Cortinarius sarcoflammeus sp. nov, a new species of subgenus Dermocybe (Agaricales) growing in Sphagnum bogs

 Cortinarius sarcoflammeus is proposed as a new species belonging to subgenus Dermocybe, on the basis of its morphological, chemical and ecological characters. The strong red-orange colour of the context and stipe base, large spores, sphagnicolous habitat and high dermorubin content are characteristic for the new species. Holotypes of C. huronensis and C. huronensis var. olivaceus have been examined for comparison, and their differences discussed. Photographs and line drawings of C. sarcoflammeus are added. Received February 13, 2001 Accepted March 23, 2001     

Genetic analysis of hypertropic mutants of Phycomyces

A new class of Phycomyces behavioral mutants with enhanced tropic responses has been analyzed genetically to determine the number of genes involved and the nature of their expression. These hypertropic mutants carry pleiotropic nuclear mutations. Besides their effects on sensory behavior, they also affect morphology and meiotic processes. Behavioral analyses of heterokaryons containing hypertropic and wild-type nuclei in varying proportions show that the hypertropic mutations in strains L82, L84, L86, and L88 are strongly dominant. Conversely, the hypertropic mutations carried by the strains L83, L85, and L87 are strongly recessive. We performed recombination analyses between hypertropic mutants and mutants with diminished phototropism, affected in the seven genes madA to madG. We found no evidence of linkage between the hypertropic mutations and any of these mad mutations. From crosses, we isolated double mutants carrying hypertropic mutations together with madC (night blind) and madG (stiff) mutations. The behavioral phenotypes of the double mutants are intermediate between those of the parentals. Complementation analyses show that the three recessive hypertropic mutations affect the same gene, which we call madH. The expression of the recessive hypertropic allele becomes dominant in heterokaryons carrying madC and madH nuclei; the madC gene has been implicated separately with the photoreceptor at the input to the sensory pathway, while the madH gene is associated with the growth control output. This result suggests the physical interaction of both gene products, madH and madC, in a molecular complex for the photosensory transduction chain.     

Circadian clock adjustment to plant iron status depends on chloroplast and phytochrome function

Plant chloroplasts are not only the main cellular location for storage of elemental iron (Fe), but also the main site for Fe, which is incorporated into chlorophyll, haem and the photosynthetic machinery. How plants measure internal Fe levels is unknown. We describe here a new Fe‐dependent response, a change in the period of the circadian clock. In Arabidopsis, the period lengthens when Fe becomes limiting, and gradually shortens as external Fe levels increase. Etiolated seedlings or light‐grown plants treated with plastid translation inhibitors do not respond to changes in Fe supply, pointing to developed chloroplasts as central hubs for circadian Fe sensing. Phytochrome‐deficient mutants maintain a short period even under Fe deficiency, stressing the role of early light signalling in coupling the clock to Fe responses. Further mutant and pharmacological analyses suggest that known players in plastid‐to‐nucleus signalling do not directly participate in Fe sensing. We propose that the sensor governing circadian Fe responses defines a new retrograde pathway that involves a plastid‐encoded protein that depends on phytochromes and the functional state of chloroplasts.     

Ferritin in normal human peripheral blood T-lymphocyte subpopulations

Six peripheral blood lymphoid fractions (total lymphocytes, non-T, T, Tar (autologous rosette-forming T cells/precursor), T mu (helper), and T gamma (suppressor) lymphocytes) isolated through rosetting procedures were examined for the presence of ferritin by a direct immunofluorescence technique. Although ferritin was present in all lymphoid fractions studied, a significantly higher proportion of ferritin-containing cells were detected in the T-cell fraction than in the non-T-cell fraction, (mean +/- SD = 7.9 +/- 1.6% and 5.0 +/- 1.2%, respectively). T mu- and T gamma-cell fractions showed a twofold increase in the number of ferritin-positive cells (14.1 +/- 1.4% and 15.4 +/- 2.6%, respectively), as compared with Tar (7.0 +/- 0.9%)-and total lymphocyte (6.9 +/- 1.3%)-cell fractions. These results indicate that ferritin is preferentially distributed in T mu and T gamma lymphocytes and may constitute the basis for explaining some of the roles exercised by these cells in the control of other biological systems.     

Group-selective reagent modification of the sodium- and chloride-coupled glycine transporter under native and reconstituted conditions.

