scholarly journals The fourth immunoglobulin-like domain of NCAM contains a carbohydrate recognition domain for oligomannosidic glycans implicated in association with L1 and neurite outgrowth.

1993 ◽  
Vol 121 (6) ◽  
pp. 1409-1421 ◽  
Author(s):  
R Horstkorte ◽  
M Schachner ◽  
J P Magyar ◽  
T Vorherr ◽  
B Schmitz
Keyword(s):  
Cell Surface ◽  
Neurite Outgrowth ◽  
Adhesion Molecules ◽  
Consensus Sequence ◽  
Carbohydrate Recognition ◽  
Cell Biol ◽  
Carbohydrate Recognition Domains ◽  
Fibronectin Type Iii ◽  
Fibronectin Type

We have previously shown that the neural adhesion molecules L1 and NCAM interact with each other to form a complex which binds more avidly to L1 than L1 to L1 alone (Kadmon, G., A. Kowitz, P. Altevogt, and M. Schachner. 1990a. J. Cell Biol. 110:193-208). This cis-association between L1 and NCAM is carbohydrate-dependent (Kadmon, G., A. Kowitz, P. Altevogt, and M. Schachner. 1990b. J. Cell Biol. 110:209-218). In the present study, we report that L1 and NCAM bind to each other via oligomannosidic carbohydrates expressed by L1, but not by NCAM, as shown in several experiments: (a) complex formation between L1 and NCAM is inhibited by a mAb to oligomannosidic carbohydrates and by the oligosaccharides themselves; (b) NCAM binds to oligomannosidic carbohydrates; (c) within the L1/NCAM complex, the oligomannosidic carbohydrates are hidden from accessibility to a mAb against oligomannosidic carbohydrates; (d) the recombinant protein fragment of NCAM containing the immunoglobulin-like domains and not the fragment containing the fibronectin type III homologous repeats binds to oligomannosidic glycans. Furthermore, the fourth immunoglobulin-like domain of NCAM shows sequence homology with carbohydrate recognition domains of animal C-type lectins and, surprisingly, also with plant lectins. A peptide comprising part of the C-type lectin consensus sequence in the fourth immunoglobulin-like domain of NCAM interferes with the association between L1 and NCAM. The functional importance of oligomannosidic glycans at the cell surface was shown for neurite outgrowth in vitro. When neurons from early postnatal mouse cerebellum were maintained on laminin or poly-L-lysine, neurite outgrowth was inhibited by oligomannosidic glycans, by glycopeptides, glycoproteins, or neoglycolipids containing oligomannosidic glycans, but not by nonrelated oligosaccharides or oligosaccharide derivates. Neurite outgrowth was also inhibited by the peptide comprising part of the C-type lectin consensus sequence in the fourth immunoglobulin-like domain of NCAM. The combined results suggest that carbohydrate-mediated cis-associations between adhesion molecules at the cell surface modulate their functional properties.

scholarly journals Characterization of functional domains of the tenascin-R (restrictin) polypeptide: cell attachment site, binding with F11, and enhancement of F11-mediated neurite outgrowth by tenascin-R.

1995 ◽  
Vol 130 (2) ◽  
pp. 473-484 ◽  
Author(s):  
U Nörenberg ◽  
M Hubert ◽  
T Brümmendorf ◽  
A Tárnok ◽  
F G Rathjen
Keyword(s):  
Neurite Outgrowth ◽  
Cell Attachment ◽  
Attachment Site ◽  
Direct Interaction ◽  
Bacterial Cells ◽  
Fibronectin Type Iii ◽  
Attachment Region ◽  
A Cell ◽  
Function Relationship

The extracellular matrix glycoprotein tenascin-R (TN-R) is a multidomain protein implicated in neural cell adhesion. To analyze the structure-function relationship of the different domains of TN-R, several recombinant TN-R fragments were expressed in bacterial cells. Two distinct binding regions were localized on the TN-R polypeptide: a region binding the axon-associated immunoglobulin (Ig)-like F11 protein and a cell attachment site. The binding region of the glycosylphosphatidylinositol (GPI)-anchored F11 was allocated to the second and third fibronectin type III (FNIII)-like domain within TN-R. By using a mutant polypeptide of F11 containing only Ig-like domains, a direct interaction between the Ig-like domains of F11 and FNIII-like domains 2-3 of TN-R was demonstrated. The interaction of TN-R with F11 in in vitro cultures enhanced F11-mediated neurite outgrowth, suggesting that the combined action of F11 and TN-R might be of regulatory influence on axon extension. A cell attachment region was identified in the FNIII-like domain eight of TN-R by domain-specific antibodies and fusion constructs. This site is distinct from the F11 binding site within TN-R.

