Mapping of the ligand-binding site on the b' domain of human PDI: interaction with peptide ligands and the x-linker region.

PDI (protein disulfide-isomerase) catalyses the formation of native disulfide bonds of secretory proteins in the endoplasmic reticulum. PDI consists of four thioredoxin-like domains, of which two contain redox-active catalytic sites (a and a'), and two do not (b and b'). The b' domain is primarily responsible for substrate binding, although the nature and specificity of the substrate-binding site is still poorly understood.

Total hip replacement as primary treatment of unstable intertrochanteric fractures in elderly patients.

Fifty-three patients with A2.2 and A2.3 intertrochanteric fracture according to the Muller classification were treated with total hip replacement between April 2000 and February 2004.

Partial regulation of serotonin transporter function by gamma-synuclein.

Human alpha-synuclein (alpha-Syn) is instrumental in maintaining homeostasis of monoamine neurotransmitters in brain, through its trafficking, and regulation of the cell surface expression and, thereby, activity of dopamine, serotonin and norepinephrine transporters. Here we have investigated whether other members of the synuclein family of proteins, gamma-synuclein (gamma-Syn) and beta-synuclein (beta-Syn) can similarly modulate the serotonin transporter (SERT). In Ltk(-) cells co-transfected with SERT and gamma-Syn, gamma-Syn reduced [(3)H]5-HT uptake, in a manner dependent on its expression levels.

Alpha-Synuclein contributes to GSK-3beta-catalyzed Tau phosphorylation in Parkinson's disease models.

We have shown in the parkinsonism-inducing neurotoxin MPP(+)/MPTP model that alpha-Synuclein (alpha-Syn), a presynaptic protein causal in Parkinson's disease (PD), contributes to hyperphosphorylation of Tau (p-Tau), a protein normally linked to tauopathies, such as Alzheimer's disease (AD). Here, we investigated the kinase involved and show that the Tau-specific kinase, glycogen synthase kinase 3beta (GSK-3beta), is robustly activated in various MPP(+)/MPTP models of Parkinsonism (SH-SY5Y cotransfected cells, mesencephalic neurons, transgenic mice overexpressing alpha-Syn, and postmortem striatum of PD patients). The activation of GSK-3beta was absolutely dependent on the presence of alpha-Syn, as indexed by the absence of p-GSK-3beta in cells lacking alpha-Syn and in alpha-Syn KO mice.

Use of high-density tiling microarrays to identify mutations globally and elucidate mechanisms of drug resistance in Plasmodium falciparum.

Background: The identification of genetic changes that confer drug resistance or other phenotypic changes in pathogens can help optimize treatment strategies, support the development of new therapeutic agents, and provide information about the likely function of genes. Elucidating mechanisms of phenotypic drug resistance can also assist in identifying the mode of action of uncharacterized but potent antimalarial compounds identified in high-throughput chemical screening campaigns against Plasmodium falciparum.

Results: Here we show that tiling microarrays can detect de novo a large proportion of the genetic changes that differentiate one genome from another.

Dopamine promotes striatal neuronal apoptotic death via ERK signaling cascades.

Although the mechanisms underlying striatal neurodegeneration are poorly understood, we have shown that striatal pathogenesis may be initiated by high synaptic levels of extracellular dopamine (DA). Here we investigated in rat striatal primary neurons the mobilization of the mitogen-activated protein kinase (MAPK) signaling pathways after treatment with DA. Instead of observing an elevation of the archetypical pro-cytotoxic MAPKs, p-JNK and p-p38 MAPK, we found that DA, acting through D1 DA receptors, induced a sustained stimulation of the phosphorylated form of extracellular signal-regulated kinase (p-ERK) via a cAMP/protein kinase A (PKA)/Rap1/B-Raf / MAPK/ERK kinase (MEK) pathway.

The fatty acid biosynthesis enzyme FabI plays a key role in the development of liver-stage malarial parasites.

The fatty acid synthesis type II pathway has received considerable interest as a candidate therapeutic target in Plasmodium falciparum asexual blood-stage infections. This apicoplast-resident pathway, distinct from the mammalian type I process, includes FabI. Here, we report synthetic chemistry and transfection studies concluding that Plasmodium FabI is not the target of the antimalarial activity of triclosan, an inhibitor of bacterial FabI.

Reconstitution of human Ero1-Lalpha/protein-disulfide isomerase oxidative folding pathway in vitro. Position-dependent differences in role between the a and a' domains of protein-disulfide isomerase.

