The key mechanism to cell growth has been elucidated

Takeshi NODAShiou-Ling Lu, Center for Frontier Oral Science, Graduate School of Dentistry

A research group led by Prof. Takeshi NODA has revealed for the first time that a type of amino acid, cysteine, binds to the Pib2 protein and activates cells. Cells sense the presence of nutrients such as amino acids, and the protein kinase complex called TORC1 is activated, promoting the synthesis of proteins and lipids to increase cell proliferation. On the other hand, when nutrients are depleted, TORC1 becomes inactive, and the degradation process such as autophagy begins. TORC1 is thought to act as a switch for cell growth and autophagy based on these findings.

Until now, it was not clear how the 20 types of amino acids used in living organisms activate TORC1 in yeast. However, they has recently analyzed the pathways by which various amino acids affect TORC1 and revealed that cysteine directly binds to the Pib2 protein and activates TORC1. This discovery is expected to deepen our understanding of how amino acids are utilized by cells.

The article, “Pib2 is a cysteine sensor involved in TORC1 activation in Saccharomyces cerevisiae,” was published in Cell Reports at DOI: