Related Experiment Video
Updated: Feb 8, 2026

Self-Assembly of Microtubule Tactoids
Published on: June 23, 2022
MAP1B-LC1 prevents autophagosome formation by linking syntaxin 17 to microtubules
Kohei Arasaki1, Haruki Nagashima2, Yuri Kurosawa2
1School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, Japan karasaki@toyaku.ac.jp tagaya@toyaku.ac.jp.
Abstract:
In fed cells, syntaxin 17 (Stx17) is associated with microtubules at the endoplasmic reticulum-mitochondria interface and promotes mitochondrial fission by determining the localization and function of the mitochondrial fission factor Drp1. Upon starvation, Stx17 dissociates from microtubules and Drp1, and binds to Atg14L, a subunit of the phosphatidylinositol 3-kinase complex, to facilitate phosphatidylinositol 3-phosphate production and thereby autophagosome formation, but the mechanism underlying this phenomenon remains unknown. Here we identify MAP1B-LC1 (microtubule-associated protein 1B-light chain 1) as a critical regulator of Stx17 function. Depletion of MAP1B-LC1 causes Stx17-dependent autophagosome accumulation even under nutrient-rich conditions, whereas its overexpression blocks starvation-induced autophagosome formation. MAP1B-LC1 links microtubules and Stx17 in fed cells, and starvation causes the dephosphorylation of MAP1B-LC1 at Thr217, allowing Stx17 to dissociate from MAP1B-LC1 and bind to Atg14L. Our results reveal the mechanism by which Stx17 changes its binding partners in response to nutrient status.
More Related Videos
Related Concept Videos
Microtubule Formation
Microtubules
Microtubules
Microtubules have two structurally similar globular protein subunits: α and β tubulins. In the cytosol, the α and β tubulins form a heterodimer....
Covalently Linked Protein Regulators
These groups modify specific amino acids in a protein....
Microtubule Instability
Destabilization of Microtubules

