RT Journal Article
SR Electronic
T1 Structural and Functional analysis of the GABARAP Interaction Motif (GIM)
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 083659
DO 10.1101/083659
A1 Vladimir V. Rogov
A1 Alexandra Stolz
A1 Arvind C. Ravicahandran
A1 Alexander Law
A1 Hironori Suzuki
A1 Andreas Kniss
A1 Diana O. Rios-Szwed
A1 Frank Löhr
A1 Soichi Wakatsuki
A1 Volker Dötsch
A1 Ivan Dikic
A1 Renwick C.J. Dobson
A1 David G. McEwan
YR 2016
UL http://biorxiv.org/content/early/2016/10/28/083659.abstract
AB 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 LC3s and GABARAPs. From these, we define a GABARAP Interaction Motif (GIM) sequence (W/F-V-X2-V) that the adaptor protein PLEKHM1 tightly conforms to. Using biophysical and structural approaches, we show that the PLEKHM1-LIR is indeed eleven-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 the canonical p62/SQSTM1-LIR into our newly defined GIM, by introducing two valine residues, enhances p62/SQSTM1 interaction with endogenous GABARAP over LC3B. The identification of a GABARAP-specific interaction motif will aid the identification and characterization of the continually expanding array of autophagy receptor and adaptor proteins and their in vivo functions.