132 research outputs found
LRRK2 directly phosphorylates Akt1 as a possible physiological substrate: Impairment of the kinase activity by Parkinson’s disease-associated mutations
AbstractLRRK2 is the causal molecule for autosomal-dominant familial Parkinson’s disease, although its true function, including its physiological substrates, remains unknown. Here, using in vitro kinase assay with recombinant proteins, we demonstrated for the first time that LRRK2 directly phosphorylates Akt1, a central molecule involved in signal transduction for cell survival and prevention of apoptosis. Ser473, one of two amino acids essential for Akt1 activation, was the target site for LRRK2. A knockdown experiment using intact cells also demonstrated LRRK2-mediated phosphorylation of Akt1 (Ser473), suggesting that Akt1 is a convincing candidate for the physiological substrate of LRRK2. The disease-associated mutations, R1441C, G2019S, and I2020T, exhibited reduced interaction with, and phosphorylation of, Akt1, suggesting one possible mechanism for the neurodegeneration caused by LRRK2 mutations.Structured summary of protein interactionsLRRK2phosphorylates Akt1 by protein kinase assay (View Interaction 1, 2, 3).LRRK2 phosphorylates MBP by protein kinase assay (View Interaction 1, 2).LRRK2 binds to Akt1 by pull down (View Interaction 1, 2, 3)
Emergence of physiological rhythmicity in term and preterm neonates in a neonatal intensive care unit
BACKGROUND: Biological rhythmicity, particularly circadian rhythmicity, is considered to be a key mechanism in the maintenance of physiological function. Very little is known, however, about biological rhythmicity pattern in preterm and term neonates in neonatal intensive care units (NICU). In this study, we investigated whether term and preterm neonates admitted to NICU exhibit biological rhythmicity during the neonatal period. METHODS: Twenty-four-hour continuous recording of four physiological variables (heart rate: HR recorded by electrocardiogram; pulse rate: PR recorded by pulse oxymetry; respiratory rate: RR; and oxygen saturation of pulse oxymetry: SpO(2)) was conducted on 187 neonates in NICU during 0–21 days of postnatal age (PNA). Rhythmicity was analyzed by spectral analysis (SPSS procedure Spectra). The Fisher test was performed to test the statistical significance of the cycles. The cycle with the largest peak of the periodogram intensities was determined as dominant cycle and confirmed by Fourier analysis. The amplitudes and amplitude indexes for each dominant cycle were calculated. RESULTS: Circadian cycles were observed among 23.8% neonates in HR, 20% in PR, 27.8% in RR and 16% in SpO(2 )in 0–3 days of PNA. Percentages of circadian cycles were the highest (40%) at <28 wks of gestational age (GA), decreasing with GA, and the lowest (14.3%) at >= 37 wks GA within 3 days of PNA in PR and were decreased in the later PNA. An increase of the amplitude with GA was observed in PR, and significant group differences were present in all periods. Amplitudes and amplitude indexes were positively correlated with postconceptional age (PCA) in PR (p < 0.001). Among clinical parameters, oxygen administration showed significant association (p < 0.05) with circadian rhythms of PR in the first 3 days of life. CONCLUSION: Whereas circadian rhythmicity in neonates may result from maternal influence, the increase of amplitude indexes in PR with PCA may be related to physiological maturity. Further studies are needed to elucidate the effect of oxygenation on physiological rhythmicity in neonates
Poly[[{μ3-tris[2-(4-phenyl-1,2,3-triazol-1-yl)ethyl]amine}silver(I)] hexafluoridophosphate]
The title compound, {[Ag(L)]PF6)n {L is tris[2-(4-phenyl-1,2,3-triazol-1-yl)ethyl]amine, C30H30N10}, consists of alternating two-dimensional cationic layers of [Ag(L)]+ and anionic PF6
− layers. Each AgI atom is three coordinated in a T-shaped geometry by three N atoms from three ligands. Each ligand links three AgI atoms, generating a two-dimensional network structure with two different metallacycles, A and B. In A, eight coordination units from four ligands connect four AgI atoms, forming a 48-membered ring. In B, four coordination units from two ligands link two AgI atoms, forming a 24-membered ring. Each B ring is surrounded by four A rings, and each A ring has four A and four B rings as neighbours. This cationic layer thus generates a 4.82 topology network, with each AgI centre and ligand acting as a three-connected topological node
Tight-Binding Molecular Dynamics with Fermi Operator Expansion:Application to Vacancy Defects in Silicon
By using tight-binding molecular dynamics with Fermi operator expansion, we study vacancy defects in Silicon. The code has been developed for checking silicon crystal, point defect formation energies, etc. The crystal configuration for checking varies among the systems of 64, 216, 512, and 1000 atoms. We have also checked the expansion condition of Fermi operator; the smearing width (∆ε), the maximum order of expansion polynomials. The testing shows the good results, compared with the ab initio results. The dynamical behaviors of defects both in the liquid state and the non-self-diffusion state, are still being investigated. In order to support the data analysis, a visualization of multi-vacancy is also constructed
Implementation of Parallel Matrix Diagonalization for Ab-Initio Molecular Dynamics Program using ScaLAPACK
A matrix diagonalization is one of the most time-consuming parts of the ab-initio molecular dynamics programs. The bigger system to be simulated, the bigger matrix needs to be diagonalized to obtain the eigenvalues and eigenvectors. To raise this matter, we have applied ma-trix diagonalization provided by Scalable Linear Algebra PACKage (ScaLAPACK) to the ab-initio molecular dynamics program. We analyzed the efficiency of RS routine provided by EISPACK and PDSYEVX and PZHEEVX by ScaLAPACK
Magnetic, structural, and electronic properties of Co doped Fe/MgO interface: Density functional approach
We performed ab-initio electronic structure calculation in Co doped Fe/MgO interface on the basis of density functional theory. Two different slab models are considered, depending on the place of Co atom; at the interface and in the Fe layer. With using atomic forces, we obtained the optimized structure at the interface and discussed the layer distance of interface and the local structure around Co. Spin magnetic moments on Fe and Co atoms are also discussed. In the band dispersion at the Fermi level, distribution of the angular orbital component shows the possibility of perpendicular magnetic anisotropy
Wigner formula of rotation matrices and quantum walks
Quantization of a random-walk model is performed by giving a qudit (a
multi-component wave function) to a walker at site and by introducing a quantum
coin, which is a matrix representation of a unitary transformation. In quantum
walks, the qudit of walker is mixed according to the quantum coin at each time
step, when the walker hops to other sites. As special cases of the quantum
walks driven by high-dimensional quantum coins generally studied by Brun,
Carteret, and Ambainis, we study the models obtained by choosing rotation as
the unitary transformation, whose matrix representations determine quantum
coins. We show that Wigner's -dimensional unitary representations of
rotations with half-integers 's are useful to analyze the probability laws
of quantum walks. For any value of half-integer , convergence of all moments
of walker's pseudovelocity in the long-time limit is proved. It is generally
shown for the present models that, if is even, the probability measure
of limit distribution is given by a superposition of terms of scaled
Konno's density functions, and if is odd, it is a superposition of
terms of scaled Konno's density functions and a Dirac's delta function at the
origin. For the two-, three-, and four-component models, the probability
densities of limit distributions are explicitly calculated and their dependence
on the parameters of quantum coins and on the initial qudit of walker is
completely determined. Comparison with computer simulation results is also
shown.Comment: v2: REVTeX4, 15 pages, 4 figure
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