Roles of calcium ions in the membrane binding of C2 domains

2001 ◽  
Vol 359 (3) ◽  
pp. 679-685 ◽  
Author(s):  
Robert V. STAHELIN ◽  
Wonhwa CHO
Keyword(s):  
Conformational Changes ◽  
Membrane Trafficking ◽  
Electrostatic Interactions ◽  
Membrane Binding ◽  
The Other ◽  
Lipid Monolayer ◽  
Dependent Manner ◽  
C2 Domain ◽  
Membrane Penetration ◽  
C2 Domains

The C2 domain is a membrane-targeting domain found in many cellular proteins involved in signal transduction or membrane trafficking. The majority of C2 domains co-ordinate multiple Ca2+ ions and bind the membrane in a Ca2+-dependent manner. To understand the mechanisms by which Ca2+ mediates the membrane binding of C2 domains, we measured the membrane binding of the C2 domains of group IV cytosolic phospholipase A2 (cPLA2) and protein kinase C-α (PKC-α) by surface plasmon resonance and lipid monolayer analyses. Ca2+ ions mainly slow the membrane dissociation of cPLA2-C2, while modulating both membrane association and dissociation rates for PKC-α-C2. Further studies with selected mutants showed that for cPLA2 a Ca2+ ion bound to the C2 domain of cPLA2 induces the intra-domain conformational change that leads to the membrane penetration of the C2 domain whereas the other Ca2+ is not directly involved in membrane binding. For PKC-α, a Ca2+ ion induces the inter-domain conformational changes of the protein and the membrane penetration of non-C2 residues. The other Ca2+ ion of PKC-α-C2 is involved in more complex interactions with the membrane, including both non-specific and specific electrostatic interactions. Together, these studies of isolated C2 domains and their parent proteins allow for the determination of the distinct and specific roles of each Ca2+ ion bound to different C2 domains.

scholarly journals The EF-Hand Ca2+-binding Protein p22 Plays a Role in Microtubule and Endoplasmic Reticulum Organization and Dynamics with Distinct Ca2+-binding Requirements

2004 ◽  
Vol 15 (2) ◽  
pp. 481-496 ◽  
Author(s):  
Josefa Andrade ◽  
Hu Zhao ◽  
Brian Titus ◽  
Sandra Timm Pearce ◽  
Margarida Barroso
Keyword(s):  
Endoplasmic Reticulum ◽  
Conformational Changes ◽  
Membrane Trafficking ◽  
Secretory Pathway ◽  
Network Formation ◽  
Binding Protein ◽  
Dependent Manner ◽  
Microtubule Depolymerization ◽  
Independent Manner ◽  
Ef Hand

We have reported that p22, an N-myristoylated EF-hand Ca2+-binding protein, associates with microtubules and plays a role in membrane trafficking. Here, we show that p22 also associates with membranes of the early secretory pathway membranes, in particular endoplasmic reticulum (ER). On binding of Ca2+, p22's ability to associate with membranes increases in an N-myristoylation-dependent manner, which is suggestive of a nonclassical Ca2+-myristoyl switch mechanism. To address the intracellular functions of p22, a digitonin-based “bulk microinjection” assay was developed to load cells with anti-p22, wild-type, or mutant p22 proteins. Antibodies against a p22 peptide induce microtubule depolymerization and ER fragmentation; this antibody-mediated effect is overcome by preincubation with the respective p22 peptide. In contrast, N-myristoylated p22 induces the formation of microtubule bundles, the accumulation of ER structures along the bundles as well as an increase in ER network formation. An N-myristoylated Ca2+-binding p22 mutant, which is unable to undergo Ca2+-mediated conformational changes, induces microtubule bundling and accumulation of ER structures along the bundles but does not increase ER network formation. Together, these data strongly suggest that p22 modulates the organization and dynamics of microtubule cytoskeleton in a Ca2+-independent manner and affects ER network assembly in a Ca2+-dependent manner.