scholarly journals Mertk Interacts with Tim-4 to Enhance Tim-4-Mediated Efferocytosis

Cells ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 1625 ◽  
Author(s):  
Byeongjin Moon ◽  
Juyeon Lee ◽  
Sang-Ah Lee ◽  
Chanhyuk Min ◽  
Hyunji Moon ◽  
...  
Keyword(s):  
Cell Surface ◽  
Molecular Mechanism ◽  
Soluble Form ◽  
Physical Interaction ◽  
Apoptotic Cells ◽  
Type Iii ◽  
Biochemical Interaction ◽  
Fibronectin Type Iii ◽  
Fibronectin Type Iii Domain ◽  
Fibronectin Type

Apoptotic cells expressing phosphatidylserine (PS) on their cell surface are directly or indirectly recognized by phagocytes through PS-binding proteins. The PS-binding protein Tim-4 secures apoptotic cells to phagocytes to facilitate the engulfment of apoptotic cells. However, the molecular mechanism by which Tim-4 transduces signals to phagocytes during Tim-4-mediated efferocytosis is incompletely understood. Here, we report that Tim-4 collaborates with Mertk during efferocytosis through a biochemical interaction with Mertk. Proximal localization between the two proteins in phagocytes was observed by immunofluorescence and proximal ligation assays. Physical association between Tim-4 and Mertk, which was mediated by an interaction between the IgV domain of Tim-4 and the fibronectin type-III domain of Mertk, was also detected with immunoprecipitation. Furthermore, the effect of Mertk on Tim-4-mediated efferocytosis was abolished by GST-MertkFnIII, a soluble form of the fibronectin type-III domain of Mertk that disrupts the interaction between Tim-4 and Mertk. Taken together, the results from our study suggest that a physical interaction between Tim-4 and Mertk is necessary for Mertk to enhance efferocytosis mediated by Tim-4.

scholarly journals Affinity of galectin-8 and its carbohydrate recognition domains for ligands in solution and at the cell surface

Glycobiology ◽  
2007 ◽  
Vol 17 (6) ◽  
pp. 663-676 ◽  
Author(s):  
Susanne Carlsson ◽  
Christopher T Öberg ◽  
Michael C Carlsson ◽  
Anders Sundin ◽  
Ulf J Nilsson ◽  
...  
Keyword(s):  
Cell Surface ◽  
Carbohydrate Recognition ◽  
Carbohydrate Recognition Domains

scholarly journals Tenascin promotes cerebellar granule cell migration and neurite outgrowth by different domains in the fibronectin type III repeats.

1992 ◽  
Vol 116 (6) ◽  
pp. 1475-1486 ◽  
Author(s):  
K Husmann ◽  
A Faissner ◽  
M Schachner
Keyword(s):  
Cell Migration ◽  
Neurite Outgrowth ◽  
Granule Cell ◽  
Soluble Form ◽  
Cerebellar Granule ◽  
Type Iii ◽  
The Third ◽  
Extracellular Matrix Molecule ◽  
Fibronectin Type Iii ◽  
Fibronectin Type

The extracellular matrix molecule tenascin has been implicated in neuron-glia recognition in the developing central and peripheral nervous system and in regeneration. In this study, its role in Bergmann glial process-mediated neuronal migration was assayed in vitro using tissue explants of the early postnatal mouse cerebellar cortex. Of the five mAbs reacting with nonoverlapping epitopes on tenascin, mAbs J1/tn1, J1/tn4, and J1/tn5, but not mAbs J1/tn2 and J1/tn3 inhibited granule cell migration. Localization of the immunoreactive domains by EM of rotary shadowed tenascin molecules revealed that the mAbs J1/tn4 and J1/tn5, like the previously described J1/tn1 antibody, bound between the third and fifth fibronectin type III homologous repeats and mAb J1/tn3 bound between the third and fifth EGF-like repeats. mAb J1/tn2 had previously been found to react between fibronectin type III homologous repeats 10 and 11 of the mouse molecule (Lochter, A., L. Vaughan, A. Kaplony, A. Prochiantz, M. Schachner, and A. Faissner. 1991. J. Cell Biol. 113:1159-1171). When postnatal granule cell neurons were cultured on tenascin adsorbed to polyornithine, both the percentage of neurite-bearing cells and the length of outgrowing neurites were increased when compared to neurons growing on polyornithine alone. This neurite outgrowth promoting effect of tenascin was abolished only by mAb J1/tn2 or tenascin added to the culture medium in soluble form. The other antibodies did not modify the stimulatory or inhibitory effects of the molecule. These observations indicate that tenascin influences neurite outgrowth and migration of cerebellar granule cells by different domains in the fibronectin type III homologous repeats.

scholarly journals Tenascin-C contains distinct adhesive, anti-adhesive, and neurite outgrowth promoting sites for neurons.

