scholarly journals Involvement of ZO-1 in Cadherin-based Cell Adhesion through Its Direct Binding to α Catenin and Actin Filaments

1997 ◽  
Vol 138 (1) ◽  
pp. 181-192 ◽  
Author(s):  
Masahiko Itoh ◽  
Akira Nagafuchi ◽  
Seiji Moroi ◽  
Shoichiro Tsukita
Keyword(s):  
Cell Adhesion ◽  
Dissociation Constant ◽  
Actin Filaments ◽  
Full Length ◽  
Amino Terminal ◽  
Adhesion Sites ◽  
Direct Binding ◽  
Carboxyl Terminal ◽  
E Cadherin

ZO-1, a 220-kD peripheral membrane protein consisting of an amino-terminal half discs large (dlg)-like domain and a carboxyl-terminal half domain, is concentrated at the cadherin-based cell adhesion sites in non-epithelial cells. We introduced cDNAs encoding the full-length ZO-1, its amino-terminal half (N-ZO-1), and carboxyl-terminal half (C-ZO-1) into mouse L fibroblasts expressing exogenous E-cadherin (EL cells). The full-length ZO-1 as well as N-ZO-1 were concentrated at cadherin-based cell–cell adhesion sites. In good agreement with these observations, N-ZO-1 was specifically coimmunoprecipitated from EL transfectants expressing N-ZO-1 (NZ-EL cells) with the E-cadherin/α, β catenin complex. In contrast, C-ZO-1 was localized along actin stress fibers. To examine the molecular basis of the behavior of these truncated ZO-1 molecules, N-ZO-1 and C-ZO-1 were produced in insect Sf9 cells by recombinant baculovirus infection, and their direct binding ability to the cadherin/catenin complex and the actin-based cytoskeleton, respectively, were examined in vitro. Recombinant N-ZO-1 bound directly to the glutathione-S-transferase fusion protein with α catenin, but not to that with β catenin or the cytoplasmic domain of E-cadherin. The dissociation constant between N-ZO-1 and α catenin was ∼0.5 nM. On the other hand, recombinant C-ZO-1 was specifically cosedimented with actin filaments in vitro with a dissociation constant of ∼10 nM. Finally, we compared the cadherin-based cell adhesion activity of NZ-EL cells with that of parent EL cells. Cell aggregation assay revealed no significant differences among these cells, but the cadherin-dependent intercellular motility, i.e., the cell movement in a confluent monolayer, was significantly suppressed in NZ-EL cells. We conclude that in nonepithelial cells, ZO-1 works as a cross-linker between cadherin/catenin complex and the actin-based cytoskeleton through direct interaction with α catenin and actin filaments at its amino- and carboxyl-terminal halves, respectively, and that ZO-1 is a functional component in the cadherin-based cell adhesion system.

scholarly journals Agouti-Related Protein Is Posttranslationally Cleaved by Proprotein Convertase 1 to Generate Agouti-Related Protein (AGRP)83–132: Interaction between AGRP83–132 and Melanocortin Receptors Cannot Be Influenced by Syndecan-3

Endocrinology ◽  
2006 ◽  
Vol 147 (4) ◽  
pp. 1621-1631 ◽  
Author(s):  
John W. M. Creemers ◽  
Lynn E. Pritchard ◽  
Amy Gyte ◽  
Philippe Le Rouzic ◽  
Sandra Meulemans ◽  
...  
Keyword(s):  
Food Intake ◽  
Core Body Temperature ◽  
Full Length ◽  
Related Protein ◽  
Amino Terminal ◽  
Terminal Domain ◽  
Carboxyl Terminal ◽  
Agouti Related Protein

Agouti-related protein (AGRP) plays a key role in energy homeostasis. The carboxyl-terminal domain of AGRP acts as an endogenous antagonist of the melanocortin-4 receptor (MC4-R). It has been suggested that the amino-terminal domain of AGRP binds to syndecan-3, thereby modulating the effects of carboxyl-terminal AGRP at the MC4-R. This model assumes that AGRP is secreted as a full-length peptide. In this study we found that AGRP is processed intracellularly after Arg79-Glu80-Pro81-Arg82. The processing site suggests cleavage by proprotein convertases (PCs). RNA interference and overexpression experiments showed that PC1/3 is primarily responsible for cleavage in vitro, although both PC2 and PC5/6A can also process AGRP. Dual in situ hybridization demonstrated that PC1/3 is expressed in AGRP neurons in the rat hypothalamus. Moreover, hypothalamic extracts from PC1-null mice contained 3.3-fold more unprocessed full-length AGRP, compared with wild-type mice, based on combined HPLC and RIA analysis, demonstrating that PC1/3 plays a role in AGRP cleavage in vivo. We also found that AGRP83–132 is more potent an antagonist than full-length AGRP, based on cAMP reporter assays, suggesting that posttranslational cleavage is required to potentiate the effect of AGRP at the MC4-R. Because AGRP is cleaved into distinct amino-terminal and carboxyl-terminal peptides, we tested whether amino-terminal peptides modulate food intake. However, intracerebroventricular injection of rat AGRP25–47 and AGRP50–80 had no effect on body weight, food intake, or core body temperature. Because AGRP is cleaved before secretion, syndecan-3 must influence food intake independently of the MC4-R.

