RESUMO
In this study we present a detailed, mechanism-based mathematical framework of Drosophila circadian rhythms. This framework facilitates a more systematic approach to understanding circadian rhythms using a comprehensive representation of the network underlying this phenomenon. The possible mechanisms underlying the cytoplasmic "interval timer" created by PERIOD-TIMELESS association are investigated, suggesting a novel positive feedback regulatory structure. Incorporation of this additional feedback into a full circadian model produced results that are consistent with previous experimental observations of wild-type protein profiles and numerous mutant phenotypes.
Assuntos
Relógios Biológicos/fisiologia , Ritmo Circadiano/fisiologia , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/fisiologia , Retroalimentação/fisiologia , Modelos Biológicos , Proteínas Nucleares/metabolismo , Animais , Simulação por Computador , Oscilometria/métodos , Proteínas Circadianas Period , Transdução de Sinais/fisiologia , Fatores de TempoRESUMO
This article reviews the current state of systems biology approaches, including the experimental tools used to generate 'omic' data and computational frameworks to interpret this data. Through illustrative examples, systems biology approaches to understand gene expression and gene expression regulation are discussed. Some of the challenges facing this field and the future opportunities in the systems biology era are highlighted.
Assuntos
Regulação da Expressão Gênica/fisiologia , Biologia de Sistemas/métodos , Animais , Galactose/genética , Galactose/metabolismo , Humanos , Modelos Biológicos , Neoplasias/genética , Neoplasias/metabolismo , SoftwareRESUMO
Multiple sequence alignment separates members of glycoside hydrolase Family 6 into eight subfamilies: one of mainly actinobacterial endoglucanases (EGs), one of ascomycotal EGs, one of chytridiomycotal EGs and cellobiohydrolases (CBHs), one of actinobacterial and proteobacterial CBHs, one of chytridiomycotal CBHs, two of ascomycotal CBHs, and one of basidiomycotal CBHs. Each also has some proteins of unknown function. Multiple sequence alignment also extends to all of Family 6 the observation that lengths of loops that form the active-site tunnel in CBHs vary among subfamilies, and along with loop conformations, determine enzyme function.