A NovelDictyostelium discoideumGene Required for cAMP-Dependent Cell Aggregation

AbstractLI-cadherin is a member of cadherin superfamily which is a Ca2+-dependent cell adhesion protein. Its expression is observed on various types of cells in the human body such as normal small intestine and colon cells, and gastric cancer cells. Because its expression is not observed on normal gastric cells, LI-cadherin is a promising target for gastric cancer imaging. However, since the cell adhesion mechanism of LI-cadherin has remained unknown, rational design of therapeutic molecules targeting this cadherin has been complicated. Here, we have studied the homodimerization mechanism of LI-cadherin. We report the crystal structure of the LI-cadherin EC1-4 homodimer. The EC1-4 homodimer exhibited a unique architecture different from that of other cadherins reported so far. The crystal structure also revealed that LI-cadherin possesses a noncanonical calcium ion-free linker between EC2 and EC3. Various biochemical techniques and molecular dynamics (MD) simulations were employed to elucidate the mechanism of homodimerization. We also showed that the formation of the homodimer observed by the crystal structure is necessary for LI-cadherin-dependent cell adhesion by performing cell aggregation assay.

Download Full-text

Release of an invasion promoter E-cadherin fragment by matrilysin and stromelysin-1

Journal of Cell Science ◽

10.1242/jcs.114.1.111 ◽

2001 ◽

Vol 114 (1) ◽

pp. 111-118 ◽

Cited By ~ 5

Author(s):

V. Noe ◽

B. Fingleton ◽

K. Jacobs ◽

H.C. Crawford ◽

S. Vermeulen ◽

...

Keyword(s):

Cell Adhesion ◽

Cell Surface ◽

Collagen Type ◽

Cell Aggregation ◽

Collagen Type I ◽

Type I ◽

Tissue Inhibitor Of Metalloproteinases ◽

Dependent Cell ◽

Mcf 7 ◽

E Cadherin

The function of many transmembrane molecules can be altered by cleavage and subsequent release of their ectodomains. We have investigated ectodomain cleavage of the cell-cell adhesion and signal-transducing molecule E-cadherin. The E-cadherin ectodomain is constitutively shed from the surface of MCF-7 and MDCKts.srcC12 cells in culture. Release of the 80 kDa soluble E-cadherin fragment is stimulated by phorbol-12-myristate-13-acetate and is inhibited by overexpression of the tissue inhibitor of metalloproteinases-2. The metalloproteinases matrilysin and stromelysin-1 both cleave E-cadherin at the cell surface and release sE-CAD into the medium. The soluble E-cadherin fragment thus released inhibits E-cadherin functions in a paracrine way, as indicated by induction of invasion into collagen type I and inhibition of E-cadherin-dependent cell aggregation. Our results, therefore, suggest a novel mechanism by which metalloproteinases can influence invasion.

Download Full-text

Loss of E-cadherin-dependent cell-cell adhesion due to mutation of the beta-catenin gene in a human cancer cell line, HSC-39.

Molecular and Cellular Biology ◽

10.1128/mcb.15.3.1175 ◽

1995 ◽

Vol 15 (3) ◽

pp. 1175-1181 ◽

Cited By ~ 154

Author(s):

J Kawanishi ◽

J Kato ◽

K Sasaki ◽

S Fujii ◽

N Watanabe ◽

...

Keyword(s):

Cell Adhesion ◽

Cell Line ◽

Cancer Cell ◽

Cancer Cell Line ◽

Cell Aggregation ◽

Expression Vectors ◽

Beta Catenin ◽

Dependent Cell ◽

E Cadherin ◽

Cell Cell

Detachment of cell-cell adhesion is indispensable for the first step of invasion and metastasis of cancer. This mechanism is frequently associated with the impairment of either E-cadherin expression or function. However, mechanisms of such abnormalities have not been fully elucidated. In this study, we demonstrated that the function of E-cadherin was completely abolished in the human gastric cancer cell line HSC-39, despite the high expression of E-cadherin, because of mutations in one of the E-cadherin-associated cytoplasmic proteins, beta-catenin. Although immunofluorescence staining of HSC-39 cells by using an anti-E-cadherin antibody (HECD-1) revealed the strong and uniform expression of E-cadherin on the cell surface, cell compaction and cell aggregation were not observed in this cell. Western blotting (immunoblotting) using HECD-1 exhibited a 120-kDa band which is equivalent to normal E-cadherin. Northern (RNA) blotting demonstrated a 4.7-kb band, the same as mature E-cadherin mRNA. Immunoprecipitation of metabolically labeled proteins with HECD-1 revealed three bands corresponding to E-cadherin, alpha-catenin, and gamma-catenin and a 79-kDa band which was apparently smaller than that of normal beta-catenin, indicating truncated beta-catenin. The 79-kDa band was immunologically identified as beta-catenin by using immunoblotting with anti-beta-catenin antibodies. Examination of beta-catenin mRNA by the reverse transcriptase-PCR method revealed a transcript which was shorter than that of normal beta-catenin. The sequencing of PCR product for beta-catenin confirmed deletion in 321 bases from nucleotides +82 to +402. Southern blotting of beta-catenin DNA disclosed mutation at the genomic level. Expression vectors of Beta-catenin were introduced into HSC-39 cells by transfection. In the obtained transfectants, E-cadherin-dependent cell-cell adhesiveness was recovered, as revealed by cell compaction, cell aggregation, and immunoflourescence staining. From these results, it was concluded that in HSC-39 cells, impaired cell-cell adhesion is due to mutations in beta-catenin which results in the dysfunction of E-cadherin.