scholarly journals Regulation of Cell–Cell Adhesion by Rac and Rho Small G Proteins in MDCK Cells

1997 ◽  
Vol 139 (4) ◽  
pp. 1047-1059 ◽  
Author(s):  
Kenji Takaishi ◽  
Takuya Sasaki ◽  
Hirokazu Kotani ◽  
Hideo Nishioka ◽  
Yoshimi Takai
Keyword(s):  
Cell Adhesion ◽  
Tight Junction ◽  
Cell Lines ◽  
Actin Filaments ◽  
Mdck Cells ◽  
Wild Type ◽  
Cell Functions ◽  
Adhesion Sites ◽  
E Cadherin ◽  
Cell Cell

The Rho small G protein family, consisting of the Rho, Rac, and Cdc42 subfamilies, regulates various cell functions, such as cell shape change, cell motility, and cytokinesis, through reorganization of the actin cytoskeleton. We show here that the Rac and Rho subfamilies furthermore regulate cell–cell adhesion. We prepared MDCK cell lines stably expressing each of dominant active mutants of RhoA (sMDCK-RhoDA), Rac1 (sMDCK-RacDA), and Cdc42 (sMDCK-Cdc42DA) and dominant negative mutants of Rac1 (sMDCK-RacDN) and Cdc42 (sMDCK-Cdc42DN) and analyzed cell adhesion in these cell lines. The actin filaments at the cell–cell adhesion sites markedly increased in sMDCK-RacDA cells, whereas they apparently decreased in sMDCK-RacDN cells, compared with those in wild-type MDCK cells. Both E-cadherin and β-catenin, adherens junctional proteins, at the cell–cell adhesion sites also increased in sMDCK-RacDA cells, whereas both of them decreased in sMDCK-RacDN cells. The detergent solubility assay indicated that the amount of detergent-insoluble E-cadherin increased in sMDCK-RacDA cells, whereas it slightly decreased in sMDCK-RacDN cells, compared with that in wild-type MDCK cells. In sMDCK-RhoDA, -Cdc42DA, and -Cdc42DN cells, neither of these proteins at the cell–cell adhesion sites was apparently affected. ZO-1, a tight junctional protein, was not apparently affected in any of the transformant cell lines. Electron microscopic analysis revealed that sMDCK-RacDA cells tightly made contact with each other throughout the lateral membranes, whereas wild-type MDCK and sMDCK-RacDN cells tightly and linearly made contact at the apical area of the lateral membranes. These results suggest that the Rac subfamily regulates the formation of the cadherin-based cell– cell adhesion. Microinjection of C3 into wild-type MDCK cells inhibited the formation of both the cadherin-based cell–cell adhesion and the tight junction, but microinjection of C3 into sMDCK-RacDA cells showed little effect on the localization of the actin filaments and E-cadherin at the cell–cell adhesion sites. These results suggest that the Rho subfamily is necessary for the formation of both the cadherin-based cell– cell adhesion and the tight junction, but not essential for the Rac subfamily-regulated, cadherin-based cell– cell adhesion.

scholarly journals The Catenin p120ctnInteracts with Kaiso, a Novel BTB/POZ Domain Zinc Finger Transcription Factor

1999 ◽  
Vol 19 (5) ◽  
pp. 3614-3623 ◽  
Author(s):  
Juliet M. Daniel ◽  
Albert B. Reynolds
Keyword(s):  
Transcription Factor ◽  
Monoclonal Antibodies ◽  
Cell Adhesion ◽  
Mammalian Cells ◽  
Yeast Two Hybrid ◽  
Amino Terminal ◽  
Juxtamembrane Region ◽  
Carboxy Terminal ◽  
Two Hybrid ◽  
E Cadherin

