Liquid-liquid phase separation, driven by collective interactions among multivalent and intrinsically disordered proteins, is thought to mediate the formation of membrane-less organelles in cells. ...Using parallel cellular and in vitro assays, we show that the Nephrin intracellular domain (NICD), a disordered protein, drives intracellular phase separation via complex coacervation, whereby the negatively charged NICD co-assembles with positively charged partners to form protein-rich dense liquid droplets. Mutagenesis reveals that the driving force for phase separation depends on the overall amino acid composition and not the precise sequence of NICD. Instead, phase separation is promoted by one or more regions of high negative charge density and aromatic/hydrophobic residues that are distributed across the protein. Many disordered proteins share similar sequence characteristics with NICD, suggesting that complex coacervation may be a widely used mechanism to promote intracellular phase separation.
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•Disordered Nephrin intracellular domain (NICD) forms phase-separated nuclear bodies•NICD phase separates via complex coacervation•Aromatic/hydrophobic residues and high (−) charge density promote phase separation•Disordered regions with NICD-like sequence features are common in human proteome
Pak et al. describe cellular liquid-liquid phase separation of a negatively charged intrinsically disordered protein, the Nephrin intracellular domain. Phase separation is driven by co-assembly with positively charged partners, a process termed complex coacervation. Disordered regions with NICD-like sequence features are common in the human proteome, suggesting complex coacervation may be widespread.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Liquid-liquid phase separation (LLPS) is believed to underlie formation of biomolecular condensates, cellular compartments that concentrate macromolecules without surrounding membranes. Physical ...mechanisms that control condensate formation/dissolution are poorly understood. The RNA-binding protein fused in sarcoma (FUS) undergoes LLPS in vitro and associates with condensates in cells. We show that the importin karyopherin-β2/transportin-1 inhibits LLPS of FUS. This activity depends on tight binding of karyopherin-β2 to the C-terminal proline-tyrosine nuclear localization signal (PY-NLS) of FUS. Nuclear magnetic resonance (NMR) analyses reveal weak interactions of karyopherin-β2 with sequence elements and structural domains distributed throughout the entirety of FUS. Biochemical analyses demonstrate that most of these same regions also contribute to LLPS of FUS. The data lead to a model where high-affinity binding of karyopherin-β2 to the FUS PY-NLS tethers the proteins together, allowing multiple, distributed weak intermolecular contacts to disrupt FUS self-association, blocking LLPS. Karyopherin-β2 may act analogously to control condensates in diverse cellular contexts.
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•Karyopherin-β2 inhibits liquid-liquid phase separation of FUS•Kapβ2 binds tightly to the PY-NLS and weakly to multiple regions across FUS•Many of these regions also promote FUS phase separation•Kapβ2-FUS interactions compete with FUS-FUS interactions to disrupt phase separation
Distributed, energetically weak interactions between a karyopherin and the FUS nuclear localization signal disrupt FUS phase separation.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
13
C Methyl TROSY NMR spectroscopy has emerged as a powerful method for studying the dynamics of large systems such as macromolecular assemblies and membrane proteins. Specific
13
C labeling of ...aliphatic methyl groups and perdeuteration has been limited primarily to proteins expressed in
E. coli
, preventing studies of many eukaryotic proteins of physiological and biomedical significance. We demonstrate the feasibility of efficient
13
C isoleucine δ1-methyl labeling in a deuterated background in an established eukaryotic expression host,
Pichia pastoris
, and show that this method can be used to label the eukaryotic protein actin, which cannot be expressed in bacteria. This approach will enable NMR studies of previously intractable targets.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Propagation and interaction of three solitons are studied within the framework of the Korteweg-de Vries (KdV) equation. The KdV equation is derived from an unmagnetised, collision-less dusty plasma ...containing cold inertial ions, stationary dusts with negative charge, and non-inertial kappa-distributed electrons, using the reductive perturbation technique (RPT). Adopting Hirota’s bilinear method, the three-soliton solution of the KdV equation is obtained and, as an elementary act of soliton turbulence, a study on the soliton interaction is presented. The concavity of the resulting pulse is studied at the strongest interaction point of three solitons. At the time of soliton interaction, the first- and second-order moments as well as the skewness and kurtosis of the wave field are calculated. The skewness and kurtosis decrease as a result of soliton interaction, whereas the first- and second-order moments remain invariant. Also, it is observed that the spectral index
and the unperturbed dust-to-ion ratio
have great influence on the skewness and kurtosis of the wave field.
The nature of the growth rate due to streaming instability in a semiconductor quantum plasma implanted with nanoparticles has been analyzed using the quantum hydrodynamic model. In this study, the ...intriguing effect of temperature, beam electron speed, and electron-hole density on growth rate and frequency is investigated. The results show that the growth rate demonstrates a nonlinear behavior, strongly linked to the boron implantation, beam electron streaming speed and quantum correction factor. A noteworthy finding in this work is the discontinuous nature of the growth rate of streaming instability in boron implanted semiconducting plasma system. The implantation leads to a gap in the growth rate which further gets enhanced upon increase in concentration of implantation. This behavior is apparent only for a specific range of the ratio of thermal speed of the electrons to that of the holes.
