Il Tirocinio per e nella formazione degli insegnanti. Innovare è valorizzare

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The Role of the Pleckstrin Homology Domain in Membrane Targeting and Activation of Phospholipase Cβ1

Current studies involve an investigation of the role of the pleckstrin homology (PH) domain in membrane targeting and activation of phospholipase Cbeta(1) (PLCbeta(1)). Here we report studies on the membrane localization of the isolated PH domain from the amino terminus of PLCbeta(1) (PLCbeta(1)-PH) using fluorescence microscopy of a green fluorescent protein fusion protein. Whereas PLCbeta(1)-PH does not localize to the plasma membrane in serum-starved cells, it undergoes a rapid but transient migration to the plasma membrane upon stimulation of cells with serum or lysophosphatidic acid (LPA). Regulation of the plasma membrane localization of PLCbeta(1)-PH by phosphoinositides was also investigated. PLCbeta(1)-PH was found to bind phosphatidylinositol 3-phosphate most strongly, whereas other phosphoinositides were bound with lower affinity. The plasma membrane localization of PLCbeta(1)-PH induced by serum and LPA was blocked by wortmannin pretreatment and by LY294002. In parallel, activation of PLCbeta by LPA was inhibited by wortmannin, by LY294002, or by the overexpression of PLCbeta(1)-PH. Microinjection of betagamma subunits of G proteins in serum-starved cells induced the translocation of PLCbeta(1)-PH to the plasma membrane. These results demonstrate that a cooperative mechanism involving phosphatidylinositol 3-phosphate and the Gbetagamma subunit regulates the plasma membrane localization and activation of PLCbeta(1)-PH

DOTA-Derivatives of Octreotide Dicarba-Analogs with High Affinity for Somatostatin sst2,5 Receptors

In vivo somatostatin receptor scintigraphy is a valuable method for the visualization of human endocrine tumors and their metastases. In fact, peptide ligands of somatostatin receptors (sst's) conjugated with chelating agents are in clinical use. We have recently developed octreotide dicarba-analogs, which show interesting binding profiles at sst's. In this context, it was mandatory to explore the possibility that our analogs could maintain their activity also upon conjugation with DOTA. In this paper, we report and discuss the synthesis, binding affinity and conformational preferences of three DOTA-conjugated dicarba-analogs of octreotide. Interestingly, two conjugated analogs exhibited nanomolar affinities on sst(2) and sst(5) somatostatin receptor subtypes

Immersive teacher training experience on the methodology of problem posing and solving in Mathematics

[EN] In an Italian and European context, one of the fundamental skills in Mathematics is the ability to solve problems in everyday situations, often linked to everyday life. For this reason, the problem posing and solving methodology plays a fundamental role in the process of teaching and learning Mathematics. This paper presents the results of the immersive experience "Mathematical Exploration with Problem Posing and Solving", included in the teacher training activities proposed by the national PP&S - Problem Posing & Solving - Project of the Italian Ministry of Education, which aims at enhancing the teaching and learning of Mathematics by using new methodologies and technologies. In particular, the focus will be on the work and considerations of the 50 teachers who took part in the project, from both primary and secondary school. They were guided through the individual step-by-step creation of a contextualized problem, following a process guided through stimulus-based questions. This immersive experience brought about the production of valid problems and was full of very stimulating teachers' considerations on the various phases of the problem posing and solving.Barana, A.; Brancaccio, A.; Conte, A.; Fissore, C.; Floris, F.; Marchisio, M.; Pardini, C. (2019). Immersive teacher training experience on the methodology of problem posing and solving in Mathematics. En HEAD'19. 5th International Conference on Higher Education Advances. Editorial Universitat Politècnica de València. 667-675. https://doi.org/10.4995/HEAD19.2019.9489OCS66767