PMID:23921380

Citation	Chacón-Martínez, CA, Kiessling, N, Winterhoff, M, Faix, J, Müller-Reichert, T and Jessberger, R (2013) The Switch-associated Protein 70 (SWAP-70) Bundles Actin Filaments and Contributes to the Regulation of F-actin Dynamics. J. Biol. Chem. 288:28687-28703
Abstract	Coordinated assembly and disassembly of actin into filaments and higher order structures such as stress fibers and lamellipodia are fundamental for cell migration and adhesion. However, the precise spatiotemporal regulation of F-actin structures is not completely understood. SWAP-70, a phosphatidylinositol 3,4,5-trisphosphate-interacting, F-actin-binding protein, participates in actin rearrangements through yet unknown mechanisms. Here, we show that SWAP-70 is an F-actin-bundling protein that oligomerizes through a Gln/Glu-rich stretch within a coiled-coil region. SWAP-70 bundles filaments in parallel and anti-parallel fashion through its C-terminal F-actin binding domain and delays dilution-induced F-actin depolymerization. We further demonstrate that SWAP-70 co-localizes and directly interacts with cofilin, an F-actin severing and depolymerization factor, and contributes to the regulation of cofilin activity in vivo. In line with these activities, upon stem cell factor stimulation, murine bone marrow-derived mast cells lacking SWAP-70 display aberrant regulation of F-actin and actin free barbed ends dynamics. Moreover, proper stem cell factor-dependent cofilin activation via dephosphorylation and subcellular redistribution into a detergent-resistant cytoskeletal compartment also require SWAP-70. Together, these findings reveal an important role of SWAP-70 in the dynamic spatiotemporal regulation of F-actin networks.
Links	PubMed PMC3789966 Online version:10.1074/jbc.M113.461277
Keywords
edit table

Annotations

Gene product	Qualifier	GO Term	Evidence Code	with/from	Aspect	Extension	Notes	Status
MOUSE:SWP70		GO:0030835: negative regulation of actin filament depolymerization	ECO:0000314:		P		1E shows that increased concentrations of SWAP-70 lead to delays in actin depolymerization	complete CACAO 8812
MOUSE:SWP70		GO:0051017: actin filament bundle assembly	ECO:0000314:		P		Fig 3 shows that SWAP-70 bundles actin filaments together in both parallel and anti-parallel manners	complete CACAO 8813
MOUSE:SWP70		GO:0032233: positive regulation of actin filament bundle assembly	ECO:0000315:		P		Figure 5, in vivo analysis displays that SWAP-70 -/- have signifiantly fewer actin filament bundles.	complete CACAO 8814
MOUSE:SWP70		GO:1902309: negative regulation of peptidyl-serine dephosphorylation	ECO:0000315:		P		Figure 8 A-C shows that in SWAP-70 -/- mutants, the protein "cofilin-1" remains phosphorylated for a longer than in the WT.	complete CACAO 8815
MOUSE:SWP70	involved_in	GO:0030835: negative regulation of actin filament depolymerization	ECO:0000314: direct assay evidence used in manual assertion		P		Seeded From UniProt	complete
MOUSE:SWP70	involved_in	GO:0051017: actin filament bundle assembly	ECO:0000314: direct assay evidence used in manual assertion		P		Seeded From UniProt	complete
MOUSE:SWP70	involved_in	GO:0032233: positive regulation of actin filament bundle assembly	ECO:0000315: mutant phenotype evidence used in manual assertion		P		Seeded From UniProt	complete
MOUSE:SWP70	involved_in	GO:1902309: negative regulation of peptidyl-serine dephosphorylation	ECO:0000315: mutant phenotype evidence used in manual assertion		P		Seeded From UniProt	complete
MOUSE:COF1		GO:0030836: positive regulation of actin filament depolymerization	ECO:0000314:		P		Figure 7 B-C show that when exposed to cofilin, the rate of actin filament depolymerization increases.	complete CACAO 8816
MOUSE:COF1	involved_in	GO:0030836: positive regulation of actin filament depolymerization	ECO:0000314: direct assay evidence used in manual assertion		P		Seeded From UniProt	complete

References

See Help:References for how to manage references in GONUTS.