An analysis of chick limb bud intercellular adhesion underlying the establishment of cartilage aggregates in suspension culture

1990 ◽  
Vol 96 (3) ◽  
pp. 527-536
Author(s):  
J.A. Bee ◽  
K. von der Mark
Keyword(s):  
Cell Surface ◽  
Cell Aggregation ◽  
Intercellular Adhesion ◽  
Limb Bud ◽  
Affinity Column ◽  
Type I ◽  
Surface Plasma ◽  
Aggregation Mechanism ◽  
Fab Fragments ◽  
Exogenous Calcium

To examine the mechanism of intercellular adhesion in the establishment of limb skeletal elements we have investigated the process of limb bud cell aggregation in vitro. Limb bud cells are aggregation-competent immediately after their trypsin:collagenase dissociation in the absence of calcium. This aggregation is largely Ca2(+)-independent (CI) and is completely and reversibly inhibited by cycloheximide. In contrast, when limb bud cells are first allowed to recover from Ca2(+)-free trypsin:collagenase dissociation, aggregation of the surviving population is exclusively Ca2(+)-dependent (CD) and completely and reversibly inhibited by cycloheximide. The presence of exogenous calcium during initial cell dissociation retains a functional CD aggregation mechanism. However, incubation of such cells with EGTA releases the CD component and converts the cells to a predominantly CI aggregation. Rabbits were immunized with limb bud cells exhibiting the recovered CD aggregation mechanism and the resulting immune sera were screened for their effect on cell aggregation. Relative to pre-immune sera, intact immune IgG agglutinated dissociated limb bud cells whilst immune Fab fragments inhibited their aggregation. The aggregation-inhibiting antiserum recognizes five major limb bud cell surface components with apparent molecular weights of 72K, 50K, 23K, 14.5K and 8.5K (K = 10(3) Mr), respectively. Limb bud cell surface plasma membranes were isolated by sucrose gradient density centrifugation and detergent-solubilized proteins coupled to Sepharose 4B with cyanogen bromide. Equivalent cell surface plasma membrane proteins were 125I-iodinated and applied to the affinity column. Limb bud cell surface protein affinity chromatography in the presence of exogenous calcium yields a single protein with an apparent molecular weight of approximately 8.5 K. This protein molecule elutes at 0.6 M NaCl, indicating a high affinity, is recognized by the aggregation-inhibiting antiserum, and is itself capable of inhibiting CD limb bud cell aggregation. Fab fragments prepared from rabbit antisera specifically directed against the affinity-purified material also inhibit CD limb bud cell aggregation and this inhibition is neutralized by the 8.5 K protein. Our data thus demonstrate that CD limb bud cell aggregation is not mediated by fibronectin and/or collagen type I and indicate that this process is governed by a novel 8.5 K cell adhesion molecule.

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

2001 ◽  
Vol 114 (1) ◽  
pp. 111-118 ◽  
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.

scholarly journals A Single-Pass Type I Membrane Protein from the Apicomplexan Parasite Cryptosporidium parvum with Nanomolar Binding Affinity to Host Cell Surface

2021 ◽  
Vol 9 (5) ◽  
pp. 1015
Author(s):  
Tianyu Zhang ◽  
Xin Gao ◽  
Dongqiang Wang ◽  
Jixue Zhao ◽  
Nan Zhang ◽  
...  
Keyword(s):  
Membrane Protein ◽  
Cell Surface ◽  
Host Cell ◽  
Binding Affinity ◽  
Cryptosporidium Parvum ◽  
Host Cells ◽  
Watery Diarrhea ◽  
Type I ◽  
Single Pass ◽  
Host Cell Surface

Cryptosporidium parvum is a globally recognized zoonotic parasite of medical and veterinary importance. This parasite mainly infects intestinal epithelial cells and causes mild to severe watery diarrhea that could be deadly in patients with weakened or defect immunity. However, its molecular interactions with hosts and pathogenesis, an important part in adaptation of parasitic lifestyle, remain poorly understood. Here we report the identification and characterization of a C. parvum T-cell immunomodulatory protein homolog (CpTIPH). CpTIPH is a 901-aa single-pass type I membrane protein encoded by cgd5_830 gene that also contains a short Vibrio, Colwellia, Bradyrhizobium and Shewanella (VCBS) repeat and relatively long integrin alpha (ITGA) N-terminus domain. Immunofluorescence assay confirmed the location of CpTIPH on the cell surface of C. parvum sporozoites. In congruence with the presence of VCBS repeat and ITGA domain, CpTIPH displayed high, nanomolar binding affinity to host cell surface (i.e., Kd(App) at 16.2 to 44.7 nM on fixed HCT-8 and CHO-K1 cells, respectively). The involvement of CpTIPH in the parasite invasion is partly supported by experiments showing that an anti-CpTIPH antibody could partially block the invasion of C. parvum sporozoites into host cells. These observations provide a strong basis for further investigation of the roles of CpTIPH in parasite-host cell interactions.

