A Survey of Chloroplast Protein Kinases and Phosphatases in Arabidopsis thaliana

Protein phosphorylation is a major mode of regulation of metabolism, gene expression and cell architecture. In chloroplasts, reversible phosphorylation of proteins is known to regulate a number of prominent processes, for instance photosynthesis, gene expression and starch metabolism. The complements of the involved chloroplast protein kinases (cpPKs) and phosphatases (cpPPs) are largely unknown, except 6 proteins (4 cpPKs and 2 cpPPs) which have been experimentally identified so far. We employed combinations of programs predicting N-terminal chloroplast transit peptides (cTPs) to identify 45 tentative cpPKs and 21 tentative cpPPs. However, test sets of 9 tentative cpPKs and 13 tentative cpPPs contain only 2 and 7 genuine cpPKs and cpPPs, respectively, based on experimental subcellular localization of their N-termini fused to the reporter protein RFP. Taken together, the set of enzymes known to be involved in the reversible phosphorylation of chloroplast proteins in A. thaliana comprises altogether now 6 cpPKs and 9 cpPPs, the function of which needs to be determined in future by functional genomics approaches. This includes the calcium-regulated PK CIPK13 which we found to be located in the chloroplast, indicating that calcium-dependent signal transduction pathways also operate in this organelle

Dynamics of reversible protein phosphorylation in thylakoids of flowering plants: the roles of STN7, STN8 and TAP38

Phosphorylation is the most common post-translational modification found in thylakoid membrane proteins of flowering plants, targeting more than two dozen subunits of all multiprotein complexes, including some light-harvesting proteins. Recent progress in mass spectrometry-based technologies has led to the detection of novel low-abundance thylakoid phosphoproteins and localised their phosphorylation sites. Three of the enzymes involved in phosphorylation/dephosphorylation cycles in thylakoids, the protein kinases STN7 and STN8 and the phosphatase TAP38/PPH1, have been characterised in the model species Arabidopsis thaliana. Differential protein phosphorylation is associated with changes in illumination and various other environmental parameters, and has been implicated in several acclimation responses, the molecular mechanisms of which are only partly understood. The phenomenon of State Transitions, which enables rapid adaptation to short-term changes in illumination, has recently been shown to depend on reversible phosphorylation of LHCII by STN7-TAP38/PPH1. STN7 is also necessary for long-term acclimation responses that counteract imbalances in energy distribution between PSII and PSI by changing the rates of accumulation of their reaction-centre and light-harvesting proteins. Another aspect of photosynthetic acclimation, the modulation of thylakoid ultrastructure, depends on phosphorylation of PSII core proteins, mainly executed by STN8. Here we review recent advances in the characterisation of STN7, STN8 and TAP38/ PPH1, and discuss their physiological significance within the overall network of thylakoid protein phosphorylation

INTEGRATED MID-INFRARED, FAR INFRARED AND TERAHERTZ OPTICAL HALL EFFECT (OHE) INSTRUMENT, AND METHOD OF USE

System Stage, and Optical Hall Effect (OHE) system method for evaluating such as free charge carrier effective mass, concentration, mobility and free charge carrier type in a (51) Int. Ci. sample utilizing a permanent magnet at room temperature

Soft Microreactors for the Deposition of Conductive Metallic Traces on Planar, Embossed, and Curved Surfaces

Advanced manufacturing strategies have enabled large‐scale, economical, and efficient production of electronic components that are an integral part of various consumer products ranging from simple toys to intricate computing systems; however, the circuitry for these components is (by and large) produced via top‐down lithography and is thus limited to planar surfaces. The present work demonstrates the use of reconfigurable soft microreactors for the patterned deposition of conductive copper traces on flat and embossed two‐dimensional (2D) substrates as well as nonplanar substrates made from different commodity plastics. Using localized, flow‐assisted, low‐temperature, electroless copper deposition, conductive metallic traces are fabricated, which, when combined with various off‐the‐shelf electronic components, enabled the production of simple circuits and antennas with unique form factors. This solution‐phase approach to the patterned deposition of functional inorganic materials selectively on different polymeric components will provide relatively simple, inexpensive processing opportunities for the fabrication of 2D/nonplanar devices when compared to complicated manufacturing methods such as laser‐directed structuring. Further, this approach to the patterned metallization of different commodity plastics offers unique design opportunities applicable to the fabrication of planar and nonplanar electronic and interconnect devices, and other free‐form electronics with less structural “bloat” and weight (by directly coating support elements with circuitry)

