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The heat-shock proteins in E. coli are transiently overexpressed af ter shift to a higher growth temperature. The genes that encode the HSPs are preceded by promoters transcribed in vitro by a form of RNA poly 32 32 merase holoenzyme containing a 32-kd a subunit (Ea ). The a subunit is encoded by the rpoH (htpR) gene, previously identified as a positive 32 effector of the heat-shock response. Our evidence suggests that Ea is the enzyme that transcribes heat-shock genes at all temperatures. The level 32 of a may be regulated at several points: Accumulation of rpoH mRNA 32 is affected by temperature shift, a synthesis is regulated posttranscrip 32 tionally, and a is an unstable molecule with a tl/2 of 5 min. Many mu tations in the HSPs are shown to have defects in proteolysis. References Baker. T. A. , Grossman. A. D . . and Gross. C. A. , 1984, A gene regulating the heat shock response in Escherichia coli also affects proteolysis. Proc. Natl. A cad. Sci. US. A. 81:6779-6783. Bardwell, J. C. A . . and Craig, E. A . . 1984. Major heat shock gene of Drosophila and the Escherichia coli heat-inducible dnaK gene are homologous, Proc. Natl. Acad. Sci. US. A. 81:848-852. Bukhari. A. I. . and Zipser. D . . 1973, Mutants of Escherichia coli with a defect in the degradation of nonsense fragments, Nature New Bioi. 243:238-241. Charette. M. F. , Henderson, G. W. , and Markovitz, A.
List of contents
1 The Role of Cis- and Trans-Acting Functions in Simian Virus 40 Gene Regulation.- 1. Introduction.- 2. Early Viral Transcriptional Program.- 3. Late Viral Transcriptional Program.- 4. Discussion.- References.- 2 Regulation of the Heat-Shock Response in Escherichia coli.- 1. Introduction.- 2. Transcription of the Heat-Shock Genes.- 3. Regulation of rpoH and ?32.- 4. Function of the Heat-Shock Proteins.- 5. Summary.- References.- 3 Negative Control of DNA Replication Revealed in Composite Simian Virus 40-Bovine Papillomavirus Plasmids.- 1. Overview.- 2. Introduction.- 3. Results.- 4. Discussion.- References.- 4 DNA Supercoiling as a Regulator of Bacterial Gene Expression.- 1. Introduction.- 2. Results and Discussion.- References.- 5 Retrotransposition in Yeast.- 1. Introduction.- 2. Experiments.- 3. Speculation.- References.- 6 Comparative Genetic Analysis of Homeobox Genes in Mouse and Man.- 1. Introduction.- 2. Murine Homeobox Genes.- 3. Human Homeobox Genes.- 4. Comparative Genetic Relationships between Species.- 5. Comparative Genetic Relationships within Species.- 6. Possible Functional Relationships between Homeobox Loci and Linked Genes.- 7. Discussion.- References.- 7 Eukaryotic Transcriptional Specificity Conferred by DNA-Binding Proteins.- 1. Introduction.- 2. Results and Discussion.- 3. Concluding Remarks.- References.- 8 Chromatin Structure Near an Expressed Gene.- 1. Introduction.- 2. Results.- 3. Discussion.- References.- 9 Specificity of Gene Expression and Insertional Mutagenesis in Transgenic Mice.- 1. Introduction.- 2. Experiments and Results.- References.- 10 Retroviruses as Insertional Mutagens.- 1. Introduction.- 2. Insertion of Moloney Murine Leukemia Viruses into the Germ Line of Mice.- 3. Expression of the Proviral Genome in Mov Substrains ofMice.- 4. Induction of Two Insertional Mutations.- 5. Insertional Mutagenesis by Retroviruses and DNA Injection.- References.- 11 P Transposable Elements and Their Use as Vectors for Gene Transfer in Drosophila.- 1. Introduction.- 2. Results and Discussion.- References.- 12 Mapping and Manipulating Immunoglobulin Functions.- 1. Introduction.- 2. Immunoglobulin Gene and Protein Structure.- 3. Production of Monoclonal Immunoglobulins from Mouse and Man.- 4. Uses of Specific Immunoglobulins.- 5. Optimizing Immunoglobulin Structure for Therapy.- 6. Identifying the Molecular Requirements for Immunoglobulin Synthesis and Function.- 7. Future Studies on the Structural and Regulatory Mutants.- References.- 13 T4: A T-Cell Surface Protein Mediating Cell-Cell and Cell-AIDS Virus Interactions.- 1. Introduction.- 2. Results.- References.- 14 Identifying the Determinants of Protein Function and Stability.- 1. Introduction.- 2. Repressor and Cro Background.- 3. Isolation of Phenotypically Defective Mutants.- 4. Structural Distribution of Mutant Sites.- 5. Why Are Mutant Proteins Nonfunctional?.- 6. Phenotypic Reversion.- 7. Summary.- References.
