The decreased PG content of pgp1 inhibits PSI photochemistry and limits reaction center and light-harvesting polypeptide accumulation in response to cold acclimation.

Decreased PG constrains PSI activity due to inhibition of transcript and polypeptide abundance of light-harvesting and reaction center polypeptides generating a reversible, yellow phenotype during cold acclimation of pgp1. Cold acclimation of the Arabidopsis pgp1 mutant at 5 °C resulted in a pale-yellow phenotype with abnormal chloroplast ultrastructure compared to its green phenotype upon growth at 20 °C despite a normal cold-acclimation response at the transcript level. In contrast, wild type maintained its normal green phenotype and chloroplast ultrastructure irrespective of growth temperature.

Subcellular Localization of Carotenoid Biosynthesis in Synechocystis sp. PCC 6803.

The biosynthesis pathway of carotenoids in cyanobacteria is partly described. However, the subcellular localization of individual steps is so far unknown. Carotenoid analysis of different membrane subfractions in Synechocystis sp.

Aberrant fat metabolism in Caenorhabditis elegans mutants with defects in the defecation motor program.

The molecular mechanisms by which dietary fatty acids are absorbed by the intestine, and the way in which the process is regulated are poorly understood. In a genetic screen for mutations affecting fat accumulation in the intestine of Caenorhabditis elegans, nematode worms, we have isolated mutations in the aex-5 gene, which encodes a Kex2/subtilisin-family, Ca2+-sensitive proprotein convertase known to be required for maturation of certain neuropeptides, and for a discrete step in an ultradian rhythmic phenomenon called the defecation motor program. We demonstrate that aex-5 mutants have markedly lower steady-state levels of fat in the intestine, and that this defect is associated with a significant reduction in the rate at which labeled fatty acid derivatives are taken up from the intestinal lumen.

The relationship between different spectral forms of the protochlorophyllide oxidoreductase complex and the structural organisation of prolamellar bodies isolated from Zea mays.

Incubation of prolamellar bodies (PLB) in high-salt media leads to changes in PLB structure and properties of their protochlorophyllide oxidoreductase-protochlorophyllide (POR-PChlide) complex. The paracrystalline organisation typical of PLB is disrupted and NADPH dissociates from photoconvertible POR-PChlide, with absorption maxima at 640 and 650 nm (POR-PChlide (640/650)), and a non-photoconvertible form, with absorption maxima at 635 nm (POR-PChlide (635)), is formed. These effects are strongly dependent on the valence of the cation of the perturbing salt, indicating that they involve surface double layers effects.

Laurdan fluorescence spectroscopy in the thylakoid bilayer: the effect of violaxanthin to zeaxanthin conversion on the galactolipid dominated lipid environment.

Laurdan (6-lauroyl-2-dimethylaminonaphthalene) fluorescence spectroscopy has been applied to probe the physical status of the thylakoid membrane upon conversion of violaxanthin to zeaxanthin. So far, only phospholipid-dominated membranes have been studied by this method and hereby we report the first use of laurdan in mono- and digalactosyldiacylglycerol-dominated membrane systems. The generalised polarisation (GP) of laurdan was used as a measure of the structural effect of xanthophyll cycle pigments in isolated spinach (Spinacia oleracea) thylakoids and in model membrane vesicles composed of chloroplast galactolipids.

Structural organisation of prolamellar bodies (PLB) isolated from Zea mays. Parallel TEM, SAXS and absorption spectra measurements on samples subjected to freeze-thaw, reduced pH and high-salt perturbation.

Well-organised PLB gives rise to a X-ray diffraction pattern overlaid by a scattering pattern arising from individual tubules within less well-organised regions of the lattice. TEM and SAXS measurements were used to characterise the structural changes in PLB subjected to perturbation by freeze-thaw, exposure to pH 6.5, or resuspension in high-salt media.

The induction of CP43' by iron-stress in Synechococcus sp. PCC 7942 is associated with carotenoid accumulation and enhanced fatty acid unsaturation.