scholarly journals Homophilic adhesion between Ig superfamily carcinoembryonic antigen molecules involves double reciprocal bonds

1993 ◽  
Vol 122 (4) ◽  
pp. 951-960 ◽  
Author(s):  
H Zhou ◽  
A Fuks ◽  
G Alcaraz ◽  
TJ Bolling ◽  
CP Stanners
Keyword(s):  
Carcinoembryonic Antigen ◽  
Cell Aggregation ◽  
Intercellular Adhesion ◽  
Cell Surface Expression ◽  
Adhesive Properties ◽  
Amino Terminal ◽  
Terminal Domain ◽  
Internal Repeat ◽  
Immunoglobulin Supergene Family ◽  
Supergene Family

Both carcinoembryonic antigen (CEA) and neural cell adhesion molecule (NCAM) belong to the immunoglobulin supergene family and have been demonstrated to function as homotypic Ca(++)-independent intercellular adhesion molecules. CEA and NCAM cannot associate heterotypically indicating that they have different binding specificities. To define the domains of CEA involved in homotypic interaction, hybrid cDNAs consisting of various domains from CEA and NCAM were constructed and were transfected into a CHO-derived cell line; stable transfectant clones showing cell surface expression of CEA/NCAM chimeric-proteins were assessed for their adhesive properties by homotypic and heterotypic aggregation assays. The results indicate that all five of the Ig(C)-like domains of NCAM are required for intercellular adhesion while the COOH-terminal domain containing the fibronectin-like repeats is dispensable. The results also show that adhesion mediated by CEA involves binding between the Ig(V)-like amino-terminal domain and one of the Ig(C)-like internal repeat domains: thus while transfectants expressing constructs containing either the N domain or the internal domains alone were incapable of homotypic adhesion, they formed heterotypic aggregates when mixed. Furthermore, peptides consisting of both the N domain and the third internal repeat domain of CEA blocked CEA-mediated cell aggregation, thus providing direct evidence for the involvement of the two domains in adhesion. We therefore propose a novel model for interactions between immunoglobulin supergene family members in which especially strong binding is effected by double reciprocal interactions between the V-like domains and C-like domains of antiparallel CEA molecules on apposing cell surfaces.

scholarly journals Tracking the Cartoon mouse phenotype: Hemopexin domain–dependent regulation of MT1-MMP pericellular collagenolytic activity

2018 ◽  
Vol 293 (21) ◽  
pp. 8113-8127 ◽  
Author(s):  
Moustafa Sakr ◽  
Xiao-Yan Li ◽  
Farideh Sabeh ◽  
Tamar Y. Feinberg ◽  
John J. G. Tesmer ◽  
...  
Keyword(s):  
Cell Surface ◽  
Critical Role ◽  
Collagenolytic Activity ◽  
Temperature Sensitive ◽  
Type I ◽  
Permissive Temperature ◽  
Sensitive Mutant ◽  
Temperature Sensitive Mutant ◽  
Golgi Network ◽  
Hemopexin Domain

Following ENU mutagenesis, a phenodeviant line was generated, termed the “Cartoon mouse,” that exhibits profound defects in growth and development. Cartoon mice harbor a single S466P point mutation in the MT1-MMP hemopexin domain, a 200-amino acid segment that is thought to play a critical role in regulating MT1-MMP collagenolytic activity. Herein, we demonstrate that the MT1-MMPS466P mutation replicates the phenotypic status of Mt1-mmp–null animals as well as the functional characteristics of MT1-MMP−/− cells. However, rather than a loss-of-function mutation acquired as a consequence of defects in MT1-MMP proteolytic activity, the S466P substitution generates a misfolded, temperature-sensitive mutant that is abnormally retained in the endoplasmic reticulum (ER). By contrast, the WT hemopexin domain does not play a required role in regulating MT1-MMP trafficking, as a hemopexin domain-deletion mutant is successfully mobilized to the cell surface and displays nearly normal collagenolytic activity. Alternatively, when MT1-MMPS466P–expressing cells are cultured at a permissive temperature of 25 °C that depresses misfolding, the mutant successfully traffics from the ER to the trans-Golgi network (ER → trans-Golgi network), where it undergoes processing to its mature form, mobilizes to the cell surface, and expresses type I collagenolytic activity. Together, these analyses define the Cartoon mouse as an unexpected gain-of-abnormal function mutation, wherein the temperature-sensitive mutant phenocopies MT1-MMP−/− mice as a consequence of eliciting a specific ER → trans-Golgi network trafficking defect.

