Sem­i­nal stud­ies in the Car­lier lab showed that pathogen-like propul­sion could be repro­duced in vitro with an appro­pri­ate cock­tail con­tain­ing actin, the Arp2/3 com­plex, N-WASP (or equiv­a­lent nucle­ator of Arp2/3), a cap­ping pro­tein and a sev­er­ing pro­tein (Loisel et al., 1999). Bac­ulovirus bears at one end a sur­face recep­tor (p78/83) that acti­vates the Arp2/3 com­plex and when the de-enveloped virus is incu­bated with a “motil­ity cock­tail” it induces actin comet tail for­ma­tion at one end.

Comet tail induced by bac­ulovirus in vitro and visu­al­ized in a con­ven­tional EM after neg­a­tive stain­ing.

Cryo-electron tomo­gram of actin comet formed in vitro in a mix­ture of bac­ulovirus and the motil­ity cock­tail. Movie shows a scan in Z through the tomo­gram fol­lowed by a model of the fil­a­ments tracked in green and branch junc­tions in red.

Related pub­li­ca­tions

  • Loisel TP, Bou­je­maa R, Pan­taloni D, Car­lier MF (1999) Recon­sti­tu­tion of actin-based motil­ity of Lis­te­ria and Shigella using pure pro­teins. Nature 401: 613616. NCBI PubMed