Direct association of RhoA with specific domains of PKC-alpha

Previous studies performed at our laboratory have shown that agonist-induced contraction of smooth muscle is associated with translocation of protein kinase C (PKC)- and RhoA to the membrane and that this interaction is due to a direct protein-protein interaction. To determine the domains of PKC- involved in direct interaction with RhoA, His-tagged PKC- proteins of individual domains and different combinations of PKC- domains were used to perform in vitro binding assays with the fusion protein glutathione-S-transferase (GST)-RhoA. Coimmunoprecipitation was also performed using smooth muscle cells transfected with truncated forms of PKC- in this study. The data indicate that RhoA directly bound to full-length PKC-, both in vitro (82.57 ± 15.26% above control) and in transfected cells. RhoA bound in vitro to the C1 domain of PKC- [PKC- (C1)] (70.48 ± 20.78% above control), PKC- (C2) (72.26 ± 29.96% above control), and PKC- (C4) (90.58 ± 26.79% above control), but not to PKC- (C3) (0.64 ± 5.18% above control). RhoA bound in vitro and in transfected cells to truncated forms of PKC-, PKC- (C2, C3, and C4), and PKC- (C3 and C4) (94.09 ± 12.13% and 85.10 ± 16.16% above control, respectively), but not to PKC- (C1, C2, and C3) or to PKC- (C2 and C3) (0.47 ± 1.26% and 7.45 ± 10.76% above control, respectively). RhoA bound to PKC- (C1 and C2) (60.78 ± 13.78% above control) only in vitro, but not in transfected cells, and PKC- (C2, C3, and C4) and PKC- (C3 and C4) bound well to RhoA. These data suggest that RhoA bound to fragments that may mimic the active form of PKC-. The studies using cells transfected with truncated forms of PKC- indicate that PKC- (C1 and C2), PKC- (C1, C2, and C3), and PKC- (C2 and C3) did not associate with RhoA. Only full-length PKC-, PKC- (C2, C3, and C4), and PKC- (C3 and C4) associated with RhoA. The association increased upon stimulation with acetylcholine. These results suggest that the functional association of PKC- with RhoA may require the C4 domain. domains; histidine; fusion proteins     

Role of fine needle aspirate mapping and touch imprint preparations in the evaluation of azoospermia

OBJECTIVE: To assess the utility of fine needle aspiration cytology (FNAC) and touch imprint cytology (TIC) in the evaluation of azoospermia. STUDY DESIGN: FNAC, TIC and open testicular biopsy (OTB) were used to evaluate 31 azoospermic men. RESULTS: OTB revealed normal spermatogenesis (10), spermatogenic arrest (12), Sertoli cell only syndrome (SCO) (7) and unsatisfactory cases (2). Cytologic examinations (TIC vs. FNAC) revealed normal spermatogenesis (11 vs. 9), spermatogenic arrest (13 vs. 7), SCO (2 vs. 1) and unsatisfactory cases (5 vs. 5). Sensitivity and specificity of TIC and FNAC were 98% vs. 83% and 100% vs. 93%, respectively. CONCLUSION: Testicular FNAC is a reliable and simple method for the evaluation of azoospermia.     

An interactional network of genes involved in chitin synthesis in Saccharomyces cerevisiae

Background

The identification of disease-associated genes using single nucleotide polymorphisms (SNPs) has been increasingly reported. In particular, the Affymetrix Mapping 10 K SNP microarray platform uses one PCR primer to amplify the DNA samples and determine the genotype of more than 10,000 SNPs in the human genome. This provides the opportunity for large scale, rapid and cost-effective genotyping assays for linkage analysis. However, the analysis of such datasets is nontrivial because of the large number of markers, and visualizing the linkage scores in the context of genome maps remains less automated using the current linkage analysis software packages. For example, the haplotyping results are commonly represented in the text format.

Results

Here we report the development of a novel software tool called CompareLinkage for automated formatting of the Affymetrix Mapping 10 K genotype data into the "Linkage" format and the subsequent analysis with multi-point linkage software programs such as Merlin and Allegro. The new software has the ability to visualize the results for all these programs in dChip in the context of genome annotations and cytoband information. In addition we implemented a variant of the Lander-Green algorithm in the dChipLinkage module of dChip software (V1.3) to perform parametric linkage analysis and haplotyping of SNP array data. These functions are integrated with the existing modules of dChip to visualize SNP genotype data together with LOD score curves. We have analyzed three families with recessive and dominant diseases using the new software programs and the comparison results are presented and discussed.