Analytical solitary wave solution of the dust ion acoustic (DIA) waves was studied in the framework of the damped forced Korteweg–de Vries (DFKdV) equation in superthermal collisional dusty plasmas. ...The reductive perturbation technique was applied to derive the DKdV equation. It is observed that both the rarefactive and compressive solitary wave solutions are possible for this plasma model. The effects of
and the strength (
) and frequency (
) of the external periodic force were studied on the analytical solitary wave solution of the DIA waves. It is observed that the parameters
,
and
have significant effects on the structure of the damped forced DIA solitary waves. The results of this study may have relevance in laboratory plasmas as well as in space plasmas.
Brand preference in Islamic banking Ahmad, Khaliq; Rustam, Ghulam Ali; Dent, Michael M
Journal of Islamic marketing,
01/2011, Volume:
2, Issue:
1
Journal Article
Peer reviewed
Purpose - University students have a clear need for bank accounts as they have fees, expenses and cash needs. The usefulness of a current account is therefore pre-evident and Islamic banks need to ...focus on their brand image and the services they offer. Indeed, understanding bank selection from Muslim customer's perspective can provide useful information to banks' senior management to help them allocate resources and design products that promise to attract and better satisfy customers. Literature collected so far suggests a strong Islamic brand reputation as well as better financial and banking services are the main factors which influence the selection of a brand. The purpose of this paper is to test this within a positivistic empirical framework and amongst the younger generation in Malaysia.Design methodology approach - The sample was based on 300 students at the International Islamic University of Malaysia. The study utilised five selection criteria based on previous research, personal experience and interview with bank officials and university students. The study also provides some insight into the younger generation's awareness of Islamic banking and the processes involved in the selection of their preferred brand.Findings - It would seem that whilst the importance of religion is a major driver in the choice of Islamic banking the fundamental differences between Islamic and conventional banking are poorly understood. What is important is brand, ease of use and the quality of the customer interaction.Originality value - The paper investigates the factors which determine a customer's choice of a particular bank and provides insights into cementing relationships with existing customers as well as how to gain new ones.
Head-on interaction of four dust ion acoustic (DIA) solitons and the statistical properties of the wave field due to head-on interaction of solitons moving in opposite direction is studied in the ...framework of two Korteweg de Vries (KdV) equations. The extended Poincaré–Lighthill–Kuo (PLK) method is applied to obtain two opposite moving KdV equations from an unmagnetized four component plasma model consisting of Maxwellian negative ions, cold mobile positive ions,
-distributed electrons and positively charged dust grains. Hirota’s bilinear method is adopted to obtain two-soliton solutions of both the KdV equations and accordingly act of soliton turbulence is presented due to head-on collision of four solitons. The amplitude and shape of the resultant wave profile at the point of strongest interaction are obtained. To see the effect of head-on collision on the statistical properties of wave field the first four moments are computed. It is observed that the head-on collision has no effect on the first integral moment while the second, third and fourth moments increase in the dominant interaction region of four solitons, which is a clean indication of soliton turbulence.
Positron acoustic waves (PAWs) in an unmagnetized electron-positron-ion (e-p-i) plasma consisting of mobile cold positrons, immobile positive ions, q-nonextensive distributed electrons and hot ...positrons are studied. The standard reductive perturbation technique (RPT) is applied to derive the Kurteweg-de Vries (KdV) and modified Kurteweg-de Vries (mKdV) equations for PAWs. Variations of the total energy of the conservative systems corresponding to the KdV and mKdV equations are presented. Using numerical simulations, effect of the nonextensive parameter (q), temperature ratio (σ) of electrons to hot positrons and speed (U) of the traveling wave are discussed on the positron acoustic solitary wave solutions of the KdV and mKdV equations. Considering an external periodic perturbation, the perturbed dynamical systems corresponding to the KdV and mKdV equations are analyzed by employing phase orbit analysis, Poincare section and Lyapunov exponent. The frequency (ω) of the external periodic perturbation plays the role of the switching parameter in chaotic motions of the perturbed PAWs through quasiperiodic route to chaos. This work may be useful to understand the qualitative changes in the dynamics of nonlinear perturbations in auroral acceleration regions.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
The characteristics of a dissipative dust ion acoustic soliton in a collisional dusty plasma consisting of ions, superthermal electrons, and negatively charged static dust particles are analyzed. The ...damped Korteweg-de Vries (DKdV) equation is obtained by applying the reductive perturbation technique to the fluid equations of the considered plasma model. The DKdV equation is not integrable; therefore, the homotopy analysis method is used to obtain its numerical solution, using the solution of the standard KdV equation at time zero as an initial approximation. The obtained solution is compared with one of the existing solutions, which was obtained considering the weakness of the collisional frequency. It is noticed that there is a good match between both solutions for small values of the collisional frequency, and a significant difference is observed for higher values of the collisional frequency. The effects of the ion-to-electron temperature ratio (
σ
), dust concentration (
μ
), superthermality index (
κ
), and ion-neutral collisional frequency (
ν
i
n
0
) on the obtained solitons solution are also investigated.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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