Sialylation of vitronectin regulates stress fiber formation and cell spreading of dermal fibroblasts via a heparin-binding site

2016 ◽  
Vol 33 (2) ◽  
pp. 227-236 ◽  
Author(s):  
Yasunori Miyamoto ◽  
Mio Tanabe ◽  
Kimie Date ◽  
Kanoko Sakuda ◽  
Kotone Sano ◽  
...  
Keyword(s):  
Binding Site ◽  
Cell Spreading ◽  
Stress Fiber ◽  
Dermal Fibroblasts ◽  
Fiber Formation ◽  
Heparin Binding ◽  
Stress Fiber Formation ◽  
Heparin Binding Site

Regulation of the RhoA pathway in human endothelial cell spreading on type IV collagen: role of calcium influx

1999 ◽  
Vol 112 (19) ◽  
pp. 3205-3213 ◽  
Author(s):  
L. Masiero ◽  
K.A. Lapidos ◽  
I. Ambudkar ◽  
E.C. Kohn
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Focal Adhesion ◽  
Type Iv Collagen ◽  
Cell Spreading ◽  
Stress Fiber ◽  
Fiber Formation ◽  
Stress Fibers ◽  
Type Iv ◽  
Stress Fiber Formation

We have shown that nonvoltage-operated Ca(2+) entry regulates human umbilical vein endothelial cell adhesion, migration, and proliferation on type IV collagen. We now demonstrate a requirement for Ca(2+) influx for activation of the RhoA pathway during endothelial cell spreading on type IV collagen. Reorganization of actin into stress fibers was complete when the cells where fully spread at 90 minutes. No actin organization into stress fibers was seen in endothelial cells plated on type I collagen, indicating a permissive effect of type IV collagen. CAI, a blocker of nonvoltage-operated Ca(2+) channels, prevented development of stress fiber formation in endothelial cells on type IV collagen. This permissive effect was augmented by Ca(2+) influx, as stimulated by 0. 5 microM thapsigargin or 0.1 microM ionomycin, yielding faster development of actin stress fibers. Ca(2+) influx and actin rearrangement in response to thapsigargin and ionomycin were abrogated by CAI. Activated, membrane-bound RhoA is a substrate for C3 exoenzyme which ADP-ribosylates and inactivates RhoA, preventing actin stress fiber formation. Pretreatment of endothelial cells with C3 exoenzyme prevented basal and thapsigargin-augmented stress fiber formation. While regulation of Ca(2+) influx did not alter RhoA translocation, it reduced in vitro ADP-ribosylation of RhoA (P(2)<0. 05), suggesting Ca(2+) influx is needed for RhoA activation during spreading on type IV collagen; no Ca(2+) regulated change in RhoA was seen in HUVECs spreading on type I collagen matrix. Blockade of Ca(2+) influx of HUVEC spread on type IV collagen also reduced tyrosine phosphorylation of p190Rho-GAP and blocked thapsigargin-enhanced binding of p190Rho-GAP to focal adhesion kinase. Thus, Ca(2+) influx is necessary for RhoA activation and for linkage of the RhoA/stress fiber cascade to the focal adhesion/focal adhesion kinase pathway during human umbilical vein endothelial cell spreading on type IV collagen.

Calponin 3 regulates stress fiber formation in dermal fibroblasts during wound healing

2013 ◽  
Vol 305 (7) ◽  
pp. 571-584 ◽  
Author(s):  
Etsuko Daimon ◽  
Yukinao Shibukawa ◽  
Yoshinao Wada
Keyword(s):  
Wound Healing ◽  
Stress Fiber ◽  
Dermal Fibroblasts ◽  
Fiber Formation ◽  
Stress Fiber Formation

scholarly journals ARHGAP18, a GTPase-activating protein for RhoA, controls cell shape, spreading, and motility

2011 ◽  
Vol 22 (20) ◽  
pp. 3840-3852 ◽  
Author(s):  
Masao Maeda ◽  
Hitoki Hasegawa ◽  
Toshinori Hyodo ◽  
Satoko Ito ◽  
Eri Asano ◽  
...  
Keyword(s):  
Rho Gtpases ◽  
Cell Shape ◽  
Cell Spreading ◽  
Bound State ◽  
Stress Fiber ◽  
Fiber Formation ◽  
Stress Fiber Formation ◽  
Rna Transfection ◽  
And Migration