1996 ◽  
Vol 132 (4) ◽  
pp. 681-699 ◽  
Author(s):  
B Götz ◽  
A Scholze ◽  
A Clement ◽  
A Joester ◽  
K Schütte ◽  
...  
Keyword(s):  
Neurite Outgrowth ◽  
Hippocampal Neurons ◽  
Neural Cells ◽  
Cell Binding ◽  
Tenascin C ◽  
Functional Studies ◽  
Distinct Cell ◽  
Fibronectin Type Iii ◽  
Alternatively Spliced ◽  
Fibronectin Type

The glia-derived extracellular matrix glycoprotein tenascin-C (TN-C) is transiently expressed in the developing CNS and may mediate neuron-glia interactions. Perturbation experiments with specific monoclonal antibodies suggested that TN-C functions for neural cells are encoded by distinct sites of the glycoprotein (Faissner, A., A. Scholze, and B. Götz. 1994. Tenascin glycoproteins in developing neural tissues--only decoration? Persp. Dev. Neurobiol. 2:53-66). To characterize these further, bacterially expressed recombinant domains were generated and used for functional studies. Several short-term-binding sites for mouse CNS neurons could be assigned to the fibronectin type III (FNIII) domains. Of these, the alternatively spliced insert TNfnA1,2,4,B,D supported initial attachment for both embryonic day 18 (E18) rat and postnatal day 6 (P6) mouse neurons. Only TNfn1-3 supported binding and growth of P6 mouse cerebellar neurons after 24 h, whereas attachment to the other domains proved reversible and resulted in cell detachment or aggregation. In choice assays on patterned substrates, repulsive properties could be attributed to the EGF-type repeats TNegf, and to TNfnA1,2,4. Finally, neurite outgrowth promoting properties for E18 rat hippocampal neurons and P0 mouse DRG explants could be assigned to TNfnB,D, TNfnD,6, and TNfn6. The epitope of mAb J1/tn2 which abolishes the neurite outgrowth inducing effect of intact TN-C could be allocated to TNfnD. These observations suggest that TN-C harbors distinct cell-binding, repulsive, and neurite outgrowth promoting sites for neurons. Furthermore, the properties of isoform-specific TN-C domains suggest functional significance of the alternative splicing of TN-C glycoproteins.

scholarly journals Fibronectin type III and intracellular domains of Toll-like receptor 4 interactor with leucine-rich repeats (Tril) are required for developmental signaling

2017 ◽  
Author(s):  
Hyung-Seok Kim ◽  
Autumn McKnite ◽  
Yuanyuan Xie ◽  
Jan L. Christian
Keyword(s):  
Embryonic Development ◽  
Cell Surface ◽  
Extracellular Domain ◽  
Toll Like Receptor ◽  
Toll Like Receptor 4 ◽  
Intracellular Domain ◽  
Fibronectin Type Iii ◽  
Leucine Rich Repeats ◽  
Fibronectin Type

AbstractToll-like receptor 4 interactor with leucine-rich repeats (Tril) is a transmembrane protein that functions as a coreceptor for Toll-like receptors (Tlrs) to mediate innate immune responses in the adult brain. Tril also triggers degradation of the Bmp inhibitor, Smad7, during early embryonic development to allow for normal blood formation. Tril most likely plays additional, yet to be discovered, roles during embryogenesis. In the current studies, we performed a structure-function analysis, which indicated that the extracellular domain, including the fibronectin type III (FN) domain, and the intracellular domain of Tril are required to trigger Smad7 degradation in the early Xenopus embryo. Furthermore, we found that a Tril deletion mutant lacking the FN domain (TrilΔFN) can dominantly inhibit signaling by endogenous Tril when overexpressed in vivo. This finding raises the intriguing possibility that the FN domain functions to bind endogenous Tril/Tlr4 ligands, perhaps including extracellular matrix molecules. We also show that Tril normally cycles between the cell surface and endosomes, and that the Tril extracellular domain is required to retain Tril at the cell surface, while the intracellular domain is required for Tril internalization in Xenopus ectodermal explants. Using a CHO cell aggregation assay, we further show that, unlike other transmembrane proteins that contain leucine rich repeats in the extracellular domain, Tril is not sufficient to mediate homophilic adhesion. Our findings identify TrilΔFN as a valuable tool that can be used to block the function of endogenous Tril in vivo in order to discover additional roles during embryonic development.

