Sydor A M, Su A L, Wang F S, Xu A, Jay D G
Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts 02138, USA.
J Cell Biol. 1996 Sep;134(5):1197-207. doi: 10.1083/jcb.134.5.1197.
Filopodial motility is critical for many biological processes, particularly for axon guidance. This motility is based on altering the F-actin-based cytoskeleton, but the mechanisms of how this occurs and the actin-associated proteins that function in this process remain unclear. We investigated two of these proteins found in filopodia, talin and vinculin, by inactivating them in subregions of chick dorsal root ganglia neuronal growth cones and by observing subsequent behavior by video-enhanced microscopy and quantitative morphometry. Microscale chromophore-assisted laser inactivation of talin resulted in the temporary cessation of filopodial extension and retraction. Inactivation of vinculin caused an increased incidence of filopodial bending and buckling within the laser spot but had no effect on extension or retraction. These findings show that talin acts in filopodial motility and may couple both extension and retraction to actin dynamics. They also suggest that vinculin is not required for filopodial extension and retraction but plays a role in the structural integrity of filopodia.
丝状伪足的运动对许多生物学过程至关重要，尤其是对轴突导向而言。这种运动基于改变以F-肌动蛋白为基础的细胞骨架，但这一过程如何发生以及在此过程中发挥作用的肌动蛋白相关蛋白仍不清楚。我们通过在鸡背根神经节神经元生长锥的亚区域使两种在丝状伪足中发现的蛋白——踝蛋白和纽蛋白失活，并通过视频增强显微镜和定量形态学观察后续行为，对它们进行了研究。对踝蛋白进行微尺度发色团辅助激光失活导致丝状伪足伸展和回缩暂时停止。纽蛋白失活导致激光光斑内丝状伪足弯曲和屈曲的发生率增加，但对伸展或回缩没有影响。这些发现表明，踝蛋白在丝状伪足运动中起作用，并且可能将伸展和回缩都与肌动蛋白动力学联系起来。它们还表明，丝状伪足的伸展和回缩不需要纽蛋白，但纽蛋白在丝状伪足的结构完整性中发挥作用。