Rho GTPases are molecular switches that transmit biochemical signals in response to extracellular stimuli to elicit changes in the actin cytoskeleton. Rho GTPases cycle between an active, GTP-bound state and an inactive, GDP-bound state. These states are regulated by two distinct families of proteins—guanine nucleotide exchange factors and GTPase-activating proteins (GAPs). We studied the role of a previously uncharacterized GAP, ARHGAP18 (MacGAP). Overexpression of ARHGAP18 suppressed the activity of RhoA and disrupted stress fiber formation. Conversely, silencing of ARHGAP18 by small interfering RNA transfection–enhanced stress fiber formation and induced rounding of cells. We examined the role of ARHGAP18 in cell spreading and migration. Immunofluorescence analysis revealed that ARHGAP18 was localized to the leading edge during cell spreading and migration. ARHGAP18-knockdown cells showed impaired spreading, premature formation of stress fibers, and sustained activation of RhoA upon cell attachment. In addition, knockdown and overexpression of ARHGAP18 resulted in the inhibition and promotion of cell migration, respectively. Furthermore, ARHGAP18 was required for the polarization of cells for migration. Our results define ARHGAP18 as one of the crucial factors for the regulation of RhoA for the control of cell shape, spreading, and migration.

scholarly journals Opposing FlnA and FlnB interactions regulate RhoA activation in guiding dynamic actin stress fiber formation and cell spreading

2017 ◽  
Vol 26 (7) ◽  
pp. 1294-1304 ◽  
Author(s):  
Jianjun Hu ◽  
Jie Lu ◽  
Akshay Goyal ◽  
Timothy Wong ◽  
Gewei Lian ◽  
...  
Keyword(s):  
Cell Spreading ◽  
Stress Fiber ◽  
Fiber Formation ◽  
Actin Stress Fiber ◽  
Rhoa Activation ◽  
Stress Fiber Formation ◽  
Actin Stress Fiber Formation

Antithrombin-mediated Inhibition of Factor Vlla-Tissue Factor Complex by the Synthetic Pentasaccharide Representing the Heparin Binding Site to Antithrombin

1996 ◽  
Vol 76 (01) ◽  
pp. 005-008 ◽  
Author(s):  
Jean Claude Lormeau ◽  
Jean Pascal Herault ◽  
Jean Marc Herbert
Keyword(s):  
Binding Site ◽  
Tissue Factor ◽  
Residual Activity ◽  
Coagulation Factors ◽  
Heparin Binding ◽  
Experimental Conditions ◽  
First Order ◽  
Heparin Binding Site ◽  
Coagulant Activity

SummaryWe examined the effect of the synthetic pentasaccharide representing the minimal binding site of heparin to antithrombin on the antithrombin-mediated inactivation of factor Vila bound to tissue factor. This effect was compared to the effect of unfractionated heparin. Using purified recombinant human coagulation factors and either a clotting or an amidolytic assay for the determination of the residual activity of factor Vila, we showed that the pentasaccharide was an efficient antithrombin-dependent inhibitor of the coagulant activity of tissue factor-factor Vila complex. In our experimental conditions, assuming a mean MW of 14,000 for heparin, the molar pseudo-first order rate constants for ATIII-mediated FVIIa inhibition by ATIII-binding heparin and by the synthetic pentasaccharide were found to be similar with respective values of 104,000 ± 10,500 min-1 and 112,000 ± 12,000 min-1 (mean ± s.e.m., n = 3)

scholarly journals Localization of the major heparin-binding site in fibronectin.

1991 ◽  
Vol 266 (12) ◽  
pp. 7812-7818 ◽  
Author(s):  
F J Barkalow ◽  
J E Schwarzbauer
Keyword(s):  
Binding Site ◽  
Heparin Binding ◽  
Heparin Binding Site

Regulation of Osteoblast-Like Cell Behaviors on Hydroxyapatite by Electrical Polarization

2007 ◽  
Vol 361-363 ◽  
pp. 1055-1058 ◽  
Author(s):  
Miho Nakamura ◽  
Akiko Nagai ◽  
Natalie Ohashi ◽  
Yumi Tanaka ◽  
Yasutaka Sekijima ◽  
...  
Keyword(s):  
Cell Movement ◽  
Stress Fiber ◽  
Fiber Formation ◽  
Wound Healing Assay ◽  
Cell Behaviors ◽  
Stress Fiber Formation ◽  
Cytoskeleton Reorganization ◽  
Osteoblast Adhesion ◽  
As Stress

The osteoblast adhesion to the substrates are recognized to play a fundamental role in osteoconduction process. The purpose of this study was to evaluate the in vitro behavior of osteoblasts cultured on polarized hydroxyapatite (HA), having the enhanced osteobonding abilities. Osteoblast-like cells were seeded onto the polarized HA and investigated the adhesion and motility. The polarization had no effects on the percentage of the number of the spreaded cells against all the adhered cells, but had significant effects on the elongation of adhered cells from fluorescent observation and on the cell motility showed by the wound healing assay. The charges induced on the HA surface accelerated the cytoskeleton reorganization of the adhered cells cultured on HA specimens. The acceleration was emerged as the cells shape, actin filament pattern such as stress fiber formation, and the prolongation of the cell movement distances.

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