scholarly journals The long and short of membrane curvature sensing by septins

2019 ◽  
Vol 218 (4) ◽  
pp. 1083-1085 ◽  
Author(s):  
Michael A. McMurray
Keyword(s):  
Membrane Curvature ◽  
Amphipathic Helix ◽  
Curvature Sensing ◽  
Cell Biol ◽  
Necessary And Sufficient

Septin proteins form hetero-oligomers that associate with membranes of specific curvatures, but the mechanism is unknown. In this issue, Cannon et al. (2019. J. Cell Biol. https://doi.org/10.1083/jcb.201807211) identify a single amphipathic helix that is necessary and sufficient for membrane curvature sensing by septins.

scholarly journals An amphipathic helix enables septins to sense micrometer-scale membrane curvature

2019 ◽  
Vol 218 (4) ◽  
pp. 1128-1137 ◽  
Author(s):  
Kevin S. Cannon ◽  
Benjamin L. Woods ◽  
John M. Crutchley ◽  
Amy S. Gladfelter
Keyword(s):  
Membrane Curvature ◽  
Amphipathic Helix ◽  
Curvature Sensing ◽  
C Terminus ◽  
Number Of Binding Sites ◽  
Curved Membranes ◽  
Necessary And Sufficient ◽  
Micrometer Scale

Cell shape is well described by membrane curvature. Septins are filament-forming, GTP-binding proteins that assemble on positive, micrometer-scale curvatures. Here, we examine the molecular basis of curvature sensing by septins. We show that differences in affinity and the number of binding sites drive curvature-specific adsorption of septins. Moreover, we find septin assembly onto curved membranes is cooperative and show that geometry influences higher-order arrangement of septin filaments. Although septins must form polymers to stay associated with membranes, septin filaments do not have to span micrometers in length to sense curvature, as we find that single-septin complexes have curvature-dependent association rates. We trace this ability to an amphipathic helix (AH) located on the C-terminus of Cdc12. The AH domain is necessary and sufficient for curvature sensing both in vitro and in vivo. These data show that curvature sensing by septins operates at much smaller length scales than the micrometer curvatures being detected.

scholarly journals An amphipathic helix enables septins to sense micron-scale membrane curvature

2018 ◽  
Author(s):  
Kevin S. Cannon ◽  
Benjamin L. Woods ◽  
John M. Crutchley ◽  
Amy S. Gladfelter
Keyword(s):  
Membrane Curvature ◽  
Amphipathic Helix ◽  
Curvature Sensing ◽  
C Terminus ◽  
Number Of Binding Sites ◽  
Curved Membranes ◽  
Necessary And Sufficient ◽  
Micrometer Scale

AbstractThe geometry of cells is well described by membrane curvature. Septins are filament forming, GTP-binding proteins that assemble on positive, micrometer-scale curvatures. Here, we examine the molecular basis of curvature sensing by septins. We show that differences in affinity and the number of binding sites drive curvature-specific adsorption of septins. Moreover, we find septin assembly onto curved membranes is cooperative and show that geometry influences higher-order arrangement of septin filaments. Although septins must form polymers to stay associated with membranes, septin filaments do not have to span micrometers in length to sense curvature, as we find that single septin complexes have curvature-dependent association rates. We trace this ability to an amphipathic helix (AH) located on the C-terminus of Cdc12. The AH domain is necessary and sufficient for curvature sensing both in vitro and in vivo. These data show that curvature sensing by septins operates at much smaller length scales than the micrometer curvatures being detected.

scholarly journals Interplay of septin amphipathic helices in sensing membrane-curvature and filament bundling

2020 ◽  
Author(s):  
Benjamin L. Woods ◽  
Kevin S. Cannon ◽  
Amy S. Gladfelter
Keyword(s):  
Cell Shape ◽  
Binding Proteins ◽  
Membrane Curvature ◽  
Amphipathic Helix ◽  
Multiple Functions ◽  
Gtp Binding Proteins ◽  
Amphipathic Helices ◽  
Gtp Binding ◽  
Necessary And Sufficient ◽  
Sensing Membrane

