摘要:

It is increasingly apparent that the genetic influence on the development and severity of a particular phenotype (e.g. diabetes, hyperlipidemia, hypertension, and coronary heart disease) can be strongly modulated by diet. In turn, the response of the phenotype to dietary intervention is determined by the individual genotype. The reviews in this issue provide striking examples of recent progress related to the molecular basis of nutrient-gene interactions. As our understanding of these interactions improves, we should be better equipped to identify individuals at risk of specific pathologies and make a better assessment of the risk involved. Nutritional support could then be tailored to the individual genotype to favour beneficial phenotypic expression or to suppress that leading to pathology and disease.

ISSN:1363-1950    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

The present review addresses recent advances in research into a family of bifunctional enzymes that are responsible for the twofold task of synthesizing and hydrolyzing fructose-2,6-bisphosphate (Fru-2,6-P2), which in turn regulates the rate of glycolysis in most cells. The structure of the synthetic kinase, conjoined at its carboxyl-terminus to the phosphatase, is very highly conserved throughout evolution and differentiation, with isotypic expression arising from highly variable amino-terminal and carboxyl-terminal regulatory domains. These domains, which frequently contain protein-kinase-catalyzed phosphorylation motifs, are responsible for the widely divergent kinetics observed in various tissues and species, and for the hormonal modulation that alters intracellular levels of Fru-2,6-P2. The present review discusses recent advances in relating structure to function, and the identification of new pathways of transcriptional regulation of this important family of regulatory enzymes.

ISSN:1363-1950    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Branched-chain α-keto acid dehydrogenase kinase is responsible for the inactivation and phosphorylation of the branched-chain α-keto acid dehydrogenase complex, the enzyme that catalyses the committed step of branched-chain amino acid catabolism. The activity of the branched-chain α-keto acid dehydrogenase complex is inversely correlated with kinase activity, suggesting that the relative activity of the kinase is the primary regulator of the activity of the complex. It has been shown that kinase activity and expression are affected by nutritional states imposed by low-protein diet feeding, starvation, diabetes, and exercise. Evidence has also been presented that certain hormones, particularly insulin, glucocorticoid, thyroid hormone and female sex hormones, affect the activity and expression of the kinase. The findings indicate that nutritional and hormonal control of the activity and expression of branched-chain α-keto acid dehydrogenase kinase provides an important means of control of the activity of the branched-chain α-keto acid dehydrogenase complex, with inactivation serving to conserve branched-chain amino acids for protein synthesis in some situations and activation serving to provide carbon for gluconeogenesis in others.

ISSN:1363-1950    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

There is growing recognition that amino acid availability has profound effects on many aspects of cell function, including the control of membrane transport mechanisms, cell signalling, and gene expression. The precise mechanisms by which amino acids are able to elicit control over such diverse processes have become the focus of intense investigation recently. One particular area that has seen considerable advances is the molecular characterization of amino acid transporters, including members of the System A family, which are known to be regulated by amino acid supply. Recent developments concerning how cells sense and signal amino acid availability, and how this process influences the expression and function of amino acid transporters, are reviewed here. Elucidating the molecular mechanisms of these events will be important in clarifying how amino acid transporters might be regulated during altered nutritional states, and will be crucial for the design of new strategies aimed at improving nutritional support.

ISSN:1363-1950    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Over the past 10 years it has become evident that fatty acids regulate cellular functions by modulating gene expression. Fatty acids and fatty acid metabolites exert some of their effects on gene expression by affecting the activity of nuclear transcription factors, peroxisome proliferator-activated receptors and sterol regulatory element binding protein type 1. The present review describes the latest developments in the field, with particular emphasis on the physiological roles of the various peroxisome proliferator-activated receptor isotypes, including their implication in the control of proliferation and differentiation of normal and malignant cells, and on the mechanisms implicated in the regulation of sterol regulatory element binding protein type 1 activity by polyunsaturated fatty acids.

ISSN:1363-1950    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

In mammals, the impact of nutrients on gene expression has become an important area of research. Because amino acids have multiple and important functions, their homeostasis has to be finely maintained. However, amino acidaemia can be affected by certain nutritional conditions or various forms of aggression. It follows that mammals have to adjust several of their physiological functions involved in the adaptation to amino acid availability by regulating the expression of numerous genes. It has been shown that amino acids by themselves can modify the expression of target genes. However, the current understanding of amino acid-dependent control of gene expression has just started to emerge. This review focuses on the recent advances on mechanisms involved in the amino acids control of gene expression. Several examples discussed in this paper demonstrate that amino acids regulate gene expression at the level of transcription, messenger RNA stability and translation.

ISSN:1363-1950    

出版商:OVID    

年代:2001

数据来源: OVID

ISSN:1363-1950    

出版商:OVID    

年代:2001

数据来源: OVID