Minor Bands Research Articles

Observations of non-LTE emission at 4–5 microns with the planetary Fourier spectrometer abord the Mars Express mission

We report on PFS-MEX (Planetary Fourier Spectrometer on board Mars Express) limb observations of the non-Local Thermodynamic Equilibrium emission by CO and CO 2 isotopic molecules. The CO emission is observed peaking at altitudes lower than the CO 2 emission peak. Two orbits have been considered, which explore latitudes from 75 to 15° N, located in local time at 11:30 and 06:40, and with L s = 138 ° and 168°, respectively. In general in the season considered (northern summer) the emission intensity increases going to lower latitudes. The peak emission height is also decreasing with decreasing latitude. The CO 2 isotopic molecules are emitting radiance out of proportion with respect to the normal isotopic abundance, which surely indicates a strong contribution from a large number of much weaker CO 2 bands, a result that will demand careful theoretical modeling. By comparison with Hitran data base we can identify, among the emitting bands, the second hot band for the 626 and 636 molecule, while for the 628 and 627 emission from the third hot bands are very possible. Other minor bands or lines are also observed in emission for the first time in Mars. In one of the two orbits considered, the orbit 1234 of MEX, we also observe at altitudes 80–85 km scattered radiation, with indication of CO 2 ice aerosols as scattering centers. At the same altitude the Pathfinder descending measurements show a temperature that allows CO 2 condensation. Pathfinder measurements were at 03:00 local time, while our observations are for orbit 1234 showing CO 2 ice signature at 11:30 local time. These non-LTE limb emissions, with their unprecedented spectral resolution in this portion of the near infrared and their sensitivity and geographical coverage, will represent in our opinion an excellent data set for testing current theoretical models of the martian upper atmosphere.

ISOLATION, CHARACTERIZATION AND POTENTIAL APPLICATION OF DEOXYRIBONUCLEASE-FREE PHOSPHATASE FROM CASSAVA LEAVES

A deoxyribonuclease-free acid phosphatase from cassava leaves was prepared by ammonium sulfate precipitation, chromatofocusing and hydrophobic interaction chromatography with phenyl Sepharose. The enzyme was purified 36-fold and had a specific activity of 16 U/ mg protein. The enzyme preparation revealed a major phosphatase band of 77 kDa and three minor activity bands. The pH and temperature optima for enzyme activity were 5.2 and 60°C, respectively. The enzyme was inactivated by heating at 80°C for 15 minutes and could be stored at -20°C for up to two months. The enzyme exhibited broad substrate specificity and had a K m (p-nitrophenyl phosphate) value of 1.7 mM. It was strongly inhibited by zinc and copper ions, molybdate and arsenate. Aluminium ions, ferrous ions, dithiothreitol and mercaptoethanol stimulated enzyme activity within 0.5-5.0 mM range. The enzyme partially dephosphorylated linearized pUC18 plasmid despite being an acid phosphatase and showed potential application as a substitute for alkaline phosphatase in the ELISA procedure.

Acetylation by p300 Regulates Nuclear Localization and Function of the Transcriptional Corepressor CtBP2

CtBP family members, CtBP1 and CtBP2, are unique transcriptional regulators that adapt a metabolic enzyme fold, and their activities are regulated by NAD(H)-binding. CtBP1 is both cytoplasmic and nuclear, and its subcellular localization is regulated by sumoylation, phosphorylation, and binding to a PDZ protein. In contrast, we showed that CtBP2 is exclusively nuclear. CtBP1 and CtBP2 are highly similar, but differ at the N-terminal 20 amino acid region. Substitution of the N-terminal domain of CtBP1 with the corresponding CtBP2 domain confers a dominant nuclear localization pattern to CtBP1. The N-terminal domain of CtBP2 contains three Lys residues. Our results show that these Lys residues are acetylated by the nuclear acetylase p300. Although all three Lys residues of CtBP2 (Lys-6, Lys-8, and Lys-10) appear to be acetylated, acetylation of Lys-10 is critical for nuclear localization. CtBP2 with a single amino acid substitution at Lys-10 (K10R) is predominantly localized in the cytoplasm. The cytoplasmic localization of the K10R mutant is correlated with enhanced nuclear export that is inhibited by leptomycin B. Furthermore, lack of acetylation at Lys-10 renders CtBP2 to be more efficient in repression of the E-cadherin promoter. Our studies have revealed the important roles of acetylation in regulating subcellular localization and transcriptional activity of CtBP2.

