Yeast PI(3,4,5)P3 controls vacuole fusion through Vam7 and membrane microdomain assembly.

PI(3,4,5)P3 produced by Vps34 is required for yeast vacuole fusion, with PI(3,4,5)P3 inhibition blocking fusion and disrupting SNARE pairing.

• Why it matters: Endolysosomal trafficking is known to depend on other phosphoinositides, but PI(3,4,5)P3’s role in vacuole fusion and the factors it controls was unclear.
• What they did: In Saccharomyces cerevisiae, PI(3,4,5)P3 was generated from PI(4,5)P2 via Vps34; in vitro fusion assays used C8 PI(3,4,5)P3, Grp1-PH, and PTEN, while fluorescence microscopy tracked PI(3,4,5)P3 and vertex enrichment.
• The result: PI(3,4,5)P3 was present on vacuoles and plasma membrane and was eliminated by Vps34 inhibition; it is required for Ypt7 and Vps33 enrichment, for Vam7 retention, and for vacuole acidification in vivo.

AI summary of the abstract · may contain errors · not medical advice · read the paper.