Tsang Sup-Yin. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 176-185). / Abstracts in English and Chinese. / Acknowledgments --- p.1 / Abstract --- p.2 / 摘要 --- p.4 / List of Abbreviation --- p.6 / Chapter Chapter 1 --- General Introduction / Chapter 1.1 --- Isolation and activation of mas oncogene --- p.11 / Chapter 1.2 --- Amino acid sequence of mas oncogene --- p.14 / Chapter 1.3 --- Expression of mas oncogene --- p.18 / Chapter 1.4 --- Possible physiological role of mas oncogene --- p.20 / Chapter 1.5 --- Gene related to mas family --- p.23 / Chapter 1.6 --- Aims of study --- p.26 / Chapter Chapter 2 --- Over-expression of mas oncogene / Chapter 2.1 --- Introduction --- p.28 / Chapter 2.2 --- Materials and Methods --- p.29 / Chapter 2.2.1 --- Materials --- p.30 / Chapter 2.2.1.1 --- Chemicals --- p.30 / Chapter 2.2.1.2 --- Enzyme --- p.30 / Chapter 2.2.1.3 --- DNA Purification Kit --- p.31 / Chapter 2.2.1.4 --- Others --- p.31 / Chapter 2.2.2 --- Methods --- p.31 / Chapter 2.2.2.1 --- Strategy of construct preparation --- p.31 / Chapter 2.2.2.2 --- "Preparation of linearized vector, pFRSV" --- p.32 / Chapter 2.2.2.2.1 --- Cloning of vectors --- p.32 / Chapter 2.2.2.2.2 --- Restriction enzyme digestion and DNA dephosphorylation --- p.34 / Chapter 2.2.2.2.3 --- DNA purification by agarose gel electro-elution --- p.34 / Chapter 2.2.2.3 --- Preparation of pFRSV/mas construct --- p.35 / Chapter 2.2.2.3.1 --- PCR amplification --- p.35 / Chapter 2.2.2.3.2 --- Restriction enzyme digestion --- p.36 / Chapter 2.2.2.4 --- Ligation and analysis --- p.37 / Chapter 2.2.2.5 --- Purification of DNA by cesium chloride --- p.38 / Chapter 2.2.2.5.1 --- Large-scale bacterial culturing --- p.38 / Chapter 2.2.2.5.2 --- Ethanol precipitation --- p.39 / Chapter 2.2.2.5.3 --- Cesium chloride purification --- p.39 / Chapter 2.2.2.5.4 --- Removal of DNA dye by dialysis and ethanol precipitation --- p.40 / Chapter 2.2.2.6 --- Transfection by electroporation --- p.41 / Chapter 2.2.2.7 --- Screening for the stably transfected cells --- p.42 / Chapter 2.2.2.8 --- RT-PCR analysis of the mas transfectant --- p.43 / Chapter 2.2.2.8.1 --- Isolation of the total RNA from the mas transfectants by TRIzol ® Reagent --- p.43 / Chapter 2.2.2.8.2 --- Reverse transcription of the total RNA into cDNA --- p.44 / Chapter 2.2.2.8.3 --- Analysis of the transfected mas expression by PCR --- p.44 / Chapter 2.2.2.8.4 --- Analysis of the transfected DHFR expression by PCR --- p.45 / Chapter 2.2.2.8.5 --- Analysis of endogenous GAPDH expression by PCR --- p.46 / Chapter 2.2.2.9 --- Amplification of mas transgene by using methotrexate --- p.47 / Chapter 2.2.2.9.1 --- Amplification by low dosage MTX treatment --- p.47 / Chapter 2.2.2.9.2 --- Amplification by high dosage MTX treatment --- p.49 / Chapter 2.2.2.10 --- Southern blot analysis --- p.50 / Chapter 2.2.2.10.1 --- Preparation of DIG-labelled mas probe --- p.51 / Chapter 2.2.2.10.2 --- Preparation of DIG-labelled DHFR probe --- p.51 / Chapter 2.2.2.10.3 --- Preparation of DIG-labelled GAPDH probe --- p.52 / Chapter 2.2.2.10.4 --- Isolation of Genomic DNA from the mas transfectants by DNAzol® Reagent / Chapter 2.2.2.10.5 --- Enzymatic restriction of genomic DNA and Gel electrophoresis --- p.54 / Chapter 2.2.2.10.6 --- DNA transferring to positive charged Nylon membrane --- p.54 / Chapter 2.2.2.10.7 --- Pre-hybridization and hybridization --- p.56 / Chapter 2.2.2.10.8 --- Post-hybridization washing and blocking --- p.56 / Chapter 2.2.2.10.9 --- Detection --- p.57 / Chapter 2.2.2.11 --- Northern blot analysis --- p.57 / Chapter 2.2.2.11.1 --- Preparation of the agarose gel containing formaldehyde --- p.58 / Chapter 2.2.2.11.2 --- Preparation of the RNA sample --- p.58 / Chapter 2.2.2.11.3 --- Gel electrophoresis and