Magnetic properties of substituted SrRuO3

AbstractWe have investigated structural and magnetic properties of the SrRu1–v O3 and SrRu1–x Crx O3 perovskites with uniquely suppressed and increased ferromagnetic transition temperatures, respectively. Polycrystalline samples synthesized in 600 atm. O2 at 1100 °C and in air at 1340 °C reach the v and Cr solubility limits at v ∼ 0.10 and x = 0.15, respectively. The ordered moment is dramatically suppressed by the creation of Ru vacancies. The linear decrease of the lattice parameters and bond lengths, and an increase of the bond angles with increasing x are due to substitution of the smaller Cr4+/3+ ion for Ru4+/5+. Similar decreases of the molar susceptibility, χ m, in the paramagnetic region above T C and the high‐field magnetization at 5 K with x also indicate the presence of the Cr4+/3+ and Ru4+/5+ ions. These results confirm that the Ru4+/5+(d4/3)–O2––Cr4+/3+(d2/3) minority band double‐exchange interaction that involves the Cr3+ and Cr4+ in the magnetic ordering is responsible for the enhanced ordering temperature. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Protein Kinase A-mediated Phosphorylation Modulates Cytochrome c Oxidase Function and Augments Hypoxia and Myocardial Ischemia-related Injury

We have investigated the effects of hypoxia and myocardial ischemia/reperfusion on the structure and function of cytochrome c oxidase (CcO). Hypoxia (0.1% O(2) for 10 h) and cAMP-mediated inhibition of CcO activity were accompanied by hyperphosphorylation of subunits I, IVi1, and Vb and markedly increased reactive O(2) species production by the enzyme complex in an in vitro system that uses reduced cytochrome c as an electron donor. Both subunit phosphorylation and enzyme activity were effectively reversed by 50 nm H89 or 50 nm myristoylated peptide inhibitor (MPI), specific inhibitors of protein kinase A, but not by inhibitors of protein kinase C. In rabbit hearts subjected to global and focal ischemia, CcO activity was inhibited in a time-dependent manner and was accompanied by hyperphosphorylation as in hypoxia. Additionally, CcO activity and subunit phosphorylation in the ischemic heart were nearly completely reversed by H89 or MPI added to the perfusion medium. Hyperphosphorylation of subunits I, IVi1, and Vb was accompanied by reduced subunit contents of the immunoprecipitated CcO complex. Most interestingly, both H89 and MPI added to the perfusion medium dramatically reduced the ischemia/reperfusion injury to the myocardial tissue. Our results pointed to an exciting possibility of using CcO activity modulators for controlling myocardial injury associated with ischemia and oxidative stress conditions.

110. Investigation of Biochemical Factors That May Influence Immunogencity of AAV2 Vectors

Top of pageAbstract Recombinant AAV2 expressing human coagulation factor IX has been demonstrated to efficiently transduce human hepatocytes leading to expression of therapeutic levels of human factor IX in a human subject. However a T cell response directed to the AAV2 capsid was reported that resulted in elimination of transduced cells (Manno et al, Nat. Med. 2006). In order to better understand determinants of immunogenicity, we report here preliminary assessment of biochemical features that may influence vector immunogenicity. We tested whether purposely induced vector aggregation or oxidation could lead to increased immune responses in a mouse model. To induce aggregation, a common concentrated stock (E14 particles / mL) of highly purified, non aggregated AAV2 empty capsids in PBS was subjected to conditions of reduced ionic strength (60min) followed by readjustment to physiological ionic strength. A control sample was adjusted to the same final volume and concentration by addition of PBS only. To induce oxidation, capsid was treated with 1|[mu]|M Cu2+ (60min). Modified and control capsid preparations were administered via portal vein injecftion to C57/BL6 mice previouly immunized with AAV2 empty capsids. Assessment of anti-AAV2 IgG antibody titers post administration showed no significant difference between mice receiving control, aggregated or oxidized vector. Similarly T lymphocytes isolated from spleens of animals in each group did not secrete IFNgamma in response to AAV2 capsid-derived peptides as assessed by ELISPOT and intracellular cytokine staining. A third biochemical feature that we begun to investigate is structure and provenance of the nucleic acids packaged by AAV vectors. The bacterial plasmid DNA used as a template for the transgene cassette in AAV vectors produced using transient transfection may be incorporated into vector particles. If so, a subpopulation of vector particles would be predicted to contain pathogen associated molecular patterns such as non-methylated CpG motifs. We looked for evidence of packaging of bacterial DNA by AAV2 by producing AAV2 vectors (GFP) by transient transfection using a vector plasmid prepared using the thymidine analogue BrdU. The resulting vector was purified and fractionated by CsCl gradient ultracentrifugation, and fractions were tested for transduction on HEK293 cells. We observed the major (expected) vector band at approx 1.39 g/mL, and a minor higher density band at approx. 1.44 g/mL. These data support that a subpopulation of AAV2 vectors produced using transient transfection contains bacterial plasmid DNA, which may contribute to activation of innate immune responses following in vivo administration. In vivo testing is required to further assess this parameter.

