title: β-Actin specifically controls cell growth, migration, and the G-actin pool.
abstract: Ubiquitously expressed β-actin and γ-actin isoforms play critical roles in most cellular processes; however, their unique contributions are not well understood. We generated whole-body β-actin-knockout (Actb(-/-)) mice and demonstrated that β-actin is required for early embryonic development. Lethality of Actb(-/-) embryos correlated with severe growth impairment and migration defects in β-actin-knockout primary mouse embryonic fibroblasts (MEFs) that were not observed in γ-actin-null MEFs. Migration defects were associated with reduced membrane protrusion dynamics and increased focal adhesions. We also identified migration defects upon conditional ablation of β-actin in highly motile T cells. Of great interest, ablation of β-actin altered the ratio of globular actin (G-actin) to filamentous actin in MEFs, with corresponding changes in expression of genes that regulate the cell cycle and motility. These data support an essential role for β-actin in regulating cell migration and gene expression through control of the cellular G-actin pool.
authors: Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA.
authors: Tina M
authors: TM
authors: Bunnell
authors: Brandon J
authors: BJ
authors: Burbach
authors: Yoji
authors: Y
authors: Shimizu
authors: James M
authors: JM
authors: Ervasti
mesh_terms: D000199:Actins / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D001921:Brain / Q000378:metabolism; D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism / Q000502:physiology; D002465:Cell Movement; D049109:Cell Proliferation; D002478:Cells, Cultured; D005260:Female; D005347:Fibroblasts; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D055786:Gene Knockout Techniques; D006579:Heterozygote; D053208:Kaplan-Meier Estimate; D007668:Kidney / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008168:Lung / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009928:Organ Specificity; D061251:Primary Cell Culture
chemical_list: D000199:Actins