scholarly journals The fibronectin-binding integrins α5β1 and αvβ3 differentially modulate RhoA–GTP loading, organization of cell matrix adhesions, and fibronectin fibrillogenesis

2002 ◽  
Vol 159 (6) ◽  
pp. 1071-1086 ◽  
Author(s):  
Erik H.J. Danen ◽  
Petra Sonneveld ◽  
Cord Brakebusch ◽  
Reinhard Fässler ◽  
Arnoud Sonnenberg
Keyword(s):  
Cell Spreading ◽  
Rapid Decrease ◽  
Cell Binding ◽  
Peripheral Cell ◽  
Rhoa Activity ◽  
Cell Matrix ◽  
Focal Contacts ◽  
Different Types ◽  
A Cell ◽  
Cell Binding Domain

We have studied the formation of different types of cell matrix adhesions in cells that bind to fibronectin via either α5β1 or αvβ3. In both cases, cell adhesion to fibronectin leads to a rapid decrease in RhoA activity. However, α5β1 but not αvβ3 supports high levels of RhoA activity at later stages of cell spreading, which are associated with a translocation of focal contacts to peripheral cell protrusions, recruitment of tensin into fibrillar adhesions, and fibronectin fibrillogenesis. Expression of an activated mutant of RhoA stimulates αvβ3-mediated fibrillogenesis. Despite the fact that α5β1-mediated adhesion to the central cell-binding domain of fibronectin supports activation of RhoA, other regions of fibronectin are required for the development of α5β1-mediated but not αvβ3-mediated focal contacts. Using chimeras of β1 and β3 subunits, we find that the extracellular domain of β1 controls RhoA activity. By expressing both β1 and β3 at high levels, we show that β1-mediated control of the levels of β3 is important for the distribution of focal contacts. Our findings demonstrate that the pattern of fibronectin receptors expressed on a cell dictates the ability of fibronectin to stimulate RhoA-mediated organization of cell matrix adhesions.

scholarly journals Mapping of a cell-binding domain in the cell adhesion molecule gp80 of Dictyostelium discoideum.

1988 ◽  
Vol 107 (5) ◽  
pp. 1835-1843 ◽  
Author(s):  
R K Kamboj ◽  
L M Wong ◽  
T Y Lam ◽  
C H Siu
Keyword(s):  
Cell Adhesion ◽  
Dictyostelium Discoideum ◽  
Fusion Proteins ◽  
Binding Activity ◽  
Binding Domain ◽  
Globular Domain ◽  
Cell Binding ◽  
Homophilic Interaction ◽  
A Cell ◽  
Cell Binding Domain

At the aggregation stage of Dictyostelium discoideum development, a cell surface glycoprotein of Mr 80,000 (gp80) has been found to mediate the EDTA-resistant type of cell-cell adhesion via homophilic interaction (Siu, C.-H., A. Cho, and A. H. C. Choi. 1987. J. Cell Biol. 105:2523-2533). To investigate the structure-function relationships of gp80, we have isolated full length cDNA clones for gp80 and determined the DNA sequence. The deduced structure of gp80 showed three major domains. An amino-terminal globular domain composed of the bulk of the protein is supported by a short stalk region, which is followed by a membrane anchor at the carboxy terminus. Structural analysis suggested that the cell-binding domain of gp80 resides within the globular domain near the amino terminus. To investigate the relationship of the cell-binding activity to this region of the polypeptide, three protein A/gp80 (PA80) gene fusions were constructed using the expression vector pRIT2T. These PA80 fusion proteins were assayed for their ability to bind to aggregation stage cells. Binding of 125I-labeled fusion proteins PA80I (containing the Val123 to Ile514 fragment of gp80) and PA80II (Val123 to Ala258) was dosage dependent and could be inhibited by precoating cells with the cell cohesion-blocking mAb 80L5C4. On the other hand, there was no appreciable binding of PA80III (Ile174 to Ile514) to cells. Reassociation of cells was significantly inhibited in the presence of PA80I or PA80II. In addition, 125I-labeled PA80II exhibited homophilic interaction with immobilized PA80I, PA80II, or gp80. The results of these studies lead to the mapping of a cell-binding domain in the region between Val123 and Leu173 of gp80 and provide direct evidence that the cell-binding activity of gp80 resides in the protein moiety.