Protein-disulfide isomerase (PDI), a critical enzyme responsible for oxidative protein folding in the eukaryotic endoplasmic reticulum, is composed of four thioredoxin domains a, b, b', a', and a linker x between b' and a'. Ero1-Lalpha, an oxidase for human PDI (hPDI), has been determined to have one molecular flavin adenine dinucleotide (FAD) as its prosthetic group. Oxygen consumption assays with purified recombinant Ero1-Lalpha revealed that it utilizes oxygen as a terminal electron acceptor producing one disulfide bond and one molecule of hydrogen peroxide per dioxygen molecule consumed.

Alternative conformations of the x region of human protein disulphide-isomerase modulate exposure of the substrate binding b' domain.

Protein disulphide isomerase (PDI) is a key multi-domain protein folding catalyst in the endoplasmic reticulum. The b' domain of PDI is essential for the non-covalent binding of incompletely folded protein substrates. Earlier, we defined the substrate binding site in the b' domain of human PDI by modelling and mutagenesis studies.

Desipramine modulation of alpha-, gamma-synuclein, and the norepinephrine transporter in an animal model of depression.

The mechanisms underlying depression remain elusive. We previously determined that alpha-synuclein (alpha-Syn) modulates the activity and trafficking of the norepinephrine transporter (NET) in a manner that is dependent on its interactions with microtubules (MTs). Here we sought to determine if alpha-Syn, or the other synuclein family members, beta-synuclein (beta-Syn) and gamma-synuclein (gamma-Syn), modulate NET activity in an animal model of depression, the Wistar-Kyoto (WKY) rat.

Novel flanking DNA sequences enhance FOXO1a DNA binding affinity but do not alter DNA bending.

FOXO1A, a member of the forkhead winged-helix family of proteins is a transcription factor with proapoptotic activities and plays a significant role in insulin and growth factor signaling. As such, FOXO1A is insulin responsive and binds to the insulin response element (IRE). However, multiple forkhead family members with diverse biological functions are also known to bind to the IRE.

Regulated interactions of the norepineprhine transporter by the actin and microtubule cytoskeletons.

One role of the actin cytoskeleton is to maintain the structural morphology and activity of the pre-synaptic terminal. We sought to determine if the actin cytoskeleton plays a role in regulating interactions between the norepinephrine transporter (NET) and alpha-Synuclein (alpha-Syn), two proteins expressed in the pre-synaptic terminal. In cells transfected with either 0.

Neuro-regulation of lower esophageal sphincter function as treatment for gastroesophageal reflux disease.

The junction between the esophagus and the stomach is a specialized region, composed of lower esophageal sphincter (LES) and its adjacent anatomical structures, the gastric sling and crural diaphragm. Together these structures work in a coordinated manner to allow ingested food into the stomach while preventing reflux of gastric contents across the esophago-gastric junction (EGJ) into the esophagus. The same zone also permits retrograde passage of air and gastric contents into esophagus during belching and vomiting.

Dabbing the Skin Surface Dry During Ice Massage Augments Rate of Temperature Drop.

While ice massage (IM) is a rapid cooling technique used to facilitate therapeutic movements in the rehabilitation process, evidence of its efficacy over alternative therapeutic protocols is scarce. We determined whether dabbing the skin surface dry during a standard IM treatment would lead to greater rate of skin temperature reduction in comparison to without dabbing; and whether dabbing the skin would lead to an acute change in flexibility. Sixteen healthy volunteers received a "dabbing" and "non-dabbing" 7-minute IM treatment over the surface of each triceps surae muscle.

Dopamine differentially induces aggregation of A53T mutant and wild type alpha-synuclein: insights into the protein chemistry of Parkinson's disease.

Aggregation of alpha-synuclein is known to be a causal factor in the genesis of Parkinson's disease and Dementia with Lewy bodies. Duplication and/or triplication and mutation of the alpha-synuclein gene are associated with sporadic and familial Parkinson's disease. Synucleinopathies appear to primarily affect dopaminergic neurons.

Alterations of striatal glutamate transmission in rotenone-treated mice: MRI/MRS in vivo studies.

Animal models treated with agricultural chemicals, such as rotenone, reproduce several degenerative features of human central nervous system (CNS) diseases. Glutamate is the most abundant excitatory amino acid transmitter in the mammalian central nervous system and its transmission is implicated in a variety of brain functions including mental behavior and memory. Dysfunction of glutamate neurotransmission in the CNS has been associated with a number of human neurodegenerative diseases, either as a primary or as a secondary factor in the excitotoxic events leading to neuronal death.

