Deletion of Phospholipase C β1 in the Thalamic Reticular Nucleus Induces Absence Seizures.

Absence seizures are caused by abnormal synchronized oscillations in the thalamocortical (TC) circuit, which result in widespread spike-and-wave discharges (SWDs) on electroencephalography (EEG) as well as impairment of consciousness. Thalamic reticular nucleus (TRN) and TC neurons are known to interact dynamically to generate TC circuitry oscillations during SWDs. Clinical studies have suggested the association of with early-onset epilepsy, including absence seizures.

Functional expression of human prostaglandin E2 receptor 4 (EP4) in and characterization of the binding property of EP4 with G proteins.

Human prostaglandin E2 receptor 4 (EP4) is one of the four subtypes of prostaglandin E (PGE) receptors and belongs to the rhodopsin-type G protein-coupled receptor (GPCR) family. Particularly, EP4 is expressed in various cancer cells and is involved in cancer-cell proliferation by a G protein signaling cascade. To prepare an active form of EP4 for biochemical characterization and pharmaceutical application, this study designed a recombinant protein comprising human EP4 fused to the P9 protein (a major envelope protein of phi6 phage) and overexpressed the P9-EP4 fusion protein in the membrane fraction of The solubilized P9-EP4 with sarkosyl (a strong anionic detergent) was purified by affinity chromatography.

Analgesic Efficacy of α Adrenergic Receptor Agonists Depends on the Chronic State of Neuropathic Pain: Role of Regulator of G Protein Signaling 4.

The analgesic effect of alpha-2 adrenergic receptor (αAR) agonists, which relieve chronic neuropathic pain, is highly variable among individuals. Here, we used a mouse model of spared nerve injury (SNI) to show that treatment time after the establishment of neuropathic pain was important for the variability in the analgesic efficacy of αAR agonists, which was related to the activity of regulator of G-protein signaling protein 4 (RGS4). Intrathecal treatment with αAR agonists, clonidine (0.

Bicine promotes rapid formation of β-sheet-rich amyloid-β fibrils.

Fibrillar aggregates of amyloid-β (Aβ) are the main component of plaques lining the cerebrovasculature in cerebral amyloid angiopathy. As the predominant Aβ isoform in vascular deposits, Aβ40 is a valuable target in cerebral amyloid angiopathy research. However, the slow process of Aβ40 aggregation in vitro is a bottleneck in the search for Aβ-targeting molecules.

The Possible Role of Neurobeachin in Extinction of Contextual Fear Memory.

Established fear memory becomes vulnerable to disruption after memory retrieval and extinction; this labile state is critical for inhibiting the return of fear memory. However, the labile state has a very narrow time window after retrieval, and underlying molecular mechanisms are not well known. To that end, we isolated the hippocampus immediately after fear memory retrieval and performed proteomics.

Oligomer Formation Propensities of Dimeric Bundle Peptides Correlate with Cell Penetration Abilities.

LK-3, an amphipathic dimeric peptide linked by two disulfide bonds, and related isomeric bundles were synthesized, and their cell penetrating abilities were investigated. The measurements using size exclusion chromatography and dynamic light scattering show that LK-3 and its isomers form cell penetrating oligomers. Calculations, performed for various types of peptide isomers, elucidate a strong correlation between the amphipathic character of dimers and cell penetration ability.

Regulator of G-Protein Signaling 4 (RGS4) Controls Morphine Reward by Glutamate Receptor Activation in the Nucleus Accumbens of Mouse Brain.

Crosstalk between G-protein signaling and glutamatergic transmission within the brain reward circuits is critical for long-term emotional effects (depression and anxiety), cravings, and negative withdrawal symptoms associated with opioid addiction. A previous study showed that Regulator of G-protein signaling 4 (RGS4) may be implicated in opiate action in the nucleus accumbens (NAc). However, the mechanism of the NAc-specific RGS4 actions that induce the behavioral responses to opiates remains largely unknown.

New role of human ribosomal protein S3: Regulation of cell cycle via phosphorylation by cyclin-dependent kinase 2.

Human ribosomal protein S3 (hRpS3) is a component of the 40S ribosomal subunit that associated in protein synthesis. hRpS3 has additional ribosomal functions such as DNA repair, transcription, metastasis, and apoptosis via interaction with numerous signaling molecules and has different modifications. Cyclin-dependent kinases (CDKs) are heterodimeric serine/threonine protein kinases that regulate cell cycle progression.

A physical association between the human mutY homolog (hMYH) and DNA topoisomerase II-binding protein 1 (hTopBP1) regulates Chk1-induced cell cycle arrest in HEK293 cells.

