Targeting SUMO E1 to ubiquitin ligases: a viral strategy to counteract sumoylation.

SUMO-1 (small ubiquitin-related modifier-1) is a ubiquitin-like family member that is conjugated to its substrates through three discrete enzymatic steps, activation (involving the E1 enzyme (SAE1/SAE2)), conjugation (involving the E2 enzyme), and substrate modification (through the cooperation of the E2 and E3 protein ligases). The adenoviral protein Gam1 inactivates E1, both in vitro and in vivo, followed by SAE1/SAE2 degradation. We have shown here that Gam1 possesses a C-terminal SOCS domain that allows its interaction with two cellular cullin RING (really interesting new gene) ubiquitin ligases. We demonstrate that Gam1 is necessary for the recruitment of SAE1/SAE2 into Cul2/5-EloB/C-Roc1 ubiquitin ligase complexes and for subsequent SAE1 ubiquitylation and degradation. The degradation of SAE2 is not tightly related to Gam1 but is a consequent effect of SAE1 disappearance. These results reveal the mechanism by which a viral protein inactivates and subsequently degrades an essential cellular enzyme, arresting a key regulatory pathway

Vaillant cabalga de nuevo?

Las consecuencias no deseadas de aceptar traducciones posteriores a 1753 de obras prelinneanas se analizan brevemente utilizando el caso de Vaillant y el género Rhaponticum como un oportuno ejemplo. Se propone una modificación del actual código de nomenclatura botánica

Surt a la llum el nou volum de Collectanea Botanica

Noticia publicada en la web institucional del Instituto Botánico de Barcelona el 18 de enero de 2016 -- Disponibles PDFs en español y catalán y capturas de pantalla de la noticia en la web.Peer reviewe

Warionia (Asteraceae): A relict genus of Cichorieae?

The genus Warionia, with its only species W. saharae, is endemic to the northwestern edge of the African Sahara desert. This is a somewhat thistle-like aromatic plant, with white latex, and fleshy, pinnately-partite leaves. Warionia is in many respects so different from any other genus of Asteraceae, that it has been tentatively placed in the tribes Cardueae, Cichorieae, Gundelieae, and Mutisieae. Until now, a comprehensive study of Warionia to have a complete context for discussing its taxonomic position is lacking. The general morphology, anatomy, palynology and chromosome number of W. saharae are investigated here, and the species is described and illustrated. Laticifers in leaves and stems indicate a relationship with Cichorieae, and are associated with the phloem, in contact with it or with the surrounding sclerenchyma sheath. The pollen features indicate a strong relation with Cardueae, namely the structure with Anthemoid pattern where the columellae are joined to the foot layer, the ectosexine with thin columellae, the endosexine with stout and ramified columellae, the conspicuous spines with globose bases and conspicuous apical channels, and the tectum surface very perforate. Chromosomal counts resulted in 2n = 34. The morphological and palynological evidence positions Warionia between the tribes Cardueae and Cichorieae suggesting that it could be a remnant of the ancestral stock that gave rise to both tribes.El género Warionia, y su única especie, W. saharae, es endémico del noroeste del desierto africano del Sahara. Es una planta semejante a un cardo, aromática, con látex blanco y hojas carnosas, pinnatipartidas. Warionia es tan diferente de otros géneros de Asteraceae que fue ubicada en las tribus Cardueae, Cichorieae, Gundelieae y Mutisieae. Hasta ahora, no existía un estudio global de Warionia como contexto para discutir su posición taxonómica. Se ha investigado aquí su morfología, anatomía, palinología y número cromosómico, y se incluyen una descripción y una ilustración de la especie. Los laticíferos en hojas y tallo están asociados al floema, en contacto directo con él o con sus casquetes esclerenquimáticos y lo relacionan con Cichorieae. El polen indica una gran relación con Cardueae, i.e., la estructura con patrón anthemoide donde las columelas se unen al estrato basal, la ectosexina con delgadas columelas, la endosexina con columelas gruesas y ramificadas, las espinas conspicuas con bases globosas y notorios canales apicales, y la superficie del tectum muy perforada. Los recuentos cromosómicos resultaron en 2n = 34. La evidencia morfológica y palinológica sitúa a Warionia entre las tribus Cardueae y Cichorieae, sugiriendo la posibilidad de que el género sea el remanente de un stock ancestral que dio origen a ambas tribus.Facultad de Ciencias Naturales y Muse

Nou projecte sobre radiacions evolutives alpines a Àsia

Noticia publicada en la web institutcional del Instituto Botánico de Barcelona el 27 de julio de 2016 -- Disponibles PDFs en español y catalán y capturas de pantalla de la noticia en la web.Peer reviewe

Typification of names of plants described by Carlos Pau from Morocco (1908-1922)

The vascular plant names proposed by Carlos Pau from Morocco between 1908 and 1922 were studied and, when necessary and possible, typified. Nine lectotypes have been designated; most of them preserved in MA and BC herbaria (isolectotypes at BCN, G, LD, and P)

Les novetats del volum 35 de Collectanea Botanica

Noticia publicada en la web institucional del Instituto Botánico de Barcelona el 17 de marzo de 2017 -- Disponibles PDFs en español y catalán y capturas de pantalla de la noticia en la webPeer reviewe

Amplificación cruzada de microsatélites en el género Centaurea (Compositae).

