A cellulose synthase–like protein governs the biosynthesis of <i>Solanum</i> alkaloids
Adam Jóźwiak, Sayantan Panda, Ryota Akiyama, Ayano Yoneda, Naoyuki Umemoto, Kazuki Saito, Shuhei Yasumoto, Toshiya Muranaka, Sachin A. Gharat, Yana Kazachkova, Yonghui Dong, Shlomy Arava, Inna Goliand, Reinat Nevo, Ilana Rogachev, Sagit Meir, Masaharu Mizutani, Asaph Aharoni
Abstract
Decades of research on the infamous antinutritional steroidal glycoalkaloids (SGAs) in Solanaceae plants have provided deep insights into their metabolism and roles. However, engineering SGAs in heterologous hosts has remained a challenge. We discovered that a protein evolved from the machinery involved in building plant cell walls is the crucial link in the biosynthesis of SGAs. We show that cellulose synthase–like M [GLYCOALKALOID METABOLISM15 (GAME15)] functions both as a cholesterol glucuronosyltransferase and a scaffold protein. Silencing GAME15 depletes SGAs, which makes plants more vulnerable to pests. Our findings illuminate plant evolutionary adaptations that balance chemical defense and self-toxicity and open possibilities for producing steroidal compounds in heterologous systems for food, cosmetics, and pharmaceuticals.