Background: Human DNA topoisomerase II-binding protein 1 (hTopBP1) plays an important role in DNA replication and the DNA damage checkpoint pathway. The human mutY homolog (hMYH) is a base excision repair DNA glycosylase that excises adenines or 2-hydroxyadenines that are mispaired with guanine or 7,8-dihydro-8-oxoguanine (8-oxoG). hTopBP1 and hMYH were involved in ATR-mediated Chk1 activation, moreover, both of them were associated with ATR and hRad9 which known as checkpoint-involved proteins.

Design, synthesis, in-vitro antiproliferative activity and kinase profile of new picolinamide based 2-amido and ureido quinoline derivatives.

New 2-amido and ureido quinoline derivatives substituted with 2-N-methylamido-pyridin-4-yloxy group at the 5-position of quinoline (18 final compounds) have been designed and synthesized as anticancer sorafenib congeners. Among the synthesized derivatives, fourteen compounds were selected for evaluation of their antiproliferative activity over a panel of 60 cancer cell lines at a single dose concentration of 10 μM at National Cancer Institute (NCI, USA). Four compounds, 9b-d and 9f showed promising mean growth inhibitions and thus were further tested at five-dose testing mode to determine their IC50 values.

Intrathecal RGS4 inhibitor, CCG50014, reduces nociceptive responses and enhances opioid-mediated analgesic effects in the mouse formalin test.

Background: The regulator of G-protein signaling protein type 4 (RGS4) accelerates the guanosine triphosphatase activity of G(αi) and G(αo), resulting in the inactivation of G-protein-coupled receptor signaling. An opioid receptor (OR), a G(αi)-coupled receptor, plays an important role in pain modulation in the central nervous system. In this study, we examined whether (1) spinal RGS4 affected nociceptive responses in the formalin pain test, (2) this RGS4-mediated effect was involved in OR activation, and (3) the µ-OR agonist-induced antinociceptive effect was modified by RGS4 modulation.

The DUSP26 phosphatase activator adenylate kinase 2 regulates FADD phosphorylation and cell growth.

Adenylate kinase 2 (AK2), which balances adenine nucleotide pool, is a multi-functional protein. Here we show that AK2 negatively regulates tumour cell growth. AK2 forms a complex with dual-specificity phosphatase 26 (DUSP26) phosphatase and stimulates DUSP26 activity independently of its AK activity.

(1)H, (13)C and (15)N resonance assignment of WHEP domains of human glutamyl-prolyl tRNA synthetase.

Human bifunctional glutamyl-prolyl tRNA synthetase (EPRS) contains three WHEP domains (R123) linking two catalytic domains. These three WHEP domains have been shown to be involved in protein-protein and protein-nucleic acid interactions. In translational control of gene expression, R12 repeats is known to interact with 3'UTR element in mRNAs of inflammatory gene for translational control mechanisms.

FcγRIIb mediates amyloid-β neurotoxicity and memory impairment in Alzheimer's disease.

Amyloid-β (Aβ) induces neuronal loss and cognitive deficits and is believed to be a prominent cause of Alzheimer's disease (AD); however, the cellular pathology of the disease is not fully understood. Here, we report that IgG Fcγ receptor II-b (FcγRIIb) mediates Aβ neurotoxicity and neurodegeneration. We found that FcγRIIb is significantly upregulated in the hippocampus of AD brains and neuronal cells exposed to synthetic Aβ.

Characterization of Helicobacter pylori adhesin thiol peroxidase (HP0390) purified from Escherichia coli.

The antioxidant protein, adhesin thiol peroxidase (HpTpx or HP0390), plays an important role in enabling Helicobacter pylori to survive gastric oxidative stress. The bacterium colonizes the host stomach and produces gastric cancer. However, little information is available about the biochemical characteristics of HpTpx.

Suppression of lipopolysaccharide-induced microglial activation by a benzothiazole derivative.

We previously reported that KHG21834, a benzothiazole derivative, attenuates the beta-amyloid (Abeta)-induced degeneration of both cortical and mesencephalic neurons in vitro. Central nervous system inflammation mediated by activated microglia is a key event in the development of neurodegenerative disease. In this study, we show that KHG21834 suppresses inflammation-mediated cytokine upregulation.

Structural insights into mouse anti-apoptotic Bcl-xl reveal affinity for Beclin 1 and gossypol.

This study reports the crystal structures of Bcl-xl wild type and three Bcl-xl mutants (Y101A, F105A, and R139A) with amino acid substitutions in the hydrophobic groove of the Bcl-xl BH3 domain. An additional 12 ordered residues were observed in a highly flexible loop between the alpha1 and alpha2 helices, and were recognized as an important deamidation site for the regulation of apoptosis. The autophagy-effector protein, Beclin 1, contains a novel BH3 domain (residues 101-125), which binds to the surface cleft of Bcl-xl, as confirmed by nuclear magnetic resonance (NMR) spectroscopy and analytical gel-filtration results.

