Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Uncovering principles that control septin-septin interactions.

ABSTRACT: Septins comprise a conserved family of GTPases important in cytokinesis. These proteins polymerize into filaments from rod-shaped heteromeric septin complexes. Septins interact with one another at two interfaces (NC and G) that alternate within the complex. Here, we show that small mutations at the N terminus greatly enhance the formation of SEPT2 homopolymers. Taking advantage of this mutation to examine polymer formation using SEPT2 alone, we show that both NC and G interfaces are required for filament formation. However, co-expression of wild type SEPT2 with SEPT2 containing mutations at either NC or G interfaces revealed that only the NC mutant suppressed filament formation. NC mutants are able to interact with one another at putative G interfaces, whereas G mutants fail to interact at NC interfaces. In addition, all promiscuous septin pairwise interactions occur at the G interface. These findings suggest that G interface interactions must occur before NC interactions during polymer formation.

SUBMITTER: Kim MS

PROVIDER: S-EPMC3436290 | biostudies-literature | 2012 Aug

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Uncovering principles that control septin-septin interactions.

Kim Moshe S MS Froese Carol D CD Xie Hong H Trimble William S WS

The Journal of biological chemistry 20120718 36

Septins comprise a conserved family of GTPases important in cytokinesis. These proteins polymerize into filaments from rod-shaped heteromeric septin complexes. Septins interact with one another at two interfaces (NC and G) that alternate within the complex. Here, we show that small mutations at the N terminus greatly enhance the formation of SEPT2 homopolymers. Taking advantage of this mutation to examine polymer formation using SEPT2 alone, we show that both NC and G interfaces are required for ...[more]

PMID: 22815479

Similar Datasets

Human septin-septin interactions as a prerequisite for targeting septin complexes in the cytosol.

Project description:Septins are a cytosolic GTP-binding protein family first characterized in yeast, but gaining increasing recognition as critical protagonists in higher eukaryotic cellular events. Mammalian septins have been associated with cytokinesis and exocytosis, along with contributing to the development of neurological disorders. Ten different septins, divided into four groups, have been identified in mammals, and individual septins are capable of interacting with each other to form macromolecular complexes. The present study characterizes the structural requirements for human septin-septin interactions using a yeast two-hybrid system. We focus on three septins that are highly expressed in platelets and neurons, SEPT4 [previously designated H5, CDCrel-2 (cell-division-control-related-2), PNUTL2], SEPT5 (CDCrel-1, PNUTL1) and SEPT8 (KIAA0202). Each of these three septins contains a characteristic domain structure consisting of unique N- and C-termini, and a central core domain conserved among the family of proteins. The yeast two-hybrid system yielded data consistent with a model where each of the three septins can interact with itself (homotypic assembly) or with one of the other septins (heterotypic assembly). For SEPT5 and SEPT8, the results illustrate a model whereby heterotypic septin assembly is dependent on the conserved central core domain and homotypic interactions require the N- and C-termini of each protein. We also characterized a model in which the proper cellular localization of SEPT5 and SEPT8 requires concomitant expression of both proteins. Co-transfection of SEPT5 and SEPT8 results in both proteins targeted to a vesicular-like location. Therefore the cellular repertoire of human septins has an impact on function by targeting septin macromolecular complexes to specific cellular locations.

| S-EPMC1133953 | biostudies-literature

Role of nucleotide binding in septin-septin interactions and septin localization in Saccharomyces cerevisiae.

Project description:Septins are a conserved family of eukaryotic GTP-binding, filament-forming proteins. In Saccharomyces cerevisiae, five septins (Cdc3p, Cdc10p, Cdc11p, Cdc12p, and Shs1p) form a complex and colocalize to the incipient bud site and as a collar of filaments at the neck of budded cells. Septins serve as a scaffold to localize septin-associated proteins involved in diverse processes and as a barrier to diffusion of membrane-associated proteins. Little is known about the role of nucleotide binding in septin function. Here, we show that Cdc3p, Cdc10p, Cdc11p, and Cdc12p all bind GTP and that P-loop and G4 motif mutations affect nucleotide binding and result in temperature-sensitive defects in septin localization and function. Two-hybrid, in vitro, and in vivo analyses show that for all four septins nucleotide binding is important in septin-septin interactions and complex formation. In the absence of complete complexes, septins do not localize to the cortex, suggesting septin localization factors interact only with complete complexes. When both complete and partial complexes are present, septins localize to the cortex but do not form a collar, perhaps because of an inability to form filaments. We find no evidence that nucleotide binding is specifically involved in the interaction of septins with septin-associated proteins.