transferring --- p.59 / Chapter 2.2.2.11.5 --- Pre-hybridization and hybridization --- p.60 / Chapter 2.2.2.11.4 --- Post-hybridization washing and blocking --- p.60 / Chapter 2.2.2.11.6 --- Detection --- p.61 / Chapter 2.2.2.11.7 --- Stripping and rehybridization --- p.61 / Chapter 2.3 --- Results --- p.62 / Chapter 2.3.1 --- RT-PCR analysis of gene expression in the stably transfectant --- p.62 / Chapter 2.3.2 --- Morphology of the mas trasnfectant --- p.64 / Chapter 2.3.3 --- Determination of mas gene copy number by Southern blot analysis in the mas transfectants --- p.66 / Chapter 2.3.4 --- Northern blot analysis of the transcriptional level of mas transcriptsin mas transfectants --- p.76 / Chapter 2.4 --- Discussion --- p.87 / Chapter Chapter 3 --- In vivo study of physiological effect of over-expression of mas / Chapter 3.1 --- Introduction --- p.92 / Chapter 3.2 --- Materials and Methods --- p.93 / Chapter 3.2.1 --- Materials --- p.93 / Chapter 3.2.2 --- Methods --- p.93 / Chapter 3.2.2.1 --- Cell culture --- p.93 / Chapter 3.2.2.2 --- Subcutaneous injection of nude mice --- p.94 / Chapter 3.2.2.3 --- Isolation of the total RNA from the tumor tissues --- p.95 / Chapter 3.2.2.4 --- Northern blot analysis --- p.96 / Chapter 3.3 --- Results --- p.96 / Chapter 3.3.1 --- Tumorgenicity assay of mas oncogene in nude mice --- p.96 / Chapter 3.3.2 --- Northern blot analysis of mas expression in the tumor tissues --- p.103 / Chapter 3.4 --- Discussion --- p.109 / Chapter Chapter 4 --- Fluorescent differential display analysis of mas transfectants / Chapter 4.1 --- Introduction --- p.111 / Chapter 4.2 --- Materials and Methods --- p.112 / Chapter 4.2.1 --- Materials --- p.112 / Chapter 4.2.1.1 --- Chemicals --- p.112 / Chapter 4.2.1.2 --- Enzyme --- p.113 / Chapter 4.2.1.3 --- Kits --- p.113 / Chapter 4.2.1.4 --- Others --- p.114 / Chapter 4.2.2 --- Methods --- p.114 / Chapter 4.2.2.1 --- Isolation of the total RNA from the mas transfectants by TRIzol ® Reagent --- p.114 / Chapter 4.2.2.2 --- DNase I treatment --- p.115 / Chapter 4.2.2.3 --- Reverse transcription (RT) and non-fluorescent PCR --- p.116 / Chapter 4.2.2.4 --- Reverse transcription and fluorescent differential display-PCR --- p.118 / Chapter 4.2.2.5 --- High resolution fluorescent differential display (Fluoro DD) gel --- p.118 / Chapter 4.2.2.6 --- Gel band excision of differentially expressed cDNA fragments --- p.120 / Chapter 4.2.2.7 --- Gel band reamplification --- p.120 / Chapter 4.2.2.8 --- Subcloning of reamplified cDNA fragments --- p.121 / Chapter 4.2.2.9 --- Purification of plasmid DNA from recombinant clones for reverse dot blot analysis --- p.122 / Chapter 4.2.2.10 --- Reverse dot blot analysis --- p.123 / Chapter 4.2.2.10.1 --- Preparation of cDNA dot blot --- p.123 / Chapter 4.2.2.10.2 --- Preparation of DIG-labeled cDNA library probes --- p.124 / Chapter 4.2.2.10.3 --- Hybridization --- p.126 / Chapter 4.2.2.11 --- Northern blot analysis --- p.127 / Chapter 4.3 --- Results --- p.128 / Chapter 4.3.1 --- Fluorescent differential display (FluoroDD) --- p.128 / Chapter 4.3.2 --- Reverse dot blot analysis --- p.135 / Chapter 4.3.3 --- DNA sequencing analysis of the clones --- p.141 / Chapter 4.3.4 --- Confirmation of differential display pattern of the subclones by Northern blot analysis --- p.160 / Chapter 4.4 --- Discussion --- p.166 / Chapter Chapter 5 --- General Discussion / Chapter 5.1 --- General model for mos-induced tumor formation --- p.169 / Chapter 5.2 --- Future aspect --- p.174 / References --- p.176 / Appendix I Buffer composition --- p.186 / Appendix II Sequences of fluoroDD TMR-Anchored primers and arbitrary primers --- p.190

