(2) MF-binding proteins End-blocking (ca Monomer. ong sequestering Monomers filaments Depolymerizing Membrane-binding Filament-severing
(2) MF-binding proteins
成核蛋白( nucleating proteins): actin- related proteins,ARPs 单体-隔离蛋白( monomer-sequestering protein): thymosin 封端(加帽)蛋白(End- blocking( capping) proteins):capZ 单体-聚合蛋白( monomer-polymerizing proteins):抑制蛋白 ( profilin)是一种与ATP肌动蛋白单体结合的蛋白质 肌动蛋白纤维解聚蛋白( actin filament-depolymerizing proteins): cofilin、ADF以及蚕食蛋白与肌动蛋白纤维的减端结合,大大促进肌动 蛋白纤维解聚成单体。 交联蛋白( cross-linking proteins):ABP280和细丝蛋白,促进形成近 于正交相互联系的纤维松散网络 纤维切割蛋自( filament-severing proteins): gelsolin 膜结合蛋白( membrane- binding proteins):连接膜与肌动蛋白的蛋 白质包括联结蛋白( vinculin),ERM家族的成员包括埃兹蛋白 ( ezrin)、根蛋白( radixin)和膜突蛋白( moesin)
成核蛋白（nucleating proteins）: actin-related proteins, ARPs 单体–隔离蛋白（monomer-sequestering protein）: thymosin 封端（加帽）蛋白（End-blocking(capping) proteins）:capZ 单体–聚合蛋白（monomer-polymerizing proteins）:抑制蛋白 （profilin）是一种与ATP-肌动蛋白单体结合的蛋白质 肌动蛋白纤维解聚蛋白（actin filament-depolymerizing proteins）: cofilin、ADF以及蚕食蛋白与肌动蛋白纤维的减端结合，大大促进肌动 蛋白纤维解聚成单体。 交联蛋白（cross-linking proteins）: ABP280和细丝蛋白,促进形成近 于正交相互联系的纤维松散网络 纤维–切割蛋白（filament-severing proteins）: gelsolin 膜结合蛋白（membrane-binding proteins）:连接膜与肌动蛋白的蛋 白质包括联结蛋白（vinculin），ERM家族的成员包括埃兹蛋白 （ezrin）、根蛋白（radixin）和膜突蛋白（moesin）
w Unactivated Profilin ATP-G-actin Bl Actated ATP ADP Proine-rich ADP Ml Exchange ATP-G-actin ADP-G-actin ATP Model of the complementary roles of profilin and thymosin B4 in regulating polymerization of G-actin
Model of the complementary roles of profilin and thymosin β4 in regulating polymerization of G-actin
4 Actin filaments are likewise strongly affected by the binding of accessory proteins along their sides. >Actin filaments in most cells are sta bilized by the binding of tropomyosin, an elongated protein. which can prevent the filament from interacting with other proteins. > Another important actin filament binding protein, cofilin, present in all eucaryotic cells, which destabilized actin filaments(also called actin depolymerizing factor). Cofilin binds along the length of the actin filament, forcing the filament to twist a little more tightly. In addition, cofilin binding cause a large increase in the rate of actin filament treadmilling
❖Actin filaments are likewise strongly affected by the binding of accessory proteins along their sides. ➢Actin filaments in most cells are stabilized by the binding of tropomyosin, an elongated protein. Which can prevent the filament from interacting with other proteins. ➢Another important actin filament binding protein, cofilin, present in all eucaryotic cells, which destabilized actin filaments(also called actin depolymerizing factor). ▪Cofilin binds along the length of the actin filament, forcing the filament to twist a little more tightly. ▪In addition, cofilin binding cause a large increase in the rate of actin filament treadmilling
The modular structures of four actin-cross-linking proteins spectrin (tetramer) 00 (monomer) or-actinin Dimer) 峡峡以峡峡 filamin (dimer) The formation of two types of actin filament bundles. >Contractile bundle mediated by a-actinin parallel bundle mediated contractile bundle parallel bundle by fimbrin loose packing allows myosin-lI ight packing prevents myosin. to enter bundle rom entering bundle
The modular structures of four actin-cross-linking proteins The formation of two types of actin filament bundles: ➢Contractile bundle mediated by α-actinin ➢parallel bundle mediated by fimbrin