ABSTRACT p120 ctn is an Armadillo repeat domain protein with structural similarity to the cell adhesion cofactors β-catenin and plakoglobin. All three proteins interact directly with the cytoplasmic domain of the transmembrane cell adhesion molecule E-cadherin; β-catenin and plakoglobin bind a carboxy-terminal region in a mutually exclusive manner, while p120 binds the juxtamembrane region. Unlike β-catenin and plakoglobin, p120 does not interact with α-catenin, the tumor suppressor adenomatous polyposis coli (APC), or the transcription factor Lef-1, suggesting that it has unique binding partners and plays a distinct role in the cadherin-catenin complex. Using p120 as bait, we conducted a yeast two-hybrid screen and identified a novel transcription factor which we named Kaiso. Kaiso’s deduced amino acid sequence revealed an amino-terminal BTB/POZ protein-protein interaction domain and three carboxy-terminal zinc fingers of the C2H2 DNA-binding type. Kaiso thus belongs to a rapidly growing family of POZ-ZF transcription factors that include the Drosophila developmental regulators Tramtrak and Bric à brac, and the human oncoproteins BCL-6 and PLZF, which are causally linked to non-Hodgkins’ lymphoma and acute promyelocytic leukemia, respectively. Monoclonal antibodies to Kaiso were generated and used to immunolocalize the protein and confirm the specificity of the p120-Kaiso interaction in mammalian cells. Kaiso specifically coprecipitated with a variety of p120-specific monoclonal antibodies but not with antibodies to α- or β-catenin, E-cadherin, or APC. Like other POZ-ZF proteins, Kaiso localized to the nucleus and was associated with specific nuclear dots. Yeast two-hybrid interaction assays mapped the binding domains to Arm repeats 1 to 7 of p120 and the carboxy-terminal 200 amino acids of Kaiso. In addition, Kaiso homodimerized via its POZ domain but it did not heterodimerize with BCL-6, which heterodimerizes with PLZF. The involvement of POZ-ZF proteins in development and cancer makes Kaiso an interesting candidate for a downstream effector of cadherin and/or p120 signaling.

scholarly journals Talin mechanosensitivity is modulated by a direct interaction with cyclin-dependent kinase-1

2021 ◽  
Author(s):  
Rosemarie E. Gough ◽  
Matthew C. Jones ◽  
Thomas Zacharchenko ◽  
Shimin Le ◽  
Miao Yu ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Cell Adhesion ◽  
Cell Division ◽  
Mechanical Response ◽  
Direct Interaction ◽  
Cyclin Dependent Kinase ◽  
Cell Cycle Regulator ◽  
Direct Binding

AbstractTalin is a mechanosensitive component of adhesion complexes that directly couples integrins to the actin cytoskeleton. In response to force, talin undergoes switch-like behaviour of its multiple rod domains that modulate interactions with its binding partners. Cyclin-dependent kinase-1 (CDK1) is a key regulator of the cell cycle, exerting its effects through synchronised phosphorylation of a large number of protein targets. CDK1 activity also maintains adhesion during interphase, and its inhibition is a prerequisite for the tightly choreographed changes in cell shape and adhesiveness that are required for successful completion of mitosis. Using a combination of biochemical, structural and cell biological approaches, we demonstrate a direct interaction between talin and CDK1 that occurs at sites of integrin-mediated adhesion. Mutagenesis demonstrated that CDK1 contains a functional talin-binding LD motif, and the binding site within talin was pinpointed to helical bundle R8 through the use of recombinant fragments. Talin also contains a consensus CDK1 phosphorylation motif centred on S1589; a site that was phosphorylated by CDK1in vitro. A phosphomimetic mutant of this site within talin lowered the binding affinity of KANK and weakened the mechanical response of the region, potentially altering downstream mechanotransduction pathways. The direct binding of the master cell cycle regulator, CDK1, to the primary integrin effector, talin, therefore provides a primordial solution for coupling the cell proliferation and cell adhesion machineries, and thereby enables microenvironmental control of cell division in multicellular organisms.SummaryThe direct binding of the master cell cycle regulator, CDK1, to the primary integrin effector, talin, provides a primordial solution for coupling the cell proliferation and cell adhesion machineries, and thereby enables microenvironmental control of cell division.

scholarly journals Ultrastructural localization of E-cadherin cell adhesion molecule on the cytoplasmic membrane of keratinocytes in vivo and in vitro.

