Transforming growth factor-β (TGF-β) is a multifunctional peptide growth factor with a wide range of effects. TGF-β signals are conveyed through cell-surface serine/threonine kinase receptors to the downstream cyto...Transforming growth factor-β (TGF-β) is a multifunctional peptide growth factor with a wide range of effects. TGF-β signals are conveyed through cell-surface serine/threonine kinase receptors to the downstream cytoplasmic mediators, known as Smads proteins. Receptor-regulated Smads become phosphorylated by activated type Ⅰ receptors and form heteromeric complexes with a common Smad-Smad4, which translocates into the nucleus to regulate gene transcription. Inhibitory Smads inhibit the activation of receptor-regulated Smads. There are positive, negative and feedback regulations in the Smads mediated TGF-β signaling pathway.展开更多
采用膜片钳技术对烟草根皮层原生质体质膜上的钾通道进行全细胞记录,从而深入研究烟草K+的吸收机制和调控机理。结果表明,内向钾通道在膜电压低于-40 mV时,可以被K+激活。内向电流可以被钾通道的专一抑制剂TEA+抑制。动力学分析表明内...采用膜片钳技术对烟草根皮层原生质体质膜上的钾通道进行全细胞记录,从而深入研究烟草K+的吸收机制和调控机理。结果表明,内向钾通道在膜电压低于-40 mV时,可以被K+激活。内向电流可以被钾通道的专一抑制剂TEA+抑制。动力学分析表明内向钾电流产生的K+表观解离常数(Km)≈15.2 mm o l/L,类似于低亲和性钾通道。该通道具有依赖于胞外K+浓度的特性,对胞外NH4+、C a2+、M g2+浓度变化反应敏感,内向K+电流可被不同程度地抑制。展开更多
文摘Transforming growth factor-β (TGF-β) is a multifunctional peptide growth factor with a wide range of effects. TGF-β signals are conveyed through cell-surface serine/threonine kinase receptors to the downstream cytoplasmic mediators, known as Smads proteins. Receptor-regulated Smads become phosphorylated by activated type Ⅰ receptors and form heteromeric complexes with a common Smad-Smad4, which translocates into the nucleus to regulate gene transcription. Inhibitory Smads inhibit the activation of receptor-regulated Smads. There are positive, negative and feedback regulations in the Smads mediated TGF-β signaling pathway.
文摘采用膜片钳技术对烟草根皮层原生质体质膜上的钾通道进行全细胞记录,从而深入研究烟草K+的吸收机制和调控机理。结果表明,内向钾通道在膜电压低于-40 mV时,可以被K+激活。内向电流可以被钾通道的专一抑制剂TEA+抑制。动力学分析表明内向钾电流产生的K+表观解离常数(Km)≈15.2 mm o l/L,类似于低亲和性钾通道。该通道具有依赖于胞外K+浓度的特性,对胞外NH4+、C a2+、M g2+浓度变化反应敏感,内向K+电流可被不同程度地抑制。