Effects of band division on radiative calculations

Band division is an important basis in radiative calculations, and the configuration of band divisions for various research purposes directly influences the accuracy and speed of radiative transfer compu- tations. We explore four band-division schemes and their impacts on computed radiative fluxes and cooling rates. We explain that discrepan- cies in solar radiation at the surface that exist between radiation models and observations under clear-sky conditions arise partly from ignoring minor gases and weak absorption bands for major gases. © 2006 Society of

CARBOHYDRATE AFFINITY CHROMATOGRAPHY INDICATES THAT ARYLSULFATASE-A FROM CAPACITATED BOAR SPERM HAS MANNOSE AND N-ACETYLGLUCOSAMINE/SIALIC ACID RESIDUES

Carbohydrate residues on membrane proteins from sperm are important in gamete interaction. In recent years, Arylsulfatase A (AS-A) has been acquiring an important role from the various putative gamete interaction responsibles in sperm. The aim of this study was to determine if the capacitated boar sperm Arylsulfatase-A (AS-A), contains D-mannose, N-acetylglucosamine and/or sialic acid residues by its purification using affinity chromatography with Concanavalia ensiformis Agglutinin(Con-A) or Wheat Germ Agglutinin (WGA) as ligands. Sperm samples were capacitated in TALP-HEPES medium. Protein extract was added to the affinity columns. Sequencing of retained proteins was done after SDS-PAGE. Total capacitated sperm proteins electrophoresis showed molecular masses between 14 kDa and 102 kDa. A major band of 68 kDa, and 2 minor bands of 52 kDa and 47 kDa were observed. They were AS-A, hyaluronidase and lactadherin, respectively. The Con-A-retained proteins (RP) pattern showed bands from 14 to 98 kDa. After sequencing and BLAST analysis, the 62 kDa band corresponded to Arylsulfatase-A. The WGA RP fraction showed bands from 14 to 100 kDa. The 65 kDa band corresponded to AS-A. This study showed that AS-A has mannose, N-acetylglucosamine and/or sialic acid residues as part of its glycosilation. In this study AS-A was isolated from boar capacitated sperm by affinity chromatography using separately Con-A and WGA, indicating that there are mannose, N-acetylglucosamine and/or sialic acid residues in its glycosilation. AS-A is a membrane protein of capacitated sperm. Further investigation is needed to fully characterize the glycosidic residues bore by AS-A and to determine its function.

Characterisation of Outer Membrane Protein of Leptospira borgpetersenii Serovar Hardjo

Singh, A., Kumar, M., Kumar, A.A. and Srivastava, S.K. 2005. Characterisation of outer membrane protein of Leptospira borgpetersenii serovar hardjo. J. Appl. Anim. Res., 28: 107–112. Outer membrane protein (OMP) from Leptospira borgpetersenii serovar Hardjo, grown under different cultural conditions, was extracted and characterized for its polypeptide composition and serodiagnostic ability. SDS-PAGE revealed that the detergent insoluble (SI) fraction of OMP from cells grown at the ideal temperature (29C) composed of 5 major polypeptide bands (77, 42.6, 36, 28.8 and 22.5), 4 minor bands (59.5, 47.4, 41.6 and 32 kDa) and 3 very faint bands. In the soluble fraction (SS), different bands were visible, of these 32 kDa and 41 kDa proteins were the most prominant. Cells grown at 22C did not express the minor 18 kDa protein but over expression of 77 kDa was observed. Growth at 38C did not express any additional protein but an enhanced expression of a 31 kDa protein was visible. Change in iron concentration in culture medium did not change the protein profile. Use of OMP as an antigen for conducting ELISA on convalescent animal sera (1:100) revealed that as compared to Microscopic Agglutination Test, it had a Sensitivity and specificity of 100% and 86.4%, respectively.