Conclusions

The CompareLinkage and dChipLinkage software packages are freely available. They provide the visualization tools for high-density oligonucleotide SNP array data, as well as the automated functions for formatting SNP array data for the linkage analysis programs Merlin and Allegro and calling these programs for linkage analysis. The results can be visualized in dChip in the context of genes and cytobands. In addition, a variant of the Lander-Green algorithm is provided that allows parametric linkage analysis and haplotyping.     

Synthesis of some new 1,3/ or 1,4-bis(glucopyranosyl-1,2,4-triazol-5-ylthio)propanes/ or butanes as potential antimicrobial agents

Glucosidation of the appropriate 1,3 or 1,4-bis(4-amino or arylideneamino-2,4-dihydro-3-thioxo-3H-1,2,4-triazol-5-ylthio)propanes or butanes with 2,3,4,6-tetra-O-acetyl-alpha-D-glucopyranosyl bromide followed by chromatographic separation gave the corresponding N-, S-, and N,S-bis(glucosides). Chemical transformation leading to new functionalities has been achieved. Antimicrobial screening of 10 selected compounds resulted in their activity against Aspergillus fumigatus, Penicillium italicum, Syncephalastrum racemosum, Candida albicans, Staphylococcus aureus, Pseudomonas aeruginosa, Bacillus subtilis, and Escherichia coli.     

Synthesis of some novel N-ribosyl-1,2,4-triazin-6(1H)-/ones or thiones as potential antibacterial and antifungal chemotherapeutics

Ribosylation of 3-aryl-5-benzyl(or substituted benzyl)-1,2,4-triazin-6(1H)-/ones or thiones with 1-O-acetyl-2,3,5-tri-O-benzoyl-beta-D-ribofuranose gave the corresponding 3-aryl-5-benzyl(or substituted benzyl)-1-(2,3,5-tri-O-benzoyl-beta-D-ribofuranosyl)-1,2,4-triazin-6(1H)-/ones or thiones. The structure of the new ribosides was confirmed chemically and spectroscopically.     

Proliferation of pulmonary interstitial fibroblasts is mediated by transforming growth factor-beta1-induced release of extracellular fibroblast growth factor-2 and phosphorylation of p38 MAPK and JNK

Idiopathic pulmonary fibrosis (IPF; a progressive lung disease) is characterized by parenchymal remodeling with enlarged air spaces called honeycomb cysts and palisades of fibroblasts called fibroblast foci. In IPF, lung epithelial cells covering honeycomb cysts and fibroblast foci aberrantly express the active conformation of the potent fibrogenic cytokine transforming growth factor-beta1 (TGF-beta1). Using explanted rat lung slices, we transfected alveolar epithelial cells with the retrovirus pMX containing a site-directed mutation in which Cys223 and Cys225 were substituted with serines, resulting in release of biologically active TGF-beta1 and fibroblast proliferation and remodeling that resembled IPF. Fibroblasts obtained from transfected explants and in culture for 6 weeks incorporated 6.59 +/- 1.55-fold more [3H]thymidine compared with control fibroblasts without transfection or fibroblasts obtained from transfected explants cultured with antibody to fibroblast growth factor-2 (FGF-2). Primary lung fibroblasts obtained from normal rat lungs cultured with TGF-beta1 expressed increased levels of phosphorylated p38 MAPK and JNK, but not ERK1/2. The presence of TGF-beta1 caused an immediate release of extracellular FGF-2 from primary pulmonary fibroblasts; and in the presence of anti-FGF-2 antibody, phosphorylated p38 MAPK and JNK were abrogated. TGF-beta inhibits cell proliferation by suppression of c-Myc and induction of p15INK46, p21CIP1, or p27KIP. Fibroblasts cultured with TGF-beta1 showed no regulation of c-Myc or induction of p15INK46, p21CIP1,or p27KIP. These findings suggest that pulmonary fibroblasts may not respond to the anti-proliferative effects of TGF-beta1, but proliferate in response to TGF-beta1 indirectly by the release of FGF-2, which induces phosphorylation of p38 MAPK and JNK.     

