@article{1114c294bb0746dbbb30fcea50ac1d77,
title = "Structural basis for the binding of tryptophan-based motifs by δ-COP",
abstract = "Coatomer consists of two subcomplexes: the membrane-targeting, ADP ribosylation factor 1 (Arf1):GTP-binding βγδζ-COP F-subcomplex, which is related to the adaptor protein (AP) clathrin adaptors, and the cargo-binding αβ'ϵ-COP B-subcomplex. We present the structure of the C-terminal μ-homology domain of the yeast δ-COP subunit in complex with the WxW motif from its binding partner, the endoplasmic reticulum-localized Dsl1 tether. The motif binds at a site distinct from that used by the homologous AP μ subunits to bind YxxΦ cargo motifs with its two tryptophan residues sitting in compatible pockets. We also show that the Saccharomyces cerevisiae Arf GTPase-activating protein (GAP) homolog Gcs1p uses a related WxxF motif at its extreme C terminus to bind to δ-COP at the same site in the same way. Mutations designed on the basis of the structure in conjunction with isothermal titration calorimetry confirm the mode of binding and show that mammalian δ-COP binds related tryptophan-based motifs such as that from ArfGAP1 in a similar manner. We conclude that δ-COP subunits bind Wxn(1-6) [WF] motifs within unstructured regions of proteins that influence the lifecycle of COPI-coated vesicles; this conclusion is supported by the observation that, in the context of a sensitizing domain deletion in Dsl1p, mutating the tryptophan-based motif-binding site in yeast causes defects in both growth and carboxypeptidase Y trafficking/processing.",
keywords = "COPI, Coatomer, Homology domain-binding motifs, Membrane trafficking, Vesicle coat, δ-copμ",
author = "Suckling, {Richard J.} and Poon, {Pak Phi} and Travis, {Sophie M.} and Majoul, {Irina V.} and Hughson, {Frederick M.} and Evans, {Philip R.} and Rainer Duden and Owen, {David J.}",
note = "Funding Information: ACKNOWLEDGMENTS. We thank the beamline scientists at the Diamond Light Source and Mike Lewis [Medical Research Council (MRC) Laboratory of Molecular Biology], Gerry Johnston (Dalhousie University), and Mark Rose (Princeton University) for helpful discussions and technical advice. R.J.S. and D.J.O. were funded by Wellcome Trust Fellowship 090909 (to D.J.O.) and funding from Wellcome Trust Strategic Award 100140. P.P.P. was funded by the Canadian Institute of Health Research. R.D. received support from the German Research Foundation Clusters of Excellence “Inflammation and Interfaces” ECX306 and the University of Lubeck. S.M.T. and F.M.H. were supported by NIH Grant GM071574. P.R.E. was supported by MRC Grant U105178845. Funding Information: We thank the beamline scientists at the Diamond Light Source and Mike Lewis [Medical Research Council (MRC) Laboratory of Molecular Biology], Gerry Johnston (Dalhousie University), and Mark Rose (Princeton University) for helpful discussions and technical advice. R.J.S. and D.J.O. were funded by Wellcome Trust Fellowship 090909 (to D.J.O.) and funding from Wellcome Trust Strategic Award 100140. P.P.P. was funded by the Canadian Institute of Health Research. R.D. received support from the German Research Foundation Clusters of Excellence {"}Inflammation and Interfaces{"} ECX306 and the University of Lubeck. S.M.T. and F.M.H. were supported by NIH Grant GM071574. P.R.E. was supported by MRC Grant U105178845.",
year = "2015",
month = nov,
day = "17",
doi = "10.1073/pnas.1506186112",
language = "English (US)",
volume = "112",
pages = "14242--14247",
journal = "Proceedings of the National Academy of Sciences of the United States of America",
issn = "0027-8424",
publisher = "National Academy of Sciences",
number = "46",
}