The Roles of Two Clip Domain Serine Proteases in Innate Immune Responses of the Malaria Vector Anopheles gambiae

The malaria vector Anopheles gambiae is capable of multiple immune responses against Plasmodium ookinetes. Accumulating evidence in several insect species suggests the involvement of serine protease cascades in the initiation and coordination of immune responses. We report molecular and reverse genetic characterization of two mosquito clip domain serine proteases, CLIPB14 and CLIPB15, which share structural similarity to proteases involved in prophenoloxidase activation in other insects. Both CLIPs are expressed in mosquito hemocytes and are transcriptionally induced by bacterial and Plasmodium challenges. Functional studies applying RNA interference revealed that both CLIPs are involved in the killing of Plasmodium ookinetes in Anopheles. Studies on parasite melanization demonstrated an additional role for CLIPB14 in the prophenoloxidase cascade. We further report that both CLIPs participate in defense toward Gram-negative bacteria. Our findings strongly suggest that clip domain serine proteases serve multiple functions and play distinctive roles in several immune pathways of A. gambiae.

Baseline Nucleophosmin Status in Mutated(M) Versus Unmutated (U) Immunoglobulin B-CLL Is a Nuclear Reflection of Different Signal Transduction Physiology.

Aim: The difference in prognosis between B-CLL patients with (M) and wihout (U) somatic hypermutations of the immunoglobulin genes has led to a search for surrogate markers in routine practice. cDNA-Microarray differentiation between M and U led to further analysis of Zap-70, fibromodulin and LPLase, all of which succesfully discriminate the majority of M vs U.. In 1 of 2 proteomic studies searching the difference between M and U B-CLL, nucleophosmin came out as uniformly absent in 6 U patients and present in all 6 with M B-CLL. Nucleophosmin is a nucleolar non-ribosomal protein, associated with cellular proliferation. It is implicated in carcinogenesis as a differentiation blocker in K562 myeloid leukemias where its degradation from a 35 to a 21 kD form accompanies phorbol ester induced differentiation. In K562 this degradation is dependent on P-Erk-translocation to the nucleus that by itself depends on prolonged Erk-activation. We have recently demonstrated that SDF-1, an important microenvironment factor in B-CLL, is capable of inducing prolonged Erk-activation in Zap-70+ but not in Zap-70- B-CLL cells in vitro. This prompted us to study the unstimulated expression of nucleophosmin and other nuclear proteins by Westen blot in 16 patients with B-CLL.Methods: Histones and other alkalic proteins were extracted from the nuclei (pellet fraction) upon treatment with 0.4 M HCl. Following precipitation in acetone, histones and proteins were resuspended in sample buffer and separated by SDS PAGE or acid urea gel electrophoresis. Subsequently, the proteins were electrotransferred to a nitrocellulose membrane. Western blot analysis was performed against nucleophosmin, histone H3 or H4, and final signal detection was revealed by enhanced chemiluminescence reaction.Results: The 35 kD nucleophosmin signal was uniformly expressed in all samples and related to total histone content, irrespective of mutation status, cytogenetics and stage of disease. However, a minor band at 21 kD reflecting degradation was present in 6/6 patients with U B-CLL and absent in 8/10 with M B-CLL. Pan-histone H3 and H4 antibodies revealed similar banding patterns for histone H3 in all patients, but the presence of a heavier (probably ubiquinated) double band for histone H4 in some. This ubiquinated fraction was important in 7/16, faint in 5/16 and absent in 4/16. Morphology was atypical in 4/7 with an important fraction, and typical in all others. 5/7 with important bands and 4/5 with faint bands were M B-CLL against only 1 out of 4 in the group with absence of ubiquitination bands.Discussion: In contrast to previous proteomic studies, we found the 35 kD form of nucleophosmin present in both M and U B-CLL. However, nucleophosmin metabolisation to the 21 kD form is observed preferentially in the U B-CLL. The increased baseline degradation of nucleophosmin in 6/6 U B-CLL all of whom are Zap-70+ can be explained as a downstream nuclear signal from constitutive increased Erk-phosphorylation upon environmental signals in Zap-70+ B-CLL.