scholarly journals HDL-Mediated Lipid Influx to Endothelial Cells Contributes to Regulating Intercellular Adhesion Molecule (ICAM)-1 Expression and eNOS Phosphorylation

2018 ◽  
Vol 19 (11) ◽  
pp. 3394 ◽  
Author(s):  
Mónica Muñoz-Vega ◽  
Felipe Massó ◽  
Araceli Páez ◽  
Gilberto Vargas-Alarcón ◽  
Ramón Coral-Vázquez ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Adhesion Molecule ◽  
Hdl Cholesterol ◽  
Intercellular Adhesion ◽  
Intercellular Adhesion Molecule ◽  
High Density Lipoproteins ◽  
Type I ◽  
Intercellular Adhesion Molecule 1 ◽  
Apo Ai

Reverse cholesterol transport (RCT) is considered as the most important antiatherogenic role of high-density lipoproteins (HDL), but interventions based on RCT have failed to reduce the risk of coronary heart disease. In contrast to RCT, important evidence suggests that HDL deliver lipids to peripheral cells. Therefore, in this paper, we investigated whether HDL could improve endothelial function by delivering lipids to the cells. Internalization kinetics using cholesterol and apolipoprotein (apo) AI fluorescent double-labeled reconstituted HDL (rHDL), and human dermal microvascular endothelial cells-1 (HMEC-1) showed a fast cholesterol influx (10 min) and a slower HDL protein internalization as determined by confocal microscopy and flow cytometry. Sphingomyelin kinetics overlapped that of apo AI, indicating that only cholesterol became dissociated from rHDL during internalization. rHDL apo AI internalization was scavenger receptor class B type I (SR-BI)-dependent, whereas HDL cholesterol influx was independent of SR-BI and was not completely inhibited by the presence of low-density lipoproteins (LDL). HDL sphingomyelin was fundamental for intercellular adhesion molecule-1 (ICAM-1) downregulation in HMEC-1. However, vascular cell adhesion protein-1 (VCAM-1) was not inhibited by rHDL, suggesting that components such as apolipoproteins other than apo AI participate in HDL’s regulation of this adhesion molecule. rHDL also induced endothelial nitric oxide synthase eNOS S1177 phosphorylation in HMEC-1 but only when the particle contained sphingomyelin. In conclusion, the internalization of HDL implies the dissociation of lipoprotein components and a SR-BI-independent fast delivery of cholesterol to endothelial cells. HDL internalization had functional implications that were mainly dependent on sphingomyelin. These results suggest a new role of HDL as lipid vectors to the cells, which could be congruent with the antiatherogenic properties of these lipoproteins.

The steady state distribution of humTGN46 is not significantly altered in cells defective in clathrin-mediated endocytosis

1998 ◽  
Vol 111 (23) ◽  
pp. 3451-3458 ◽  
Author(s):  
G. Banting ◽  
R. Maile ◽  
E.P. Roquemore
Keyword(s):  
Steady State ◽  
Cell Surface ◽  
Dominant Negative ◽  
Type I ◽  
Steady State Distribution ◽  
State Distribution ◽  
Trans Golgi Network ◽  
Defective Mutant ◽  
Dynamin I ◽  
Golgi Network

It has been shown previously that whilst the rat type I integral membrane protein TGN38 (ratTGN38) is predominantly localised to the trans-Golgi network this protein does reach the cell surface from where it is internalised and delivered back to the trans-Golgi network. This protein thus provides a suitable tool for the investigation of trafficking pathways between the trans-Golgi network and the cell surface and back again. The human orthologue of ratTGN38, humTGN46, behaves in a similar fashion. These proteins are internalised from the cell surface via clathrin mediated endocytosis, a process which is dependent upon the GTPase activity of dynamin. We thus reasoned that humTGN46 would accumulate at the surface of cells rendered defective in clathrin mediated endocytosis by virtue of the fact that they express a GTPase defective mutant of dynamin I. It did not. In fact, expression of a dominant negative GTPase defective mutant of dynamin I had no detectable effect on the steady state distribution of humTGN46. One explanation for this observation is that humTGN46 does not travel directly to the cell surface from the trans-Golgi network. Further studies on cells expressing the dominant negative GTPase defective mutant of dynamin I indicate that the major recycling pathway for humTGN46 is in fact between the trans-Golgi network and the early endosome.

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