TorC1 and nitrogen catabolite repression control of integrated GABA shunt and retrograde pathway gene expression.

Despite our detailed understanding of how the lower GABA shunt and retrograde genes are regulated, there is a paucity of validated information concerning control of GAD1, the glutamate decarboxylase gene which catalyzes the first reaction of the GABA shunt. Further, integration of glutamate degradation via the GABA shunt has not been investigated. Here, we show that while GAD1 shares a response to rapamycin-inhibition of the TorC1 kinase, it does so independently of the Gln3 and Gat1 NCR-sensitive transcriptional activators that mediate transcription of the lower GABA shunt genes.

N- and C-terminal Gln3-Tor1 interaction sites: one acting negatively and the other positively to regulate nuclear Gln3 localization.

Gln3 activates Nitrogen Catabolite Repression, NCR-sensitive expression of the genes required for Saccharomyces cerevisiae to scavenge poor nitrogen sources from its environment. The global TorC1 kinase complex negatively regulates nuclear Gln3 localization, interacting with an α-helix in the C-terminal region of Gln3, Gln3656-666. In nitrogen replete conditions, Gln3 is sequestered in the cytoplasm, whereas when TorC1 is down-regulated, in nitrogen restrictive conditions, Gln3 migrates into the nucleus.

Reduced Testicular Steroidogenesis and Increased Semen Oxidative Stress in Male Partners as Novel Markers of Recurrent Miscarriage.

Background: Recurrent pregnancy loss, (RPL) affecting 1%-2% of couples, is defined as ≥3 consecutive pregnancy losses before 20-week' gestation. Women with RPL are routinely screened for etiological factors, but routine screening of male partners is not currently recommended. Recently it has been suggested that sperm quality is reduced in male partners of women with RPL, but the reasons underlying this lower quality are unclear.

General Amino Acid Control and 14-3-3 Proteins Bmh1/2 Are Required for Nitrogen Catabolite Repression-Sensitive Regulation of Gln3 and Gat1 Localization.

Nitrogen catabolite repression (NCR), the ability of Saccharomyces cerevisiae to use good nitrogen sources in preference to poor ones, derives from nitrogen-responsive regulation of the GATA family transcription activators Gln3 and Gat1 In nitrogen-replete conditions, the GATA factors are cytoplasmic and NCR-sensitive transcription minimal. When only poor nitrogen sources are available, Gln3 is nuclear, dramatically increasing GATA factor-mediated transcription. This regulation was originally attributed to mechanistic Tor protein kinase complex 1 (mTorC1)-mediated control of Gln3 However, we recently showed that two regulatory systems act cumulatively to maintain cytoplasmic Gln3 sequestration, only one of which is mTorC1.

PROMISE: first-trimester progesterone therapy in women with a history of unexplained recurrent miscarriages - a randomised, double-blind, placebo-controlled, international multicentre trial and economic evaluation.

Background And Objectives: Progesterone is essential to maintain a healthy pregnancy. Guidance from the Royal College of Obstetricians and Gynaecologists and a Cochrane review called for a definitive trial to test whether or not progesterone therapy in the first trimester could reduce the risk of miscarriage in women with a history of unexplained recurrent miscarriage (RM). The PROMISE trial was conducted to answer this question.

Multiple Targets on the Gln3 Transcription Activator Are Cumulatively Required for Control of Its Cytoplasmic Sequestration.

A remarkable characteristic of nutritional homeostatic mechanisms is the breadth of metabolite concentrations to which they respond, and the resolution of those responses; adequate but rarely excessive. Two general ways of achieving such exquisite control are known: stoichiometric mechanisms where increasing metabolite concentrations elicit proportionally increasing responses, and the actions of multiple independent metabolic signals that cumulatively generate appropriately measured responses. Intracellular localization of the nitrogen-responsive transcription activator, Gln3, responds to four distinct nitrogen environments: nitrogen limitation or short-term starvation, i.

A Randomized Trial of Progesterone in Women with Recurrent Miscarriages.

Background: Progesterone is essential for the maintenance of pregnancy. However, whether progesterone supplementation in the first trimester of pregnancy would increase the rate of live births among women with a history of unexplained recurrent miscarriages is uncertain.

Methods: We conducted a multicenter, double-blind, placebo-controlled, randomized trial to investigate whether treatment with progesterone would increase the rates of live births and newborn survival among women with unexplained recurrent miscarriage.

Nuclear Gln3 Import Is Regulated by Nitrogen Catabolite Repression Whereas Export Is Specifically Regulated by Glutamine.

Gln3, a transcription activator mediating nitrogen-responsive gene expression in Saccharomyces cerevisiae, is sequestered in the cytoplasm, thereby minimizing nitrogen catabolite repression (NCR)-sensitive transcription when cells are grown in nitrogen-rich environments. In the face of adverse nitrogen supplies, Gln3 relocates to the nucleus and activates transcription of the NCR-sensitive regulon whose products transport and degrade a variety of poorly used nitrogen sources, thus expanding the cell's nitrogen-acquisition capability. Rapamycin also elicits nuclear Gln3 localization, implicating Target-of-rapamycin Complex 1 (TorC1) in nitrogen-responsive Gln3 regulation.

