skip to main content

DOE PAGESDOE PAGES

Title: Conformational Flexibility Enables the Function of a BECN1 Region Essential for Starvation-Mediated Autophagy

BECN1 is essential for autophagy, a critical eukaryotic cellular homeostasis pathway. Here in this study, we delineate a highly conserved BECN1 domain located between previously characterized BH3 and coiled-coil domains and elucidate its structure and role in autophagy. The 2.0 Å sulfur-single-wavelength anomalous dispersion X-ray crystal structure of this domain demonstrates that its N-terminal half is unstructured while its C-terminal half is helical; hence, we name it the flexible helical domain (FHD). Circular dichroism spectroscopy, double electron–electron resonance–electron paramagnetic resonance, and small-angle X-ray scattering (SAXS) analyses confirm that the FHD is partially disordered, even in the context of adjacent BECN1 domains. Molecular dynamic simulations fitted to SAXS data indicate that the FHD transiently samples more helical conformations. FHD helicity increases in 2,2,2-trifluoroethanol, suggesting it may become more helical upon binding. Finally, cellular studies show that conserved FHD residues are required for starvation-induced autophagy. Thus, the FHD likely undergoes a binding-associated disorder-to-helix transition, and conserved residues critical for this interaction are essential for starvation-induced autophagy.
Authors:
 [1] ; ORCiD logo [2] ;  [1] ; ORCiD logo [3] ;  [4] ;  [5] ;  [1] ;  [1] ;  [1]
  1. North Dakota State Univ., Fargo, ND (United States). Department of Chemistry and Biochemistry
  2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Health Data Sciences Institute, Computational Science and Engineering Division
  3. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Biology and Soft Matter Division
  4. Argonne National Lab. (ANL), Argonne, IL (United States). GMCA@APS, X-ray Science Division, Advanced Photon Source
  5. Bio-CAT, Advanced Photon Source, Argonne, IL (United States)
Publication Date:
Grant/Contract Number:
AC05-00OR22725; AC02-06CH11357
Type:
Accepted Manuscript
Journal Name:
Biochemistry
Additional Journal Information:
Journal Volume: 55; Journal Issue: 13; Journal ID: ISSN 0006-2960
Publisher:
American Chemical Society (ACS)
Research Org:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org:
USDOE Office of Science (SC)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; 59 BASIC BIOLOGICAL SCIENCES
OSTI Identifier:
1424488

Mei, Yang, Ramanathan, Arvind, Glover, Karen, Stanley, Christopher B., Sanishvili, Ruslan, Chakravarthy, Srinivas, Yang, Zhongyu, Colbert, Christopher L., and Sinha, Sangita C.. Conformational Flexibility Enables the Function of a BECN1 Region Essential for Starvation-Mediated Autophagy. United States: N. p., Web. doi:10.1021/acs.biochem.5b01264.
Mei, Yang, Ramanathan, Arvind, Glover, Karen, Stanley, Christopher B., Sanishvili, Ruslan, Chakravarthy, Srinivas, Yang, Zhongyu, Colbert, Christopher L., & Sinha, Sangita C.. Conformational Flexibility Enables the Function of a BECN1 Region Essential for Starvation-Mediated Autophagy. United States. doi:10.1021/acs.biochem.5b01264.
Mei, Yang, Ramanathan, Arvind, Glover, Karen, Stanley, Christopher B., Sanishvili, Ruslan, Chakravarthy, Srinivas, Yang, Zhongyu, Colbert, Christopher L., and Sinha, Sangita C.. 2016. "Conformational Flexibility Enables the Function of a BECN1 Region Essential for Starvation-Mediated Autophagy". United States. doi:10.1021/acs.biochem.5b01264. https://www.osti.gov/servlets/purl/1424488.
@article{osti_1424488,
title = {Conformational Flexibility Enables the Function of a BECN1 Region Essential for Starvation-Mediated Autophagy},
author = {Mei, Yang and Ramanathan, Arvind and Glover, Karen and Stanley, Christopher B. and Sanishvili, Ruslan and Chakravarthy, Srinivas and Yang, Zhongyu and Colbert, Christopher L. and Sinha, Sangita C.},
abstractNote = {BECN1 is essential for autophagy, a critical eukaryotic cellular homeostasis pathway. Here in this study, we delineate a highly conserved BECN1 domain located between previously characterized BH3 and coiled-coil domains and elucidate its structure and role in autophagy. The 2.0 Å sulfur-single-wavelength anomalous dispersion X-ray crystal structure of this domain demonstrates that its N-terminal half is unstructured while its C-terminal half is helical; hence, we name it the flexible helical domain (FHD). Circular dichroism spectroscopy, double electron–electron resonance–electron paramagnetic resonance, and small-angle X-ray scattering (SAXS) analyses confirm that the FHD is partially disordered, even in the context of adjacent BECN1 domains. Molecular dynamic simulations fitted to SAXS data indicate that the FHD transiently samples more helical conformations. FHD helicity increases in 2,2,2-trifluoroethanol, suggesting it may become more helical upon binding. Finally, cellular studies show that conserved FHD residues are required for starvation-induced autophagy. Thus, the FHD likely undergoes a binding-associated disorder-to-helix transition, and conserved residues critical for this interaction are essential for starvation-induced autophagy.},
doi = {10.1021/acs.biochem.5b01264},
journal = {Biochemistry},
number = 13,
volume = 55,
place = {United States},
year = {2016},
month = {3}
}