11p. Fotog. en color. Tablas.[EN] Microsatellites are widely used for population genetic studies although the development of these species-specific markers is costly and time-consuming. One strategy for saving time and money is the use of markers developed for one species (source species) in a different species (target species). This is known as cross-amplification. In the present work, two sets of microsatellites are used to test their transferability to six narrow endemic Centaurea species: i) 16 nuclear loci previously published for three congeneric species and ii) 10 universal chloroplast markers designed from Nicotiana tabacum sequences. Seventeen of the 26 markers tested were transferable and 14 of them were also polymorphic and therefore useful for future works. Nuclear markers were more variable and thus more informative than chloroplast markers. Interspecific amplification performed better for the nuclear loci developed for different Centaurea species than for the universal chloroplast markers developed for Nicotiana tabacum. Likewise, transferability was more successful for the species from sect. Phalolepis than for sect. Lepteranthus. Therefore, our results support the idea that the success of the cross-amplification is influenced by the evolutionary distance between the target and the source species.[ES] Los microsatélites se usan habitualmente en estudios de genética de poblaciones aunque su desarrollo es un proceso caro y largo dada su elevada especificidad. Una estrategia que permite ahorrar tiempo y dinero es la llamada amplificación cruzada que consiste en amplificar el DNA de una especie determinada (especie objetivo) usando marcadores que han sido diseñados para una especie diferente (especie fuente). En este trabajo se ha realizado un ensayo sobre amplificación cruzada usando seis endemismos del género Centaurea y dos conjuntos de microsatélites: i) 16 marcadores nucleares desarrollados para tres especies congenéricas y ii) 10 marcadores cloroplásticos universales diseñados para Nicotiana tabacum. Diecisiete de los 26 marcadores evaluados resultaron transferibles, de los cuales 14 fueron polimórficos siendo así útiles para futuros trabajos. Las regiones nucleares se mostraron más variables y por lo tanto más informativas que las cloroplásticas. La amplificación cruzada funcionó mejor para los marcadores nucleares específicos de Centaurea que para los cloroplásticos universales específicos de Nicotiana tabacum. A su vez, se obtuvo mejor resultado para las especies de la sección Phalolepis que para las de la sección Lepteranthus. En consecuencia, nuestros resultados apoyan la idea de que el éxito de la amplificación cruzada está estrechamente ligado a la distancia evolutiva entre especie fuente y especie objetivo.Financial support from the Spanish MICINN (Project CGL2007-60781 and CGL2010/18631) and the Generalitat de Catalunya (Ajuts a Grups de Recerca Consolidats 2009/ SGR/00439-GREB) is gratefully acknowledged.Peer reviewe

Systematics and evolution of the needle grasses (Poaceae: Pooideae: Stipeae) based on analysis of multiple chloroplast loci, ITS, and lemma micromorphology

27 p.We conducted a molecular phylogenetic study of the tribe Stipeae using nine plastid DNA sequences (trnK-matK, matK, trnH-psbA, trnL-F, rps3, ndhF, rpl32-trnL, rps16-trnK, rps16 intron), the nuclear ITS DNA regions, and micromorphological characters from the lemma surface. Our large original dataset includes 156 accessions representing 139 species of Stipeae representing all genera currently placed in the tribe. The maximum likelihood and Bayesian analyses of DNA sequences provide strong support for the monophyly of Stipeae; including, in phylogenetic order, Macrochloa as remote sister lineage to all other Stipeae, then a primary stepwise divergence of three deep lineages with a saw-like (SL) lemma epidermal pattern (a plesiomorphic state). The next split is between a lineage (SL1) which bifurcates into separate Eurasian and American clades, and a lineage of three parts; a small Patis (SL2) clade, as sister to Piptatherum s.str. (SL3), and the achnatheroid clade (AC). The AC exhibits a maize-like lemma epidermal pattern throughout. AC consists of a core clade of Austral-Eurasian distribution and a “major American clade” of North and South American distribution. The base chromosome number for Stipeae is somewhat ambiguous but based on our survey it seems most likely to be x = 11 or 12. Our phylogenetic hypothesis supports the recognition of the following genera and groups (listed by region): Eurasia—Achnatherum, “Miliacea group”, “Neotrinia” (monotypic), Orthoraphium (monotypic), Patis (also 1 from North America), Piptatherum s.str., Psammochloa (monotypic), Ptilagrostis, Stipa, “Timouria group”, and Trikeraia; Mediterranean—Ampelodesmos (monotypic), Celtica (monotypic), Macrochloa (monotypic), and “Stipella-Inaequiglumes group”; Australasia —Anemanthele (monotypic), and Austrostipa; North America (NA)—“Eriocoma group”, Hesperostipa, Oryzopsis (monotypic), Piptatheropsis, “Pseudoeriocoma group”, and “Stillmania” (monotypic); South America—Aciachne, Amelichloa (also NA), Anatherostipa (s.str.), Jarava (polyphyletic), Lorenzochloa, Nassella (also NA), Ortachne, Pappostipa (also NA), and Piptochaetium (also NA). Monophyly of Phaenospermateae including Duthieinae is demonstrated, and its inclusion within or treatment as sister to Stipeae is rejected.Peer reviewe