Induction of estrus in suckled female yaks (Bos grunniens) and synchronization of ovulation in the non-sucklers for timed artificial insemination using progesterone treatments and Co-Synch regimens.

The objectives of the present study were to evaluate the induction of estrus and fertility in yak cows treated with Co-Synch regimens or progesterone (P(4)). In Experiment 1, postpartum suckled yaks were assigned to three treatments: (1) A (n=28), insertion of an intravaginal device containing P(4) (CIDR) on Day 0, PGF(2alpha) (i.m.

Cloning and functional characterization of two cDNAs encoding NADPH-dependent 3-ketoacyl-CoA reductased from developing cotton fibers.

Genes encoding enzymes involved in biosynthesis of very long chain fatty acids were significantly up-regulated during early cotton fiber development. Two cDNAs, GhKCR1 and GhKCR2 encoding putative cotton 3-ketoacyl-CoA reductases that catalyze the second step in fatty acid elongation, were isolated from developing cotton fibers. GhKCR1 and 2 contain open reading frames of 963 bp and 924 bp encoding proteins of 320 and 307 amino acid residues, respectively.

Microtubule regulation of N-methyl-D-aspartate receptor channels in neurons.

N-Methyl-D-aspartate (NMDA) receptors (NMDARs), which play a key role in synaptic plasticity, are dynamically regulated by many signaling molecules and scaffolding proteins. Although actin cytoskeleton has been implicated in regulating NMDAR stability in synaptic membrane, the role of microtubules in regulating NMDAR trafficking and function is largely unclear. Here we show that microtubule-depolymerizing agents inhibited NMDA receptor-mediated ionic and synaptic currents in cortical pyramidal neurons.

Alzheimer's disease: interactions between cholinergic functions and beta-amyloid.

Alzheimer's disease (AD) is characterized by two major features: (1) degeneration of basal forebrain cholinergic neurons and ensuing deficient cholinergic functions in cortex and hippocampus; (2) extracellular protein aggregates containing beta-amyloid peptides (Abeta) in these cholinergic target areas. So far, the most effective therapy for AD is to enhance cholinergic transmission. Neuromodulatory functions of the cholinergic system are mainly mediated by muscarinic receptors (mAChRs).

Serotonin 5-HT1A receptors regulate NMDA receptor channels through a microtubule-dependent mechanism.

The serotonin system and NMDA receptors (NMDARs) in prefrontal cortex (PFC) are both critically involved in the regulation of cognition and emotion under normal and pathological conditions; however, the interactions between them are essentially unknown. Here we show that serotonin, by activating 5-HT(1A) receptors, inhibited NMDA receptor-mediated ionic and synaptic currents in PFC pyramidal neurons, and the NR2B subunit-containing NMDA receptor is the primary target of 5-HT(1A) receptors. This effect of 5-HT(1A) receptors was blocked by agents that interfere with microtubule assembly, as well as by cellular knock-down of the kinesin motor protein KIF17 (kinesin superfamily member 17), which transports NR2B-containing vesicles along microtubule in neuronal dendrites.

Parkin stabilizes microtubules through strong binding mediated by three independent domains.

Mutations of parkin, a protein-ubiquitin isopeptide ligase (E3), appear to be the most frequent cause of familial Parkinson's disease (PD). Our previous studies have demonstrated that parkin binds strongly to alpha/beta tubulin heterodimers and microtubules. Here we show that the strong binding between parkin and tubulin, as well as that between parkin and microtubules, was mediated by three independent domains: linker, RING1, and RING2.

Dentin matrix protein 1 gene cis-regulation: use in osteocytes to characterize local responses to mechanical loading in vitro and in vivo.

Dentin matrix protein 1 (DMP1) is highly expressed in osteocytes and is mechanically responsive. To study osteocyte-specific and mechanically regulated DMP1 gene expression, the transcriptional activity of three cis-regulatory regions was first examined in an osteoblast differentiation model in vitro using a green fluorescent protein (GFP) reporter. Expression of the -9624 to +1996 bp (10 kb) and -7892 to +4439 bp (8 kb) DMP1 cis-regulatory regions dramatically increased in areas of mineralized matrix, in dendritic, osteocyte-like cells.