C-terminal heparin-binding domain of fibronectin regulates integrin-mediated cell spreading but not the activation of mitogen-activated protein kinase

2001 ◽  
Vol 360 (1) ◽  
pp. 239-245 ◽  
Author(s):  
Jungyean KIM ◽  
Innoc HAN ◽  
Yeonhee KIM ◽  
Seungin KIM ◽  
Eok-Soo OH
Keyword(s):  
Cell Spreading ◽  
Binding Domain ◽  
Mitogen Activated Protein Kinase ◽  
Heparin Binding ◽  
Cell Binding ◽  
Rat Embryo ◽  
Mapk Activation ◽  
Mitogen Activated Protein ◽  
Heparin Binding Domain ◽  
Cell Binding Domain

Fibronectin (FN) stimulates multiple signalling events including mitogen-activated protein kinase (MAPK) activation. During cell spreading, both the cell-binding domain and the C-terminal heparin-binding domain (HepII) of FN co-operatively regulate cytoskeleton organization. However, in comparison with the large number of studies on the functions of cell-binding domain, there is little information about the role of HepII. We therefore investigated the effect of HepII on integrin-mediated cell spreading and adhesion on FN and MAPK activation. In contrast with cells on FN substrates, rat embryo fibroblasts on FN120, which lacks HepII, were less spread, had weaker adhesion to FN and failed to form focal adhesions and actin stress fibres. Phosphotyrosine was present in the focal contacts of rat embryo fibroblasts on FN within 30min but was absent from cells on FN120. Overall, tyrosine phosphorylation was much less in cell lysates from cells on FN120, with decreased phosphorylation of focal adhesion kinase (‘pp125FAK’) on tyrosine-397, implying additional regulation of tyrosine phosphorylation by HepII. Nevertheless, adhesion-mediated MAPK activity was similar in cells on FN and on FN120. Furthermore, cells spread on FN and on FN120 substrates showed similar MAPK activation in response to treatment with epidermal growth factor and with platelet-derived growth factor. Consistently, overexpression of syndecan-4, which binds to HepII, enhanced cell spreading and adhesion on FN but did not affect integrin-mediated MAPK activation. We therefore conclude that both HepII and syndecan-4 regulate integrin-mediated cell spreading but not MAPK activation.

scholarly journals Bacteriophage Tuc2009 Encodes a Tail-Associated Cell Wall-Degrading Activity

2004 ◽  
Vol 186 (11) ◽  
pp. 3480-3491 ◽  
Author(s):  
John G. Kenny ◽  
Stephen McGrath ◽  
Gerald F. Fitzgerald ◽  
Douwe van Sinderen
Keyword(s):  
Cell Wall ◽  
Comparative Sequence Analysis ◽  
Coding Region ◽  
Cell Binding ◽  
Binding Studies ◽  
Dna Injection ◽  
A Cell ◽  
Host Lysis ◽  
Tail Tip ◽  
Cell Binding Domain

ABSTRACT Tuc2009 is a P335-type member of the tailed-phage supergroup Siphoviridae and was originally identified as a resident prophage of the gram-positive bacterium Lactococcus lactis UC509. A Tuc2009 gene designated tal2009 which is located within the morphogenic module was shown to specify a lytic activity within the 3′ portion of its coding region. Comparative sequence analysis indicated that the cell wall-degrading part of Tal2009 is a member of the M37 protein family and that Tal2009 lacks a cell-binding domain, a finding supported by binding studies. Tal2009 appears to undergo self-mediated posttranslational processing in both L. lactis and Escherichia coli. Antibodies directed against a purified C-terminal portion of Tal2009 were used for immunoelectron microscopy, which showed that Tal2009 is located at the tail tip of Tuc2009. Antibody neutralization studies demonstrated that Tal2009-directed antibodies inhibited the ability of phage to mediate host lysis by more than 100-fold. These data indicate that tal2009 encodes a tail-associated lysin involved in localized cell wall degradation, thus allowing the Tuc2009 DNA injection machinery access to the membrane of its bacterial host.

scholarly journals Monoclonal antibody characterization of two distant sites required for function of the central cell-binding domain of fibronectin in cell adhesion, cell migration, and matrix assembly.

