10779/crick.11353700.v1
Åsa Birna Birgisdottir
Åsa Birna
Birgisdottir
Stephane Mouilleron
Stephane
Mouilleron
Zambarlal Bhujabal
Zambarlal
Bhujabal
Martina Wirth
Martina
Wirth
Eva Sjøttem
Eva
Sjøttem
Gry Evjen
Gry
Evjen
Wenxin Zhang
Wenxin
Zhang
Rebecca Lee
Rebecca
Lee
Nicola O'Reilly
Nicola
O'Reilly
Sharon A Tooze
Sharon A
Tooze
Trond Lamark
Trond
Lamark
Terje Johansen
Terje
Johansen
Members of the autophagy class III phosphatidylinositol 3-kinase complex I interact with GABARAP and GABARAPL1 via LIR motifs
The Francis Crick Institute
2019
ATG14
Autophagy
BECN1
GABARAP
LIR
PIK3C3
Tooze FC001187
PC
SB
FERM-ack
Biochemistry & Molecular Biology
0601 Biochemistry and Cell Biology
2019-12-11 16:05:47
Journal contribution
https://crick.figshare.com/articles/journal_contribution/Members_of_the_autophagy_class_III_phosphatidylinositol_3-kinase_complex_I_interact_with_GABARAP_and_GABARAPL1_via_LIR_motifs/11353700
Autophagosome formation depends on a carefully orchestrated interplay between membrane-associated protein complexes. Initiation of macroautophagy/autophagy is mediated by the ULK1 (unc-51 like autophagy activating kinase 1) protein kinase complex and the autophagy-specific class III phosphatidylinositol 3-kinase complex I (PtdIns3K-C1). The latter contains PIK3C3/VPS34, PIK3R4/VPS15, BECN1/Beclin 1 and ATG14 and phosphorylates phosphatidylinositol to generate phosphatidylinositol 3-phosphate (PtdIns3P). Here, we show that PIK3C3, BECN1 and ATG14 contain functional LIR motifs and interact with the Atg8-family proteins with a preference for GABARAP and GABARAPL1. High resolution crystal structures of the functional LIR motifs of these core components of PtdIns3K-C1were obtained. Variation in hydrophobic pocket 2 (HP2) may explain the specificity for the GABARAP family. Mutation of the LIR motif in ATG14 did not prevent formation of the PtdIns3K-C1 complex, but blocked colocalization with MAP1LC3B/LC3B and impaired mitophagy. The ULK-mediated phosphorylation of S29 in ATG14 was strongly dependent on a functional LIR motif in ATG14. GABARAP-preferring LIR motifs in PIK3C3, BECN1 and ATG14 may, via coincidence detection, contribute to scaffolding of PtdIns3K-C1 on membranes for efficient autophagosome formation. Abbreviations: ATG: autophagy-related; BafA1: bafilomycin A1; GABARAP: GABA type A receptor-associated protein; GABARAPL1: GABA type A receptor associated protein like 1; GFP: enhanced green fluorescent protein; KO: knockout; LDS: LIR docking site; LIR: LC3-interacting region; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; PIK3C3: phosphatidylinositol 3-kinase catalytic subunit type 3; PIK3R4: phosphoinositide-3-kinase regulatory subunit 4; PtdIns3K: phosphatidylinositol 3-kinase; PtdIns3P: phosphatidylinositol-3-phosphate; SQSTM1/p62: sequestosome 1; VPS: Vacuolar protein sorting; ULK: unc-51 like autophagy activating kinase.