scholarly journals Rap1 controls cell adhesion and cell motility through the regulation of myosin II

2007 ◽  
Vol 176 (7) ◽  
pp. 1021-1033 ◽  
Author(s):  
Taeck J. Jeon ◽  
Dai-Jen Lee ◽  
Sylvain Merlot ◽  
Gerald Weeks ◽  
Richard A. Firtel
Keyword(s):  
Cell Adhesion ◽  
Cell Motility ◽  
Myosin Ii ◽  
Leading Edge ◽  
In Vitro Assay ◽  
Filamentous Actin ◽  
Guanosine Triphosphate ◽  
Vitro Assay

We have investigated the role of Rap1 in controlling chemotaxis and cell adhesion in Dictyostelium discoideum. Rap1 is activated rapidly in response to chemoattractant stimulation, and activated Rap1 is preferentially found at the leading edge of chemotaxing cells. Cells expressing constitutively active Rap1 are highly adhesive and exhibit strong chemotaxis defects, which are partially caused by an inability to spatially and temporally regulate myosin assembly and disassembly. We demonstrate that the kinase Phg2, a putative Rap1 effector, colocalizes with Rap1–guanosine triphosphate at the leading edge and is required in an in vitro assay for myosin II phosphorylation, which disassembles myosin II and facilitates filamentous actin–mediated leading edge protrusion. We suggest that Rap1/Phg2 plays a role in controlling leading edge myosin II disassembly while passively allowing myosin II assembly along the lateral sides and posterior of the cell.

The role of serum in the in vitro assay of lymphocyte-mediated cytolysis

1976 ◽  
Vol 21 (2) ◽  
pp. 350-357
Author(s):  
Paul Vadnais ◽  
Peter Cresswell ◽  
D.Bernard Amos
Keyword(s):  
In Vitro Assay ◽  
Vitro Assay

Aromatase (CYP19) inhibition by biflavonoids obtained from the branches of Garcinia gardneriana (Clusiaceae)

2019 ◽  
Vol 74 (9-10) ◽  
pp. 279-282 ◽  
Author(s):  
Angelica Maria Recalde-Gil ◽  
Luiz Klein-Júnior ◽  
Juliana Salton ◽  
Sérgio Bordignon ◽  
Valdir Cechinel-Filho ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Aromatase Inhibitors ◽  
Anticancer Agents ◽  
Breast Cancer Cells ◽  
In Vitro Assay ◽  
Aromatase Activity ◽  
Vitro Assay

Abstract Overexpression of aromatase in breast cancer cells may substantially influence its progression and maintenance. In this sense, the inhibition of aromatase is a key target for the treatment of breast cancer in postmenopausal women. Although several flavonoids had already demonstrated the capacity of inhibiting aromatase activity, the role of biflavonoids as aromatase inhibitors is poorly studied. In this work, the biflavonoids isolated from Garcinia gardneriana, morelloflavone (1), Gb-2a (2) and Gb-2a-7-O-glucose (3) were submitted to in vitro assay to evaluate the aromatase modulatory effect. As results, it was demonstrated that all biflavonoids were able to inhibit the enzyme, with IC50 values ranging from 1.35 to 7.67 μM. This demonstrates that biflavonoids are an important source of scaffolds for the development of new aromatase inhibitors, focusing on the development of new anticancer agents.

scholarly journals The role of mRNA competition in regulating translation. II. Development of a quantitative in vitro assay.

1981 ◽  
Vol 256 (22) ◽  
pp. 11747-11754
Author(s):  
T. Brendler ◽  
T. Godefroy-Colburn ◽  
R.D. Carlill ◽  
R.E. Thach
Keyword(s):  
In Vitro Assay ◽  
Vitro Assay

scholarly journals Cell adhesion molecules: detection with univalent second antibody.

1980 ◽  
Vol 87 (3) ◽  
pp. 703-707 ◽  
Author(s):  
W R Springer ◽  
S H Barondes
Keyword(s):  
Cell Adhesion ◽  
Adhesion Molecules ◽  
Cell Adhesion Molecules ◽  
In Vitro Assay ◽  
Cell Surface Molecules ◽  
Rabbit Antibody ◽  
Vitro Assay ◽  
Surface Molecules ◽  
Cell Cell

Identification of cell surface molecules that play a role in cell-cell adhesion (here called cell adhesion molecules) has been achieved by demonstrating the inhibitory effect of univalent antibodies that bind these molecules in an in vitro assay of cell-cell adhesion. A more convenient reagent, intact (divalent) antibody, has been avoided because it might agglutinate the cells rather than blocking cell-cell adhesion. In this report, we show that intact rabbit immunoglobulin directed against certain cell surface molecules of Dictyostelium discoideum blocks cell-cell adhesion when the in vitro assay is performed in the presence of univalent goat anti-rabbit antibody. Under appropriate experimental conditions, the univalent second antibody blocks agglutination induced by the rabbit antibody without significantly interfering with its effect on cell-cell adhesion. This method promises to be useful for screening monoclonal antibodies raised against potential cell adhesion molecules because: (a) it allows for the screening of large numbers of antibody samples without preparation of univalent fragments; and (b) it requires much less antibody because of the greater affinity of divalent antibodies for antigens.

A new in vitro assay for cell motility and proliferation

1987 ◽  
Vol 20 (1) ◽  
pp. 109-119
Author(s):  
H. B. Benestad ◽  
H. J. K. Saxholm ◽  
E. M. Siebke
Keyword(s):  
Cell Motility ◽  
In Vitro Assay ◽  
Vitro Assay

In Vitro Assay of Platelet Adhesiveness with Washed and Tanned Human Red Cells

1968 ◽  
Vol 20 (03/04) ◽  
pp. 384-396 ◽  
Author(s):  
G Zbinden ◽  
S Tomlin
Keyword(s):  
Platelet Adhesion ◽  
Sodium Citrate ◽  
Blood Platelets ◽  
In Vitro Assay ◽  
Red Cells ◽  
Platelet Adhesiveness ◽  
Vitro Assay ◽  
In Vitro System ◽  
Human Red Cells

SummaryAn in vitro system is described in which adhesion of blood platelets to washed and tannic acid-treated red cells was assayed quantitatively by microscopic observation. ADP, epinephrine and TAME produced a reversible increase in platelet adhesiveness which was antagonized by AMP. With Evans blue, polyanetholsulfonate, phthalanilide NSC 38280, thrombin and heparin at concentrations above 1-4 u/ml the increase was irreversible. The ADP-induced increase in adhesiveness was inhibited by sodium citrate, EDTA, AMP, ATP and N-ethylmaleimide. EDTA, AMP and the SH-blocker N-ethylmaleimide also reduced spontaneous platelet adhesion to red cells. No significant effects were observed with adenosine, phenprocoumon, 5-HT, phthalanilide NSC 57155, various estrogens, progestogens and fatty acids, acetylsalicylic acid and similarly acting agents, hydroxylamine, glucose and KCN. The method may be useful for the screening of thrombogenic and antithrombotic properties of drugs.

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