Like bacteria, yeasts are found everywhere, including within and around our bodies. Additionally, yeasts can cause illness and infection just like bacteria. Each year, yeast infects roughly 150 million people, and it kills about 1.7 million people, mostly immunocompromised people.

Human immune system cells and yeast cells both employ chemical processes to choose when to divide. University of Arizona researchers have found minuscule distinctions between the two cell types that could facilitate the development of antifungal medications that could focus on the body's disease-causing yeasts while safeguarding the immune system.

Their study, which was published in the journal eLife, has implications for medication development as well as for understanding the historical evolution of a growth regulation system that is common to all multicellular creatures. Target of Rapamycin Kinase Complex 1, or TORC1, is a protein complex that the scientific community is well aware controls cell proliferation in a variety of organisms, including yeasts and humans. But lately, a protein known as Ait1 was found to be the catalyst for this process in yeasts. It is a TORC1 regulator and nutrition sensor.

When Ait1 is working properly, it shuts down TORC1 in yeast cells to prevent cell proliferation when the cells are starved for nutrients. In terms of evolution, Ait1 has only undergone significant change in the last 200 million years. A TORC1 regulator known as Rheb appears to have vanished from the cells of numerous creatures around 200 million years ago, precisely at the same time when Ait1 developed.

We demonstrated that some of the early TORC1 regulators discovered in humans, such as Rheb, had been lost in yeasts that had acquired Ait1 200 million years earlier, according to Capaldi. The likelihood that other single-celled creatures acquired novel regulators akin to Ait1 is therefore very high. Now that they are potential drug targets, people can go out and hunt them down.

The National Institute of General Medical Sciences financed the research. Through Tech Launch Arizona, the university division that commercialises academic discoveries, the researchers have applied for a patent for their discovery as a target for antifungal drugs.