Structural and functional analysis of the GABARAP interaction motif (GIM). (27th June 2017)

• Record Type: Journal Article
• Authors: Rogov, Vladimir V; Stolz, Alexandra; Ravichandran, Arvind C; Rios‐Szwed, Diana O; Suzuki, Hironori; Kniss, Andreas; Löhr, Frank; Wakatsuki, Soichi; Dötsch, Volker; Dikic, Ivan; Dobson, Renwick CJ; McEwan, David G
• Is Part Of: EMBO reports. Volume 18:Number 8(2017)
• Page Start: 1382
• Page End: 1396
• Publication Date: 2017-06-27
• Subjects: autophagy -- Atg8 -- GABARAP -- LC3 -- PLEKHM1; Molecular biology -- Periodicals; Molecular Biology -- Periodicals; Molecular biology; Periodicals; 572.8
• DOI: 10.15252/embr.201643587
• Languages: English
• ISSNs: 1469-221X

Abstract

Abstract: Through the canonical LC3 interaction motif (LIR), [W/F/Y]‐X1 ‐X2 ‐[I/L/V], protein complexes are recruited to autophagosomes to perform their functions as either autophagy adaptors or receptors. How these adaptors/receptors selectively interact with either LC3 or GABARAP families remains unclear. Herein, we determine the range of selectivity of 30 known core LIR motifs towards individual LC3s and GABARAPs. From these, we define aG ABARAPI nteractionM otif (GIM) sequence ([W/F]‐[V/I]‐X2 ‐V) that the adaptor protein PLEKHM1 tightly conforms to. Using biophysical and structural approaches, we show that the PLEKHM1‐LIR is indeed 11‐fold more specific for GABARAP than LC3B. Selective mutation of the X1 and X2 positions either completely abolished the interaction with all LC3 and GABARAPs or increased PLEKHM1‐GIM selectivity 20‐fold towards LC3B. Finally, we show that conversion of p62/SQSTM1, FUNDC1 and FIP200 LIRs into our newly defined GIM, by introducing two valine residues, enhances their interaction with endogenous GABARAP over LC3B. The identification of a GABARAP‐specific interaction motif will aid the identification and characterization of the expanding array of autophagy receptor and adaptor proteins and their in vivo functions. Synopsis: Mammalian Atg8 proteins are separated into LC3 and GABARAP families that interact with autophagy receptors or adaptors via an LC3 interaction region (LIR). This study defines a GABARAP interaction motif (GIM) to aid our understanding of the individual families' function. Identification of aG ABARAPI nteractionM otif (GIM; [W/F]‐[V/I]‐x2 ‐V). The LIR of the lysosomal adaptor protein PLEKHM1 conforms to the newly defined GIM and interacts with GABARAP in vivo . LIR specificity can be altered by single amino acid substitutions in the previously unassigned X1 and X2 residues in the classical W‐X1 ‐X2 ‐L motif. Mutation of known LIRs to a GIM, drives interaction with endogenous GABARAP over LC3. Abstract : Mammalian LC3 and GABARAP family proteins interact with autophagy receptors or adaptors via an LC3 interaction region (LIR). This study defines a GABARAP interaction motif (GIM) to aid our understanding of the individual families' function.