RESUMO
AIMS: Statins - inhibitors of the 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase - are known to reduce blood cholesterol levels. In this paper, we present a Saccharomyces cerevisiae expression system, which enables quick evaluation of the sensitivity of the wild-type and/or mutant forms of human HMG-CoA reductase towards statins or other drugs. METHODS AND RESULTS: We analysed the sequence of the HMG-CoA reductase gene in DNA extracted from blood samples of 16 patients with cardiovascular disorders. We applied the yeast system to examine the sensitivity of the wild-type and mutated versions of the hHMG-CoA reductase to different types of statins. CONCLUSION: The yeast and mammalian HMG-CoA reductases demonstrate structural and functional conservation, and expression of human HMG-CoA reductase in yeast complements the lethal phenotype of strains lacking the HMG1 and HMG2 genes. SIGNIFICANCE AND IMPACT OF THE STUDY: These data indicate that a yeast expression system can serve to study the influence of selected mutations in human HMG-CoA reductase on the sensitivity of the enzyme to commonly prescribed statins. Our results suggest that this model system is suitable for the development and selection of lipid-lowering drugs as well as for the examination of DNA sequence variations in the context of statin therapy.
Assuntos
Doenças Cardiovasculares/tratamento farmacológico , Hidroximetilglutaril-CoA Redutases/genética , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Saccharomyces cerevisiae/enzimologia , Primers do DNA/genética , Éxons , Proteína HMGB1/genética , Proteína HMGB2/genética , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Mutagênese Sítio-Dirigida , Reação em Cadeia da Polimerase , Saccharomyces cerevisiae/efeitos dos fármacosRESUMO
The amount of tryptophanase was estimated in Escherichia coli deltadnaJ and deltadnaKdnaJ mutants. Densitometric analysis of polyacrylamide gels demonstrated that the amount of tryptophanase was diminished in both mutants. DnaK and DnaJ molecular chaperones apparently influence the amount of tryptophanase, the expression of which is regulated at all transcription steps, including transcription elongation. The half-life of GreA and GreB proteins (being activators of transcription elongation of the tna operon) are diminished in both mutants suggesting the involvement of DnaK and DnaJ in the stability of these proteins.
Assuntos
Proteínas de Escherichia coli/metabolismo , Escherichia coli/metabolismo , Proteínas de Choque Térmico HSP70/metabolismo , Proteínas de Choque Térmico/metabolismo , Fatores de Transcrição/metabolismo , Triptofanase/metabolismo , Escherichia coli/genética , Proteínas de Escherichia coli/genética , Expressão Gênica , Genes Bacterianos , Proteínas de Choque Térmico HSP40 , Proteínas de Choque Térmico HSP70/genética , Meia-Vida , Proteínas de Choque Térmico/genética , Mutação , Fatores de Elongação da Transcrição , Triptofanase/genéticaRESUMO
1. The American workplace is experiencing rapid change in the 1990s. Throughout the past 100 years, occupational health nursing has evolved to meet the demands of the workplace. 2. Nursing practices at some worksites are not keeping up with rapid changes impacting business and workers today. 3. A different model of occupational health nursing practice is needed to meet current and future health requirements within organizations. 4. Occupational health nurses need to identify the most critical health issues impacting their organizations and to implement a model of occupational health nursing practice designed specifically to meet those essential organizational needs.