Dynamic expression of de novo DNA methyltransferases Dnmt3a and Dnmt3b in the central nervous system.

To explore the role of DNA methylation in the brain, we examined the expression pattern of de novo DNA methyltransferases Dnmt3a and Dnmt3b in the mouse central nervous system (CNS). By comparing the levels of Dnmt3a and Dnmt3b mRNAs and proteins in the CNS, we showed that Dnmt3b is detected within a narrow window during early neurogenesis, whereas Dnmt3a is present in both embryonic and postnatal CNS tissues. To determine the precise pattern of Dnmt3a and Dnmt3b gene expression, we carried out X-gal histochemistry in transgenic mice in which the lacZ marker gene is knocked into the endogenous Dnmt3a or Dnmt3b gene locus (Okano et al.

Enhanced Ca2+ response to AVP in preglomerular vessels from rats with genetic hypertension during different hydration states.

Exaggerated arginine vasopressin (AVP)-induced calcium signaling and renal vasoconstriction, characteristic in young spontaneously hypertensive rats (SHR) during euvolemia, are related to greater amounts of V1a receptor mRNA and V1a protein in preglomerular resistance arterioles. The present study determined whether V1a receptor density and calcium signal transduction in the renal vasculature of young SHR is regulated appropriately during physiological changes in hydration state. [3H]AVP ligand binding documented two- to threefold greater density of V1a receptors in euvolemic SHR vs.

Different presynaptic roles of synapsins at excitatory and inhibitory synapses.

The functions of synapsins were examined by characterizing the phenotype of mice in which all three synapsin genes were knocked out. Although these triple knock-out mice were viable and had normal brain anatomy, they exhibited a number of behavioral defects. Synaptic transmission was altered in cultured neurons from the hippocampus of knock-out mice.

Dmp1-deficient mice display severe defects in cartilage formation responsible for a chondrodysplasia-like phenotype.

Understanding the molecular mechanisms by which cartilage formation is regulated is essential toward understanding the physiology of both embryonic bone development and postnatal bone growth. Although much is known about growth factor signaling in cartilage formation, the regulatory role of noncollagenous matrix proteins in this process are still largely unknown. In the present studies, we present evidence for a critical role of DMP1 (dentin matrix protein 1) in postnatal chondrogenesis.

Determination of the transphosphorylation sites of Jak2 kinase.

Janus kinases are the key enzymes involved in the initial transmission of signals in response to type I and II cytokines. Activation of the signal begins with the transphosphorylation of Jak kinases. Substrates that give rise to downstream events are recruited to the receptor complex in part by interactions with phosphorylated tyrosines.

Parkin increases dopamine uptake by enhancing the cell surface expression of dopamine transporter.

Mutations of parkin, a protein-ubiquitin E3 ligase, are linked to Parkinson's disease (PD). Although a variety of parkin substrates have been identified, none of these is selectively expressed in dopaminergic neurons, whose degeneration plays a critical role in PD. Here we show that parkin significantly increased dopamine uptake in the human dopaminergic neuroblastoma cell line SH-SY5Y.

Critical role of calbindin-D28k in calcium homeostasis revealed by mice lacking both vitamin D receptor and calbindin-D28k.

Calbindin (CaBP)-D28k and CaBP-D9k are cytosolic vitamin D-dependent calcium-binding proteins long thought to play an important role in transepithelial calcium transport. However, recent genetic studies suggest that CaBP-D28k is not essential for calcium metabolism. Genetic ablation of this gene in mice leads to no calcemic abnormalities.

Effect of sodium sulfide on Ni-containing carbon monoxide dehydrogenases.

The structure of the active-site C-cluster in CO dehydrogenase from Carboxydothermus hydrogenoformans includes a mu(2)-sulfide ion bridged to the Ni and unique Fe, whereas the same cluster in enzymes from Rhodospirillum rubrum (CODH(Rr)) and Moorella thermoacetica (CODH(Mt)) lack this ion. This difference was investigated by exploring the effects of sodium sulfide on activity and spectral properties. Sulfide partially inhibited the CO oxidation activity of CODH(Rr) and generated a lag prior to steady-state.

Spinophilin blocks arrestin actions in vitro and in vivo at G protein-coupled receptors.

