Increased Site-Specific Phosphorylation of Tyrosine Hydroxylase Accompanies Stimulation of Enzymatic Activity Induced by Cessation of Dopamine Neuronal Activity

1999 ◽  
Vol 55 (2) ◽  
pp. 202-209 ◽  
Author(s):  
Jow Y. Lew ◽  
Antonio Garcia-Espana ◽  
Kwan Y. Lee ◽  
Kenneth D. Carr ◽  
Menek Goldstein ◽  
...  
Keyword(s):  
Tyrosine Hydroxylase ◽  
Enzymatic Activity ◽  
Neuronal Activity ◽  
Site Specific ◽  
Stimulation Of

Isolation of Antithrombin III from Normal and α1-Antitrypsin-Deficient Human Plasma

1977 ◽  
Vol 38 (02) ◽  
pp. 0475-0485 ◽  
Author(s):  
Anna D. Borsodi ◽  
Ralph A. Bradshaw
Keyword(s):  
Enzymatic Activity ◽  
Isoelectric Focusing ◽  
Antithrombin Iii ◽  
Factor Xa ◽  
Antithrombin Activity ◽  
Bovine Trypsin ◽  
Normal Plasma ◽  
Antitrypsin Deficiency ◽  
Simplified Procedure ◽  
Stimulation Of

SummaryThe plasma of individuals, hetero- or homozygous for α1-antitrypsin deficiency, contains greatly decreased amounts of antithrombin activity as assayed against factor Xa. However, heparin stimulation of the residual antithrombin activity is observed, which is comparable to that of normal plasma. Antithrombins isolated from both normal and α1-antitrypsin deficient plasma by a simplified procedure are indistinguishable in both properties and yields. The microheterogeneity observed on isoelectric focusing of both preparations can be eliminated by treatment with neuraminidase. Neither purified human antithrombin nor α1-antitrypsin, when assayed against bovine trypsin, is stimulated by heparin. These results clearly establish the unique natures of antithrombin and α1-antitrypsin and show that about 75% of the antithrombin activity measured in normal plasma is due to α1-antitrypsin. Estimates of anti thrombin III activity in normal plasma by assays dependent on enzymatic activity can probably be obtained only in the presence of heparin.

scholarly journals Effect of aluminium oxide nanoparticles on the enzymatic activity on microorganisms of activated sludge

2018 ◽  
Vol 44 ◽  
pp. 00033 ◽  
Author(s):  
Nina Doskocz ◽  
Katarzyna Affek ◽  
Monika Załęska-Radziwiłł
Keyword(s):  
Enzymatic Activity ◽  
Activated Sludge ◽  
Hydrolytic Enzymes ◽  
Aluminium Oxide ◽  
Cellular Respiration ◽  
Oxide Nanoparticles ◽  
Oxide Compound ◽  
Commercial Use ◽  
Aluminium Oxide Nanoparticles ◽  
Stimulation Of

The increased production and commercial use of nanoparticles (NPs), combined with a lack of regulation regarding their disposal, may result in the unwanted introduction of NPs to wastewater. Wastewater nutrient removal depends on the metabolisms of activated sludge bacteria and their related key enzymes. Therefore, the aim of this work was to determine the effect of aluminium oxide nanoparticles concentrations on the activated sludge enzymatic activity of microorganisms. Tested nanoparticles inhibition cellular respiration in TTC method in the four highest tested concentrations. Moreover, in most samples observed increase dehydrogenase activity. In this study, nano-Al2O3 also caused a clear stimulation of the activity of hydrolytic enzymes microorganisms of activate sludge. Effects of aluminum oxide (compound in bulk forms) on enzymatic activity were different than in the case of the nano from of Al2O3.

scholarly journals The Hrq1 helicase stimulates Pso2 translesion nuclease activity to promote DNA inter-strand crosslink repair

2019 ◽  
Author(s):  
Cody M. Rogers ◽  
Chun-Ying Lee ◽  
Samuel Parkins ◽  
Nicholas J. Buehler ◽  
Sabine Wenzel ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Dna Damage Response ◽  
Nuclease Activity ◽  
Site Specific ◽  
Damage Response ◽  
Physical Barriers ◽  
A Site ◽  
Translesion Polymerases ◽  
Stimulation Of

