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31.
Modulation of the cardiac sodium channel Nav1.5 by fibroblast growth factor homologous factor 1B 总被引:1,自引:0,他引:1
Liu CJ Dib-Hajj SD Renganathan M Cummins TR Waxman SG 《The Journal of biological chemistry》2003,278(2):1029-1036
We have previously shown that fibroblast growth factor homologous factor 1B (FHF1B), a cytosolic member of the fibroblast growth factor family, associates with the sensory neuron-specific channel Na(v)1.9 but not with the other sodium channels present in adult rat dorsal root ganglia neurons. We show in this study that FHF1B binds to the C terminus of the cardiac voltage-gated sodium channel Na(v)1.5 and modulates the properties of the channel. The N-terminal 41 amino acid residues of FHF1B are essential for binding to Na(v)1.5, and the conserved acidic rich domain (amino acids 1773-1832) in the C terminus of Na(v)1.5 is sufficient for association with this factor. Binding of the growth factor to recombinant wild type human Na(v)1.5 in human embryonic kidney 293 cells produces a significant hyperpolarizing shift in the voltage dependence of channel inactivation. An aspartic acid to glycine substitution at position 1790 of the channel, which underlies one of the LQT-3 phenotypes of cardiac arrythmias, abolishes the interaction of the Na(v)1.5 channel with FHF1B. This is the first report showing that interaction with a growth factor can modulate properties of a voltage-gated sodium channel. 相似文献
32.
Dunham RA Chatakondi N Nichols AJ Kucuktas H Chen TT Powers DA Weete JD Cummins K Lovell RT 《Marine biotechnology (New York, N.Y.)》2002,4(6):604-611
The effect of rainbow trout growth hormone complementary DNA on body shape, dress-out yield, and body composition were assessed
in the F1 and F2 generations of transgenic common carp (Cyprinus carpio). All measurements were compared with those for nontransgenic
full-sibling common carp in their respective families, and the fish were communally evaluated in earthen ponds. The body weight
and length were highly correlated (P <0.01) in both genotypes in all the families. Head morphometrics were negatively correlated
(P <0.05) to weight and length of the fish. Various head, body, and caudal traits grew disproportionately faster in transgenic
fish in both generations. The altered body shape of transgenic fish resulted in improved dressing percentage in the F2 generation.
The carcass composition of transgenic muscle had a lower percentage of (P <0.01) moisture and lipids and higher (P <0.01)
percentage of protein in both generations. Six of the 18 amino acids analyzed in F1 transgenic common carp muscle were higher
F1 (P <0.05) than the control genotype; however, amino acid ratios were minimally changed. Also, the fatty acid profiles of
both genotypes were minimally altered. Higher histidine and lysine ratios in the diet are recommended for maximum growth and
health of transgenic common carp in intensive culture systems on the basis of essential amino acid ratios. 相似文献
33.
34.
Karagiannides I Tchkonia T Dobson DE Steppan CM Cummins P Chan G Salvatori K Hadzopoulou-Cladaras M Kirkland JL 《American journal of physiology. Regulatory, integrative and comparative physiology》2001,280(6):R1772-R1780
Fat mass, adipocyte size and metabolic responsiveness, and preadipocyte differentiation decrease between middle and old age. We show that expression of CCAAT/enhancer binding protein (C/EBP)-alpha, a key regulator of adipogenesis and fat cell function, declined substantially with aging in differentiating preadipocytes cultured under identical conditions from rats of various ages. Overexpression of C/EBP alpha in preadipocytes cultured from old rats restored capacity to differentiate into fat cells, indicating that downstream differentiation-dependent genes maintain responsiveness to regulators of adipogenesis. C/EBP alpha-expression also decreased with age in fat tissue from three different depots and in isolated fat cells. The overall level of C/EBP beta, which modulates C/EBP alpha-expression, did not change with age, but the truncated, dominant-negative C/EBP beta-liver inhibitory protein (LIP) isoform increased in cultured preadipocytes and isolated fat cells. Overexpression of C/EBP beta-LIP in preadipocytes from young rats impaired adipogenesis. C/EBP delta, which acts with full-length C/EBP beta to enhance adipogenesis, decreased with age. Thus processes intrinsic to adipose cells involving changes in C/EBP family members contribute to impaired adipogenesis and altered fat tissue function with aging. These effects are potentially reversible. 相似文献
35.
