Complement Factor H-Related Protein 3 Serum Levels Are Low Compared to Factor H and Mainly Determined by Gene Copy Number Variation in CFHR3

The major human complement regulator in blood, complement factor H (FH), has several closely related proteins, called FH-related (FHR) proteins. As all FHRs lack relevant complement regulatory activity, their physiological role is not well understood. FHR protein 3 (FHR-3) has been suggested to compete with FH for binding to Neisseria meningitidis, thereby affecting complement-mediated clearance. Clearly, the in vivo outcome of such competition greatly depends on the FH and FHR-3 concentrations. While FH levels have been established, accurate FHR-3 levels were never unequivocally reported to date. Moreover, CFHR3 gene copy numbers commonly vary, which may impact the FHR-3 concentration. Hence, we generated five anti-FHR-3 mAbs to specifically measure FHR-3 in human healthy donors of which we determined the gene copy number variation at the CFH/CFHR locus. Finally, we examined the acute-phase response characteristics of FHR-3 in a small sepsis cohort. We determined FHR-3 levels to have a mean of 19 nM and that under normal conditions the copy number of CFHR3 correlates to a very large extent with the FHR-3 serum levels. On average, FHR-3 was 132-fold lower compared to the FH concentration in the same serum samples and FHR-3 did not behave as a major acute phase response protein.     

Expression of a C3 plant Rubisco SSU gene in regenerated C4 Flaveria plants

We report the successful transformation, via Agrobacterium tumefaciens infection, and regeneration of two species of the genus Flaveria: F. brownii and F. palmeri. We document the expression of a C₃ plant gene, an abundantly expressed ribulose 1,5-bisphosphate carboxylase/oxygenase small subunit gene isolated from petunia, in these C₄ plants. The organ-specific expression of this petunia gene in Flaveria brownii is qualitatively identical to its endogenous pattern of expression.     

SERUM ENZYMES—Variations of Activity in Disease of Muscle

In a study of 58 patients with various diseases of muscle or of the neuromuscular system, the serum activity of various enzymes was measured. Abnormal elevation of serum activities of aldolase, lactic dehydrogenase and, to a lesser extent, glutamic-oxalacetic transaminase and phosphohexose isomerase, was an almost constant feature in patients with progressive muscular dystrophy. These elevations were very frequent in dermatomyositis, common in acute cerebral vascular accidents, and rarely seen in other neurological disorders. Abnormal serum activity of iso-citric dehydrogenase was not observed in the course of the present study.Supplementary protein feeding of patients with muscular dystrophy had no effect on serum enzyme activity, no consistent effect on urinary creatine excretion and no effect on the strength of the patient or the course of the disease.Dystrophic muscles from a dystrophic strain of mice showed a decrease in activity of lactic dehydrogenase and aldolase below that of control muscle and an increase of iso-citric dehydrogenase activity. These findings, taken with the differences in serum activities of lactic dehydrogenase, aldolase and isocitric dehydrogenase in the dystrophic animals, support the conclusion that dystrophic animals handle these soluble enzymes in quite different ways.     

The contrasting role of auxin in submergence-induced petiole elongation in two species from frequently flooded wetlands

The involvement of auxin in the submergence-induced petiole elongation has been investigated in Rumex palustris and Ranunculus sceleratus. Both wetland species are capable of enhanced petiole elongation upon submergence or treatment with exogenous ethylene (5μl l⁻¹). Treatment of intact Rumex palustris plants with 1-naphthalene acetic acid (NAA) at 10⁻⁴ M enhanced petiole elongation, while treatment with N -1-naphthylphthalamic acid (NPA) had no effect on petiole elongation. The elongation response after NAA or NPA treatment was comparable for plants in both submerged and drained conditions. Pre-ageing of detached petioles of Rumex palustris for 3 h in light or in dark conditions had no effect on the submergence-induced elongation. In comparison to intact plants, detached petioles of Rumex palustris , with or without lamina, did not show significant differences in responsiveness to IAA between drained or submerged conditions. This was in contrast to Ranunculus sceleratus where submergence caused a clear increase in responsiveness towards IAA. Removal of the lamina, the putative source of auxin, or treatment with NPA did not hinder the submergence-induced elongation of detached Rumex palustris petioles, but severely inhibited elongation of detached Ranunculus sceleratus petioles. This inhibition could be restored by application of NAA, suggesting the specific involvement of auxin in the submergence response of Ranunculus sceleratus. It is concluded that, in contrast to Ranunculus sceleratus , auxin is probably not involved in the submergence-induced petiole elongation of Rumex palustris.     

