Daily rhythmicity of high affinity copper transport

A differential demand for copper (Cu) of essential cupro-proteins that act within the mitochondrial and chloroplastal electronic transport chains occurs along the daily light/dark cycles. This requires a fine-tuned spatiotemporal regulation of Cu delivery, becoming especially relevant under non-optimal growth conditions. When scarce, Cu is imported through plasma membrane-bound high affinity Cu transporters (COPTs) whose coding genes are transcriptionally induced by the SPL7 transcription factor. Temporal homeostatic mechanisms are evidenced by the presence of multiple light- and clock-responsive regulatory cis elements in the promoters of both SPL7 and its COPT targets. A model is presented here for such temporal regulation that is based on the synchrony between the basal oscillatory pattern of SPL7 and its targets, such as COPT2. Conversely, Cu feeds back to coordinate intracellular Cu availability on the SPL7-dependent regulation of further Cu acquisition. This occurs via regulation at COPT transporters. Moreover, exogenous Cu affects several circadian-clock components, such as the timing of GIGANTEA transcript abundance. Together we propose that there is a dynamic response to Cu that is integrated over diurnal time to maximize metabolic efficiency under challenging conditions

Comparison of global responses to mild deficiency and excess copper levels in Arabidopsis seedlings

[EN] Copper is an essential micronutrient in higher plants, but it is toxic in excess. The fine adjustments required to fit copper nutritional demands for optimal growth are illustrated by the diverse, severe symptoms resulting from copper deficiency and excess. Here, a differential transcriptomic analysis was done between Arabidopsis thaliana plants suffering from mild copper deficiency and those with a slight copper excess. The effects on the genes encoding cuproproteins or copper homeostasis factors were included in a CuAt database, which was organised to collect additional information and connections to other databases. The categories overrepresented under copper deficiency and copper excess conditions are discussed. Different members of the categories overrepresented under copper deficiency conditions were both dependent and independent of the general copper deficiency transcriptional regulator SPL7. The putative regulatory elements in the promoter of the copper deficiency overrepresented genes, particularly of the iron superoxide dismutase gene FSD1, were also analysed. A 65 base pair promoter fragment, with at least three GTAC sequences, was found to be not only characteristic of them all, but was responsible for most of the FSD1 copper-dependent regulations. Moreover, a new molecular marker for the slight excess copper nutritional status is proposed. Taken together, these data further contribute to characterise copper nutritional responses in higher plants.We thank Dr Toshiharu Shikanai for the spl7 mutant and the Unitat d'Analisi Elemental, Serveis Cientificotecnics at the Universitat de Barcelona. This work has been supported by Grants BIO2011-24848 and CSD2007-00057 to L.P. from the Spanish Ministry of Economy and Competitiveness, and by FEDER funds from the European Union and the Generalitat Valenciana (Regional Valencian Government; ACOMP07-159). N.A.-C., A.G.-M. and A.P.-G were recipients of predoctoral fellowships from the Spanish Ministry of Economy and Competitiveness.Andres-Colas, N.; Perea García, A.; Mayo, S.; Garcia-Molina, A.; Dorcey, E.; Rodríguez-Navarro, S.; Perez Amador, MA.... (2013). Comparison of global responses to mild deficiency and excess copper levels in Arabidopsis seedlings. Metallomics. 5(9):1234-1246. https://doi.org/10.1039/c3mt00025g123412465

El coraje de filmar cuando la patria no ampara

This article reflects on the contradictions in the ci- nematographic creation of a country, Cuba, which is home to one of the most prestigious film schools in the world, the International Film and Television School of San Antonio de los Baños (Escuela Inter- nacional de Cine y Televisión de San Antonio de los Baños, EICTV). Since its foundation in 1986, this institution has clearly had a transnational vocation. EICTV is a film school open to students from Latin America, Africa and Asia, and, in its three deca- des of existence, thousands of professionals and students from over fifty countries have made it a space for cultural diversity. However, the peculia- rities of the Cuban socialist system limit cinemato- graphic creation ideologically, conditioned by the absence of freedom of expression and marked by state censorship. Screenwriter, producer and do- cumentary filmmaker Lola Mayo, professor of the School’s Documentary Department since 2010, presents the cases of several Cuban filmmakers who have graduated from this institution and have a difficult struggle with the Cuban state to produ- ce and make their films, including Miguel Coyula.Este artículo reflexiona sobre las contradicciones de la creación cinematográfica de un país, Cuba, que acoge uno de los más prestigiosos centros educativos cinematográficos del mundo, la Es- cuela Internacional de Cine y Televisión de San Antonio de los Baños (EICTV). Desde su funda- ción en 1986, esta institución proyecta una clara vocación transnacional. La EICTV es una escuela de cine abierta a estudiantes de América Latina, África y Asia, y, en sus tres décadas de vida, miles de profesionales y estudiantes provenientes de más de cincuenta países la han convertido en un espacio para la diversidad cultural. Sin embargo, las peculiaridades del sistema socialista cubano limitan ideológicamente la creación cinemato- gráfica, condicionada por la ausencia de libertad de expresión y marcada por la censura estatal. La guionista, productora y documentalista Lola Mayo, profesora de la Cátedra de Documental de la Es- cuela desde 2010, expone los casos de varios ci- neastas cubanos egresados de esta institución, entre los que destaca Miguel Coyula, que man- tienen un dificultoso pulso con el Estado cubano para conseguir producir y realizar sus películas