AbstractDNA inter-strand crosslink (ICL) repair requires a complicated network of DNA damage response pathways. Removal of these lesions is vital as they are physical barriers to essential DNA processes that require the separation of duplex DNA, such as replication and transcription. The Fanconi anemia (FA) pathway is the principle mechanism for ICL repair in metazoans and is coupled to replication. In Saccharomyces cerevisiae, a degenerate FA pathway is present, but ICLs are predominantly repaired by a pathway involving the Pso2 nuclease that is hypothesized to digest through the lesion to provide access for translesion polymerases. However, Pso2 lacks translesion nuclease activity in vitro, and mechanistic details of this pathway are lacking, especially relative to FA. We recently identified the Hrq1 helicase, a homolog of the disease-linked RECQL4, as a novel component of Pso2- mediated ICL repair. Here, we show that Hrq1 stimulates the Pso2 nuclease in a mechanism that requires Hrq1 catalytic activity. Importantly, Hrq1 also stimulates Pso2 translesion nuclease activity through a site- specific ICL in vitro. Stimulation of Pso2 nuclease activity is specific to eukaryotic RecQ4 subfamily helicases, and Hrq1 likely interacts with Pso2 through their N-terminal domains. These results advance our understanding of FA-independent ICL repair and establish a role for the RecQ4 helicases in the repair of these dangerous lesions.

scholarly journals Synaptic transmission induces site-specific changes in sialylation on N-linked glycoproteins in rat nerve terminals

2020 ◽  
Author(s):  
Inga Boll ◽  
Pia Jensen ◽  
Veit Schwämmle ◽  
Martin R. Larsen
Keyword(s):  
Synaptic Transmission ◽  
Structure And Function ◽  
Synaptic Proteins ◽  
Nerve Terminals ◽  
Membrane Glycoproteins ◽  
Site Specific ◽  
Specific Alteration ◽  
And Function ◽  
Rat Nerve ◽  
Stimulation Of

AbstractSynaptic transmission leading to release of neurotransmitters in the nervous system is a fast and highly dynamic process. Previously, protein interaction and phosphorylation have been thought to be the main regulators of synaptic transmission. Here we show a novel potential modulator of synaptic transmission, sialylation of N-linked glycosylation. The negatively charged sialic acids can be modulated, similarly to phosphorylation, by the action of sialyltransferases and sialidases thereby changing local structure and function of membrane glycoproteins. We characterized site-specific alteration in sialylation on N-linked glycoproteins in isolated rat nerve terminals after brief depolarization using quantitative sialiomics. We identified 1965 formerly sialylated N-linked glycosites in synaptic proteins and found that the abundances of 430 glycosites changed after five seconds depolarization. We observed changes on essential synaptic proteins such as synaptic vesicle proteins, ion channels and transporters, neurotransmitter receptors and cell adhesion molecules. This study is to our knowledge the first to describe ultra-fast site-specific modulation of the sialiome after brief stimulation of a biological system.

Sleep-related c-Fos protein expression in the preoptic hypothalamus: effects of ambient warming

2000 ◽  
Vol 279 (6) ◽  
pp. R2079-R2088 ◽  
Author(s):  
Hui Gong ◽  
Ronald Szymusiak ◽  
Janice King ◽  
Teresa Steininger ◽  
Dennis McGinty
Keyword(s):  
Protein Expression ◽  
Ambient Temperature ◽  
Neuronal Activity ◽  
Preoptic Area ◽  
Thermal Stimulation ◽  
Preoptic Nucleus ◽  
Ambient Temperatures ◽  
Median Preoptic Nucleus ◽  
Fos Protein ◽  
Stimulation Of