The C2 domains of classical/conventional PKCs are specific PtdIns(4,5)P2-sensing domains

2007 ◽  
Vol 35 (5) ◽  
pp. 1046-1048 ◽  
Author(s):  
S. Corbalán-García ◽  
M. Guerrero-Valero ◽  
C. Marín-Vicente ◽  
J.C. Gómez-Fernández
Keyword(s):  
Plasma Membrane ◽  
Protein Kinase ◽  
Living Cells ◽  
Model Membranes ◽  
Membrane Localization ◽  
Dependent Manner ◽  
C2 Domain ◽  
C2 Domains ◽  
Local Densities

The C2 domains of cPKCs [classical/conventional PKCs (protein kinase Cs)] bind to membranes in a Ca2+-dependent manner and thereby act as cellular Ca2+ effectors. Recent findings have demonstrated that the C2 domain of cPKCs interacts specifically with PtdIns(4,5)P2 through its polybasic cluster located in the β3–β4-strands, this interaction being critical for the membrane localization of these enzymes in living cells. In addition, these C2 domains exhibit higher affinity to bind PtdIns(4,5)P2 than any other polyphosphate phosphatidylinositols. It has also been shown that the presence of PtdIns(4,5)P2 in model membranes decreases the Ca2+ concentration required for classical C2 domains to bind them. Overall, the studies reviewed here suggest a new mechanism of membrane docking by the C2 domains of cPKCs in which the local densities of phosphatidylserine and PtdIns(4,5)P2 on the inner leaflet of the plasma membrane are sufficient to drive Ca2+-activated membrane docking during a physiological Ca2+ signal.

scholarly journals Phosphatidylinositol 4,5-bisphosphate drives Ca2+-independent membrane penetration by the tandem C2 domain proteins synaptotagmin-1 and Doc2β

2019 ◽  
Vol 294 (28) ◽  
pp. 10942-10953 ◽  
Author(s):  
Mazdak M. Bradberry ◽  
Huan Bao ◽  
Xiaochu Lou ◽  
Edwin R. Chapman
Keyword(s):  
Vesicle Fusion ◽  
Membrane Lipid ◽  
Neuroendocrine Cells ◽  
Dependent Manner ◽  
C2 Domain ◽  
Binding Modes ◽  
Membrane Penetration ◽  
Time Resolved ◽  
High Affinity ◽  
Fluorescence Measurements

Exocytosis mediates the release of neurotransmitters and hormones from neurons and neuroendocrine cells. Tandem C2 domain proteins in the synaptotagmin (syt) and double C2 domain (Doc2) families regulate exocytotic membrane fusion via direct interactions with Ca2+ and phospholipid bilayers. Syt1 is a fast-acting, low-affinity Ca2+ sensor that penetrates membranes upon binding Ca2+ to trigger synchronous vesicle fusion. The closely related Doc2β is a slow-acting, high-affinity Ca2+ sensor that triggers spontaneous and asynchronous vesicle fusion, but whether it also penetrates membranes is unknown. Both syt1 and Doc2β bind the dynamically regulated plasma membrane lipid phosphatidylinositol 4,5-bisphosphate (PIP2), but it is unclear whether PIP2 serves only as a membrane contact or enables specialized membrane-binding modes by these Ca2+ sensors. Furthermore, it has been shown that PIP2 uncaging can trigger rapid, syt1-dependent exocytosis in the absence of Ca2+ influx, suggesting that current models for the action of these Ca2+ sensors are incomplete. Here, using a series of steady-state and time-resolved fluorescence measurements, we show that Doc2β, like syt1, penetrates membranes in a Ca2+-dependent manner. Unexpectedly, we observed that PIP2 can drive membrane penetration by both syt1 and Doc2β in the absence of Ca2+, providing a plausible mechanism for Ca2+-independent, PIP2-dependent exocytosis. Quantitative measurements of penetration depth revealed that, in the presence of Ca2+, PIP2 drives Doc2β, but not syt1, substantially deeper into the membrane, defining a biophysical regulatory mechanism specific to this high-affinity Ca2+ sensor. Our results provide evidence of a novel role for PIP2 in regulating, and under some circumstances triggering, exocytosis.

scholarly journals Stepwise membrane binding of the C2 domains of the extended synaptotagmins revealed by optical tweezers