1991 ◽  
Vol 114 (6) ◽  
pp. 1295-1305 ◽  
Author(s):  
T Nagai ◽  
N Yamakawa ◽  
S Aota ◽  
S S Yamada ◽  
S K Akiyama ◽  
...  
Keyword(s):  
Cell Spreading ◽  
Binding Domain ◽  
Central Cell ◽  
Site Directed Mutagenesis ◽  
Cell Binding ◽  
Matrix Assembly ◽  
Fibronectin Receptor ◽  
Molar Basis ◽  
Rgd Site ◽  
Cell Binding Domain

Site-directed mutagenesis studies have suggested that additional peptide information in the central cell-binding domain of fibronectin besides the minimal Arg-Gly-Asp (RGD) sequence is required for its full adhesive activity. The nature of this second, synergistic site was analyzed further by protein chemical and immunological approaches using biological assays for adhesion, migration, and matrix assembly. Fragments derived from the cell-binding domain were coupled covalently to plates, and their specific molar activities in mediating BHK cell spreading were compared with that of intact fibronectin. A 37-kD fragment purified from chymotryptic digests of human plasma fibronectin had essentially the same specific molar activity as intact fibronectin. In contrast, other fragments such as an 11.5-kD fragment lacking NH2-terminal sequences of the 37-kD fragment had only poor spreading activity on a molar basis. Furthermore, in competitive inhibition assays of fibronectin-mediated cell spreading, the 37-kD fragment was approximately 325-fold more active than the GRGDS synthetic peptide on a molar basis. mAbs were produced using the 37-kD protein as an immunogen and their epitopes were characterized. Two separate mAbs, one binding close to the RGD site and the other to a site approximately 15 kD distant from the RGD site, individually inhibited BHK cell spreading on fibronectin by greater than 90%. In contrast, an antibody that bound between these two sites had minimal inhibitory activity. The antibodies found to be inhibitory in cell spreading assays for BHK cells also inhibited both fibronectin-mediated cell spreading and migration of human HT-1080 cells, functions which were also dependent on function of the alpha 5 beta 1 integrin (fibronectin receptor). Assembly of endogenously synthesized fibronectin into an extracellular matrix was not significantly inhibited by most of the anti-37-kD mAbs, but was strongly inhibited only by the antibodies binding close to the RGD site or the putative synergy site. These results indicate that a second site distant from the RGD site on fibronectin is crucial for its full biological activity in diverse functions dependent on the alpha 5 beta 1 fibronectin receptor. This site is mapped by mAbs closer to the RGD site than previously expected.

scholarly journals A Cell Binding Domain from the α3 Chain of Type IV Collagen Inhibits Proliferation of Melanoma Cells

1997 ◽  
Vol 272 (33) ◽  
pp. 20395-20401 ◽  
Author(s):  
Jing Han ◽  
Nobuko Ohno ◽  
Sylvie Pasco ◽  
Jean-Claude Monboisse ◽  
Jacques P. Borel ◽  
...  
Keyword(s):  
Type Iv Collagen ◽  
Melanoma Cells ◽  
Binding Domain ◽  
Cell Binding ◽  
Type Iv ◽  
A Cell ◽  
Cell Binding Domain

scholarly journals Thrombospondin modulates alpha v beta 3 function through integrin-associated protein.

1996 ◽  
Vol 135 (2) ◽  
pp. 533-544 ◽  
Author(s):  
A G Gao ◽  
F P Lindberg ◽  
J M Dimitry ◽  
E J Brown ◽  
W A Frazier
Keyword(s):  
Tyrosine Kinases ◽  
Kinase Inhibitors ◽  
Cell Binding ◽  
Mutant Peptide ◽  
Gi Protein ◽  
A Cell ◽  
Carboxyl Terminal ◽  
Alpha V Beta 3 ◽  
Cell Binding Domain ◽  
Common Cell

Integrin-associated protein (IAP) is a receptor for the carboxyl-terminal "cell-binding domain" (CBD) of thrombospondin 1 (TS1). IAP associates with alpha v beta 3 integrin and mAbs against IAP inhibit certain integrin functions. Here we examine the effects of the TS1 CBD and 4N1K (KRFYVVMWKK), a cell-binding peptide derived from it, on the adhesion and spreading on vitronectin (VN) of C32 human melanoma cells which express IAP, alpha v beta 3, and alpha v beta 5. Cells adhere to VN at low surface densities via alpha v beta 5 and spread very slowly while adhesion to higher density VN involves both alpha v beta 5 and alpha v beta 3 and results in rapid spreading. Spreading of the cells, but not adhesion, on sparse VN coatings is markedly enhanced by the presence of soluble TS1, the recombinant CBD and 4N1K, but not the "mutant" peptide 4NGG, KRFYGGMWKK, which fails to bind IAP. This enhanced spreading is completely blocked by mAb LM609 against alpha v beta 3 and the anti-IAP mAb B6H12. Correlated with this enhanced spreading is increased tyrosine phosphorylation of focal adhesion kinase (FAK), paxillin, and a protein of ca. 90 kD. The enhanced spreading induced by TS1 and 4N1K and the constitutive spreading on higher density VN are both blocked by calphostin C (100 nM), wortmannin (10 nM), and tyrosine kinase inhibitors. In contrast, pertussis toxin specifically blocks only the TS1 stimulated spreading on low density VN, indicating that IAP exerts its effects on signal transduction via a heterotrimeric Gi protein acting upstream of a common cell spreading pathway which includes PI-3 kinase, PKC, and tyrosine kinases.