AbstractThe curvature of the membrane defines cell shape. Septins are GTP-binding proteins that assemble into heteromeric complexes and polymerize into filaments at areas of micron-scale membrane curvature. An amphipathic helix (AH) domain within the septin complex is necessary and sufficient for septins to preferentially assemble onto micron-scale curvature. Here we report that the non-essential fungal septin, Shs1, also has an AH domain capable of recognizing membrane curvature. In mutants lacking a fully functional Cdc12 AH domain, the Shs1 AH domain becomes essential. Moreover, we find that the Cdc12 AH domain is also important for septin bundling, suggesting multiple functions for septin AH domains.

scholarly journals Mechanism of Membrane Curvature Sensing by Amphipathic Helix Containing Proteins

2011 ◽  
Vol 100 (5) ◽  
pp. 1271-1279 ◽  
Author(s):  
Haosheng Cui ◽  
Edward Lyman ◽  
Gregory A. Voth
Keyword(s):  
Membrane Curvature ◽  
Amphipathic Helix ◽  
Curvature Sensing

scholarly journals An Amphipathic Helix Directs Cellular Membrane Curvature Sensing and Function of the BAR Domain Protein PICK1

Cell Reports ◽  
2018 ◽  
Vol 23 (7) ◽  
pp. 2056-2069 ◽  
Author(s):  
Rasmus Herlo ◽  
Viktor K. Lund ◽  
Matthew D. Lycas ◽  
Anna M. Jansen ◽  
George Khelashvili ◽  
...  
Keyword(s):  
Cellular Membrane ◽  
Membrane Curvature ◽  
Amphipathic Helix ◽  
Bar Domain ◽  
Curvature Sensing ◽  
Domain Protein ◽  
And Function

scholarly journals Interplay of septin amphipathic helices in sensing membrane-curvature and filament bundling

2021 ◽  
pp. mbc.E20-05-0303
Author(s):  
Benjamin L. Woods ◽  
Kevin S. Cannon ◽  
Ellysa J.D. Vogt ◽  
John M. Crutchley ◽  
Amy S. Gladfelter
Keyword(s):  
Mutant Strain ◽  
Cell Shape ◽  
Binding Proteins ◽  
Membrane Curvature ◽  
Amphipathic Helix ◽  
Amphipathic Helices ◽  
Gtp Binding ◽  
Necessary And Sufficient ◽  
Sensing Membrane ◽  
Septin Filament

The curvature of the membrane defines cell shape. Septins are GTP-binding proteins that assemble into heteromeric complexes and polymerize into filaments at areas of micron-scale membrane curvature. An amphipathic helix (AH) domain within the septin complex is necessary and sufficient for septins to preferentially assemble onto micron-scale curvature. Here we report that the non-essential fungal septin, Shs1, also has an AH domain capable of recognizing membrane curvature. In a septin mutant strain lacking a fully functional Cdc12 AH domain ( cdc12-6), the C-terminal extension of Shs1, containing an AH domain, becomes essential. Additionally, we find that the Cdc12 AH domain is important for regulating septin filament bundling, suggesting septin AH domains have multiple, distinct functions and that bundling and membrane binding may be coordinately controlled. [Media: see text]

scholarly journals Membrane curvature sensing by the C-terminal domain of complexin

2014 ◽  
Vol 5 (1) ◽  
Author(s):  
David Snead ◽  
Rachel T. Wragg ◽  
Jeremy S. Dittman ◽  
David Eliezer
Keyword(s):  
Membrane Curvature ◽  
Curvature Sensing ◽  
Terminal Domain

Osmotically-induced tension and the binding of N-BAR protein to lipid vesicles

Soft Matter ◽  
2016 ◽  
Vol 12 (8) ◽  
pp. 2465-2472 ◽  
Author(s):  
Jaime B. Hutchison ◽  
Aruni P. K. K. Karunanayake Mudiyanselage ◽  
Robert M. Weis ◽  
Anthony D. Dinsmore
Keyword(s):  
Osmotic Stress ◽  
Binding Affinity ◽  
Lipid Vesicles ◽  
Membrane Curvature ◽  
Protein Domain ◽  
Curvature Sensing

The binding affinity of a curvature-sensing protein domain (N-BAR) is measured as a function of applied osmotic stress while the membrane curvature is nearly constant.

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