Suppression of glutamate-induced excitotoxicity by 2-cyclopropylimino-3-methyl-1,3-thiazoline hydrochloride in rat glial cultures.

We have screened new drugs with a view to developing effective drugs against glutamate-induced excitotoxicity. In the present work, we show effects of a new drug, 2-cyclopropylimino-3-methyl-1,3-thiazoline hydrochloride against glutamate-induced excitotoxicity in primary rat glial cultures. Pretreatment of glial cells with 2-cyclopropylimino-3-methyl-1,3-thiazoline hydrochloride for 2 h significantly protected glial cells against glutamate-induced excitotoxicity in a time- and dose-dependent manner with an optimum concentration of 100 microM.

Localization of the death effector domain of Fas-associated death domain protein into the membrane of Escherichia coli induces reactive oxygen species-involved cell death.

The death effector domain (DED) of the mammalian apoptosis mediator, Fas-associated death domain protein (FADD), induces Escherichia coli cell death under aerobic culture conditions, yet the mechanisms by which FADD-DED induces cell death are not fully understood. Oxidative stress has been implicated as one of the mechanisms. Using a proteomic approach and validation by coexpression analysis, we illustrate that overexpression of FADD-DED in E.

RGS11 interacts preferentially with R7BP over Galpha(oa)--characterization of Gbeta5-free RGS11.

Regulator of G protein signaling 11 (RGS11) is the least characterized member of the R7 family of Ggamma-like GGL domain-containing RGS proteins. All R7-RGS proteins of a variety of cell types are found in Gbeta5-containing complexes that exhibit a number of unique functional properties. However, presence of Gbeta5 reduced the affinity of R7-RGS7 for Galpha subunits, also only RGS7 bound to Muscarinic M3-Receptor, but the Gbeta5-RGS7 dimer did not, making it difficult to study differential interaction of R7-RGS proteins.

Structural insights of the MenD from Escherichia coli reveal ThDP affinity.

MenD (2-succinyl-5-enolpyruvyl-6-hydroxy-3-cyclohexadiene-1-carboxylate) synthase belongs to the superfamily of thiamin diphosphate-dependent decarboxylases, which converts isochorismate and 2-oxoglutarate to SHCHC, pyruvate, and carbon dioxide. Here, we report the first crystal structure of apo-MenD from Escherichia coli determined in tetragonal crystal form. The subunit displays the typical three-domain structure observed for ThDP-dependent enzymes.

In vitro activation of procaspase-8 by forming the cytoplasmic component of the death-inducing signaling complex (cDISC).

Procaspase-8 is activated by forming a death-inducing signaling complex (DISC) with the Fas-associated death domain (FADD) and the Fas receptor, but the mechanism of its activation is not well understood. Procaspase-8 devoid of the death effector domain at its N-terminus (delta nprocaspase-8) was reported to be activated by kosmotropic salts, but it has not been induced to form a DISC in vitro because it cannot interact with FADD. Here, we report the production of full-length procaspase-8 and show that it is activated by adding the Fas death domain (Fas-DD) and the FADD forming the cytoplasmic part of the DISC (cDISC).

Structure-activity relations of parasin I, a histone H2A-derived antimicrobial peptide.

The structure-activity relations and mechanism of action of parasin I, a 19-amino acid histone H2A-derived antimicrobial peptide, were investigated. Parasin I formed an amphipathic alpha-helical structure (residues 9-17) flanked by two random coil regions (residues 1-8 and 18-19) in helix-promoting environments. Deletion of the lysine residue at the N-terminal [Pa(2-19)] resulted in loss of antimicrobial activity, but did not affect the alpha-helical content of the peptide.

Structural and biochemical bases for the inhibition of autophagy and apoptosis by viral BCL-2 of murine gamma-herpesvirus 68.

All gammaherpesviruses express homologues of antiapoptotic B-cell lymphoma-2 (BCL-2) to counter the clearance of infected cells by host antiviral defense machineries. To gain insights into the action mechanisms of these viral BCL-2 proteins, we carried out structural and biochemical analyses on the interactions of M11, a viral BCL-2 of murine gamma-herpesvirus 68, with a fragment of proautophagic Beclin1 and BCL-2 homology 3 (BH3) domain-containing peptides derived from an array of proapoptotic BCL-2 family proteins. Mainly through hydrophobic interactions, M11 bound the BH3-like domain of Beclin1 with a dissociation constant of 40 nanomole, a markedly tighter affinity compared to the 1.