| S-EPMC2519708 | biostudies-literature

Control of septin filament flexibility and bundling by subunit composition and nucleotide interactions.

Project description:Septins self-assemble into heteromeric rods and filaments to act as scaffolds and modulate membrane properties. How cells tune the biophysical properties of septin filaments to control filament flexibility and length, and in turn the size, shape, and position of higher-order septin structures, is not well understood. We examined how rod composition and nucleotide availability influence physical properties of septins such as annealing, fragmentation, bundling, and bending. We found that septin complexes have symmetric termini, even when both Shs1 and Cdc11 are coexpressed. The relative proportion of Cdc11/Shs1 septin complexes controls the biophysical properties of filaments and influences the rate of annealing, fragmentation, and filament flexibility. Additionally, the presence and apparent exchange of guanine nucleotide also alters filament length and bundling. An Shs1 mutant that is predicted to alter nucleotide hydrolysis has altered filament length and dynamics in cells and impacts cell morphogenesis. These data show that modulating filament properties through rod composition and nucleotide binding can control formation of septin assemblies that have distinct physical properties and functions.

| S-EPMC6003234 | biostudies-literature

Uncovering interactions in the frequency domain.

Project description:Oscillatory activity plays a critical role in regulating biological processes at levels ranging from subcellular, cellular, and network to the whole organism, and often involves a large number of interacting elements. We shed light on this issue by introducing a novel approach called partial Granger causality to reliably reveal interaction patterns in multivariate data with exogenous inputs and latent variables in the frequency domain. The method is extensively tested with toy models, and successfully applied to experimental datasets, including (1) gene microarray data of HeLa cell cycle; (2) in vivo multi-electrode array (MEA) local field potentials (LFPs) recorded from the inferotemporal cortex of a sheep; and (3) in vivo LFPs recorded from distributed sites in the right hemisphere of a macaque monkey.

| S-EPMC2398781 | biostudies-literature

Principles of protein-protein interactions.

Project description:This review examines protein complexes in the Brookhaven Protein Databank to gain a better understanding of the principles governing the interactions involved in protein-protein recognition. The factors that influence the formation of protein-protein complexes are explored in four different types of protein-protein complexes--homodimeric proteins, heterodimeric proteins, enzyme-inhibitor complexes, and antibody-protein complexes. The comparison between the complexes highlights differences that reflect their biological roles.

| S-EPMC40170 | biostudies-other

Uncovering heterogeneous interactions in online commercial networks.

Project description:With the rapid development of Internet, the research on online commercial networks has become crucial for filtering out irrelevant information for users and predicting their future interest. The common methods for understanding such typical user-item networks are mainly projecting them to unipartite ones with only positive ratings, which may result in losing a large amount of information. In this paper, we propose a novel approach to construct a signed unipartite network with heterogeneous interactions (i.e. positive or negative) between users from the original bipartite network. Based on the signed similarity, we carry out the percolation analysis on this signed unipartite network, which reveals a phase transition phenomenon. The statistical features of the giant component consisting of the positive and negative interactions are investigated respectively. Finally, the roles of the negative links and weak ties are revealed by adding them back to the giant component. This work not only deepens our understanding of the online commercial networks, but also has potential applications in the design of recommendation algorithms.

| S-EPMC5722876 | biostudies-literature

Uncovering Two Principles of Multivariate Hierarchical Metal-Organic Framework Synthesis via Retrosynthetic Design.

