No description available.

As an important posttranslational modification, protein acetylation plays critical roles in many biological processes such as gene transcription, DNA damage repair, apoptosis and metabolism. The acetylation occurs on the ε-amino group of specific lysine residues, and is catalyzed by histone acetyltransferases (HATs). In cellular contexts, HATs are found to target hundreds and thousands of substrates including histone and nonhistone proteins. Lysine acetylation changes the microenvironment of protein and may potentially alter protein activity and protein-protein interaction. The goal of this dissertation project is to investigate the impact of lysine acetylation on the catalysis of MYST HATs, and to establish the strategy for labeling substrates of the MYST HATs at cellular level. To understand the regulatory mechanism of MYST HATs, a detailed study was carried out to investigate the active site lysine acetylation of two MYST HATs (MOF and Tip60). Autoradiography and immunoblotting data shows that mutation of active site lysine differentially affects the enzyme autoacetylation activity and the cognate substrate acetylation activity. In addition, deacetylated MOF and Tip60 were prepared by using the nonspecific lysine deacetylase Sirt1. Kinetic study demonstrated that the acetylation of the active site lysine on MYST HATs marginally modulates the HAT catalysis. This work provides new insights into the regulatory mechanism of MYST catalysis. In the second part of my work, we designed and synthesized a series of Ac-CoA analogs conjugated with alkynyl or azido functional groups. Meanwhile, the active site of the MOF was engineered to expand the cofactor binding capability. Fluorescence screening was carried out to characterize the enzyme activity to Ac-CoA analogs. MOF-I317A with all analogs and MOF-I317A/H273A–5HYCoA were identified and further applied in the labeling of the cognate histone H4 protein and HAT substrates in 293T cell lysate. Visualizing of the labeled substrate was achieved using the alkynyl or azido-tagged fluorescent reporters through the copper-catalyzed azide−alkyne cycloaddition. As expected, the histone H4 protein was successfully labeled by the active enzyme-cofactor pairs. More intriguingly, multiple protein bands in cell lysate were labeled and observed. This work provides a new versatile strategy in exploring the substrates of MYST HATs at the proteomic level.

Los cítricos, al igual que muchas otras especies vegetales, poseen tres sistemas de transporte para la absorción del ión nitrato, separados genéticamente, y que actúan y se regulan en función de diferentes factores para hacer frente a las demandas nutricionales de la planta. Existen dos sistemas de transporte de alta afinidad, uno constitutivo (cHATS) y otro inducible (iHATS) que operan a bajas concentraciones externas de nitrato y que siguen una cinética de Michaelis-Menten. El sistema de transporte de baja afinidad (LATS) opera a altas concentraciones externas de nitrato y sigue una cinética lineal. Los parámetros cinéticos de estos sistemas son más bajos que los de las especies herbáceas estudiadas, lo que podría indicar una menor capacidad de estos sistemas. Ambos necesitan energía metabólica en forma de ATP para poder realizar la absorción del ión nitrato. En lo referente al efecto de la salinidad, en todos los casos el ión cloruro reduce la absorción del ión nitrato, pero de forma diferente si se trata del HATS o el LATS. En el HATS se da una inhibición competitiva entre ambos iones, mientras que para el LATS, es necesario que se acumule cloruro en los tejidos, para que se de la reducción de la absorción del ión nitrato, por un mecanismo no conocido, independiente de la reducción de la transpiración y en el que podría estara implicada la enzima nitrato reductasa.

Thesis (M.D.)--Dept. of Surgery, University of Adelaide, Dept. of Surgery, 1992. / Typescript (Photocopy). Includes bibliographical references (leaves 243-284).

Many complicated problems have simple or at least understandable version, which can be pleasant to listen to and to think about. This work presents the reader with an interesting problem about hats, which, as it turns out, surprises with a number of variations, diversity of procedures and unexpected results. Work will (hopefully) serve as entertaining mathematical literature for anyone who wants to look at these problems, or as a good source of logical problems of this kind. The first part is therefore written in a relaxed language and style, problems are set in one (perhaps overly fairy-tale) story. Mathematics hidden behind problem solving is presented in the second part. 1

The Book of Hats" is a novel of adult literary fiction that comes in six hat-inspired sections. The novel opens late on a Saturday night when the phone rings and Ida Velikowsky, seventy-year-old wannabe tough guy who, in actuality, is a bit of a marshmallow, is woken out of a dream of hats. She runs into the living room and picks up the phone and hears on the other end of it the unwelcome voice of her no-goodnik brother Benny. She hasn't talked to him in forty years. Ida is someone who likes to keep her world small. She plays her cards close to her chest and faces each day as if it were an obstacle course in which memory and intimacy are the things that must be avoided at all costs. She is most comfortable when reading the “National Geographic” and avoiding friends. For nearly six years, since the death of her lover Gertie, she’s managed to stay in a fairly comfortable state of emotional shut-down. Then Benny calls and she finds herself vulnerable to memory, hope and rage, and even more painful, regret. She doesn't want to see Benny. She knows it's not a good idea to see him. But she finds herself wondering if, by seeing him, something in her life could be restored. The novel opens with Benny's call and moves, comic and menacing, toward a possible reunion.

No description available.

Dear All, Eros moves. In January of 2007 I decided to do research about Eros and his presence in architecture. I decided to do a thesis about LOVE. This thesis it is a story about me, since when you love architecture you give yourself completely to it. What you see in these pages, it's me: my life, my desires, my passion for architecture, my fears, my bad moments, my good moments, my joy--all of me. Desire in architecture seemed to me at that moment something with which I didn’t know how to start working. It was so abstract that, when considered, almost anything can be a desire, and maybe it is. But this thesis is a story of how desire opened for me an infinite world of imagination and wonder--how Eros made me love the drawing, the line, the color, the wall, the shadow, the material....the architecture. I have chosen to explore desire through the designing of a post office, theatre school, and retail shops. The site is in Washington DC, in between 7th and 8th streets SE, adjacent to Eastern Market. / Master of Architecture

Tip60 is a 60 kDa nuclear protein which exists in three isoforms, belongs to the MYST/HAT family of proteins and was discovered after its interaction with the Human HIV-1 Tat. As a nuclear protein, Tip60 can act as a coactivator or repressor. To understand the HAT action of Tip60, two possible catalytic models exist; the ping-pong and the ternary complex formation models. In correlation with the exploration of HAT catalytic action, mutations of a Cys to Ala and a Glu to Gln on Esa1 (yeast homolog of Tip60 and MYST/HAT prototype), was reported to show wild type-like and decreased acetylating properties, respectively. In this work, Tip60 HAT action was explored. In Tip60, the Cys in the active site is important for acetylation of the H4(1-20) substrate and the Glu showed semi loss in acetylating the H4(1-20) peptide substrate. These data highlight a unique mechanism of Tip60 catalysis.

Typescript (Photocopy) / Bibliography: leaves 243-284 / 284 leaves : / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (M.D.)--Dept. of Surgery, University of Adelaide, Dept. of Surgery, 1992