Plasma membrane-spanning G-protein-linked receptors transduce approximately 60% of all extracellular stimuli in higher animals. Many G-protein-linked receptor pathways are yet to be elucidated, with the receptor, G-protein or effector system as yet unidentified. In addition, many fundamental issues pertaining to G-protein signalling remain unresolved, such as the factors governing the specificity of G-protein receptor coupling and the control of signal amplitude in response to G-protein activation. In order to address some of these issues, the use of replication-deficient adenoviruses as gene transfer vectors for investigations of G-protein signalling has been developed, facilitating dissection of G-protein-linked signal transduction pathways in an extensive range of cultured cells, as well as in vivo. The present review focuses on the versatility and utility of adenoviruses for the investigation of signalling by heterotrimeric G-proteins and explores some of the recent advances in adenoviral technology as they relate to the study of signal transduction. 相似文献
36.
Glutathione-mediated detoxification systems in plants 总被引:17,自引:0,他引:17
Recent work has highlighted the presence of diverse glutathione-dependent enzymes in plants with potential roles in the detoxification of both xenobiotic and endogenous compounds. In particular, studies on glutathione transferases are further characterising their role in xenobiotic metabolism, and also raising intriguing possible roles in endogenous metabolism. The solution of their three-dimensional structures together with studies on their molecular diversity and substrate specificity is providing new insights into the function and classification of these enigmatic enzymes. 相似文献
37.
Concerns over water quality in Ireland have increased in recent years, in part due to the more frequent contamination of drinking water by pathogens such as Escherichia coli and Cryptosporidium. The objective of this study was to assess the use of SWAT for pathogen source estimation and to analyze the effects of various source scenarios on pathogen outputs in Irish catchments. Two agricultural catchments in Ireland susceptible to pathogen contamination of source water were the center of the SWAT model development with the primary focus on levels of E. coli in surface water. Model simulations used site and source specific information which was analyzed considering the total E. coli count for the simulation period (Fergus: January 2005–October 2006; Kilshanvey: January 2006–July 2007). Pathogen source estimation identified point sources as the most significant contributors to E. coli output with direct deposition the primary contributor (95%) in Kilshanvey and wastewater treatment plant outflow (89%) the main contributor in the Fergus catchment. A scenario analysis evaluated possible situations that may occur in study locations. The analysis indicated that restriction of livestock access to water sources and improved wastewater treatment would represent effective methods of improving water quality in both catchments. 相似文献
38.
Carmen Martínez José A Molina Hortensia Alonso-Navarro Félix J Jiménez-Jiménez José AG Agúndez Elena García-Martín 《BMC neurology》2010,10(1):71
Background
Human serum paraoxonase 1 (PON1) plays a major role in the metabolism of several organophosphorus compounds. The enzyme is encoded by the polymorphic gene PON1, located on chromosome 7q21.3. Aiming to identify genetic variations related to the risk of developing brain tumors, we investigated the putative association between common nonsynonymous PON1 polymorphisms and the risk of developing astrocytoma and meningioma. 相似文献39.
Quantitative autoradiographic techniques demonstrate that chronic alcohol administration causes a decrease in [3H]-glutamate binding to hippocampal N-methyl-D-aspartate (NMDA) receptors. A 14% decrease in [3H]-glutamate binding in the hippocampal CA1 region is seen both in the rat after five days of ethanol administration and in postmortem hippocampal tissues from alcoholics. In the rat, 24 hr ethanol withdrawal values are intermediate between control and alcohol binding levels. There was no significant effect of ethanol on [3H]-glutamate binding in the cortex or caudate. 相似文献
40.