Project description:Multivariate (MTV) hierarchical metal-organic frameworks (MOFs), which contain multiple regions arranged in ordered structures, show promise for applications such as gas separation, size-selective catalysis, and controlled drug delivery. However, the complexity of these hierarchical MOFs is limited by a lack of control during framework assembly. Herein, we report the controlled generation of hierarchical MOF-on-MOF structural formation under the guidance of two design principles, surface functionalization and retrosynthetic techniques for stability control. Accordingly, the tunability of spatial distributions, compositions, and crystal sizes has been achieved in these hierarchical systems. The resulting MOF-on-MOF hierarchical structures represent a unique crystalline porous material which contains a controllable distribution of functional groups and metal clusters that are associated together within a framework composite. This general synthetic approach not only expands the scope and tunability of the traditional MTV strategy to multicomponent materials, but also offers a facile route to introduce variants and sequences to sophisticated three-dimensional hierarchical and cooperative systems. As a proof of concept, the photothermal effects of a porphyrinic core-MOF are exploited to trigger the controlled guest release from a shell-MOF with high guest capacity, highlighting the integrated cooperative behaviors in multivariate hierarchical systems.

| S-EPMC6311690 | biostudies-literature

Septin-containing barriers control the differential inheritance of cytoplasmic elements.

Project description:Fusion of haploid cells of Saccharomyces cerevisiae generates zygotes. We observe that the zygote midzone includes a septin annulus and differentially affects redistribution of supramolecular complexes and organelles. Redistribution across the midzone of supramolecular complexes (polysomes and Sup35p-GFP [PSI+]) is unexpectedly delayed relative to soluble proteins; however, in [psi-] × [PSI+] crosses, all buds eventually receive Sup35p-GFP [PSI+]. Encounter between parental mitochondria is further delayed until septins relocate to the bud site, where they are required for repolarization of the actin cytoskeleton. This delay allows rationalization of the longstanding observation that terminal zygotic buds preferentially inherit a single mitochondrial genotype. The rate of redistribution of complexes and organelles determines whether their inheritance will be uniform.

| S-EPMC3563757 | biostudies-literature

Principles of allosteric interactions in cell signaling.

Project description:Linking cell signaling events to the fundamental physicochemical basis of the conformational behavior of single molecules and ultimately to cellular function is a key challenge facing the life sciences. Here we outline the emerging principles of allosteric interactions in cell signaling, with emphasis on the following points. (1) Allosteric efficacy is not a function of the chemical composition of the allosteric pocket but reflects the extent of the population shift between the inactive and active states. That is, the allosteric effect is determined by the extent of preferred binding, not by the overall binding affinity. (2) Coupling between the allosteric and active sites does not decide the allosteric effect; however, it does define the propagation pathways, the allosteric binding sites, and key on-path residues. (3) Atoms of allosteric effectors can act as "driver" or "anchor" and create attractive "pulling" or repulsive "pushing" interactions. Deciphering, quantifying, and integrating the multiple co-occurring events present daunting challenges to our scientific community.

| S-EPMC4291754 | biostudies-literature

Modeling disordered protein interactions from biophysical principles.

Project description:Disordered protein-protein interactions (PPIs), those involving a folded protein and an intrinsically disordered protein (IDP), are prevalent in the cell, including important signaling and regulatory pathways. IDPs do not adopt a single dominant structure in isolation but often become ordered upon binding. To aid understanding of the molecular mechanisms of disordered PPIs, it is crucial to obtain the tertiary structure of the PPIs. However, experimental methods have difficulty in solving disordered PPIs and existing protein-protein and protein-peptide docking methods are not able to model them. Here we present a novel computational method, IDP-LZerD, which models the conformation of a disordered PPI by considering the biophysical binding mechanism of an IDP to a structured protein, whereby a local segment of the IDP initiates the interaction and subsequently the remaining IDP regions explore and coalesce around the initial binding site. On a dataset of 22 disordered PPIs with IDPs up to 69 amino acids, successful predictions were made for 21 bound and 18 unbound receptors. The successful modeling provides additional support for biophysical principles. Moreover, the new technique significantly expands the capability of protein structure modeling and provides crucial insights into the molecular mechanisms of disordered PPIs.

| S-EPMC5402988 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data