39 research outputs found
A Novel ZAP-70 Dependent FRET Based Biosensor Reveals Kinase Activity at both the Immunological Synapse and the Antisynapse
Many hypotheses attempting to explain the speed and sensitivity with which a T-cell discriminates the antigens it encounters include a notion of relative spatial and temporal control of particular biochemical steps involved in the process. An essential step in T-cell receptor (TCR) mediated signalling is the activation of the protein tyrosine kinase ZAP-70. ZAP-70 is recruited to the TCR upon receptor engagement and, once activated, is responsible for the phosphorylation of the protein adaptor, Linker for Activation of T-cells, or LAT. LAT phosphorylation results in the recruitment of a signalosome including PLCÎł1, Grb2/SOS, GADS and SLP-76. In order to examine the real time spatial and temporal evolution of ZAP-70 activity following TCR engagement in the immune synapse, we have developed ROZA, a novel FRET-based biosensor whose function is dependent upon ZAP-70 activity. This new probe not only provides a measurement of the kinetics of ZAP-70 activity, but also reveals the subcellular localization of the activity as well. Unexpectedly, ZAP-70 dependent FRET was observed not only at the T-cell -APC interface, but also at the opposite pole of the cell or âantisynapseâ
Phylogeny and nomenclature of the genus Talaromyces and taxa accommodated in Penicillium subgenus Biverticillium
The taxonomic history of anamorphic species attributed to Penicillium subgenus Biverticillium is reviewed, along with evidence supporting their relationship with teleomorphic species classified in Talaromyces. To supplement previous conclusions based on ITS, SSU and/or LSU sequencing that Talaromyces and subgenus Biverticillium comprise a monophyletic group that is distinct from Penicillium at the generic level, the phylogenetic relationships of these two groups with other genera of Trichocomaceae was further studied by sequencing a part of the RPB1 (RNA polymerase II largest subunit) gene. Talaromyces species and most species of Penicillium subgenus Biverticillium sensu Pitt reside in a monophyletic clade distant from species of other subgenera of Penicillium. For detailed phylogenetic analysis of species relationships, the ITS region (incl. 5.8S nrDNA) was sequenced for the available type strains and/or representative isolates of Talaromyces and related biverticillate anamorphic species. Extrolite profiles were compiled for all type strains and many supplementary cultures. All evidence supports our conclusions that Penicillium subgenus Biverticillium is distinct from other subgenera in Penicillium and should be taxonomically unified with the Talaromyces species that reside in the same clade. Following the concepts of nomenclatural priority and single name nomenclature, we transfer all accepted species of Penicillium subgenus Biverticillium to Talaromyces. A holomorphic generic diagnosis for the expanded concept of Talaromyces, including teleomorph and anamorph characters, is provided. A list of accepted Talaromyces names and newly combined Penicillium names is given. Species of biotechnological and medical importance, such as P. funiculosum and P. marneffei, are now combined in Talaromyces. Excluded species and taxa that need further taxonomic study are discussed. An appendix lists other generic names, usually considered synonyms of Penicillium sensu lato that were considered prior to our adoption of the name Talaromyces
Fungos conidiais em Euterpe oleracea Mart. (açaizeiro) na Ilha do Combu, Parå-Brasil
Mycological discoveries in the Middle East region in the second part of the last century
The arid Middle East extends over 9 million kmÂČ in the Eastern part of the Mediterranean Sea. Interest in the fungi of this region after the Second World War led to the discovery of species then regarded as being new to Science. A scan of the Index of Fungi issued in the period running from 1940-2000 revealed that 240 novel taxa had then been proposed. The recorded novelties were examined following the chronology of their introduction, their distribution in the local fifteen political states and their gross taxonomic characters at the Class level. These new additions were characterised at the rate of 40 units / decade. Most originated from Egypt, Iraq and the Palestine-Israel area and relate to the Classes Mitosporic Fungi, Ascomycetes and Basidiomycetes. All together 145 generic names are reported in this group of novelties; twelve were based on type material collected in Egypt (5 genera), the Palestine-Israel area, Iraq, Kuwait, Lebanon and Sudan. The present group of novelties was also surveyed in relation to the nature of the substrate sustaining the selected holotypes. The relevant Mitosporic fungi (93 taxa) were equally isolated from soil or from living or decaying plant parts. For Ascomycetous novelties (86 taxa), although their soil-borne elements outnumber the plant related ones, several also developed on other types of substrates. In the case of novel Basidiomycetes (37 taxa), the plant-parasitic species encompass those collected on the ground surface. Finally, a limited number of these novelties disclosed notable thermotolerant abilities and some even qualify as thermophiles. The main features of these novel records underlines that in Egypt more attention was awarded to the local Mitosporic fungi and to Ascomycetes inhabiting its soil-borne communities. For the Basidiomycetes (sensu lato) marked interest developed solely in the Palestine-Israel area while in Iraq taxonomic studies focussed on Ascomycetes including those developing on dung substrates. The distribution of the few reported Chytridiomycetes, Zygomycetes and âOomycetesâ also proved to be restricted to the former three states. Present data clearly underlines limited interest has been awarded to the fungi of a region presumed to harbour a specific mycobiota due to its marked arid features. Since 1940, only four novel taxa were thus proposed per annum from a small fraction of the Middle East. Future research should focus on plant related forms of lower (basal clades) and higher (Dikarya) fungi of the area. Conservation measures should also be adopted to ensure an adequate protection of the natural local habitats against the negative pressures generated by the increase in population and the detrimental effects of its activities. Finally, in view of the overwhelming implication of mycology in the fields of biotechnology, significant knowledge of the Middle East fungi is promising