Role of Phosphorylation of the Oxysterol Binding Protein (OSBP) in (PI(4)P) and Sterol-Containing Membrane Recognition and Binding

Studies have demonstrated that the oxysterol binding protein (OSBP) acts as a phosphatidylinositol phosphate (PIP)-sterol exchanger at membrane contact sites (MCS) of the endoplasmic reticulum (ER) and Golgi. OSBP is known to pick up phosphatidylinositol-4-phosphate (PI(4)P) from the ER, transfer it to the trans-Golgi in exchange for a cholesterol molecule that is then transferred from the trans-Golgi to the ER. Upon further examination of this pathway by Ridgway et al. (1), it appeared that phosphorylation of OSBP played a role in the localization of OSBP. The dephosphorylation state of OSBP was linked to Golgi localization and the depletion of cholesterol at the ER. To mimic the phosphorylated state of OSBP, the mutant OSBP-S5E was designed by Ridgway et al. (1). The lipid and sterol recognition by wt-OSBP and its phosphomimic mutant OSBP-S5E were investigated using immobilized lipid bilayers and dual polarization interferometry (DPI). DPI is a technique in which the protein binding affinity to immobilized lipid bilayers is measured and the binding behavior is examined through real time. Lipid bilayers containing 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) and varying concentrations of PI(4)Ps or sterols (cholesterol or 25-hydroxycholesterol) were immobilized on a silicon nitride chip. It was determined that wt-OSBP binds differently to PI(4)P-containing bilayers compared to OSBP-S5E. The binding behavior suggested that wt-OSBP extracts PI(4)P and the change in the binding behavior, in the case of OSBP-S5E, suggested that the phosphorylation of OSBP may prevent the recognition and/or extraction of PI(4)P. In the presence of sterols, the overall binding behavior of OSBP, regardless of phosphorylation state, was fairly similar. The maximum specific bound mass of OSBP to sterols did not differ as the concentration of sterols increased. However, comparing the maximum specific bound mass of OSBP to cholesterol with oxysterol (25-hydroxycholesterol), OSBP displayed nearly a 2-fold increase in bound mass. With the absence of the wt-OSBP-PI(4)P binding behavior, it can be speculated that the sterols were not extracted. In addition, the binding behavior of OSBP was further tested using a fluorescence based binding assay. Using 22-(N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino)-23,24-bisnor-5-cholen-3β-ol (22-NBD cholesterol), wt-OSBP a one site binding dissociation constant Kd, of 15 ± 1.4 nM was determined. OSBP-S5E did not bind to 22-NBD cholesterol and Kd value was not obtained.

Discurso que por encargo de la Junta Patriótica, pronunció en el panteón de Santa Paula el ciudadano Ignacio Sierra Rosso, en la colocación del pié que perdió en Veracruz el Esco. Sr. General de División, Benemérito de la Patria D. Antonio López de Santa-Anna, en la gloriosa jornada del 5 de diciembre de 1838.

UANL

La Madre de Dios, Madre de los hombres, ó, Explicación del misterio de la Santísima Virgen al pié de la cruz por J. Ventura de Ráulica.

UANL

La PI et seulement la PI ? De nouvelles alternatives à la gouvernance de l'innovation

Wendy Adams, professeure adjointe à la Faculté de droit de l'Université McGill et chercheure associée au CRDP. Communication organisée par Konstantia Koutouki, chercheure régulière au CRDP et professeure à la Faculté de droit de l'Université de Montréal.

Mesure du rapport d'embranchement des désintégrations B^0--> pi^- l^+v et B^+--> êta^(') l^+v, du spectre des facteurs de forme des désintégrations B^0--> pi^- l^+v et B^+--> êta l^+v, et extraction de |V_ub| dans l'expérience BABAR