1994 ◽  
Vol 42 (10) ◽  
pp. 1333-1340 ◽  
Author(s):  
Y Horiguchi ◽  
F Furukawa ◽  
M Fujita ◽  
S Imamura
Keyword(s):  
Cell Adhesion ◽  
Free Surface ◽  
Adhesion Molecules ◽  
Cell Adhesion Molecules ◽  
Cytoplasmic Membrane ◽  
Ultrastructural Localization ◽  
In Vivo Studies ◽  
E Cadherin

We examined the ultrastructural localization of E (epithelial)-cadherin cell adhesion molecules by immunoperoxidase electron microscopy on the epithelium of mouse intestine, epidermis of human skin, and cultured human keratinocytes. The in vivo studies demonstrated that E-cadherin was present at the intermediate junction but not at the desmosome of the mouse intestinal single epithelium, and was found on the cytoplasmic membranes of keratinocytes with condensation in the intercellular space of the desmosomes, except for the basal surface of the basal cells. In vitro studies demonstrated that keratinocytes cultured in medium containing a low Ca2+ concentration (0.1 mM) lacked the tight connection through desmosomes, and that E-cadherin showed diffuse distribution and dot-like accumulation around the free surface of the cytoplasmic membrane. In culture medium containing a high concentration of Ca2+ (0.6 mM), keratinocytes formed desmosomal adhesion structures in which E-cadherin was accumulated. The free surface of the keratinocytes in this medium showed weaker distribution and a lesser amount of dot-like accumulation of E-cadherin than that in a low Ca2+ condition. These findings suggest that the distribution pattern of the E-cadherin cell adhesion molecules on the keratinocytes is different from that on the single epithelium of the intestine, and that E-cadherin on the cytoplasmic membrane of the keratinocytes shifts to the desmosomes under physiological conditions, participating in adhesion in association with other desmosomal cadherins.

scholarly journals The Ubiquitin-associated Domain of hPLIC-2 Interacts with the Proteasome

2003 ◽  
Vol 14 (9) ◽  
pp. 3868-3875 ◽  
Author(s):  
Maurits F. Kleijnen ◽  
Rodolfo M. Alarcón ◽  
Peter M. Howley
Keyword(s):  
Proteasomal Degradation ◽  
Binding Domain ◽  
Full Length ◽  
Degradation Pathways ◽  
Wild Type ◽  
Amino Terminal ◽  
Uba Domain ◽  
Carboxyl Terminal ◽  
Protein Ligases

The ubiquitin-like hPLIC proteins can associate with proteasomes, and hPLIC overexpression can specifically interfere with ubiquitin-mediated proteolysis ( Kleijnen et al., 2000 ). Because the hPLIC proteins can also interact with certain E3 ubiquitin protein ligases, they may provide a link between the ubiquitination and proteasomal degradation machineries. The amino-terminal ubiquitin-like (ubl) domain is a proteasome-binding domain. Herein, we report that there is a second proteasome-binding domain in hPLIC-2: the carboxyl-terminal ubiquitin-associated (uba) domain. Coimmunoprecipitation experiments of wild-type and mutant hPLIC proteins revealed that the ubl and uba domains each contribute independently to hPLIC-2–proteasome binding. There is specificity for the interaction of the hPLIC-2 uba domain with proteasomes, because uba domains from several other proteins failed to bind proteasomes. Furthermore, the binding of uba domains to polyubiquitinated proteins does not seem to be sufficient for the proteasome binding. Finally, the uba domain is necessary for the ability of full-length hPLIC-2 to interfere with the ubiquitin-mediated proteolysis of p53. The PLIC uba domain has been reported to bind and affect the functions of proteins such as GABAAreceptor and presenilins. It is possible that the function of these proteins may be regulated or mediated through proteasomal degradation pathways.

In vivo effect of sodium orthovanadate on pp60c-src kinase

1987 ◽  
Vol 7 (3) ◽  
pp. 1139-1147
Author(s):  
J W Ryder ◽  
J A Gordon
Keyword(s):  
Tyrosine Kinase ◽  
Chicken Embryo ◽  
Sodium Orthovanadate ◽  
Normal Cells ◽  
Amino Terminal ◽  
Carboxyl Terminal ◽  
Embryo Fibroblasts ◽  
Chicken Embryo Fibroblasts

We have compared the tyrosine kinase activity of pp60c-src isolated from intact chicken embryo fibroblasts treated with micromolar sodium orthovanadate for 4 h and from untreated cells. We found an approximate 50% reduction in both autophosphorylation of pp60c-src and phosphorylation of casein when examined in the immune complex kinase assay. The reduction of in vitro enzymatic activity correlated with a vanadate-induced increase in in vivo phosphorylation of pp60c-src at the major site of tyrosine phosphorylation in the carboxyl-terminal half of the molecule and at serine in the amino-terminal half of the molecule. Our observations in vivo and those of Courtneidge in vitro (EMBO J. 4:1471-1477, 1985) suggest that vanadate may enhance a cellular regulatory mechanism that inhibits the activity of pp60c-src in normal cells. A likely candidate for this mechanism is phosphorylation at a tyrosine residue distinct from tyrosine 416, probably tyrosine 527 in the carboxyl-terminal sequence of amino acids unique to pp60c-src. The regulatory role, if any, of serine phosphorylation in pp60c-src remains unclear. The 36-kilodalton phosphoprotein, a substrate of pp60v-src, showed a significant phosphorylation at tyrosine after treatment of normal chicken embryo fibroblasts with vanadate. Assuming that pp60c-src is inhibited intracellularly by vanadate, either another tyrosine kinase is stimulated by vanadate (e.g., a growth factor receptor) or the 36-kilodalton phosphoprotein in normal cells is no longer rapidly dephosphorylated by a tyrosine phosphatase in the presence of vanadate.