Effects of amphipathic peptides,including presequences,on the functional integrity of rat liver mitochondrial membranes

A number of amphipathic peptides were tested for their effects on structural and functional properties of isolated rat liver mitochondria. The peptides included the matrix targeting sequence of subunit IV of (yeast) cytochromec oxidase. Titration experiments in which the mitochondria were incubated with increasing concentrations of the peptides revealed two major stages in the interaction. First, at low peptide/mitochondria ratios, peptide binding to the outer membrane occurred which was accompanied by gradual lysis of the outer membrane at higher ratios. The latter was deduced from the release of adenylate kinase, the classical marker enzyme of the intermembrane space. Secondly, at still higher peptide/mitochondria ratios, the permeability of the inner membrane progressively increased, as evidenced by measurements of respiratory control and of the membrane potential. Complete uncoupling of respiration seemed to precede dissipation of the membrane potential.     

The X-ray crystal structure of 6-deoxy-α-l-sorbofuranose. Conformational analysis of ketohexofuranosides and their comparison with ribofuranosides and arabinofuranosides

The crystal and molecular structure of 6-deoxy-l-sorbose have been determined by the application of multisolution methods and refined to an R-index of 0.063 for 560 reflections, using three-dimensional intensity data collected on a Picker automatic diffractometer. The compound crystallizes in the space group P2₁2₁2₁ with unit-cell dimensions a = 18.470 (10), b = 7.636 (10), and c = 5.371 (8) Å; Z = 4. The molecule occurs as the α-furanose form, which is also the preponderant tautomer in solution. The puckering of the furanoid ring is C-3′-exo-C-4′-endo (₃T⁴) [equivalent to C-2′-exo-C-3′-endo (₂T³) in the numbering for d-ribose], with P and τ_m angles of -6.5 and 42.7° respectively. Conformational analysis of the known ketofuranosides shows that the ₃T⁴ (₂T³ in d-ribose numbering) puckering mode, which is typical of α-nucleosides, is favored, in contrast to the favored ³T₂ or ²T₃ puckering mode for the β-d-ribonucleosides and β-d-arabinonucleosides. The conformational differences among furanoid rings are mainly influenced by the configuration at the anomeric carbon atom. The favored orientation about the C-2′-C-1′ bond (O-5′-C-2′-C-1′-O-1′)of the ketofuranosidesis — gauche. All four hydroxyl groups are involved in donor-acceptor hydrogen bonding, and O-4′-8 appears to be involved in a bifurcated hydrogen bond to O-2′ and O-3′ of neighboring molecules.     

Cerebellar Cortex Granular Layer Interneurons in the Macaque Monkey Are Functionally Driven by Mossy Fiber Pathways through Net Excitation or Inhibition

The granular layer is the input layer of the cerebellar cortex. It receives information through mossy fibers, which contact local granular layer interneurons (GLIs) and granular layer output neurons (granule cells). GLIs provide one of the first signal processing stages in the cerebellar cortex by exciting or inhibiting granule cells. Despite the importance of this early processing stage for later cerebellar computations, the responses of GLIs and the functional connections of mossy fibers with GLIs in awake animals are poorly understood. Here, we recorded GLIs and mossy fibers in the macaque ventral-paraflocculus (VPFL) during oculomotor tasks, providing the first full inventory of GLI responses in the VPFL of awake primates. We found that while mossy fiber responses are characterized by a linear monotonic relationship between firing rate and eye position, GLIs show complex response profiles characterized by “eye position fields” and single or double directional tunings. For the majority of GLIs, prominent features of their responses can be explained by assuming that a single GLI receives inputs from mossy fibers with similar or opposite directional preferences, and that these mossy fiber inputs influence GLI discharge through net excitatory or inhibitory pathways. Importantly, GLIs receiving mossy fiber inputs through these putative excitatory and inhibitory pathways show different firing properties, suggesting that they indeed correspond to two distinct classes of interneurons. We propose a new interpretation of the information flow through the cerebellar cortex granular layer, in which mossy fiber input patterns drive the responses of GLIs not only through excitatory but also through net inhibitory pathways, and that excited and inhibited GLIs can be identified based on their responses and their intrinsic properties.