ESCRT elicits vacuolar fission in the absence of Vps4 in budding yeast

Most Naoshia Tasnin; Tsuneyuki Takuma; Yuka Takahashi; Takashi Ushimaru

doi:10.1016/j.bbrc.2024.151244

ESCRT elicits vacuolar fission in the absence of Vps4 in budding yeast

Biochem Biophys Res Commun. 2024 Dec 31:746:151244. doi: 10.1016/j.bbrc.2024.151244. Online ahead of print.

Authors

Most Naoshia Tasnin¹, Tsuneyuki Takuma¹, Yuka Takahashi², Takashi Ushimaru³

Affiliations

¹ Graduate School of Science and Technology, Shizuoka University, Ohya 836, Suruga-ku, Shizuoka, 422-8021, Japan.
² Course of Biological Science, Department of Science, Graduate School of Integrated Science and Technology, Shizuoka University, Ohya 836, Suruga-ku, Shizuoka, 422-8021, Japan.
³ Graduate School of Science and Technology, Shizuoka University, Ohya 836, Suruga-ku, Shizuoka, 422-8021, Japan; Course of Biological Science, Department of Science, Graduate School of Integrated Science and Technology, Shizuoka University, Ohya 836, Suruga-ku, Shizuoka, 422-8021, Japan. Electronic address: ushimaru.takashi@shizuoka.ac.jp.

PMID: 39756210
DOI: 10.1016/j.bbrc.2024.151244

Abstract

In budding yeast, endosomal sorting complex required for transport (ESCRT) mediates microautophagy by vacuolar membrane invagination into the vacuolar lumen, followed by Vps4-assisted membrane constriction and abscission. Here, we show that ESCRT elicits vacuolar fission in the absence of Vps4 after nutrient starvation, although vacuolar fusion is facilitated in wild-type cells in these conditions. ESCRT mediated vacuolar membrane invagination in vps4Δ cells, thereby causing vacuolar fission. It is known that vacuolar fission requires phosphatidylinositol 3,5-bisphosphate (PI(3,5)P2) and β-propellers that bind polyphosphoinositides (PROPPINs), PI(3,5)P2-binding proteins. However, PROPPIN, but not PI(3,5)P2, was dispensable for the ESCRT-mediated vacuolar fragmentation. Finally, we showed evidence that microlipophagy triggers vacuolar fission. Thus, disruption of the coordinated sequence of ESCRT-Vps4 operations in microautophagy leads to vacuolar fragmentation. This study provides insight into the ESCRT-Vps4 axis-dependent cellular disfunctions and related diseases.

Keywords: ESCRT; Microautophagy; PI(3,5)P2; PROPPIN; TORC1; Vps4.