Design of magnetic materials: the electronic structure of the ordered, doped Heusler compoundCo2Cr1−xFexAl

The doped Heusler compoundsCo2Cr1−xFexAl with varyingCr to Fe ratio x were investigated experimentally and theoretically. The electronic structure of the ordered, doped Heuslercompound Co2Cr1−xFexAl (x = n/4,n = 0,1,2,3,4) was calculated using band structure calculations of different types. The orderedcompounds turned out to be ferromagnetic with the small Al magnetic moment alignedantiparallel to the 3d transition metal moments. All compounds show a gap around theFermi energy in the minority bands. The pure compounds exhibit an indirectminority gap, whereas the ordered, doped compounds exhibit a direct gap. Themagnetic circular dichroism in the x-ray absorption spectra was measured at theL2,3 edges of Co, Fe, and Cr of the pure compounds and thex = 0.4 alloy in order to determine element-specific magnetic moments. Calculations andmeasurements show an increase of the magnetic moments with increasing iron content.The experimentally observed reduction of the magnetic moment of Cr can beexplained by Co–Cr site disorder. The presence of the gap in the minority bands ofCo2CrAl can be attributed to the occurrence of pureCo2 and mixed CrAl(001)planes in the L 21 structure. It is retained in structures with different order of the CrAl planes but vanishes in theX structure with alternating CoCr and CoAl planes.

Truncation and Activation of Calcineurin A by Calpain I in Alzheimer Disease Brain

A disturbance of calcium homeostasis is believed to play an important role in the neurodegeneration of the brains of Alzheimer disease (AD) patients, but the molecular pathways by which it contributes to the disease are not well understood. Here we studied the activation of two major Ca(2+)-regulated brain proteins, calpain and calcineurin, in AD brain. We found that calpain I is activated, which in turn cleaves and activates calcineurin in AD brain. Mass spectrometric analysis indicated that the cleavage of calcineurin by calpain I is at lysine 501, a position C-terminal to the autoinhibitory domain, which produces a 57-kDa truncated form. The 57-kDa calcineurin maintains its Ca(2+)/calmodulin dependence of the phosphatase activity, but the phosphatase activity is remarkably activated upon truncation. The cleavage and activation of calcineurin correlate to the number of neurofibrillary tangles in human brains. These findings suggest that the overactivation of calpain I and calcineurin may mediate the role of calcium homeostatic disturbance in the neurodegeneration of AD.

High-T phase transition of synthetic ANaB(LiMg)CMg5Si8O22(OH)2 amphibole: an X-ray synchrotron powder diffraction and FTIR spectroscopic study

The synthetic amphibole Na0.95(Li0.95Mg1.05)Mg5Si8O22(OH)2 was studied in situ at high-T, using IR OH-stretching spectroscopy and synchrotron X-ray powder diffraction. At room-T the sample has P21/m symmetry, as shown by the FTIR spectrum. It shows in the OH region two well-defined and intense absorptions at 3,748 and 3,712 cm−1, respectively, and two minor bands at 3,667 and 3,687 cm−1. The main bands are assigned to the two independent O–H groups in the primitive structure. The two minor bands evidencing the presence of small amount of vacant A-site (A□0.05). With increasing T, these bands shift continuously and merge into a unique absorption at high temperature. A change as a function of increasing T is revealed by the evolution of the refined unit-cell parameters, whose trend shows a transition to C2/m at about 320–330°C. The spontaneous scalar strain, fitted with a tricritical 2–6 Landau potential, gives a Tc of 325(10)°C (β parameter = 0.27). Comparison with the second-order P21/m ⇔ C2/m phase transition at 255°C for synthetic amphibole ANa0.8B(Na0.8Mg1.2)CMg5Si8O22(OH)2 indicates that the substitution of Na with Li at the B-sites strongly affects the thermodynamic character and the Tc of the phase transition. The comparison of LNMSH amphiboles with cummingtonitic ones shows that the high-T thermodynamic behaviour is affected by A-site occupancy.

