Publications by authors named "Westrich L"

In land plants and cyanobacteria, co-translational association of chlorophyll (Chl) to the nascent D1 polypeptide, a reaction center protein of photosystem II (PSII), requires a Chl binding complex consisting of a short-chain dehydrogenase (high chlorophyll fluorescence 244 [HCF244]/uncharacterized protein 39 [Ycf39]) and one-helix proteins (OHP1 and OHP2 in chloroplasts) of the light-harvesting antenna complex superfamily. Here, we show that an ohp2 mutant of the green alga Chlamydomonas (Chlamydomonas reinhardtii) fails to accumulate core PSII subunits, in particular D1 (encoded by the psbA mRNA). Extragenic suppressors arose at high frequency, suggesting the existence of another route for Chl association to PSII.

View Article and Find Full Text PDF

Photosynthesis is a central determinant of plant biomass production, but its homeostasis is increasingly challenged by heat. Little is known about the sensitive regulatory principles involved in heat acclimation that underly the biogenesis and repair of chloroplast-encoded core subunits of photosynthetic complexes. Employing time-resolved ribosome and transcript profiling together with selective ribosome proteomics, we systematically deciphered these processes in chloroplasts of Chlamydomonas reinhardtii.

View Article and Find Full Text PDF

In plant cells, chloroplast gene expression is predominantly controlled through post-transcriptional regulation. Such fine-tuning is vital for precisely orchestrating protein complex assembly as for the photosynthesis machinery and for quickly responding to environmental changes. While regulation of chloroplast protein synthesis is of central importance, little is known about the degree and nature of the regulatory network, mainly due to challenges associated with the specific isolation of transient ribosome interactors.

View Article and Find Full Text PDF

Biochemical processes in chloroplasts are important for virtually all life forms. Tight regulation of protein homeostasis and the coordinated assembly of protein complexes, composed of both imported and locally synthesized subunits, are vital to plastid functionality. Protein biogenesis requires the action of cotranslationally acting molecular chaperones.

View Article and Find Full Text PDF

Currently, all second-generation antipsychotics are approved for schizophrenia. Many are also approved for bipolar disorder, with some also approved as adjunctive treatment for depression and autism-related irritability. Second-generation antipsychotics are increasingly being prescribed for indications other than those approved by the Food and Drug Administration, such as in dementia, anxiety, and post-traumatic stress disorder to name a few.

View Article and Find Full Text PDF

Microalgae are regarded as promising organisms to develop innovative concepts based on their photosynthetic capacity that offers more sustainable production than heterotrophic hosts. However, to realize their potential as green cell factories, a major challenge is to make microalgae easier to engineer. A promising approach for rapid and predictable genetic manipulation is to use standardized synthetic biology tools and workflows.

View Article and Find Full Text PDF

The generation of novel secondary metabolites by reengineering or refactoring biochemical pathways is a rewarding but also challenging goal of synthetic biology. For this, the development of tools for the reconstruction of secondary metabolite gene clusters as well as the challenge of understanding the obstacles in this process is of great interest. The artificial gene operon assembly system (AGOS) is a plug-and-play method developed as a tool to consecutively assemble artificial gene operons into a destination vector and subsequently express them under the control of a de-repressed promoter in a Streptomyces host strain.

View Article and Find Full Text PDF

Neuroplasticity is fundamental for brain functions, abnormal changes of which are associated with mood disorders and cognitive impairment. Neuroplasticity can be affected by neuroactive medications and by aging. Vortioxetine, a multimodal antidepressant, has shown positive effects on cognitive functions in both pre-clinical and clinical studies.

View Article and Find Full Text PDF

Antidepressants often disrupt sleep. Vortioxetine, a multimodal antidepressant acting through serotonin (5-HT) transporter (SERT) inhibition, 5-HT3, 5-HT7 and 5-HT1D receptor antagonism, 5-HT1B receptor partial agonism, and 5-HT1A receptor agonism, had fewer incidences of sleep-related adverse events reported in depressed patients. In the accompanying paper a polysomnographic electroencephalography (sleep-EEG) study of vortioxetine and paroxetine in healthy subjects indicated that at low/intermediate levels of SERT occupancy, vortioxetine affected rapid eye movement (REM) sleep differently than paroxetine.

View Article and Find Full Text PDF

Background: A San Francisco Bay Area school health initiative was established in fall 2010 to improve wellness programs in 4 local school districts using the Coordinated School Health (CSH) model. This study examines the role of district-wide wellness coordinators and the ways in which they contribute to intentional coordination of health and wellness programs and activities in their school districts.

Methods: This study included 8 schools across 4 school districts.

View Article and Find Full Text PDF

Since poor circadian synchrony and cognitive dysfunction have been linked to affective disorders, antidepressants that target key 5-HT (serotonin) receptor subtypes involved in circadian rhythm and cognitive regulation may have therapeutic utility. Vortioxetine is a multimodal antidepressant that inhibits 5-HT1D, 5-HT3, 5-HT7 receptor activity, 5-HT reuptake, and enhances the activity of 5-HT1A and 5-HT1B receptors. In this study, we investigated the effects of vortioxetine on the period length of PER2::LUC expression, circadian behavior, and episodic memory, using tissue explants from genetically modified PER2::LUC mice, locomotor activity rhythm monitoring, and the object recognition test, respectively.

View Article and Find Full Text PDF

Background: Recess is a part of the elementary school day with strong implications for school climate. Positive school climate has been linked to a host of favorable student outcomes, from attendance to achievement. We examine 6 low-income elementary schools' experiences implementing a recess-based program designed to provide safe, healthy, and inclusive play to study how improving recess functioning can affect school climate.

