RRC ID 82086
Author Shinoda S, Sakai Y, Matsui T, Uematsu M, Koyama-Honda I, Sakamaki JI, Yamamoto H, Mizushima N.
Title Syntaxin 17 recruitment to mature autophagosomes is temporally regulated by PI4P accumulation.
Journal Elife
Abstract During macroautophagy, cytoplasmic constituents are engulfed by autophagosomes. Lysosomes fuse with closed autophagosomes but not with unclosed intermediate structures. This is achieved in part by the late recruitment of the autophagosomal SNARE syntaxin 17 (STX17) to mature autophagosomes. However, how STX17 recognizes autophagosome maturation is not known. Here, we show that this temporally regulated recruitment of STX17 depends on the positively charged C-terminal region of STX17. Consistent with this finding, mature autophagosomes are more negatively charged compared with unclosed intermediate structures. This electrostatic maturation of autophagosomes is likely driven by the accumulation of phosphatidylinositol 4-phosphate (PI4P) in the autophagosomal membrane. Accordingly, dephosphorylation of autophagosomal PI4P prevents the association of STX17 to autophagosomes. Furthermore, molecular dynamics simulations support PI4P-dependent membrane insertion of the transmembrane helices of STX17. Based on these findings, we propose a model in which STX17 recruitment to mature autophagosomes is temporally regulated by a PI4P-driven change in the surface charge of autophagosomes.
Volume 12
Published 2024-6-4
DOI 10.7554/eLife.92189
PII 92189
PMID 38831696
PMC PMC11152571
MeSH Autophagosomes* / metabolism Autophagy / physiology Humans Molecular Dynamics Simulation Phosphatidylinositol Phosphates* / metabolism Qa-SNARE Proteins* / genetics Qa-SNARE Proteins* / metabolism
IF 7.08
Resource
Human and Animal Cells HeLa 293T(RCB2202)