Regulation of the norepinephrine transporter by alpha-synuclein-mediated interactions with microtubules.

alpha-Synuclein (alpha-Syn) regulates catecholaminergic neurotransmission. We demonstrate that alpha-Syn regulates the activity and surface expression of the norepinephrine transporter (NET), depending on its expression levels. In cells co-transfected with NET and low amounts of alpha-Syn, NET activity and cell surface expression were increased and protein interactions with alpha-Syn decreased, compared with cells transfected with NET alone.

Gene encoding a deubiquitinating enzyme is mutated in artesunate- and chloroquine-resistant rodent malaria parasites.

Artemisinin- and artesunate-resistant Plasmodium chabaudi mutants, AS-ART and AS-ATN, were previously selected from chloroquine-resistant clones AS-30CQ and AS-15CQ respectively. Now, a genetic cross between AS-ART and the artemisinin-sensitive clone AJ has been analysed by Linkage Group Selection. A genetic linkage group on chromosome 2 was selected under artemisinin treatment.

What's new on CDC25 phosphatase inhibitors.

The CDC25 phosphatases are key regulators of cell cycle progression and play a central role in the checkpoint response to DNA damage. Their inhibition may therefore represent a promising therapeutic approach in oncology, and small molecule design strategies are currently leading to the identification of various classes of CDC25 inhibitors. Most structures developed so far are quinonoid-based compounds, but also phosphate surrogates or electrophilic entities.

An ontology for protein data models.

Accelerating availability of protein sequences and structures has transformed both the theory and practice of computational biology. The current systems of nomenclature for proteins remain divergent even when the experts appreciate the underlying similarities. Interoperability of protein databases is limited to lack of progress in the way the biologists describe and conceptualize the shared biological elements in protein data.

Attenuation of the norepinephrine transporter activity and trafficking via interactions with alpha-synuclein.

Alpha-synuclein (alpha-Syn) has been studied in the context of Parkinson's disease, but its normative role remains elusive. We have shown that alpha-Syn regulates the homeostasis of dopaminergic and serotonergic synapses, through trafficking of the dopamine and serotonin transporter, respectively. In the present study we sought to determine if alpha-Syn could also modulate noradrenergic signaling, by studying its interactions with the norepinephrine transporter (NET).

In vitro efficacy, resistance selection, and structural modeling studies implicate the malarial parasite apicoplast as the target of azithromycin.

Azithromycin (AZ), a broad-spectrum antibacterial macrolide that inhibits protein synthesis, also manifests reasonable efficacy as an antimalarial. Its mode of action against malarial parasites, however, has remained undefined. Our in vitro investigations with the human malarial parasite Plasmodium falciparum document a remarkable increase in AZ potency when exposure is prolonged from one to two generations of intraerythrocytic growth, with AZ producing 50% inhibition of parasite growth at concentrations in the mid to low nanomolar range.

Alpha-synuclein induces hyperphosphorylation of Tau in the MPTP model of parkinsonism.

Many neurodegenerative diseases associated with functional Tau dysregulation, including Alzheimer's disease (AD) and other tauopathies, also show alpha-synuclein (alpha-Syn) pathology, a protein associated with Parkinson's disease (PD) pathology. Here we show that treatment of primary mesencephalic neurons (48 h) or subchronic treatment of wild-type (WT) mice with the Parkinsonism-inducing neurotoxin MPP+/MPTP, results in selective dose-dependent hyperphosphorylation of Tau at Ser396/404 (PHF-1-reactive Tau, p-Tau), with no changes in pSer202 but with nonspecific increases in pSer262 levels. The presence of alpha-Syn was absolutely mandatory to observe MPP+/MPTP-induced increases in p-Tau levels, since no alterations in p-Tau were seen in transfected cells not expressing alpha-Syn or in alpha-Syn-/- mice.

The neurotoxin, MPP+, induces hyperphosphorylation of Tau, in the presence of alpha-Synuclein, in SH-SY5Y neuroblastoma cells.

Alzheimer's disease (AD) is characterized, in part, by intracellular neurofibrillary tangles composed of hyperphosphorylated filamentous aggregates of the microtubule-associated protein, Tau. Such hyperphosphorylated Tau is also found in Lewy bodies (LBs), and cytoplasmic inclusion bodies in certain forms of Parkinson's disease (PD). Further, LBs also contain aggregates of alpha-synuclein (alpha-Syn), also a microtubule-associated protein, which has been linked to the genesis of PD.