2021 ◽  
Author(s):  
Jinghua Ge ◽  
Xin Bian ◽  
Lu Ma ◽  
Yiying Cai ◽  
Yanghui Li ◽  
...  
Keyword(s):  
Optical Tweezers ◽  
Membrane Binding ◽  
Binding Energies ◽  
Dependent Manner ◽  
C2 Domains ◽  
Binding Domains ◽  
Lipid Exchange ◽  
Membrane Contacts ◽  
Kinetics Of

Abstract Extended synaptotagmins (E-Syts) mediate lipid exchange between the endoplasmic reticulum (ER) and the plasma membrane (PM). Anchored on ER, E-Syts bind the PM via an array of C2 domains in a Ca2+- and lipid-dependent manner, drawing the two membranes close to facilitate lipid exchange. How these C2 domains bind the PM and regulate the ER-PM distance have not been well understood. Here, we applied optical tweezers to dissect PM membrane binding by E-Syt1 and E-Syt2. We detected Ca2+- and lipid-dependent membrane binding kinetics of both E-Syts and determined the binding energies and rates of individual C2 domains or pairs. We incorporated these parameters in a theoretical model to recapitulate various properties of E-Syt-mediated membrane contacts observed in vivo, including their equilibrium distances and probabilities. Our methods can be applied to study other proteins containing multiple membrane-binding domains linked by disordered polypeptides.

Structure of the C2 domain from novel protein kinase Cϵ. A membrane binding model for Ca2+-independent C2 domains

2001 ◽  
Vol 311 (4) ◽  
pp. 837-849 ◽  
Author(s):  
Wendy F Ochoa ◽  
Josefa Garcia-Garcia ◽  
Ignacio Fita ◽  
Senena Corbalan-Garcia ◽  
Nuria Verdaguer ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Membrane Binding ◽  
C2 Domain ◽  
Binding Model ◽  
C2 Domains ◽  
Novel Protein

scholarly journals Myo1c Binds Phosphoinositides through a Putative Pleckstrin Homology Domain

2006 ◽  
Vol 17 (11) ◽  
pp. 4856-4865 ◽  
Author(s):  
David E. Hokanson ◽  
Joseph M. Laakso ◽  
Tianming Lin ◽  
David Sept ◽  
E. Michael Ostap
Keyword(s):  
Binding Site ◽  
Membrane Trafficking ◽  
Cellular Localization ◽  
Membrane Binding ◽  
Pleckstrin Homology Domain ◽  
Dependent Manner ◽  
Ph Domain ◽  
Pleckstrin Homology

Myo1c is a member of the myosin superfamily that binds phosphatidylinositol-4,5-bisphosphate (PIP2), links the actin cytoskeleton to cellular membranes and plays roles in mechano-signal transduction and membrane trafficking. We located and characterized two distinct membrane binding sites within the regulatory and tail domains of this myosin. By sequence, secondary structure, and ab initio computational analyses, we identified a phosphoinositide binding site in the tail to be a putative pleckstrin homology (PH) domain. Point mutations of residues known to be essential for polyphosphoinositide binding in previously characterized PH domains inhibit myo1c binding to PIP2 in vitro, disrupt in vivo membrane binding, and disrupt cellular localization. The extended sequence of this binding site is conserved within other myosin-I isoforms, suggesting they contain this putative PH domain. We also characterized a previously identified membrane binding site within the IQ motifs in the regulatory domain. This region is not phosphoinositide specific, but it binds anionic phospholipids in a calcium-dependent manner. However, this site is not essential for in vivo membrane binding.

scholarly journals PEA-15 engages in allosteric interactions using a common scaffold in a phosphorylation-dependent manner

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Joyce Ikedife ◽  
Jianlin He ◽  
Yufeng Wei
Keyword(s):  
Conformational Changes ◽  
Electrostatic Interactions ◽  
Mitogen Activated Protein Kinase ◽  
Dependent Manner ◽  
Death Domain ◽  
Signaling Complex ◽  
Mitogen Activated Protein ◽  
Apoptosis Pathways ◽  
Arginine Residues ◽  
Death Effector