Tau-Positive Fine Granules in the Cerebral White Matter: A Novel Finding Among the Tauopathies Exclusive to Parkinsonism-Dementia Complex of Guam

We examined the autopsied brains of cases of 6 types of tauopathy: parkinsonism-dementia complex of Guam (PDC), corticobasal degeneration (CBD), progressive supranuclear palsy (PSP), Pick disease, Alzheimer disease (AD), and myotonic dystrophy together with Guamanian controls. Light microscopy sections of these brains were examined using anti-tau antibodies. Tau-positive fine granules (TFGs) were globe-shaped, and 3 to 6 mum in diameter, were observed predominantly in the frontal white matter in 30 of the 35 patients with PDC. However, no TFGs were found in association with PSP, myotonic dystrophy, Pick disease, AD, or CBD. Western blot analysis of frozen brain tissue taken from the PDC cases revealed that the frontal cortex was hyperphosphorylated and contained 6 tau isoforms (3R+4R tau). However, in the present study, it was revealed that the novel TFGs in the white matter of patients with PDC was composed of 4R tau. Western blot analysis of sarkosyl-insoluble tau from the white matter of the PDC cases showed 2 major bands of 60 and 64 kDa and one minor band of 67 kDa. After dephosphorylation, these bands resolved into one major band of 4-repeat (4R) tau isoform and 3 minor bands of 3-repeat (3R) and 4R tau isoforms. Moreover, the TFGs observed in cases in which the number of neurofibrillary tangles (NFTs) was higher than the threshold level were not correlated with the presence of cortical NFTs. In conclusion, these novel TFGs were found almost exclusively in PDC brains and could therefore be considered as a characteristic neuropathologic marker of this particular tauopathy. The TFGs were hyperphosphorylated tau-positive structures that may be formed by a different mechanism from that used to produce cortical NFTs.

P300/CBP-associated Factor Drives DEK into Interchromatin Granule Clusters

DEK is a mammalian protein that has been implicated in the pathogenesis of autoimmune diseases and cancer, including acute myeloid leukemia, melanoma, glioblastoma, hepatocellular carcinoma, and bladder cancer. In addition, DEK appears to participate in multiple cellular processes, including transcriptional repression, mRNA processing, and chromatin remodeling. Sub-nuclear distribution of this protein, with the attendant functional ramifications, has remained a controversial topic. Here we report that DEK undergoes acetylation in vivo at lysine residues within the first 70 N-terminal amino acids. Acetylation of DEK decreases its affinity for DNA elements within the promoter, which is consistent with the involvement of DEK in transcriptional repression. Furthermore, deacetylase inhibition results in accumulation of DEK within interchromatin granule clusters (IGCs), sub-nuclear structures that contain RNA processing factors. Overexpression of P/CAF acetylase drives DEK into IGCs, and addition of a newly developed, synthetic, cell-permeable P/CAF inhibitor blocks this movement. To our knowledge, this is the first reported example of acetylation playing a direct role in relocation of a protein to IGCs, and this may explain how DEK can function in multiple pathways that take place in distinct sub-nuclear compartments. These findings also suggest that DEK-associated malignancies and autoimmune diseases might be amenable to treatment with agents that alter acetylation.

Reduced N-Acetylaspartate Levels in Mice Lacking Aralar, a Brain- and Muscle-type Mitochondrial Aspartate-glutamate Carrier

Aralar is a mitochondrial calcium-regulated aspartate-glutamate carrier mainly distributed in brain and skeletal muscle, involved in the transport of aspartate from mitochondria to cytosol, and in the transfer of cytosolic reducing equivalents into mitochondria as a member of the malate-aspartate NADH shuttle. In the present study, we describe the characteristics of aralar-deficient (Aralar-/-) mice, generated by a gene-trap method, showing no aralar mRNA and protein, and no detectable malate-aspartate shuttle activity in skeletal muscle and brain mitochondria. Aralar-/- mice were growth-retarded, exhibited generalized tremoring, and had pronounced motor coordination defects along with an impaired myelination in the central nervous system. Analysis of lipid components showed a marked decrease in the myelin lipid galactosyl cerebroside. The content of the myelin lipid precursor, N-acetylaspartate, and that of aspartate are drastically decreased in the brain of Aralar-/- mice. The defect in N-acetylaspartate production was also observed in cell extracts from primary neuronal cultures derived from Aralar-/- mouse embryos. These results show that aralar plays an important role in myelin formation by providing aspartate for the synthesis of N-acetylaspartate in neuronal cells.

