Membrane Binding Assays for Peripheral Proteins

2001 ◽  
Vol 296 (2) ◽  
pp. 153-161 ◽  
Author(s):  
Wonhwa Cho ◽  
Lenka Bittova ◽  
Robert V. Stahelin
Keyword(s):  
Membrane Binding ◽  
Binding Assays ◽  
Peripheral Proteins

scholarly journals 3D Packing Defects in Lipid Membrane as a Function of Membrane Order

2019 ◽  
Author(s):  
Madhusmita Tripathy ◽  
Anand Srivastava
Keyword(s):  
Lipid Membrane ◽  
Membrane Binding ◽  
Computationally Efficient ◽  
Protein Motifs ◽  
Liquid Phases ◽  
Preferential Localization ◽  
Peripheral Proteins ◽  
Packing Defects ◽  
3D Packing ◽  
Key Steps

AbstractLipid membrane packing defects are considered as essential parameter that regulates specific membrane binding of several peripheral proteins. In absence of direct experimental characterization, lipid packing defects and their role in the binding of peripheral proteins are generally investigated through computational studies, which have been immensely successful in unraveling the key steps of the membrane-binding process. However, packing defects are calculated using 2-dimensional projections and the crucial information on their depths is generally overlooked. Here we present a simple yet computationally efficient algorithm, which identifies these defects in 3-dimensions. We employ the algorithm to understand the nature of packing defects in flat bilayer membranes exhibiting liquid-ordered (Lo), liquid-disordered (Ld) and co-existing Lo/Ld phases. Our results indicate the presence of shallower and smaller defects in the Lo phase membranes as compared to the defects in Ld and mixed Lo/Ld phase membranes. Such analyses can elucidate the molecular scale mechanisms that drive the preferential localization of certain proteins to either of the liquid phases or their interface. Moreover, on the methodology front, our analyses suggest that the projection based 2-dimensional calculation of packing defects might result in inaccurate quantification of their sizes - a very important feature for membrane association of protein motifs, thus advocating the importance of the 3-dimensional calculations.

scholarly journals Direct membrane binding and self-interaction contribute to Mmr1 function in mitochondrial inheritance

2018 ◽  
Vol 29 (19) ◽  
pp. 2346-2357 ◽  
Author(s):  
WeiTing Chen ◽  
Holly A. Ping ◽  
Laura L. Lackner
Keyword(s):  
Structure Function ◽  
Membrane Binding ◽  
Coiled Coil ◽  
Mitochondrial Inheritance ◽  
Binding Assays ◽  
Membrane Interaction ◽  
Coiled Coil Domain ◽  
Necessary And Sufficient

Mitochondrial transport and anchoring mechanisms work in concert to position mitochondria to meet cellular needs. In yeast, Mmr1 functions as a mitochondrial adaptor for Myo2 to facilitate actin-based transport of mitochondria to the bud. Posttransport, Mmr1 is proposed to anchor mitochondria at the bud tip. Although both functions require an interaction between Mmr1 and mitochondria, the molecular basis of the Mmr1–mitochondria interaction is poorly understood. Our in vitro phospholipid binding assays indicate Mmr1 can directly interact with phospholipid membranes. Through structure–function studies we identified an unpredicted membrane-binding domain composed of amino acids 76–195 that is both necessary and sufficient for Mmr1 to interact with mitochondria in vivo and liposomes in vitro. In addition, our structure–function analyses indicate that the coiled-coil domain of Mmr1 is necessary and sufficient for Mmr1 self-interaction and facilitates the polarized localization of the protein. Disrupting either the Mmr1–membrane interaction or Mmr1 self-interaction leads to defects in mitochondrial inheritance. Therefore, direct membrane binding and self-interaction are necessary for Mmr1 function in mitochondrial inheritance and are utilized as a means to spatially and temporally regulate mitochondrial positioning.

Sign in / Sign up

Export Citation Format

Share Document