title: The Arp2/3 complex is required for lamellipodia extension and directional fibroblast cell migration.
abstract: The Arp2/3 complex nucleates the formation of the dendritic actin network at the leading edge of motile cells, but it is still unclear if the Arp2/3 complex plays a critical role in lamellipodia protrusion and cell motility. Here, we differentiated motile fibroblast cells from isogenic mouse embryonic stem cells with or without disruption of the ARPC3 gene, which encodes the p21 subunit of the Arp2/3 complex. ARPC3(-/-) fibroblasts were unable to extend lamellipodia but generated dynamic leading edges composed primarily of filopodia-like protrusions, with formin proteins (mDia1 and mDia2) concentrated near their tips. The speed of cell migration, as well as the rates of leading edge protrusion and retraction, were comparable between genotypes; however, ARPC3(-/-) cells exhibited a strong defect in persistent directional migration. This deficiency correlated with a lack of coordination of the protrusive activities at the leading edge of ARPC3(-/-) fibroblasts. These results provide insights into the Arp2/3 complex's critical role in lamellipodia extension and directional fibroblast migration.
authors.affiliation: Stowers Institute for Medical Research, Kansas City, MO 64110, USA.
authors.forename: Praveen
authors.initials: P
authors.lastname: Suraneni
authors.forename: Boris
authors.initials: B
authors.lastname: Rubinstein
authors.forename: Jay R
authors.initials: JR
authors.lastname: Unruh
authors.forename: Michael
authors.initials: M
authors.lastname: Durnin
authors.forename: Dorit
authors.initials: D
authors.lastname: Hanein
authors.forename: Rong
authors.initials: R
authors.lastname: Li
mesh_terms: D051376:Actin-Related Protein 2-3 Complex / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D002454:Cell Differentiation; D002465:Cell Movement; D002478:Cells, Cultured; D053595:Embryonic Stem Cells / Q000378:metabolism / Q000502:physiology; D005260:Female; D005347:Fibroblasts / Q000502:physiology* / Q000648:ultrastructure; D055786:Gene Knockout Techniques; D005838:Genotype; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D011554:Pseudopodia / Q000502:physiology*; D014945:Wound Healing / Q000235:genetics / Q000502:physiology
chemical_list: D051376:Actin-Related Protein 2-3 Complex; C513333:Arpc3 protein, mouse