scholarly journals Fibronectin/integrin interaction induces tyrosine phosphorylation of a 120-kDa protein.

1991 ◽  
Vol 2 (11) ◽  
pp. 951-964 ◽  
Author(s):  
J L Guan ◽  
J E Trevithick ◽  
R O Hynes
Keyword(s):  
Tyrosine Phosphorylation ◽  
Concanavalin A ◽  
Cell Spreading ◽  
Binding Domain ◽  
Heparin Binding ◽  
Cell Binding ◽  
Heparin Binding Domain ◽  
Coated Surfaces ◽  
Cell Binding Domain ◽  
In Cells

We describe a 120-kDa protein (pp120) that is phosphorylated on tyrosine in cells attached to fibronectin-coated surfaces. The protein appears to be located in focal contacts where it codistributes with beta 1 integrins. pp120 is distinct from the beta 1 subunit of integrins and from vinculin and alpha-actinin. pp120 is rapidly dephosphorylated in cells suspended by trypsinization but becomes rapidly phosphorylated in cells attaching and spreading on fibronectin. Attachment of cells to RGD-containing peptides, polylysine, or concanavalin A is not sufficient to induce phosphorylation of pp120. The 120-kDa cell-binding domain of fibronectin can induce some phosphorylation of pp120, but further phosphorylation occurs in the presence also of the heparin-binding domain of fibronectin. Phosphorylation of pp120 precedes, but is correlated with, subsequent cell spreading. Phosphorylation of pp120 can also be triggered by attachment of cells to anti-integrin antibodies, and this requires the cytoplasmic domain of the integrin beta 1 subunit. Thus interaction of beta 1 integrins with extracellular ligands (fibronectin or antibodies) triggers phosphorylation of an intracellular 120-kDa protein, pp120, that may be involved in the responses of cells to attachment.

Digital Technologies – Innovative Solutions for Agriculture

2020 ◽  
Vol 67 (1) ◽  
pp. 127-132
Author(s):  
Marina A. Nikitina ◽  
Dmitriy N. Osyanin ◽  
Irina V. Petrunina
Keyword(s):  
Farm Animals ◽  
High Tech ◽  
Mathematical Apparatus ◽  
Online Mode ◽  
Cell Matrix ◽  
Algorithmic Support ◽  
Quality Product ◽  
A Cell ◽  
Parametric Description ◽  
Animal Feeding

High-tech decision support systems based on the knowledge of experts in the field of animal feeding and a rigorous mathematical apparatus make it possible to increase the productivity of the animals and provide a high-quality product with the ability to trace the trophological chain from the field to the counter. (Research purpose) To identify methodological approaches for the development of algorithmic support and software for assessment and optimizing the animals diet. (Materials and Methods) The authors complied a structural-parametric model of a productive animal feeding in a cell matrix form. They represented the whole variety of existing known and unknown relationships between the factors of the farm animal state and the feeding ration characteristics. It was found that when forming a feeding ration, it was necessary to assess the degree of influence on productivity of not individual indicators, but its combination. (Results and discussion) The authors considered parametric descriptions of farm animals; diet with selected groups of indicators, characteristics and properties. It was stated that the parametric description of feeding contained a set of parameters taking into account at least 25 nutritional indicators. They presented a mathematical apparatus for evaluating and optimizing the feeding ration. It was determined that the automation of the process of calculating the daily ration of an animal allowed to change the diets depending on the availability of feed in the farm and their chemical composition in real time. The authors found out that an increase in the productivity of animals and poultry by 30-50 percent was possible due to balanced full-fledged feeding. (Conclusions) The authors showed a systematic approach to the development of software for evaluating and optimizing the animal feeding diet. It was revealed that a computer system in the online mode would help to find the best option for a feeding ration, taking into account multifactor and limitations.

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