View Article and Find Full Text PDF

Disruption of circadian rhythms may lead to mood disorders. The present study investigated the potential therapeutic utility of combining a 5-HT7 antagonist with a selective serotonin (5-HT) reuptake inhibitor (SSRI), the standard of care in depression, on circadian rhythm regulation. In tissue explants of the suprachiasmatic nucleus (SCN) from PER2::LUC mice genetically modified to report changes in the expression of a key clock protein, the period length of PER2 bioluminescence was shortened in the presence of AS19, a 5-HT7 partial agonist.

View Article and Find Full Text PDF

The biosynthetic gene cluster for endophenazines, i.e., prenylated phenazines from Streptomyces anulatus 9663, was heterologously expressed in several engineered host strains derived from Streptomyces coelicolor M145.

View Article and Find Full Text PDF

1-[2-(2,4-Dimethylphenyl-sulfanyl)-phenyl]-piperazine (Lu AA21004) is a human (h) serotonin (5-HT)(3A) receptor antagonist (K(i) = 3.7 nM), h5-HT(7) receptor antagonist (K(i) = 19 nM), h5-HT(1B) receptor partial agonist (K(i) = 33 nM), h5-HT(1A) receptor agonist (K(i) = 15 nM), and a human 5-HT transporter (SERT) inhibitor (K(i) = 1.6 nM) (J Med Chem 54:3206-3221, 2011).

View Article and Find Full Text PDF

The biosynthetic gene clusters of the aminocoumarin antibiotics clorobiocin and coumermycin A(1) and of the liponucleoside antibiotic caprazamycin were stably integrated into the genomes of different host strains derived from Streptomyces coelicolor A3(2). For the heterologous expression of clorobiocin derivatives in a chemically defined medium, inclusion of 0.6% of the siloxylated ethylene oxide/propylene oxide copolymer Q2-5247 into the growth medium proved to result in a 4.

View Article and Find Full Text PDF

When circadian rhythms - the daily oscillations of various physiological and behavioral events that are controlled by a central timekeeping mechanism - become desynchronized with the prevailing light:dark cycle, a maladaptative response can result. Animal data based primarily on genetic manipulations and clinical data from biomarker and gene expression studies support the notion that circadian abnormalities underlie certain psychiatric disorders. In particular, bipolar disorder has an interesting link to rhythm-related disease biology; other mood disturbances, such as major depressive disorder, seasonal affective disorder and the agitation and aggression accompanying severe dementia (sundowning), are also linked to changes in circadian rhythm function.

View Article and Find Full Text PDF

The biosynthetic gene cluster of the aminocoumarin antibiotic novobiocin comprises 20 coding sequences. Sixteen of them code for essential enzymes for novobiocin formation, transcribed in the form of a single 18-kb polycistronic mRNA. In the present study, we replaced the genuine promoter of this operon by the tetracycline-inducible promoter tcp830 and at the same time deleting the two pathway-specific positive regulator genes of novobiocin biosynthesis.

View Article and Find Full Text PDF

The D3 but not D2 dopamine receptors exhibit a tolerance property in which agonist-induced D3 receptor response progressively decreases upon repeated agonist stimulation. We have previously shown that the D3 receptor tolerance property is not mediated by receptor internalization, persistent agonist binding or a decrease in receptor binding affinity. In this paper, we test the hypothesis that alterations in D3 receptor conformation underlie the tolerance property.

View Article and Find Full Text PDF

The depsipeptide antibiotic hormaomycin, which is produced by Streptomyces griseoflavus W-384, contains a 5-chloropyrrole moiety. In the producer strain we identified the gene hrmQ that shows sequence similarity to FADH(2)-dependent halogenases. This gene was cloned and heterologously expressed in Streptomyces roseochromogenes var.

View Article and Find Full Text PDF

A putative prenyltransferase gene, Afu3g12930, was identified in the genome sequence of Aspergillus fumigatus. EAL92290, encoded by Afu3g12930, consists of 472 aa, with a molecular mass of about 53 kDa. The coding sequence of Afu3g12930 was cloned in pQE60, and overexpressed in Escherichia coli.

View Article and Find Full Text PDF

The D2 and D3 dopamine receptor subtypes are structurally homologous and couple to the same signal transduction pathways. Nevertheless, their evolutionary conservation suggests that the two subtypes might exhibit unique signaling characteristics. We previously determined that D3 but not D2S dopamine receptor exhibits a tolerance property in which the D3 receptor-activated G-protein coupled inward rectifier potassium currents progressively decreases upon repeated agonist stimulation.

View Article and Find Full Text PDF

Fnq26 from Streptomyces cinnamonensis DSM 1042 is a new member of the recently identified CloQ/Orf2 class of prenyltransferases. The enzyme was overexpressed in E. coli and purified to apparent homogeneity, resulting in a soluble, monomeric protein of 33.

View Article and Find Full Text PDF

A putative prenyltransferase gene, cdpNPT, was identified in the genome sequence of Aspergillus fumigatus by a homology search by using known prenyltransferases and sequence analysis. CdpNPT consists of 440 amino acids and has a molecular mass of about 50 kDa. The coding sequence of cdpNPT was cloned in pQE60 and overexpressed in E.

View Article and Find Full Text PDF

Among dopamine receptors, the function and properties of the D3 receptor subtype are poorly understood. Here we report the identification and characterization of two unique properties of the human D3 receptor. The D3 receptor exhibits a tolerance property wherein the magnitude of the second agonist-induced response is reduced by 60% compared to the first response and progressively decreases upon repeated agonist application.

View Article and Find Full Text PDF