The relationship between perceived social support and depressive symptoms in informal caregivers of community-dwelling older persons in Chile

AIM: Depression among caregivers of older persons is a serious concern, but it is often overlooked and neglected in developing countries. The aim of this study was to examine the relationship between perceived social support and depression in informal caregivers of community-dwelling older persons in Chile. Methods: We analyzed cross-sectional secondary data on 377 dyads of community-dwelling older persons and their informal caregivers from a nationwide survey in Chile. The Duke-UNC Functional Social Support Questionnaire (FSSQ) was used to measure caregivers’ perceived social support, and the Center for Epidemiologic Studies Depression Scale assessed their depression. Results: In this study, 76.9% of the caregivers perceived a high level of social support, and 46.9% were assessed as having depression. Based on multivariable analysis, factors that decrease the likelihood of being depressed are a high level of social support (odds ratio (OR) = 0.311, 95% confidence interval (CI): 0.167–0.579) and having taken holidays in the past 12 months (OR = 0.513, 95%CI: 0.270–0.975). Factors that increase the likelihood of being depressed are being a female caregiver (OR = 2.296, 95%CI: 1.119–4.707), being uninsured (OR = 4.321, 95%CI: 1.750–10.672), being the partner or spouse of the care recipient (OR = 3.832, 95%CI: 1.546–9.493), and the number of hours of care (OR = 1.053, 95%CI: 1.021–1.085). Conclusion: Higher levels of perceived social support and holidays were associated with lower levels of depression. However, being female, being the care recipient's partner or spouse, being uninsured, and having long care periods had detrimental effects. Interventions to preserve and enhance perceived social support could help improve depressive symptoms in informal caregivers. Additionally, support should be available to caregivers who are women, uninsured, and the care recipient's partner or spouse, as well as those who provide care for long hours, to ensure they have respite from their caregiving role

Asthma patients' self-reported behaviours toward inhaled corticosteroids

SummaryBackgroundPatient adherence to recommended use of ICS is questionable in asthma, with irregular use or interruptions occurring frequently. Factors explaining discontinuation of controller therapy could orientate interventions. The characteristics of patients with interruptions of inhaled corticosteroids (ICSs), intentional or accidental, were investigated.MethodsAsthma patients regularly prescribed ICS by GPs (Cegedim network) were included. Patients' characteristics and behaviours toward ICS (accidental/intentional interruptions, less frequent use of ICS and change in dosing) were identified from self-report questionnaires, and linked to data prescription database. Interrelations between declared behaviours toward ICS were studied with a Multiple Component Analysis (MCA) and the correlates of ICS interruptions were identified.ResultsDuring the past 3 months, 31.6% of 204 patients (mean age: 53.8 years, females: 59.3%) intentionally interrupted ICS when feeling better, 25.4% forgot ICS and 18.3% deliberately changed the doses. A quarter of patients considered constant use of respiratory medicines as unhealthy. MCA revealed that intentional, accidental interruptions and less frequent use of ICS were closely correlated. Risk of intentional interruption was increased when patients considered constant use of respiratory therapy to be unhealthy (OR=3.36, 95%CI=[1.47–7.66]). Conversely, risk was significantly lower when ICS was associated or combined with another controller (OR=0.24, 95%CI=[0.08–0.73]), compared to ICS in monotherapy. Less frequent interruptions were observed in patients older than 65 (OR=0.35, 95%CI=[0.13–0.89]).ConclusionsOur study suggests that discontinuation of use of controllers is associated with other inadequate behaviours or beliefs about inhaled controllers. Efforts should be targeted at patients' perceptions and behaviours toward controller therapy

Gun1 controls accumulation of the plastid ribosomal protein S1 at the protein level and interacts with proteins involved in plastid protein homeostasis