Arrestin regulates almost all G protein-coupled receptor (GPCR)-mediated signaling and trafficking. We report that the multidomain protein, spinophilin, antagonizes these multiple arrestin functions. Through blocking G protein receptor kinase 2 (GRK2) association with receptor-Gbetagamma complexes, spinophilin reduces arrestin-stabilized receptor phosphorylation, receptor endocytosis, and the acceleration of mitogen-activated protein kinase (MAPK) activity following endocytosis.

Parkin protects human dopaminergic neuroblastoma cells against dopamine-induced apoptosis.

Parkinson's disease (PD) is characterized by the selective degeneration of dopaminergic (DA) neurons in substantia nigra pars compacta (SNpc). A combination of genetic and environmental factors contributes to such a specific loss. Among the five PD-linked genes identified so far, parkin, a protein-ubiquitin E3 ligase, appears to be the most prevalent genetic factor in PD.

Evidence for a proton transfer network and a required persulfide-bond-forming cysteine residue in Ni-containing carbon monoxide dehydrogenases.

Carbon monoxide dehydrogenase from Moorella thermoacetica catalyzes the reversible oxidation of CO to CO(2) at a nickel-iron-sulfur active site called the C-cluster. Mutants of a proposed proton transfer pathway and of a cysteine residue recently found to form a persulfide bond with the C-cluster were characterized. Four semiconserved histidine residues were individually mutated to alanine.

Molecular determinants of synapsin targeting to presynaptic terminals.

Although synapsins are abundant synaptic vesicle proteins that are widely used as markers of presynaptic terminals, the mechanisms that target synapsins to presynaptic terminals have not been elucidated. We have addressed this question by imaging the targeting of green fluorescent protein-tagged synapsins in cultured hippocampal neurons. Whereas all synapsin isoforms targeted robustly to presynaptic terminals in wild-type neurons, synapsin Ib scarcely targeted in neurons in which all synapsins were knocked-out.

[The importance and approaches of physicochemical properties analysis of active compounds of traditional Chinese herbs in development of new medicine].

Biological activity and physicochemical properties are two key factors to screen active compounds of traditional Chinese herbs during early discovery phases. As a great number of the compounds are got in the world, a new strategy is developed to research the physicochemical properties of the compositions of herbs, so that the election of active compounds from the compositions has become more effective and more economical than before. The new strategy and associated technology have emerged and it was used extensively.

Deletion of dentin matrix protein-1 leads to a partial failure of maturation of predentin into dentin, hypomineralization, and expanded cavities of pulp and root canal during postnatal tooth development.

The dentin matrix protein-1 (DMP-1) gene is identified in odontoblasts during both embryonic and postnatal development. In vitro study suggests that this noncollagen acidic phosphoprotein plays a role in mineralization. However, deletion of the Dmp-1 gene has little effect on tooth development during embryogenesis.

Carbon monoxide dehydrogenase from Rhodospirillum rubrum: effect of redox potential on catalysis.

The Ni-Fe-S-containing C-cluster of carbon monoxide dehydrogenases is the active site for catalyzing the reversible oxidation of CO to CO(2). This cluster can be stabilized in redox states designated C(ox), C(red1), C(int), and C(red2). What had until recently been the best-supported mechanism of catalysis involves a one-electron reductive activation of C(ox) to C(red1) and a catalytic cycle in which the C(red1) state binds and oxidizes CO, forming C(red2) and releasing CO(2).

Identification of the haematopoietic stem cell niche and control of the niche size.

Haematopoietic stem cells (HSCs) are a subset of bone marrow cells that are capable of self-renewal and of forming all types of blood cells (multi-potential). However, the HSC 'niche'--the in vivo regulatory microenvironment where HSCs reside--and the mechanisms involved in controlling the number of adult HSCs remain largely unknown. The bone morphogenetic protein (BMP) signal has an essential role in inducing haematopoietic tissue during embryogenesis.

Parkin is recruited to the centrosome in response to inhibition of proteasomes.

Parkin is a protein-ubiquitin E3 ligase linked to Parkinson's disease. Although several substrates of parkin have been identified, the subcellular location for parkin to recognize and ubiquitinate its targets is unclear. Here we report that parkin was accumulated in the centrosome when SH-SY5Y or transfected HEK293 cells were treated with the proteasome inhibitor lactacystin.