Glycine transporter from rat brain stem and spinal cord is inactivated by specific sulfhydryl reagents. Modification of lysine residues also promotes a decrease of the transporter activity but in a lesser extent than that promoted by thiol group reagents. Mercurials showed a more marked inhibitory effect than maleimide derivatives. SH groups display a similar reactivity for p-chloromercuribenzenesulfonate (pCMBS) and mersalyl in synaptosomal membrane vesicles and proteoliposomes reconstituted with the solubilized transporter. However, different reactivity is observed with N-ethylmaleimide (MalNEt), the greatest effect being attained in membrane vesicles. The rate of inactivation by pCMBS and MalNEt is pseudo-first-order showing time- and concentration-dependence. pCMBS and MalNEt decrease the Vmax for glycine transport and to a lesser extent act on the apparent Km. Treatment with dithiothreitol (DTT) of the transporter modified by pCMBS results in a complete restoration of transporter activity indicating that the effect exercised by the reagent is specific for cysteine residues on the protein. It is concluded that SH groups are involved in the glycine transporter function and that these critical residues are mostly located in a relatively hydrophilic environment of the protein.     

The Hemagglutinin of Bat-Associated Influenza Viruses Is Activated by TMPRSS2 for pH-Dependent Entry into Bat but Not Human Cells

New World bats have recently been discovered to harbor influenza A virus (FLUAV)-related viruses, termed bat-associated influenza A-like viruses (batFLUAV). The internal proteins of batFLUAV are functional in mammalian cells. In contrast, no biological functionality could be demonstrated for the surface proteins, hemagglutinin (HA)-like (HAL) and neuraminidase (NA)-like (NAL), and these proteins need to be replaced by their human counterparts to allow spread of batFLUAV in human cells. Here, we employed rhabdoviral vectors to study the role of HAL and NAL in viral entry. Vectors pseudotyped with batFLUAV-HAL and -NAL were able to enter bat cells but not cells from other mammalian species. Host cell entry was mediated by HAL and was dependent on prior proteolytic activation of HAL and endosomal low pH. In contrast, sialic acids were dispensable for HAL-driven entry. Finally, the type II transmembrane serine protease TMPRSS2 was able to activate HAL for cell entry indicating that batFLUAV can utilize human proteases for HAL activation. Collectively, these results identify viral and cellular factors governing host cell entry driven by batFLUAV surface proteins. They suggest that the absence of a functional receptor precludes entry of batFLUAV into human cells while other prerequisites for entry, HAL activation and protonation, are met in target cells of human origin.     

The antigen-antibody interaction algebraically interpreted as a relational process.

The antigen-antibody interaction occurring previous to the triggering of the immunological response is analyzed as a relational process in terms of lattices. Accordingly, this process is expressed as a lattice belonging to a pseudo-Boolean algebraic variety. The Heyting arrow operation, which appears in this kind of algebra, is used to analyze behaviors between non-comparable biological states expressed by the lattice. The resulting states coming from the arrows are connected with the influence of increasing and decreasing energies involved in the linking process.     

Hypermodified nucleoside carboxyl group as a target site for specific tRNA modification

The free carboxyl group of hypermodified nucleosides N6-methyl-N6-(threoninocarbonyl)adenosine (mt6A37) and 3-(3-amino-3-carboxypropyl)uridine (acp3U20:1) in tRNAmMet (yellow lupine), and N6-(threoninocarbonyl)adenosine (t6A37) in tRNAiMet (yellow lupine) can be converted quantitatively and under very mild conditions into the respective anilides in a reaction with aniline and a water-soluble carbodiimide. The tRNA reactions proceed with rates very similar to that reported previously for t6A nucleoside. Detailed analysis of the products of tRNA modification with [3H]aniline on tRNA (chromatography on BD-DEAE-cellulose), oligonucleotide (polyacrylamide gel electrophoresis) and nucleoside (HPLC on Aminex A6) levels clearly indicates that only the hypermodified nucleoside residues undergo the reaction. The site of modification is confirmed for mono-modified (at mt6A37) and bis-modified (at mt6A37 and acp3U20:1) tRNAmMet, and for mono-modified (at t6A37) tRNAiMet by sequence analysis using 5'end 32P-labeled tRNAs. The modification procedure seems to be universally applicable for all hypermodified nucleosides bearing a free carboxyl group and for different amine reagents designed for the studies on tRNA function.