Reactions of seven coordinate complexes. Synthesis, structure, and copper complex of the novel ligand 3-methyltriazolo(1,5-a)6-acetylsemicarbazonepyridine

The reaction of aquachloro(2,6-diacetylpyridinedisemicarbazone)copper(II) with hydrazine hydrate gave the copper complex of 3-methyltriazolo(1,5-a)6-acetylsemicarbazonepyridine. The free ligand was isolated from the copper complex. The X-ray structures of both the copper complex and the free ligand are reported. The copper complex and the free ligand both crystallize in the triclinic space group with 2 molecules per cell. The Cu complex has cell dimensions of a=8.8574(4), b=10.1764(5), c=10.4434(5) Å, α=71.956(1), β=64.913(1), and γ=81.597(1)°. The Cu ion is in a square pyramidal arrangement, with the Cu, the ligand, and a Cl in the plane and a disordered Cl and H₂O in the apical position. The ligand has cell dimensions of a=7.2696(7), b=8.0516(7), c=9.9326(9) Å, α=110.534(2), β=96.730(2), and γ=100.089(2)°. The ligand is planar with a conformation determined by an internal N-H?H hydrogen bond. The role of the Cu ion in the formation of the triazolopyridine is discussed.     

Identification and characterisation of a novel KCNQ1 mutation in a family with Romano-Ward syndrome

Romano-Ward syndrome (RWS), the autosomal dominant form of the congenital long QT syndrome, is characterised by prolongation of the cardiac repolarisation process associated with ventricular tachyarrhythmias of the torsades de pointes type. Genetic studies have identified mutations in six ion channel genes, KCNQ1, KCNH2, SCN5A, KCNE1 and KCNE2 and the accessory protein Ankyrin-B gene, to be responsible for this disorder. Single-strand conformation polymorphism (SSCP) analysis and subsequent DNA sequence analysis have identified a KCNQ1 mutation in a family that were clinically conspicuous due to several syncopes and prolonged QTc intervals in the ECG. The mutant subunit was expressed and functionally characterised in the Xenopus oocyte expression system. A novel heterozygous missense mutation with a C to T transition at the first position of codon 343 (CCA) of the KCNQ1 gene was identified in three concerned family members (QTc intervals: 500, 510 and 530 ms, respectively). As a result, proline 343 localised within the highly conserved transmembrane segment S6 of the KCNQ1 channel is replaced by a serine. Co-expression of mutant (KCNQ1-P343S) and wild-type (KCNQ1) cRNA in Xenopus oocytes produced potassium currents reduced by approximately 92%, while IKs reconstitution experiments with a combination of KCNQ1 mutant, wild-type and KCNE1 subunits yielded currents reduced by approximately 60%. A novel mutation (P343S) identified in the KCNQ1 subunit gene of three members of a RWS family showed a dominant-negative effect on native IKs currents leading to prolongation of the heart repolarisation and possibly increases the risk of malign arrhythmias with sudden cardiac death.     

A bacterial expression system revisited for the recombinant production of cystine-rich plant lipid transfer proteins

Non-specific lipid transfer proteins (nsLTPs) are abundant and ubiquitous cystine-rich proteins that are capable, in vitro, of binding lipids and hydrophobic molecules. In view to probe the lipid binding properties of the wheat nsLTP1, mutant variants may represent a powerful tool. To this end, a synthetic gene, encoding a mature wheat nsLTP1 polypeptide, was designed to ensure high level expression in Escherichia coli. The bacterial expression host strain, a translational fusion strategy, and convenient cleavage and purification procedures were optimized to produce in standard fermentation conditions, a significant amount (15 mg/L final yield), of a soluble and correctly folded recombinant nsLTP1. This highly amenable expression system is helpful in order to investigate structure-activity relationships of plant nsLTP.     

PLA2G6 mutation underlies infantile neuroaxonal dystrophy

Infantile neuroaxonal dystrophy (INAD) is an autosomal recessive progressive neurodegenerative disease that presents within the first 2 years of life and culminates in death by age 10 years. Affected individuals from two unrelated Bedouin Israeli kindreds were studied. Brain imaging demonstrated diffuse cerebellar atrophy and abnormal iron deposition in the medial and lateral globus pallidum. Progressive white-matter disease and reduction of the N-acetyl aspartate : chromium ratio were evident on magnetic resonance spectroscopy, suggesting loss of myelination. The clinical and radiological diagnosis of INAD was verified by sural nerve biopsy. The disease gene was mapped to a 1.17-Mb locus on chromosome 22q13.1 (LOD score 4.7 at recombination fraction 0 for SNP rs139897), and an underlying mutation common to both affected families was identified in PLA2G6, the gene encoding phospholipase A2 group VI (cytosolic, calcium-independent). These findings highlight a role of phospholipase in neurodegenerative disorders.