Nitrogen starvation and TorC1 inhibition differentially affect nuclear localization of the Gln3 and Gat1 transcription factors through the rare glutamine tRNACUG in Saccharomyces cerevisiae.

A leucine, leucyl-tRNA synthetase-dependent pathway activates TorC1 kinase and its downstream stimulation of protein synthesis, a major nitrogen consumer. We previously demonstrated, however, that control of Gln3, a transcription activator of catabolic genes whose products generate the nitrogenous precursors for protein synthesis, is not subject to leucine-dependent TorC1 activation. This led us to conclude that excess nitrogen-dependent down-regulation of Gln3 occurs via a second mechanism that is independent of leucine-dependent TorC1 activation.

Constitutive and nitrogen catabolite repression-sensitive production of Gat1 isoforms.

Nitrogen catabolite repression (NCR)-sensitive transcription is activated by Gln3 and Gat1. In nitrogen excess, Gln3 and Gat1 are cytoplasmic, and transcription is minimal. In poor nitrogen, Gln3 and Gat1 become nuclear and activate transcription.

gln3 mutations dissociate responses to nitrogen limitation (nitrogen catabolite repression) and rapamycin inhibition of TorC1.

The GATA family transcription activator, Gln3 responds to the nitrogen requirements and environmental resources of the cell. When rapidly utilized, "good" nitrogen sources, e.g.

Genetic analysis of phage Mu Mor protein amino acids involved in DNA minor groove binding and conformational changes.

Gene expression during lytic development of bacteriophage Mu occurs in three phases: early, middle, and late. Transcription from the middle promoter, P(m), requires the phage-encoded activator protein Mor and the bacterial RNA polymerase. The middle promoter has a -10 hexamer, but no -35 hexamer.

Prevalence and pattern of congenital heart disease in school children of eastern Uttar Pradesh.

Background And Aim: The prevalence of congenital heart disease (CHD) is not known in our country. The aim of present study was to find out the prevalence of CHD in school children of eastern Uttar Pradesh.

Method: A team consisting of a cardiologist, physicians and junior residents visited schools in the area.

Prevalence of rheumatic heart disease in school-going children of Eastern Uttar Pradesh.

Background: Rheumatic heart disease is a major health problem in our country. There is evidence from South India that its prevalence is declining. This study attempts to confirm whether this is so in North India as well.

Ammonia-specific regulation of Gln3 localization in Saccharomyces cerevisiae by protein kinase Npr1.

Events directly regulating Gln3 intracellular localization and nitrogen catabolite repression (NCR)-sensitive transcription in Saccharomyces cerevisiae are interconnected with many cellular processes that influence the utilization of environmental metabolites. Among them are intracellular trafficking of the permeases that transport nitrogenous compounds and their control by the Tor1,2 signal transduction pathway. Npr1 is a kinase that phosphorylates and thereby stabilizes NCR-sensitive permeases, e.

Differing responses of Gat1 and Gln3 phosphorylation and localization to rapamycin and methionine sulfoximine treatment in Saccharomyces cerevisiae.

Gln3 and Gat1/Nil1 are GATA-family transcription factors responsible for transcription of nitrogen-catabolic genes in Saccharomyces cerevisiae. Intracellular Gln3 localization and Gln3-dependent transcription respond in parallel to the nutritional environment and inhibitors of Tor1/2 (rapamycin) and glutamine synthetase (L-methionine sulfoximine, MSX). However, detectable Gln3 phosphorylation, though influenced by nutrients and inhibitors, correlates neither with Gln3 localization nor nitrogen catabolite repression-sensitive transcription in a consistent way.

Methionine sulfoximine treatment and carbon starvation elicit Snf1-independent phosphorylation of the transcription activator Gln3 in Saccharomyces cerevisiae.

Tor proteins are global regulators situated at the top of a signal transduction pathway conserved from yeast to humans. Specific inhibition of the two Saccharomyces cerevisiae Tor proteins by rapamycin alters many cellular processes and the expression of hundreds of genes. Among the regulated genes are those whose expression is activated by the GATA family transcription activator, Gln3.

In vivo specificity of Ure2 protection from heavy metal ion and oxidative cellular damage in Saccharomyces cerevisiae.

The S. cerevisiae Ure2 protein is a prion precursor able to form large homopolymers with the characteristics of amyloid particles, a function largely restricted to its 90 N-terminal amino acids. The remaining C-terminal domain of Ure2 plays two important roles in cellular metabolism.

Synergistic operation of four cis-acting elements mediate high level DAL5 transcription in Saccharomyces cerevisiae.

The Saccharomyces cerevisiae allantoate/ureidosuccinate permease gene (DAL5) is often used as a reporter in studies of the Tor1/2 protein kinases which are specifically inhibited by the clinically important immunosuppressant and anti-neoplastic drug, rapamycin. To date, only a single type of cis-acting element has been shown to be required for DAL5 expression, two copies of the GATAA-containing UAS(NTR) element that mediates nitrogen catabolite repression-sensitive transcription. UAS(NTR) is the binding site for the transcriptional activator, Gln3 whose intracellular localization responds to the nitrogen supply, accumulating in the nuclei of cells provided with poor nitrogen sources and in the cytoplasm when excess nitrogen is available.