G proteins diverge and conquer

Abstract

Evolution In plants, signaling through G (heterotrimeric GTP-binding) proteins involves either canonical Gα proteins, which are structurally and functionally similar to animal Gα proteins, or extra-large Gα (XLG) proteins. Urano et al. found that plant canonical Gα proteins evolved slowly, like their animal counterparts, and were involved in developmental processes. In contrast, XLG proteins rapidly diversified early in the land plant lineage and mediated stress responses. Thus, diversification of plant XLG proteins coincided with the colonization of land and may have helped plants to withstand the new stresses encountered in this environment. Sci. Signal. 9 , ra93 (2016).