E-cadherin mediated cell adhesion recruits SAP97 into the cortical cytoskeleton

1998 ◽  
Vol 111 (8) ◽  
pp. 1071-1080 ◽  
Author(s):  
S.M. Reuver ◽  
C.C. Garner
Keyword(s):  
Cell Adhesion ◽  
Model Systems ◽  
Molecular Organization ◽  
Cell Contact ◽  
Adhesion Sites ◽  
Associated Proteins ◽  
Adhesion Complex ◽  
Cortical Cytoskeleton ◽  
E Cadherin ◽  
Cell Cell

Members of the SAP family of synapse-associated proteins have recently emerged as central players in the molecular organization of synapses. In this study, we have examined the mechanism that localizes one member, SAP97, to sites of cell-cell contact. Utilizing epithelial CACO-2 cells and fibroblast L-cells as model systems, we demonstrate that SAP97 is associated with the submembranous cortical cytoskeleton at cell-cell adhesion sites. Furthermore, we show that its localization into this structure is triggered by E-cadherin. Although SAP97 can be found in an E-cadherin/catenin adhesion complex, this interaction seems to be mediated by the attachment of SAP97 to the cortical cytoskeleton. Our results are consistent with a model in which SAP97 is recruited to sites of cell-cell contact via an E-cadherin induced assembly of the cortical cytoskeleton.

scholarly journals Recruitment of E-cadherin associated with α- and β-catenins and p120ctn to the nectin-based cell-cell adhesion sites by the action of 12-O-tetradecanoylphorbol-13-acetate in MDCK cells

2005 ◽  
Vol 10 (5) ◽  
pp. 435-445 ◽  
Author(s):  
Ryoko Okamoto ◽  
Kenji Irie ◽  
Akio Yamada ◽  
Tatsuo Katata ◽  
Atsunori Fukuhara ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Mdck Cells ◽  
Adhesion Sites ◽  
E Cadherin ◽  
Cell Cell

scholarly journals In Vitro Assembly of Sindbis Virus Core-Like Particles from Cross-Linked Dimers of Truncated and Mutant Capsid Proteins

2001 ◽  
Vol 75 (6) ◽  
pp. 2810-2817 ◽  
Author(s):  
Timothy L. Tellinghuisen ◽  
Rushika Perera ◽  
Richard J. Kuhn
Keyword(s):  
Capsid Protein ◽  
Sindbis Virus ◽  
Terminal Region ◽  
Full Length ◽  
Capsid Proteins ◽  
Size Difference ◽  
Cross Linking ◽  
Cross Link ◽  
Amino Terminal

ABSTRACT A nucleic acid-bound capsid protein dimer was previously identified using a Sindbis virus in vitro nucleocapsid assembly system and cross-linking reagents. Cross-link mapping, in combination with a model of the nucleocapsid core, suggested that this dimer contained one monomer from each of two adjacent capsomeres. This intercapsomere dimer is believed to be the initial intermediate in the nucleocapsid core assembly mechanism. This paper presents the purification of cross-linked dimers of a truncated capsid protein and the partial purification of cross-linked dimers of a full-length assembly-defective mutant. The assembly of core-like particles from these cross-linked capsid protein dimers is demonstrated. Core-like particles generated from cross-linked full-length mutant CP(19-264)L52D were examined by electron microscopy and appeared to have a morphology similar to that of wild-type in vitro-assembled core-like particles, although a slight size difference was often visible. Truncated cross-linked CP(81-264) dimers generated core-like particles as well. These core-like particles could subsequently be disassembled when reversible cross-linking reagents were used to form the dimers. The ability of the covalent intercapsomere cross-link to rescue capsid proteins with assembly defects or truncations in the amino-terminal region of the capsid protein supports the previous model of assembly and suggests a possible role for the amino-terminal region of the protein.

Sign in / Sign up

Export Citation Format

Share Document