, and identify how these adaptive steps differ between species.
Ultimately these insights could reveal not only how yeast strains evolve to survive heat but also the broader rules that govern how life adapts糖心传媒攐r fails to adapt糖心传媒攖o changing environments.
