Showing papers on "Regulation of gene expression published in 1970"

Molecular Biology of the Gene

Abstract: The long-awaited Fifth Edition of James D. Watson's classic text, Molecular Biology of the Gene, has been thoroughly revised and is published to coincide with the 50th anniversary of Watson and Crick's paper on the structure of the DNA double-helix. Though completely updated, the new edition retains the distinctive character of earlier editions that made it the most widely used book in molecular biology. Twenty-one concise chapters, co-authored by five highly respected molecular biologists, provide current, authoritative coverage of a fast-changing discipline. The completely new art is printed in full color for the first time. Divided into five parts, the first (Chemistry and Genetics) begins with an overview of molecular biology, placing the discipline in historical context and introducing the basic chemical concepts that underpin our description of molecular biology today. The second and third parts (Maintenance of the Genome and Expression of the Genome) form the heart of the book, describing in detail the basic mechanisms of DNA replication, transcription and translation. The fourth part of the book (Regulation) deals with how gene expression is regulated - from the examination of basic mechanisms that regulate gene expression in bacterial and eukaryotic systems, to a description of how regulation of gene expression lies at the heart of the process of development. Recent findings from sequencing whole genomes of several animals have revealed that they all share essentially the same genes. The last chapter in the regulation section looks at how changes in gene regulation can account for how different animals can be made up of the same genes. The final part of the book (Methods) deals with the techniques and methods used in molecular biology.

Research Article 13: Cell-Free Studies on the Regulation of the lac Operon

Abstract: INTRODUCTION The ideal test for a model of gene regulation would be the measurement of gene activity as a function of the concentration of each of the alleged regulating components. A cell-free system in which it would be possible to mix the required components in any amounts and observe the effects on gene activity would be most suitable for such studies. About four years ago our laboratory began developing such a cell-free system for the lac operon. At a minimum, demonstration of gene activity would require a system containing DNA, RNA polymerase, the substrates and cofactors for RNA synthesis, and a procedure for characterization of the RNA. In vitro systems that synthesize only the immediate RNA product of the gene have thus far proven ineffective for bacterial gene studies; for some unknown reason RNA polymerase in these systems does not function with sufficient discrimination. The result is a chaotic assemblage of RNA molecules whose synthesis is insensitive to in vivo gene regulating factors (Zubay, unpublished results). Thus, the immediate challenge in developing a workable cell-free system lies in finding conditions under which RNA polymerase recognizes only true starts and true stops on the gene. In the cell-free system which we have developed, DNA-directed synthesis of the proteins of the lac operon has been studied. This system is quite complex, comprising a cell-free extract of E. coli, DNA from the defective transducing virus ϕ 80d lac (although any DNA containing the lac operon is active) and the cofactors and substrates necessary for...

Differential gene activation in isolated chromosomes.

Abstract: Publisher Summary The principle of differential gene activation states that the differences among cells having the same genetic content are the result of different sets of genes being turned on or off. Differential gene activation is the basis of cell differentiation and function. The control of gene activity in higher organisms can take place at more than one level, for example, at the level of DNA, RNA polymerase, or histone. By interacting with DNA, histone determines whether RNA polymerase can ever bind at the respective chromosome region and whether mechanisms operating at other levels can ever come into play. Because the interaction between histone and DNA is ionic, it is primarily influenced by the ionic milieu of the chromosomal environment. Inorganic anions such as chloride or phosphate may affect the histone-DNA interaction as organic ions, such as amino acids, nucleotides, polyamines, or even more complex “ions” such as phosphoprotein, acidic protein, or RNA.

Very lysine rich histone of echinoderms and molluscs

Abstract: THE similarity of the histone component F2a1 from calf and pea1 casts doubt on the hypothesis that it acts as a selective repressor of gene activity. Such a function may, however, be fulfilled by the very lysine-rich fractions F1 because they are significantly heterogeneous in vertebrate species2,3. Alternatively, the heterogeneity might be explained in terms of gene multiplicity and/or a modification of some amino-acid residues4 and may have no implication in gene regulation. It would then have an evolutionary significance, similar to that of the heterogeneity in proteins such as haemoglobin and cytochrome. We thought that it would be of interest, therefore, to study the very lysine-rich component in different species, particularly those far apart on the evolutionary scale. We chose a mollusc and an echinoderm and found that their F1 histones differed from each other in a limited but significant way and that they also differed from the equivalent F1 fraction from calf thymus.

Cis Regulatory Elements in Regulation of Plant Gene Expression: AnOverview

Abstract: Gene expression is an extensively controlled process that occurs at various levels, transcription being one of the most crucial. It depends on a variety of interactions mediated by the core promoter region, sequence specific DNA binding proteins and their cognate promoter elements. Promoters comprise cis regulatory elements, clusters of short sequences that provide binding sites for transcription factors. According to PLACE database, there are 469 cis regulatory elements present in plants. The ACGT core sequence has been established as a functionally important cis element in several promoters that respond to different stimuli like light, anaerobiosis, jasmonic acid and hormones such as salicylic acid, abscisic acid and auxin.

Limited GADD45α expression and function in IL-1β toxicity towards insulin-producing cells.

Abstract: Growth arrest and DNA damage-inducible (GADD) 45 proteins are regulators of cell death and survival. The proinflammatory cytokine IL-1β strongly increases the level of the transcript encoding GADD45α in rat insulin-producing INS-1E cells. The activation of Gadd45α gene is clearly dependent on JNK and NF-κB activation and the synthesis of the secondary mediator nitric oxide (NO). Interestingly, the observed twelve-fold increase in the GADD45α-coding transcript level is not followed by increased expression of GADD45α at the protein level. An analysis of IL-1β toxicity in INS-1E cells overexpressing GADD45α revealed no correlation between the GADD45α protein level and the sensitivity to IL-1β toxicity. These findings suggest that the potential engagement of GADD45α in IL-1β toxicity towards beta cells is limited to the effects induced by the basal expression level of this protein.