Developmental or metabolic changes in chloroplasts can have profound effects on the rest of the plant cell. Such intracellular responses are associated with signals that originate in chloroplasts and convey information on their physiological status to the nucleus, which leads to large-scale changes in gene expression (retrograde signaling). A screen designed to identify components of retrograde signaling resulted in the discovery of the so-called genomes uncoupled (gun) mutants. Genetic evidence suggests that the chloroplast protein GUN1 integrates signals derived from perturbations in plastid redox state, plastid gene expression, and tetrapyrrole biosynthesis (TPB) in Arabidopsis (Arabidopsis thaliana) seedlings, exerting biogenic control of chloroplast functions. However, the molecular mechanism by which GUN1 integrates retrograde signaling in the chloroplast is unclear. Here we show that GUN1 also operates in adult plants, contributing to operational control of chloroplasts. The gun1 mutation genetically interacts with mutations of genes for the chloroplast ribosomal proteins S1 (PRPS1) and L11. Analysis of gun1 prps1 lines indicates that GUN1 controls PRPS1 accumulation at the protein level. The GUN1 protein physically interacts with proteins involved in chloroplast protein homeostasis based on coimmunoprecipitation experiments. Furthermore, yeast two-hybrid and bimolecular fluorescence complementation experiments suggest that GUN1 might transiently interact with several TPB enzymes, including Mg-chelatase subunit D (CHLD) and two other TPB enzymes known to activate retrograde signaling. Moreover, the association of PRPS1 and CHLD with protein complexes is modulated by GUN1. These findings allow us to speculate that retrograde signaling might involve GUN1-dependent formation of protein complexes

Bi(OTf)(3)-, TfOH-, and TMSOTf-Mediated, One-Pot Epoxide Rearrangement, Addition, and Intramolecular Silyl-Modified Sakurai (ISMS) Cascade toward Dihydropyrans: Comparison of Catalysts and Role of Bi(OTf)(3)

Catalytic quantities of bismuth(III) triflate efficiently initiate the rearrangement of epoxides to aldehydes, which subsequently react with (Z)-delta-hydroxyalkenylsilanes to afford 2,6-disubstituted 3,6-dihydro-2H-pyrans. Isolated yields of desired products using Bi(OTf)(3) were compared with yields obtained when the reactions were run with TfOH and TMSOTf in the presence and absence of several additives. These studies, as well as NMR spectroscopic analyses, indicate an initial Lewis acid/base interaction between Bi(OTf)(3) and substrates providing TfOH in situ

SAMPLE ANALYSIS METHODOLOGY UTILIZNGELECTROMAGNETIC RADATION

Simultaneous use of wavelengths in at least two ranges Selected from RADIO, MICRO. FIR, IR, NIR-VIS-NUV. UV, DUV, VUV EUV, XRAY in a regression procedure to evaluate parameters in mathematical dispersion structures to model dielectric functions

Arabidopsis CURVATURE THYLAKOID1 Proteins Modify Thylakoid Architecture by Inducing Membrane Curvature

Chloroplasts of land plants characteristically contain grana, cylindrical stacks of thylakoid membranes. A granum consists of a core of appressed membranes, two stroma-exposed end membranes, and margins, which connect pairs of grana membranes at their lumenal sides. Multiple forces contribute to grana stacking, but it is not known how the extreme curvature at margins is generated and maintained. We report the identification of the CURVATURE THYLAKOID1 (CURT1) protein family, conserved in plants and cyanobacteria. The four Arabidopsis thaliana CURT1 proteins (CURT1A, B, C, and D) oligomerize and are highly enriched at grana margins. Grana architecture is correlated with the CURT1 protein level, ranging from flat lobe-like thylakoids with considerably fewer grana margins in plants without CURT1 proteins to an increased number of membrane layers (and margins) in grana at the expense of grana diameter in overexpressors of CURT1A. The endogenous CURT1 protein in the cyanobacterium Synechocystis sp PCC6803 can be partially replaced by its Arabidopsis counterpart, indicating that the function of CURT1 proteins is evolutionary conserved. In vitro, Arabidopsis CURT1A proteins oligomerize and induce tubulation of liposomes, implying that CURT1 proteins suffice to induce membrane curvature. We therefore propose that CURT1 proteins modify thylakoid architecture by inducing membrane curvature at grana margins