TY - JOUR
T1 - Roles of singleton tryptophan motifs in COPI coat stability and vesicle tethering
AU - Travis, Sophie M.
AU - Kokona, Bashkim
AU - Fairman, Robert
AU - Hughson, Frederick M.
N1 - Funding Information:
We thank Gena Whitney, Christopher Teng, and Ajibike Lapite for the kind gifts of cDNA and plasmids; and Philip Jeffrey, Angela Chan, Liz Gavis, Alexei Korennykh, Sabine Petry, Mark Rose, Venu Vandavasi, Ginger Zakian, and members of the F.M.H. laboratory for helpful advice and discussion. The Princeton Biophysics and Macromolecular Crystallography core facilities provided essential assistance with isothermal titration calorimetry and X-ray crystallography, respectively. This work was supported by National Science Foundation (NSF) Grant MCB-1243656 (R.F.) and by National Institutes of Health (NIH) Grants T32GM007388 (S.M.T.), F31GM12676 (S.M.T.), and R01GM071574 (F.M.H.). This research used the AMX and FMX beamlines of the National Synchrotron Light Source II, a US Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Brookhaven National Laboratory under Contract DE-SC0012704. The Life Science Biomedical Technology Research Resource, which supports AMX and FMX, is primarily supported by the NIH, National Institute of General Medical Sciences (NIGMS), through a Biomedical Technology Research Resource P41 grant (P41GM111244), and by the DOE Office of Biological and Environmental Research (KP1605010). This work is based upon research conducted at the Cornell High Energy Synchrotron Source (CHESS), which is supported by the NSF and the NIH/NIGMS under NSF Award DMR-1332208, using the Macromolecular Diffraction at the CHESS (MacCHESS) facility, which is supported by Award GM-103485 from the NIH, through its NIGMS.
Funding Information:
ACKNOWLEDGMENTS. We thank Gena Whitney, Christopher Teng, and Ajibike Lapite for the kind gifts of cDNA and plasmids; and Philip Jeffrey, Angela Chan, Liz Gavis, Alexei Korennykh, Sabine Petry, Mark Rose, Venu Vandavasi, Ginger Zakian, and members of the F.M.H. laboratory for helpful advice and discussion. The Princeton Biophysics and Macromolecular Crystallography core facilities provided essential assistance with isothermal titration calorimetry and X-ray crystallography, respectively. This work was supported by National Science Foundation (NSF) Grant MCB-1243656 (R.F.) and by National Institutes of Health (NIH) Grants T32GM007388 (S.M.T.), F31GM12676 (S.M.T.), and R01GM071574 (F.M.H.). This research used the AMX and FMX beamlines of the National Synchrotron Light Source II, a US Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Brookhaven National Laboratory under Contract DE-SC0012704. The Life Science Biomedical Technology Research Resource, which supports AMX and FMX, is primarily supported by the NIH, National Institute of General Medical Sciences (NIGMS), through a Biomedical Technology Research Resource P41 grant (P41GM111244), and by the DOE Office of Biological and Environmental Research (KP1605010). This work is based upon research conducted at the Cornell High Energy Synchrotron Source (CHESS), which is supported by the NSF and the NIH/NIGMS under NSF Award DMR-1332208, using the Macromolecular Diffraction at the CHESS (MacCHESS) facility, which is supported by Award GM-103485 from the NIH, through its NIGMS.
Publisher Copyright:
© 2019 National Academy of Sciences. All rights reserved.
PY - 2019/11/26
Y1 - 2019/11/26
N2 - Coat protein I (COPI)-coated vesicles mediate retrograde transport from the Golgi to the endoplasmic reticulum (ER), as well as transport within the Golgi. Major progress has been made in defining the structure of COPI coats, in vitro and in vivo, at resolutions as high as 9 Å. Nevertheless, important questions remain unanswered, including what specific interactions stabilize COPI coats, how COPI vesicles recognize their target membranes, and how coat disassembly is coordinated with vesicle fusion and cargo delivery. Here, we use X-ray crystallography to identify a conserved site on the COPI subunit α-COP that binds to flexible, acidic sequences containing a single tryptophan residue. One such sequence, found within α-COP itself, mediates α-COP homo-oligomerization. Another such sequence is contained within the lasso of the ER-resident Dsl1 complex, where it helps mediate the tethering of Golgi-derived COPI vesicles at the ER membrane. Together, our findings suggest that α-COP homo-oligomerization plays a key role in COPI coat stability, with potential implications for the coordination of vesicle tethering, uncoating, and fusion.BIOCHEMISTRY
AB - Coat protein I (COPI)-coated vesicles mediate retrograde transport from the Golgi to the endoplasmic reticulum (ER), as well as transport within the Golgi. Major progress has been made in defining the structure of COPI coats, in vitro and in vivo, at resolutions as high as 9 Å. Nevertheless, important questions remain unanswered, including what specific interactions stabilize COPI coats, how COPI vesicles recognize their target membranes, and how coat disassembly is coordinated with vesicle fusion and cargo delivery. Here, we use X-ray crystallography to identify a conserved site on the COPI subunit α-COP that binds to flexible, acidic sequences containing a single tryptophan residue. One such sequence, found within α-COP itself, mediates α-COP homo-oligomerization. Another such sequence is contained within the lasso of the ER-resident Dsl1 complex, where it helps mediate the tethering of Golgi-derived COPI vesicles at the ER membrane. Together, our findings suggest that α-COP homo-oligomerization plays a key role in COPI coat stability, with potential implications for the coordination of vesicle tethering, uncoating, and fusion.BIOCHEMISTRY
KW - COPI
KW - Dsl1
KW - Membrane trafficking
KW - Tethering complex
KW - Vesicle coat
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U2 - 10.1073/pnas.1909697116
DO - 10.1073/pnas.1909697116
M3 - Article
C2 - 31712447
AN - SCOPUS:85075522600
SN - 0027-8424
VL - 116
SP - 24031
EP - 24040
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 48
ER -