High levels of nitrogen are stored as arginine during the last stages of seed formation in maritime pine (Pinus pinaster Aiton). The protein sensor PII regulates the feedback inhibition of arginine biosynthesis through interaction with the key enzyme N-acetylglutamate kinase (NAGK). In this study, the structural and functional characteristics of PII have been investigated in maritime pine to get insights into the regulation of arginine metabolism. Two different forms of PII have been identified, PpPIIa and PpPIIb, which differ in their amino acid sequence and most likely correspond to splicing variants of a single gene in the pine genome. Two PII variants are also present in other pine species but not in other conifers such as spruces. PpPIIa and PpPIIb are trimeric proteins for which structural modeling predicts similar tridimensional protein core structures. Both are located in the chloroplast, where the PII-target enzyme PpNAGK is also found. PpPIIa, PpPIIb, and PpNAGK have been recombinantly produced to investigate the formation of NAGK-PII complexes. The interaction of PpPIIa/PpPIIb and PpNAGK may be enhanced by glutamine and contribute to relieve the feedback inhibition of PpNAGK by arginine. Expression analysis of PpPII genes revealed that PpIIa transcripts were predominant during embryogenesis and germination. The potential roles of PpPIIa and PpPIIb in the regulation of arginine metabolism of maritime pine are discussed.

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ResumoEste trabalho de caráter interdisciplinar entre design e educação apresenta reflexões que serviram como norteadoras na condução da pesquisa de ressignificação dos espaços educativos, em duas pequenas ilhas do Golfo da Guiné -São Tomé e Príncipe. Também apresenta alguns dos resultados alcançados durante o processo de pesquisa visando explorar possíveis contribuições ao espaço escolar, por ser o lugar, para além do espaço familiar, em que as crianças desenvolvem competências e habilidades cognitivas, colhem suas primeiras sensações, impressões e iniciam o processo de grandes transformações. A ressignificação dos espaços se constituiu como experiência piloto, servindo de inspiração para que outras escolas possam ser contempladas e fornece subsídios para melhorar a qualidade de escolas públicas em contextos semelhantes, podendo ser estendida também a escolas de regiões específicas do Brasil. AbstractThis interdisciplinary work between design and education presents ideas that served as guides in the conduction of the research of re-signification of the educational spaces in two small islands in the Gulf of Guinea -Sao Tome and Principe. It also presents some of the results achieved during the research process in order to explore possible contributions to the school space, because it is the place, beyond the family space, in which children develop cognitive skills and abilities, gather their first feelings, impressions and initiate the process of great transformations the re-signification of the spaces was constituted as pilot experiment. This pilot can serve as an inspiration for other schools can be met and provides grants to improve quality of public schools in similar contexts and may also be extended to schools in specific regions of Brazil.