Comparative lipid analysis demonstrated reduced amount of PG (50%) and lower ratio of MGDG/DGDG in iron-stressed Synechococcus sp. PCC 7942 cells compared to cells grown under iron sufficient conditions. In parallel, the monoenoic (C:1) fatty acids in MGDG, DGDG and PG increased from 46.

Cold acclimation of the Arabidopsis dgd1 mutant results in recovery from photosystem I-limited photosynthesis.

We compared the thylakoid membrane composition and photosynthetic properties of non- and cold-acclimated leaves from the dgd1 mutant (lacking >90% of digalactosyl-diacylglycerol; DGDG) and wild type (WT) Arabidopsis thaliana. In contrast to warm grown plants, cold-acclimated dgd1 leaves recovered pigment-protein pools and photosynthetic function equivalent to WT. Surprisingly, this recovery was not correlated with an increase in DGDG.

Digalactosyl-diacylglycerol deficiency impairs the capacity for photosynthetic intersystem electron transport and state transitions in Arabidopsis thaliana due to photosystem I acceptor-side limitations.

Compared with wild type, the dgd1 mutant of Arabidopsis thaliana exhibited a lower amount of PSI-related Chl-protein complexes and lower abundance of the PSI-associated polypeptides, PsaA, PsaB, PsaC, PsaL and PsaH, with no changes in the levels of Lhca1-4. Functionally, the dgd1 mutant exhibited a significantly lower light-dependent, steady-state oxidation level of P700 (P700(+)) in vivo, a higher intersystem electron pool size, restricted linear electron transport and a higher rate of reduction of P700(+) in the dark, indicating an increased capacity for PSI cyclic electron transfer compared with the wild type. Concomitantly, the dgd1 mutant exhibited a higher sensitivity to and incomplete recovery of photoinhibition of PSI.

Iron deficiency in cyanobacteria causes monomerization of photosystem I trimers and reduces the capacity for state transitions and the effective absorption cross section of photosystem I in vivo.

The induction of the isiA (CP43') protein in iron-stressed cyanobacteria is accompanied by the formation of a ring of 18 CP43' proteins around the photosystem I (PSI) trimer and is thought to increase the absorption cross section of PSI within the CP43'-PSI supercomplex. In contrast to these in vitro studies, our in vivo measurements failed to demonstrate any increase of the PSI absorption cross section in two strains (Synechococcus sp. PCC 7942 and Synechocystis sp.

Patient satisfaction with diabetes care.

Aim: The aim of this paper is to report the findings of a study that elucidated the experiences and reflections of people with type 2 diabetes about clinical encounters.

Background: Several patient satisfaction surveys have focused on privacy, cheerfulness and amenities rather than on how the care was delivered. A great deal of research has also focused on communication and various consultation styles, particularly within health promotion and diabetes care, but how these factors tie up with patient satisfaction has rarely been discussed.

The effects of low pH on the properties of protochlorophyllide oxidoreductase and the organization of prolamellar bodies of maize (Zea mays).

Prolamellar bodies (PLB) contain two photochemically active forms of the enzyme protochlorophyllide oxidoreductase POR-PChlide640 and POR-PChlide650 (the spectral forms of POR-Chlide complexes with absorption maxima at the indicated wavelengths). Resuspension of maize PLB in media with a pH below 6.8 leads to a rapid conversion of POR-PChlide650 to POR-PChlide640 and a dramatic re-organization of the PLB membrane system.

The cytokinin 2-isopentenyladenine causes partial reversion to skotomorphogenesis and induces formation of prolamellar bodies and protochlorophyllide657 in the lip1 mutant of pea.

When grown in darkness the photomorphogenic lip1 mutant of pea (Pisum sativum L.) has a slender stem, expanded leaves, prolamellar body (PLB) lacking plastids with the size of chloroplasts and a low level of phytochrome A. The lack of PLBs in a dark-grown material (lip1) created a possibility to further study the regulation of their formation in relation to plant development.