6hog
From Proteopedia
Structure of VPS34 LIR motif bound to GABARAP
Structural highlights
FunctionPK3C3_HUMAN Catalytic subunit of the PI3K complex that mediates formation of phosphatidylinositol 3-phosphate which plays a key role in initiation and maturation of autophagosomes. Involved in the transport of lysosomal enzyme precursors to lysosomes. Required for the abcission step in cytokinesis. Required for transport from early to late endosomes.[1] [2] [3] GBRAP_HUMAN May play a role in intracellular transport of GABA(A) receptors and its interaction with the cytoskeleton. Involved in apoptosis. Involved in autophagy (By similarity).[4] Publication Abstract from PubMedAutophagosome 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. Members of the autophagy class III phosphatidylinositol 3-kinase complex I interact with GABARAP and GABARAPL1 via LIR motifs.,Birgisdottir AB, Mouilleron S, Bhujabal Z, Wirth M, Sjottem E, Evjen G, Zhang W, Lee R, O'Reilly N, Tooze SA, Lamark T, Johansen T Autophagy. 2019 Feb 15. doi: 10.1080/15548627.2019.1581009. PMID:30767700[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
| ||||||||||||||||||||
Categories: Homo sapiens | Large Structures | Bhujbal Z | Birgisdottir AB | Evjen G | Johansen T | Lamark T | Lee R | Mouilleron S | O'Reilly N | Sjottem E | Tooze S | Wirth M | Zhang W
