Phosphorylation of actopaxin regulates cell spreading and migration

Clarke, Dominic M.; Brown, Michael C.; LaLonde, David P.; Turner, Christopher E.

doi:10.1083/jcb.200404024

Cited by 50 publications

(56 citation statements)

References 64 publications

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“…3A). Notable phosphorylation sites known to be involved in cell movement and enriched in the PD include ERK, ␣-parvin, and cortactin (SI Table 3) (24)(25)(26). These findings are consistent with a significant body of evidence showing that phosphorylation is a critical component that regulates cytoskeletal and focal adhesion-signaling dynamics during PD formation (3,17).…”

Section: Functional Comparison Of Phosphoproteins In the Cb And Pdsupporting

confidence: 76%

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Profiling signaling polarity in chemotactic cells

Wang

Ding

Wang

et al. 2007

Proc. Natl. Acad. Sci. U.S.A.

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Cell movement requires morphological polarization characterized by formation of a leading pseudopodium (PD) at the front and a trailing rear at the back. However, little is known about how protein networks are spatially integrated to regulate this process at the system level. Here, we apply global proteome profiling in combination with newly developed quantitative phosphoproteomics approaches for comparative analysis of the cell body (CB) and PD proteome of chemotactic cells. The spatial relationship of 3,509 proteins and 228 distinct sites of phosphorylation were mapped revealing networks of signaling proteins that partition to the PD and/or the CB compartments. The major network represented in the PD includes integrin signaling, actin regulatory, and axon guidance proteins, whereas the CB consists of DNA/RNA metabolism, cell cycle regulation, and structural maintenance. Our findings provide insight into the spatial organization of signaling networks that control cell movement and provide a comprehensive system-wide profile of proteins and phosphorylation sites that control cell polarization.bioinformatics ͉ chemotaxis ͉ phosphoproteomics ͉ proteomics ͉ cell migration D irected cell migration or chemotaxis in response to a chemokine gradient is involved in development, immune function, angiogenesis, as well as pathological processes associated with inflammation and cancer cell metastasis (1). Cell locomotion is a highly polarized process characterized by protrusion of a leading pseudopodium (PD) (lamellipodium) at the front and establishment of a trailing rear compartment or tail region at the back (1, 2). This process is regulated through organization of the actin-myosin cytoskeleton in response to signal transduction processes that operate downstream of chemokine and integrin adhesion receptors. These receptors serve as antennae to sense changes in chemokine and extracellular matrix gradients, which provide navigational cues to direct cell movement. However, the molecular signaling mechanisms that control cell polarity and chemotaxis are not fully understood.Emerging evidence indicates that cell behavior is regulated by the complex organization of multiple signaling networks in time and space. The specific propagation of biological information in a complex biological system is achieved through the spatiotemporal assembly of multiprotein scaffolds, protein activation cascades, protein turnover, and specific posttranslational modifications of proteins, including the phosphorylation and dephosphorylation of specific amino acid residues. Although significant progress has been made in identification of specific signaling proteins and regulatory pathways that mediate cell migration, little is known about how these signals are integrated into spatial networks to achieve morphological polarity and directional movement at a system level.To understand the complexity of signal organization in migrating cells, our laboratory developed a system that facilitates the differential purification of the PD and cell body (CB) co...

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Section: Functional Comparison Of Phosphoproteins In the Cb And Pdsupporting

confidence: 76%

“…The signaling network revealed eight known ERK substrates that are enriched in PD, including ␣-parvin, myosin light chain kinase, and cortactin (18,26,33) (Fig. 4C).…”

Section: Characterization Of the Ras/erk-signaling Pathway In The Pd Bymentioning

confidence: 99%

Profiling signaling polarity in chemotactic cells

Wang

Ding

Wang

et al. 2007

Proc. Natl. Acad. Sci. U.S.A.

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“…3,4 There have been many studies of the role of individual adhesion proteins in the rounding up of mitotic cells. 5 These studies show that various phosphorylation events of cytoskeletal 6 and focal adhesion proteins [7][8][9][10][11][12] contribute to the premitotic disassembly of focal adhesions, 13 the deconstruction of the actin cytoskeleton of the interphase, 14 and the construction of a new mitotic cytoskeleton. 15 However, despite this dissociation and deconstruction, the mitotic cell remains attached to the substrate.…”

Section: Introductionmentioning

confidence: 99%

Measuring cell adhesion forces during the cell cycle by force spectroscopy

Weder¹,

Vörös²,

Giazzon³

et al. 2009

Biointerphases

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Force spectroscopy has been used to measure the adhesion of Saos-2 cells to a glass surface at different phases of the cell cycle. The cells were synchronized in three phases of the cell cycle: G 1 , S, and G 2 M. Cells in these phases were compared with unsynchronized and native mitotic cells. Individual cells were attached to an atomic force microscope cantilever, brought into brief contact with the glass surface, and then pulled off again. The force-distance curves obtained allowed the work and maximum force of detachment as well as the number, amplitude, and position of discrete unbinding steps to be determined. A statistical analysis of the data showed that the number of binding proteins or protein complexes present at the cell surface and their binding properties remain similar throughout the cell cycle. This, despite the huge changes in cell morphology and adhesion that occur as the cells enter mitosis. These changes are rather associated with the changes in cytoskeletal organization, which can be quantified by force spectroscopy as changes in cell stiffness.

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“…Cell Culture and Transfection-U2OS osteosarcoma cells expressing Xpress-tagged wild-type (WT), nonphosphorylatable (S (4,8,14,19)G/T16A) mutant referred to herein as the Quint mutant and phosphomimetic S4D/S8D actopaxin were previously described (7). U2OS (ATCC) and MDA-MB-231 (ATCC) cells were cultured in DMEM with 10% FBS, 1 mM glutamine, 50 units/ml penicillin and 50 g/ml streptomycin.…”

Section: Methodsmentioning

confidence: 99%

“…phosphorylation regulates cell migration in part through the regulation of Rac1 activity (7). Additionally, actopaxin binds CdGAP, a negative regulator of Rac1/Cdc42 activity, and this interaction with actopaxin contributes to CdGAP recruitment to focal adhesions to negatively regulate cell spreading and adhesion turnover (13).…”

mentioning

confidence: 99%