Download Full-text

Cadherin-dependent cell aggregation is affected by decapeptide derived from rat extracellular super-oxide dismutase

FEBS Letters ◽

10.1016/0014-5793(95)00334-6 ◽

1995 ◽

Vol 363 (3) ◽

pp. 289-292 ◽

Cited By ~ 25

Author(s):

Jean Willems ◽

Erik Bruyneel ◽

Veerle Noë ◽

Herman Slegers ◽

An Zwijsen ◽

...

Keyword(s):

Cell Aggregation ◽

Super Oxide Dismutase ◽

Dependent Cell

Download Full-text

Cell aggregation and apoptosis induced by hemodialysis membranes.

Journal of the American Society of Nephrology ◽

10.1681/asn.v661586 ◽

1995 ◽

Vol 6 (6) ◽

pp. 1586-1591

Author(s):

J Carracedo ◽

R Ramirez ◽

O Pintado ◽

J C Gomez-Villamandos ◽

A Martin-Malo ◽

...

Keyword(s):

Mononuclear Cell ◽

Cell Apoptosis ◽

Cell Activation ◽

Mononuclear Cells ◽

Cell Aggregation ◽

Human Mononuclear Cell ◽

Human Mononuclear Cells ◽

Dependent Cell ◽

Peripheral Mononuclear Cells ◽

Induced Apoptosis

During hemodialysis, circulating mononuclear cells can be stimulated to different degrees, depending on membrane biocompatibility. Cell activation usually leads to aggregation and proliferation. It may also result in apoptosis if cells are subjected to abnormal activation. This may be the case of cells exposed to bioincompatible hemodialysis membranes. The study presented here evaluates the effects of two hemodialysis membranes, with different degrees of biocompatibility, (Cuprophan (CU; Lundia IC 5N; GAMBRO, Sweden) and polyacrylonitrile (AN69; Biospal 3000S, Hospal, France)) on aggregation and apoptosis of circulating human mononuclear cells and the human mononuclear cell line (THP-1). The results showed that 2-h incubation with CU, a bioincompatible membrane, produces cell aggregation of both peripheral mononuclear cells and THP-1 cells (35% and 54%, respectively). After 48 h of incubation with a CU membrane, apoptotic death was observed in 32% of THP-1 cells and in 45% of normal peripheral mononuclear cells. Neither cell aggregation nor apoptosis was observed after incubation with the AN69 membrane. CU membrane-induced apoptosis was inhibited by Staurosporrin (Sigma, St. Louis, MO) a protein kinase C (PKC)-inhibitor, suggesting that cell apoptosis induced by the CU membrane is mediated by a PKC-dependent cell activation. Furthermore, cell prestimulation with phorbol 12-myristate 13-acetate, an activator of PKC, results in a increase in the percentage of THP-1 cell death by apoptosis after CU exposure (53%). Our study indicates that CU membranes induce mononuclear cell activation, leading to cell apoptosis.

Download Full-text

Neutrophil Cathepsin G, but Not Elastase, Induces Aggregation of MCF-7 Mammary Carcinoma Cells by a Protease Activity-Dependent Cell-Oriented Mechanism

Mediators of Inflammation ◽

10.1155/2014/971409 ◽

2014 ◽

Vol 2014 ◽

pp. 1-12 ◽

Cited By ~ 11

Author(s):

Satoru Yui ◽

Yuuki Osawa ◽

Takeo Ichisugi ◽

Riyo Morimoto-Kamata

Keyword(s):

Protease Activity ◽

Cell Aggregation ◽

Cathepsin G ◽

Irreversible Inhibitor ◽

Dependent Cell ◽

A Cell ◽

Mammary Carcinoma Cells ◽

High Concentrations ◽

Induced Aggregation ◽

Mcf 7

We previously found that a neutrophil serine protease, cathepsin G, weakens adherence to culture substrates and induces E-cadherin-dependent aggregation of MCF-7 human breast cancer cells through its protease activity. In this study, we examined whether aggregation is caused by degradation of adhesion molecules on the culture substrates or through an unidentified mechanism. We compared the effect of treatment with cathepsin G and other proteases, including neutrophil elastase against fibronectin- (FN-) coated substrates. Cathepsin G and elastase potently degraded FN on the substrates and induced aggregation of MCF-7 cells that had been subsequently seeded onto the substrate. However, substrate-bound cathepsin G and elastase may have caused cell aggregation. After inhibiting the proteases on the culture substrates using the irreversible inhibitor phenylmethylsulfonyl fluoride (PMSF), we examined whether aggregation of MCF-7 cells was suppressed. PMSF attenuated cell aggregation on cathepsin G-treated substrates, but the effect was weak in cells pretreated with high concentrations of cathepsin G. In contrast, PMSF did not suppress cell aggregation on elastase-treated FN. Moreover, cathepsin G, but not elastase, induced aggregation on poly-L-lysine substrates which are not decomposed by these enzymes, and the action of cathepsin G was nearly completely attenuated by PMSF. These results suggest that cathepsin G induces MCF-7 aggregation through a cell-oriented mechanism.

Download Full-text