Concerted action of tenascin-C domains in cell adhesion, anti-adhesion and promotion of neurite outgrowth

1997 ◽  
Vol 110 (13) ◽  
pp. 1513-1522 ◽  
Author(s):  
D. Fischer ◽  
M. Brown-Ludi ◽  
T. Schulthess ◽  
R. Chiquet-Ehrismann
Keyword(s):  
Cell Adhesion ◽  
Neurite Outgrowth ◽  
Molecular Characteristics ◽  
Concerted Action ◽  
New Approach ◽  
Tenascin C ◽  
Type Iii ◽  
Starting Point ◽  
Fibronectin Type Iii ◽  
Fibronectin Type

We used a new approach to identify domains of chicken tenascin-C required for interaction with cells. Instead of expressing the parts of interest, we deleted them from an otherwise intact tenascin-C molecule and scored for the concomitant change in activity. As a starting point for all mutant constructs we expressed the smallest naturally occurring tenascin-C splice variant in vertebrate cells. The tenascin-C mutants had either deletions of all EGF-like repeats, all fibronectin type III repeats or of the fibrinogen globe. In double mutants the fibronectin type III repeats were deleted together with either the EGF-like repeats or the fibrinogen globe, respectively. All tenascin-C variants assembled correctly to hexameric molecules of the expected molecular characteristics. Intact tenascin-C and the mutant missing the fibrinogen globe did not promote adhesion of chick embryo fibroblasts, whereas both, the hexamers containing solely the fibrinogen globe or the EGF-like repeats were adhesive substrates and even supported cell spreading. When tenascin-C was added to the medium of fibroblasts plated on fibronectin-coated wells, cell adhesion was blocked by intact tenascin-C, but not by mutants missing the fibrinogen globe. In neurite outgrowth assays using dorsal root ganglia, processes formed on all substrates except on the mutant missing only the fibrinogen globe, where the ganglia failed to adhere. The mutants missing the fibronectin type III repeats allowed more rapid neurite outgrowth than all other tenascin-C variants and the mutant consisting essentially of oligomerized EGF-like repeats was as active a substrate for neurite outgrowth as laminin. From the combined data, it is concluded that the activities of intact tenascin-C cannot be mimicked by investigating domain by domain, but the concerted action of several domains leads to the diverse cellular responses.

Novel alphaGalNAc containing glycans on cytokeratins are recognized invitro by galectins with type II carbohydrate recognition domains

1997 ◽  
Vol 110 (14) ◽  
pp. 1585-1596 ◽  
Author(s):  
S. Goletz ◽  
F.G. Hanisch ◽  
U. Karsten
Keyword(s):  
Posttranslational Modification ◽  
Periodate Oxidation ◽  
Sugar Residue ◽  
Type Ii ◽  
Carbohydrate Recognition ◽  
Human Carcinoma ◽  
General Sequence ◽  
Carbohydrate Recognition Domains ◽  
Mcf 7

We report on a novel posttranslational modification of cytoplasmic proteins. Presented evidences suggest that cytokeratins are bound in vitro by mammalian galectin-3 and the galectins from the sponge Geodia cydonium via their type II carbohydrate recognition domains, whose highest binding affinity is directed towards terminal alpha-N-acetylgalactosamine-bearing glycans with the general sequence GalNAcalpha1-3Gal(NAc)beta. Specificity analyses and the characterization of the critical sugar residue on cytokeratins for galectin binding were done with cytochemical and biochemical methods using various plant and animal lectins. Binding of GalNAc-specific lectins was saturable, sensitive to mild periodate oxidation, inhibitable by glycoconjugates carrying terminal GalNAc, and abolished after treatment of the cytokeratins with alpha-N-acetylgalactosaminidase. Binding to bacterially expressed recombinant cytokeratins did not exceed background binding. The presence of GalNAc residues on highly purified cytokeratins from MCF-7 and HeLa SS6 cells was confirmed by sugar composition analyses using gas chromatography/mass spectrometry. This novel posttranslational modification was not restricted to cytokeratins of MCF-7 cells, but did also occur in all of 9 other examined human carcinoma cell lines and in a normal human mammary epithelial cell line. From these cytochemical and biochemical in vitro studies we hypothesize that this glycan with its terminal alpha1-3 linked GalNAc determinant might represent the first natural cytoplasmic ligand for endogenous galectins-3 detected so far.

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