Cordon-bleu is an actin nucleation factor and controls neuronal morphology (Cell, 2007, 131:337-350)

報告日期: 2008/11/28
報告時間: 17:10/18:00
報告學生: 王仁伶
講評老師: 許桂森

Cordon-Bleu Is an Actin Nucleation Factor and Controls Neuronal Morphology


Cell (2007) 131: 337–350


Speaker: Jen-Ling Wang (王仁伶)

Commentator: Dr. Kuei-Sen Hsu (許桂森老師)

Date: 11/ 28/ 08 17:10-18:00

Place: Room 602


The organization and polymerization of actin cytoskeleton play important roles in neuronal networks. The rate-limiting step of actin filament formation is actin nucleation. Many studies have shown that Arp2/3 complex and formins are actin nucleators and create different filament networks via distinct mechanisms. However, our understanding of actin rearrangements in neuronal morphology is still incomplete. The authors discovered that cordon-bleu (Cobl) is a novel actin nucleator which has three copies of a well-established actin-binding domain, Wiskott-Aldrich syndrome protein homology 2 (WH2) motifs in C terminus (CT). Cobl promotes the formation of unbranched filaments. In vitro cosedimentation and pyrene-actin polymerization assays showed that Cobl promotes polymerization by nucleating actin filaments with barbed end in a mechanism distinct from that of the Arp2/3 complex. Cobl is a brain-enriched protein and localizes along neurites and accumulates in F-actin-rich growth cones. In cultured hippocampal neurons, overexpression of Cobl-CT increased the number of axonal and dendritic branches; whereas RNAi-mediated Cobl knockdown decreased the number of branch points and the extent of neurites. Taken together, Cobl is an actin nucleator to drive neuronal morphogenesis and development.