scholarly journals Membrane curvature generation by a C-terminal amphipathic helix in peripherin-2/rds, a tetraspanin required for photoreceptor sensory cilium morphogenesis

2013 ◽  
Vol 126 (20) ◽  
pp. 4659-4670 ◽  
Author(s):  
N. Khattree ◽  
L. M. Ritter ◽  
A. F. X. Goldberg
Keyword(s):  
Membrane Curvature ◽  
Amphipathic Helix ◽  
Sensory Cilium

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 The N-Terminal Amphipathic Helix of the Topological Specificity Factor MinE Is Associated with Shaping Membrane Curvature

PLoS ONE ◽  
2011 ◽  
Vol 6 (6) ◽  
pp. e21425 ◽  
Author(s):  
Yu-Ling Shih ◽  
Kai-Fa Huang ◽  
Hsin-Mei Lai ◽  
Jiahn-Haur Liao ◽  
Chai-Siah Lee ◽  
...  
Keyword(s):  
Membrane Curvature ◽  
Amphipathic Helix ◽  
Specificity Factor ◽  
Topological Specificity

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 Coarse-Grained Simulations Suggest the Epsin N-Terminal Homology Domain Can Sense Membrane Curvature without Its Terminal Amphipathic Helix

ACS Nano ◽  
2020 ◽  
Vol 14 (12) ◽  
pp. 16919-16928
Author(s):  
Alexis Belessiotis-Richards ◽  
Stuart G. Higgins ◽  
Mark S. P. Sansom ◽  
Alfredo Alexander-Katz ◽  
Molly M. Stevens
Keyword(s):  
Membrane Curvature ◽  
Coarse Grained ◽  
Amphipathic Helix ◽  
Coarse Grained Simulations

scholarly journals A conserved amphipathic helix is required for membrane tubule formation by Yop1p

2015 ◽  
Vol 112 (7) ◽  
pp. E639-E648 ◽  
Author(s):  
Jacob P. Brady ◽  
Jolyon K. Claridge ◽  
Peter G. Smith ◽  
Jason R. Schnell
Keyword(s):  
Smooth Endoplasmic Reticulum ◽  
Membrane Curvature ◽  
Integral Membrane Proteins ◽  
Amphipathic Helix ◽  
Spastic Paraplegia ◽  
Tubule Formation ◽  
Motor Neuron Diseases ◽  
Structure And Dynamics ◽  
Family Protein ◽  
Charged Membranes

The integral membrane proteins of the DP1 (deleted in polyposis) and reticulon families are responsible for maintaining the high membrane curvature required for both smooth endoplasmic reticulum (ER) tubules and the edges of ER sheets, and mutations in these proteins lead to motor neuron diseases, such as hereditary spastic paraplegia. Reticulon/DP1 proteins contain reticulon homology domains (RHDs) that have unusually long hydrophobic segments and are proposed to adopt intramembrane helical hairpins that stabilize membrane curvature. We have characterized the secondary structure and dynamics of the DP1 family protein produced from the YOP1 gene (Yop1p) and identified a C-terminal conserved amphipathic helix (APH) that, on its own, interacts strongly with negatively charged membranes and is necessary for membrane tubule formation. Analyses of DP1 and reticulon family members indicate that most, if not all, contain C-terminal sequences capable of forming APHs. Together, these results indicate that APHs play a previously unrecognized role in RHD membrane curvature stabilization.

scholarly journals Mechanism of membrane-curvature generation by ER-tubule shaping proteins

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ning Wang ◽  
Lindsay D. Clark ◽  
Yuan Gao ◽  
Michael M. Kozlov ◽  
Tom Shemesh ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Amino Acid ◽  
Cross Section ◽  
Network Formation ◽  
Membrane Curvature ◽  
Amphipathic Helix ◽  
Tubule Formation ◽  
Egg Extracts ◽  
High Concentrations ◽  
Restricted Mobility

AbstractThe endoplasmic reticulum (ER) network consists of tubules with high membrane curvature in cross-section, generated by the reticulons and REEPs. These proteins have two pairs of trans-membrane (TM) segments, followed by an amphipathic helix (APH), but how they induce curvature is poorly understood. Here, we show that REEPs form homodimers by interaction within the membrane. When overexpressed or reconstituted at high concentrations with phospholipids, REEPs cause extreme curvature through their TMs, generating lipoprotein particles instead of vesicles. The APH facilitates curvature generation, as its mutation prevents ER network formation of reconstituted proteoliposomes, and synthetic L- or D-amino acid peptides abolish ER network formation in Xenopus egg extracts. In Schizosaccharomyces japonicus, the APH is required for reticulon’s exclusive ER-tubule localization and restricted mobility. Thus, the TMs and APH cooperate to generate high membrane curvature. We propose that the formation of splayed REEP/reticulon dimers is responsible for ER tubule formation.

scholarly journals Arf family GTP loading is activated by, and generates, positive membrane curvature

2008 ◽  
Vol 414 (2) ◽  
pp. 189-194 ◽  
Author(s):  
Richard Lundmark ◽  
Gary J. Doherty ◽  
Yvonne Vallis ◽  
Brian J. Peter ◽  
Harvey T. McMahon
Keyword(s):  
G Proteins ◽  
Membrane Curvature ◽  
Regulatory Proteins ◽  
Dependent Manner ◽  
Amphipathic Helix ◽  
Effector Molecules ◽  
Adp Ribosylation ◽  
Cellular Processes ◽  
Adp Ribosylation Factor ◽  
Small G Proteins

Small G-proteins belonging to the Arf (ADP-ribosylation factor) family serve as regulatory proteins for numerous cellular processes through GTP-dependent recruitment of effector molecules. In the present study we demonstrate that proteins in this family regulate, and are regulated by, membrane curvature. Arf1 and Arf6 were shown to load GTP in a membrane-curvature-dependent manner and stabilize, or further facilitate, changes in membrane curvature through the insertion of an amphipathic helix.

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
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