Effects of biaxial strain on stability and half-metallicity of Cr and Mn pnictides and chalcogenides in the zinc-blende structure

The effects of biaxial strain, imposed by epitaxial growth conditions, on the half-metallicity properties of Cr and Mn pnictides and chalcogenides were investigated using local spin-density-functional calculations. The minority band gaps were found to decrease significantly under the biaxial strain, whereas the spin-flip gaps changed only slightly. The calculations show that under epitaxial conditions for any choice of substrate, CrSe, MnAs, MnSe, and MnTe cannot be half metallic; CrAs and CrTe are barely half metallic as their SF gap is close to zero; and only CrSb and MnSb remain distinct half metals with spin-flip gaps of 0.9 and $0.3\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$, respectively.

Active changes of lignification-related enzymes in pepper response to Glomus intraradices and/or Phytophthora capsici.

The activities of enzymes responsible for lignification in pepper, pre-inoculation with arbuscular mycorrhizal (AM) fungus of Glomus intraradices and/or infection with pathogenic strain of Phytophthora capsici, and the biological control effect of G. intraradices on Phytophthora blight in pepper were investigated. The experiment was carried out with four treatments: (1) plants pre-inoculated with G. intraradices (Gi), (2) plants pre-inoculated with G. intraradices and then infected with P. capsici (Gi+Pc), (3) plants infected with P. capsici (Pc), and (4) plants without any of the two microorganisms (C). Mycorrhizal colonization rate was reduced by about 10% in pathogen challenged plants. Root mortality caused by infection of P. capsici was completely eliminated by pre-inoculation with antagonistic G. intraradices. On the ninth day after pathogen infection, Peroxidase (POD) activity increased by 116.9% in Pc-treated roots but by only 21.2% in Gi+Pc-treated roots, compared with the control, respectively. Polyphenol oxidase (PPO) and Phenylalanine ammonia-lyase (PAL) activities gradually increased during the first 3 d and dramatically decreased in Pc-treated roots but slightly decreased in Gi+Pc-treated roots, respectively. On the ninth day after pathogen infection, PPO and PAL decreased by 62.8% and 73.9% in Pc-treated roots but by only 19.8% and 19.5% in Gi+Pc-treated roots, compared with the control, respectively. Three major POD isozymes (45,000, 53,000 and 114,000) were present in Pc-treated roots, while two major bands (53,000 and 114,000) and one minor band (45,000) were present in spectra of Gi+Pc-treated roots, the 45,000 POD isozyme was significantly suppressed by G. intraradices, suggesting that the 45,000 POD isozyme was induced by the pathogen infection but not induced by the antagonistic G. intraradices. A 60,000 PPO isozyme was induced in Pc-treated roots but not induced in Gi+Pc-treated roots. All these results showed the inoculation of antagonistic G. intraradices alleviates root mortality, activates changes of lignification-related enzymes and induces some of the isozymes in pepper plants infected by P. capsici. The results suggested that G. intraradices is a potentially effective protection agent against P. capsici.

Expression and intracellular localization of Pyk2 in normal and v-src transformed chicken epiphyseal chondrocytes

The expression and localization of prolin-rich tyrosine kinase 2 (Pyk2) were studied in chick embryo epiphyseal chondrocytes. Two immunoreactive bands were detected in chondrocytes, a major band with an apparent M r of 123 kDa and a minor band with an apparent M r of 68 kDa. The major band appears to migrate as a doublet with apparent M r of 116/123 kDa. Increased levels of the three forms of Pyk2 were observed in v-src transformed chondrocytes as compared to control uninfected chondrocytes. Immunofluorescent staining shows that Pyk2 is clearly visible in the cytosol and in the perinuclear region of control and v-src-chondrocytes and displays a pattern very similar to the distribution of the mitochondrial marker Mito Tracker. More, immunofluorescent staining shows that Pyk2 is nuclear in most chondrocytes. By subcellular fractionation, the p116/123 Pyk2 doublet, was found to be accumulated mainly in the cytoplasm while the p68 Pyk2 form, was found to be accumulated exclusively in the nucleus. The differential nuclear/cytoplasmic distribution of the Pyk2 forms remains unchanged after v-Src-induced transformation. The p68 Pyk2 form could no longer be detected by using a N-terminus domain-specific anti-Pyk2 antibody. Consistently, Pyk2 immunoreactivity was restricted to the cytoplasm of control and v-src transformed chondrocytes. Thus it appears that the p68 Pyk2 form that accumulates in the nucleus has a deletion in the N-terminus region.