In our previous reports, wehave verified the involvement of G protein, Ca2+ channel in plasma memband CDPK in extracellular calmodulin(CaM) signal transduction chain for theinitiatory effects of extracellular CaM onpo...In our previous reports, wehave verified the involvement of G protein, Ca2+ channel in plasma memband CDPK in extracellular calmodulin(CaM) signal transduction chain for theinitiatory effects of extracellular CaM onpollen germination and pollen tubegrowth . In this paper, both normal andexogenous CaM-enhanced pollen germination and tube growth were completelyinhibited by the phospholipase C inhibitor U-73122 (Fig. 1 ). The enhancement of pollen germination and tubegrowth by the G protein agonist choleratoxin were also completely inhibited byU-73122 (Fig. 2), whereas the inhibition of pollen germination and tubegrowth by the G protein antagonist pertussis toxin was reversed by IP3 (Fig. 2).Heparin, an antagonist Of IP3 receptor,inhibited pollen germination and tubegrowth (Fig. 3 ), while thapsigargin increased cytosolic Ca2+ by inhibiting theIP3-specific Ca2+ pump in endoplasmicreticulum, and thereby increased pollengermination and tube growth (Fig. 4).The above results suggest that phosphoinositide signaling pathway might be involved in the extracellular CaM signaltransduction chain in the initiatory effectsof extracellular CaM on pollen germination and tube growth.展开更多
G蛋白信号途径是真菌细胞信号转导网络的枢纽,在细胞的各种生物学调控过程中具有重要作用。G蛋白信号调控蛋白(Rgulators of G protein signaling,RGS)是一类重要的G蛋白信号调控因子,能通过促进G蛋白α亚基(Gα)偶联的GTP水解,使Gα和...G蛋白信号途径是真菌细胞信号转导网络的枢纽,在细胞的各种生物学调控过程中具有重要作用。G蛋白信号调控蛋白(Rgulators of G protein signaling,RGS)是一类重要的G蛋白信号调控因子,能通过促进G蛋白α亚基(Gα)偶联的GTP水解,使Gα和Gβγ亚基发生聚合,导致G蛋白失活,从而迅速关闭与G蛋白偶联的信号途径。自从第一个RGS蛋白在酿酒酵母中被鉴定以来,目前已经有30多个RGS蛋白在重要的模式真菌中被报道,包括构巢曲霉、绿僵菌、稻瘟病菌、玉米赤霉菌、轮枝镰孢菌、新型隐球菌和白色念珠菌等。RGS蛋白在真菌的营养菌丝生长、产孢、毒素和色素生产、致病性和有性生殖等过程中发挥着重要作用。本文对真菌中已报道RGS蛋白的功能进行了总结,对真菌RGS蛋白的结构特征和调控机制进行了评述。展开更多
文摘In our previous reports, wehave verified the involvement of G protein, Ca2+ channel in plasma memband CDPK in extracellular calmodulin(CaM) signal transduction chain for theinitiatory effects of extracellular CaM onpollen germination and pollen tubegrowth . In this paper, both normal andexogenous CaM-enhanced pollen germination and tube growth were completelyinhibited by the phospholipase C inhibitor U-73122 (Fig. 1 ). The enhancement of pollen germination and tubegrowth by the G protein agonist choleratoxin were also completely inhibited byU-73122 (Fig. 2), whereas the inhibition of pollen germination and tubegrowth by the G protein antagonist pertussis toxin was reversed by IP3 (Fig. 2).Heparin, an antagonist Of IP3 receptor,inhibited pollen germination and tubegrowth (Fig. 3 ), while thapsigargin increased cytosolic Ca2+ by inhibiting theIP3-specific Ca2+ pump in endoplasmicreticulum, and thereby increased pollengermination and tube growth (Fig. 4).The above results suggest that phosphoinositide signaling pathway might be involved in the extracellular CaM signaltransduction chain in the initiatory effectsof extracellular CaM on pollen germination and tube growth.
文摘G蛋白信号途径是真菌细胞信号转导网络的枢纽,在细胞的各种生物学调控过程中具有重要作用。G蛋白信号调控蛋白(Rgulators of G protein signaling,RGS)是一类重要的G蛋白信号调控因子,能通过促进G蛋白α亚基(Gα)偶联的GTP水解,使Gα和Gβγ亚基发生聚合,导致G蛋白失活,从而迅速关闭与G蛋白偶联的信号途径。自从第一个RGS蛋白在酿酒酵母中被鉴定以来,目前已经有30多个RGS蛋白在重要的模式真菌中被报道,包括构巢曲霉、绿僵菌、稻瘟病菌、玉米赤霉菌、轮枝镰孢菌、新型隐球菌和白色念珠菌等。RGS蛋白在真菌的营养菌丝生长、产孢、毒素和色素生产、致病性和有性生殖等过程中发挥着重要作用。本文对真菌中已报道RGS蛋白的功能进行了总结,对真菌RGS蛋白的结构特征和调控机制进行了评述。
