Identification of cytoskeletal, focal adhesion, and cell adhesion proteins in growth cone particles isolated from developing chick brain

Abstract

Growth cones are intimately involved in determining the direction and extent of neurite elongation during development. They are able to monitor their environment and respond to it by undergoing directed motility. We have isolated a fraction enriched in growth cone particles from embryonic chick brain. Assayed by immunoblots, this fraction is enriched in GAP-43, and contains the cytoskeletal proteins actin, myosin II, neurofilament protein, tubulin, kinesin, and dynamin. All of the major components of focal adhesions are also present: alpha-actinin, vinculin, talin, and integrin. In addition to integrin, we also identify the cell adhesion molecules A-CAM, L1, fibronectin, and laminin in these particles. This preparation of isolated growth cone particles may be a useful model system for studying growth cone adhesion and motility.

Dynamin as a mover and pincher during cell migration and invasion

“…The number of cytoskeletal and signaling components found at adhesion sites now exceeds 20, and dynamin is a newly confirmed addition to this complex, exhibiting several interactions with focal adhesion components. Recent findings now extend a seminal observation by Cypher and Letourneau (Cypher and Letourneau, 1991), who observed that dynamin is enriched at adhesion sites in growth cones from embryonic chick brain.…”

Integrins in Cell Migration

“…Focal adhesions are elongated in morphology and reside in both central and peripheral regions of the cell, and are generally found at the ends of actin filament bundles. Analogous adhesion structures have been observed in vivo in endothelial cells (Kano et al 1996), skeletal muscle myotendinous junctions (Turner et al 1991), and neuronal growth cones (Cypher and Letourneau 1991), and highly elongated adhesions have also been reported in vivo (Cukierman et al 2001).…”

Oxygen Radicals Elicit Paralysis and Collapse of Spinal Cord Neuron Growth Cones upon Exposure to Proinflammatory Cytokines

“…To examine NOX-dependent ROS production in neuronal growth cones, we utilized freshly isolated growth cone particle preparations (GCPs) obtained from chick E10 forebrain neurons, which are capable of showing complex responses to extrinsic stimuli [37–39]. As shown in Figure 4(a), addition of 100 ng/mL TNF α to laminin-adherent GCPs resulted in MAP kinase and JNK activation, which was corroborated in cultured forebrain neurons.…”