Nous rapportons les résultats d'une étude des désintégrations semileptoniques non-charmées B^+--> êta^(') l^+v et B^0--> pi^- l^+v, mesurés par le détecteur BABAR avec une production d'environ 464 millions de paires de mésons BBbar issues des collisions e^+e^- à la résonance Upsilon(4S). L'analyse reconstruit les événements avec une technique relâchée des neutrinos. Nous obtenons les rapports d'embranchement partiels pour les désintégrations B^+--> êta l^+v et B^0--> pi^- l^+v en trois et douze intervalles de q^2, respectivement, à partir desquels nous extrayons les facteurs de forme f_+(q^2) et les rapports d'embranchement totaux B(B^+--> êta l^+v) = (3.39 +/- 0.46_stat +/- 0.47_syst) x 10^-5 et B(B^0--> pi^- l^+v) = (1.42 +/- 0.05_stat +/- 0.08_syst) x 10^-4. Nous mesurons aussi B(B^+--> êta' l^+v) = (2.43 +/- 0.80_stat +/- 0.34_syst) x 10^-5. Nous obtenons les valeurs de la norme de l'élément |V_ub| de la matrice CKM en utilisant trois calculs différents de la CDQ.

Rôles et régulation du PI(4,5)P2 dans le remodelage cortical et la morphogénèse cellulaire en mitose

Doctorat réalisé en cotutelle avec le laboratoire de François Payre au Centre de Biologie du Développement à Toulouse, France (Université de Toulouse III - Paul Sabatier)

Development of Photorefractive Polymers: Synthesis and Characterization of Polymers with Donor-Pi-Acceptor Groups

Department of Polymer Science and Rubber Technology, Cochin University of Science and Technology

{2p_\pi}-{2p_\sigma} crossing in heavy symmetric ion-atom collisions: I. Level structure

Ab initio self-consistent DFS calculations are performed for five different symmetric atomic systems from Ar-Ar to Pb-Pb. The level structure for the {2p_\pi}-{2p_\sigma} crossing as function of the united atomic charge Z_u is studied and interpreted. Manybody effects, spin-orbit splitting, direct relativistic effects as well as indirect relativistic effects are differently important for different Z_u. For the I-I system a comparison with other calculations is given.

Pi: A Parallel Architecture Interface for Multi-Model Execution

This thesis defines Pi, a parallel architecture interface that separates model and machine issues, allowing them to be addressed independently. This provides greater flexibility for both the model and machine builder. Pi addresses a set of common parallel model requirements including low latency communication, fast task switching, low cost synchronization, efficient storage management, the ability to exploit locality, and efficient support for sequential code. Since Pi provides generic parallel operations, it can efficiently support many parallel programming models including hybrids of existing models. Pi also forms a basis of comparison for architectural components.

De S' Estanyol a Cala Pi, passant per S' Estalella : una passejada per la costa llucmajorera. 'De S' Estanyol a la Cala Pi, pasando por S' Estalella : un paseo por la costa de Llucmajor'

El cuaderno es una herramienta que propone una excursi??n por la costa de Llucmajor. El objetivo de la propuesta es que los escolares conozcan y valoren un paraje ??nico, con la vida que en ??l se desarrolla. S'Estalella es una de las pocas extensiones de Mallorca que a??n gozan de un buen estado de conservaci??n, ofreciendo al visitante un panorama agreste y natural, digno de ser conservado. El anuncio del prop??sito de una empresa p??blica de construir en S'Estalella una central t??rmica inici?? una campa??a de movilizaciones entre colectivos de defensa de la naturaleza, sindicatos y asociaciones ciudadanas. El presente material did??ctico es una acci??n m??s, encaminada a concienciar a la poblaci??n en pro de la conservaci??n del patrimonio natural.

Teniu cura dels vostres pins : la processionària del pi. 'Cuidad vuestros pinos : la procesionaria del pino'.

Resumen tomado de la publicación

Experiencia sobre la aproximación intuitiva en Geometría : una aproximación del número pi en la ESO.

Resumen basado en el de la publicación

Ramanujan y el número pi.

Artículo que hace una aproximación a la figura de Ramanujan, contable en la India. Se exponen algunos de los cálculos y fórmulas a los que llegó a partir del numero pi.

L'escola Pi d'en Xandri : un model d'avaluació. 'La escuela Pi de Xandri : un modelo de evaluación'.

Resumen basado en el de la publicación