Preoptic area (POA) neuronal activity promotes sleep, but the localization of critical sleep-active neurons is not completely known. Thermal stimulation of the POA also facilitates sleep. This study used the c-Fos protein immunostaining method to localize POA sleep-active neurons at control (22°C) and mildly elevated (31.5°C) ambient temperatures. At 22°C, after sleep, but not after waking, we found increased numbers of c-Fos immunoreactive neurons (IRNs) in both rostral and caudal parts of the median preoptic nucleus (MnPN) and in the ventrolateral preoptic area (VLPO). In animals sleeping at 31.5°C, significantly more Fos IRNs were found in the rostral MnPN compared with animals sleeping at 22°C. In VLPO, Fos IRN counts were no longer increased over waking levels after sleep at the elevated ambient temperature. Sleep-associated Fos IRNs were also found diffusely in the POA, but counts were lower than those made after waking. This study supports a hypothesis that the MnPN, as well as the VLPO, is part of the POA sleep-facilitating system and that the rostral MnPN may facilitate sleep, particularly at elevated ambient temperatures.

Responses of medullary raphespinal neurons to electrical stimulation of thoracic sympathetic afferents, vagal afferents, and to other sensory inputs in cats

1991 ◽  
Vol 66 (6) ◽  
pp. 2084-2094 ◽  
Author(s):  
R. W. Blair ◽  
A. R. Evans
Keyword(s):  
Electrical Stimulation ◽  
Neuronal Activity ◽  
Vagal Stimulation ◽  
Discharge Rate ◽  
Stellate Ganglion ◽  
Cell Activity ◽  
Conditioning Stimulus ◽  
Vagal Afferents ◽  
Early Peak ◽  
Stimulation Of

1. Medullary raphespinal neurons antidromically activated from the T2-T5 segments were tested for responses to electrical stimulation of cervical vagal and thoracic sympathetic afferents (by stimulating the left stellate ganglion), somatic probing, auditory stimuli, and visual stimuli in cats anesthetized with alpha-chloralose. A total of 99 neurons in the raphe nuclei were studied; the locations of 76 cells were histologically confirmed. Neurons were located in raphe magnus (RM, 65%), raphe obscurus (RO, 32%), and raphe pallidus (RPa, 4%). The mean conduction velocity of these neurons was 62 +/- 2.9 (SE) m/s with a range of 1.1-121 m/s. 2. A total of 60/99 tested neurons responded to electrical stimulation of sympathetic afferents. Quantitation of responses was obtained for 55 neurons. With one exception, all responsive neurons were excited and exhibited an early burst of spikes with a mean latency of 16 +/- 1.2 ms. From a spontaneous discharge rate of 5.2 +/- 1.2 spikes/s, neuronal activity increased by 2.9 +/- 0.3 spikes/stimulus. In addition to an early peak, 15 neurons (25%) exhibited a late burst of spikes with a latency of 182 +/- 12.9 ms; neuronal activity increased by 5.0 +/- 1.3 spikes/stimulus. Duration of the late peak (130 +/- 18.5 ms) was longer than for the early peak (18 +/- 0.7 ms), but threshold voltages for eliciting each peak were comparable. Sixteen of 29 spontaneously active neurons exhibited a postexcitatory depression of activity that lasted for 163 +/- 19.1 ms. All but one tested neuron in RO responded to stimulation of sympathetic afferents, but 65% of neurons in RM responded to this stimulus. 3. In response to vagal afferent stimulation, 19% of 57 neurons exhibited inhibition only, 11% were only excited, and 9% were either excited or inhibited, depending on the stimulus paradigm used; the remaining 61% of neurons were unresponsive. From a spontaneous rate of 7.9 +/- 3.8 spikes/s, excited cells increased their discharge rate by 1.6 +/- 0.3 spikes/stimulus. Activity of inhibited cells was reduced from 21.3 +/- 5.8 to 7.8 +/- 3.1 spikes/s. The conditioning-test (CT) technique was used to assess 11 neurons' responses. Stellate ganglion stimulation was the test stimulus, and vagal stimulation the conditioning stimulus. Vagal stimulation reduced the neuronal responses to stellate ganglion stimulation by an average of 50% with a CT interval of 60-100 ms, and cell responses returned to control after 300 ms. With spontaneous cell activity, low frequencies of vagal stimulation were generally excitatory, and high frequencies (10-20 Hz) inhibitory.(ABSTRACT TRUNCATED AT 400 WORDS)

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