2026-10-23 広島大学
図1．細胞壁肥厚の電子顕微鏡観察像．スケールバーは1μm。
＜関連情報＞
- https://www.hiroshima-u.ac.jp/news/100778
- https://www.cell.com/iscience/fulltext/S2589-0042(26)03026-9
分裂酵母における抗真菌ペプチドであるテオネラミドAによる膜撹乱を介した細胞壁グルカンの異所性過剰産生 Ectopic overproduction of cell wall glucan through membrane perturbation by an antifungal peptide theonellamide A in fission yeast
Kensuke Nakao ∙ Vanessa S.D. Carvalho, ∙ Akifumi Suganaga ∙ … ∙ Minoru Yoshida,,, ∙ Juan C. Ribas ∙ Shinichi Nishimura
iScience Published:October 1, 2026
DOI:https://doi.org/10.1016/j.isci.2026.117645
Highlights
•Theonellamide A induces an ectopic overproduction of cell wall glucan
•TNM-A causes persistent localization of glucan synthases at the cell tips and septum
•TNM-A increases active Cdc42 and membrane trafficking of glucan synthases
•Ergosterol is involved in proper activation/inactivation of Cdc42
Summary
Ergosterol has multiple functions in filamentous fungi and yeasts, although only a part of the functions seems to be understood. An antifungal peptide, theonellamide A (TNM-A) induces drastic morphological changes in fission yeast by targeting plasma membrane ergosterol. TNM-A induces overproduction and accumulation of cell wall glucan at growing tips and septum through a yet unknown mechanism. Here, we show that TNM-A causes accumulation of 1,3-β-glucan at cell-polarity sites, not by increased activity of 1,3-β-glucan synthase, but by an increased, persistent localization of the glucan synthases. Screening based on subcellular localization of proteins suggested the involvement of the Rho family GTPase Cdc42, a master regulator of cell polarity. In agreement, TNM-A increased active Cdc42 and enhanced the membrane trafficking of glucan synthases. In conclusion, our chemical genetics analyses using TNM-A suggest that membrane ergosterol regulates the Cdc42 activity, which further regulates the localization of glucan synthases and cell wall biosynthesis.