AbstractPhosphoprotein enriched in astrocytes, 15 kDa (PEA-15) is a death-effector domain (DED) containing protein involved in regulating mitogen-activated protein kinase and apoptosis pathways. In this molecular dynamics study, we examined how phosphorylation of the PEA-15 C-terminal tail residues, Ser-104 and Ser-116, allosterically mediates conformational changes of the DED and alters the binding specificity from extracellular-regulated kinase (ERK) to Fas-associated death domain (FADD) protein. We delineated that the binding interfaces between the unphosphorylated PEA-15 and ERK2 and between the doubly phosphorylated PEA-15 and FADD are similarly composed of a scaffold that includes both the DED and the C-terminal tail residues of PEA-15. While the unphosphorylated serine residues do not directly interact with ERK2, the phosphorylated Ser-116 engages in strong electrostatic interactions with arginine residues on FADD DED. Upon PEA-15 binding, FADD repositions its death domain (DD) relative to the DED, an essential conformational change to allow the death-inducing signaling complex (DISC) assembly.

Annexins – insights from knockout mice

2016 ◽  
Vol 397 (10) ◽  
pp. 1031-1053 ◽  
Author(s):  
Thomas Grewal ◽  
Sundeep J. Wason ◽  
Carlos Enrich ◽  
Carles Rentero
Keyword(s):  
Mouse Models ◽  
Membrane Trafficking ◽  
Membrane Binding ◽  
Dependent Manner ◽  
Binding Characteristics ◽  
Binding Behavior ◽  
Interaction Partners ◽  
Health And Disease ◽  
Underlying Mechanisms

AbstractAnnexins are a highly conserved protein family that bind to phospholipids in a calcium (Ca2+) – dependent manner. Studies with purified annexins, as well as overexpression and knockdown approaches identified multiple functions predominantly linked to their dynamic and reversible membrane binding behavior. However, most annexins are found at multiple locations and interact with numerous proteins. Furthermore, similar membrane binding characteristics, overlapping localizations and shared interaction partners have complicated identification of their precise functions. To gain insight into annexin functionin vivo, mouse models deficient of annexin A1 (AnxA1), A2, A4, A5, A6 and A7 have been generated. Interestingly, with the exception of one study, all mice strains lacking one or even two annexins are viable and develop normally. This suggested redundancy within annexins, but examining these knockout (KO) strains under stress conditions revealed striking phenotypes, identifying underlying mechanisms specific for individual annexins, often supporting Ca2+homeostasis and membrane transport as central for annexin biology. Conversely, mice lacking AnxA1 or A2 show extracellular functions relevant in health and disease that appear independent of membrane trafficking or Ca2+signaling. This review will summarize the mechanistic insights gained from studies utilizing mouse models lacking members of the annexin family.

scholarly journals Cooperativity of membrane-protein and protein–protein interactions control membrane remodeling by epsin 1 and affects clathrin-mediated endocytosis

2020 ◽  
Author(s):  
Benjamin Kroppen ◽  
Nelli Teske ◽  
King F. Yambire ◽  
Niels Denkert ◽  
Indrani Mukherjee ◽  
...  
Keyword(s):  
Membrane Trafficking ◽  
Molecular Mechanisms ◽  
Membrane Binding ◽  
Chemical Properties ◽  
Membrane Lipid ◽  
Membrane Curvature ◽  
Dependent Manner ◽  
Membrane Remodeling ◽  
Enth Domain

Abstract Membrane remodeling is a critical process for many membrane trafficking events, including clathrin-mediated endocytosis. Several molecular mechanisms for protein-induced membrane curvature have been described in some detail. Contrary, the effect that the physico-chemical properties of the membrane have on these processes is far less well understood. Here, we show that the membrane binding and curvature-inducing ENTH domain of epsin1 is regulated by phosphatidylserine (PS). ENTH binds to membranes in a PI(4,5)P2-dependent manner but only induces curvature in the presence of PS. On PS-containing membranes, the ENTH domain forms rigid homo-oligomers and assembles into clusters. Membrane binding and membrane remodeling can be separated by structure-to-function mutants. Such oligomerization mutants bind to membranes but do not show membrane remodeling activity. In vivo, they are not able to rescue defects in epidermal growth factor receptor (EGFR) endocytosis in epsin knock-down cells. Together, these data show that the membrane lipid composition is important for the regulation of protein-dependent membrane deformation during clathrin-mediated endocytosis.

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