by Lai Wing Hong Kevin. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1995. / Includes bibliographical references (leaves 63-74). / Acknowledgments --- p.i / Abbreviations --- p.ii / Abstract --- p.1 / Chapter Chapter 1 --- General Introduction --- p.3 / Chapter 1.1 --- Advantages of Antisense Oligonucleotides Inhibition --- p.4 / Chapter 1.2 --- The Uses of Antisense Oligonucleotide in Leukemic Therapy --- p.5 / Chapter 1.3 --- Oncogenes in the Pathogenesis of Leukemia --- p.6 / Chapter 1.4 --- Apoptosis and Apoptosis-Related Genes --- p.9 / Chapter 1.5 --- Protooncogene bcl-2 --- p.10 / Chapter 1.6 --- Bcl-2 Homologues --- p.11 / Chapter 1.7 --- Regulation of Apoptosis by Other Genes --- p.13 / Chapter 1.8 --- Promyelocytic Leukemia HL-60 Cell Line --- p.15 / Chapter 1.9 --- Aim of Project --- p.16 / Chapter Chapter 2 --- Chemical Synthesis of DNA Oligonucleotides / Chapter 2.1 --- Introduction --- p.17 / Chapter 2.2 --- Materials and Methods --- p.20 / Chapter 2.3 --- Results --- p.24 / Chapter 2.4 --- Discussion --- p.26 / Chapter Chapter 3 --- The Apoptotic Effects of TPA and Ouabain on the Promyelocytic Leukemic HL-60 cell line / Chapter 3.1 --- Introduction --- p.30 / Chapter 3.2 --- Materials and methods --- p.33 / Chapter 3.3 --- Results --- p.40 / Chapter 3.4 --- Discussion --- p.44 / Chapter Chapter 4 --- Effect of Antisense Oligonucleotides on TPA-Induced Apoptosisin Leukemic HL-60 cells / Chapter 4.1 --- Introduction --- p.48 / Chapter 4.2 --- Materials and Methods --- p.49 / Chapter 4.3 --- Results --- p.52 / Chapter 4.4 --- Discussion --- p.54 / Chapter Chapter 5 --- General Discussion --- p.57 / References --- p.63

No description available.

Phosphorylation of the alpha-subunit of the eukaryotic initiation factor 2 (eIF2alpha) on Serine 51 (Ser51) is an early event associated with downregulation of protein synthesis at the level of translation and constitutes a potent mechanism to overcome various stress conditions. In mammals, four eIF2alpha-kinases PERK, PKR, HRI and GCN2, activated following specific stresses, have been involved in this process. Our laboratory has previously demonstrated that the adaptor protein Nck, composed only of Src homology domains and classically implicated in cell signaling by activated plasma membrane receptor tyrosine kinases, modulates translation through its interaction with the beta-subunit of the eukaryotic initiation factor 2 (eIF2beta). Moreover, we reported that Nck-1 overexpression antagonizes the inhibition of translation in endoplasmic reticulum stress condition and prevents the PERK-mediated phosphorylation of the alpha-subunit of eIF2 on Ser51. In this thesis, I demonstrate that the adaptor protein Nck-1 modulates eIF2alpha-kinase-mediated eIF2alphaSer51 phosphorylation in a specific manner. More particularly, I show that Nck-1 overexpression reduces eIF2alpha phosphorylation in conditions activating PKR or HRI as described previously for PERK. In contrast, I observe that overexpression of Nck-1 in mammalian cells fails to attenuate eIF2alphaSer51 phosphorylation in response to amino acid starvation, a stress condition activating GCN2. I further confirm this observation by showing that Nck-1 fails to alter eIF2alphaSer51 phosphorylation in Saccharomyces cerevisiae, for which the sole eIF2alpha-kinase is GCN2. In addition, I report that Nck-1 reduces PKR activation in response to dsRNA. I also find that Nck-1 reduces dsRNA-induced activation of p38 MAPK, a PKR-downstream substrate, and cell death. Finally, I show that Nck-1 interacts exclusively with the inactivated form of PKR in a Src homology domain independent manner. All together these data uncover the existence of a novel mechanism regulating phosphorylation of eIF2alphaSer51 under various stress conditions and identifies Nck-1 as a modulator of the tumor suppressor and antiviral protein kinase PKR.

No description available.