Regulation of cell surface tissue transglutaminase: effects on matrix storage of latent transforming growth factor-beta binding protein-1.
Using a cytochemical approach, we examined the role of tissue transglutaminase (tTgase, Type II) in the incorporation of latent TGF-beta binding protein-1 (LTBP-1) in the extracellular matrix of Swiss 3T3 fibroblasts in which tTgase expression can be modulated through a tetracycline-controlled promoter. Increased tTgase expression led to an increased rate of LTBP-1 deposition in the matrix, which was accompanied by an increased pool of deoxycholate-insoluble fibronectin. Matrix deposition of LTBP-1 could also be reduced by the competitive amine substrate putrescine. Immunolocalization at the fluorescence and electron microscopic level showed that extracellular tTgase is located at the basal and apical surfaces of cells and at cell-cell contacts, and that LTBP-1 is co-distributed with cell surface tTgase, suggesting an early contribution of tTgase to the binding of LTBP-1 to matrix proteins. LTPB-1 was also found to co-localize with both intracellular and extracellular fibronectin, and increased immunoreactivity for LTBP-1 and fibronectin was found in large molecular weight polymers in the deoxycholate-insoluble matrix of fibroblasts overexpressing tTgase. We conclude that regulation of tTgase expression is important for controlling matrix storage of latent TGF-beta1 complexes and that fibronectin may be one extracellular component to which LTBP-1 is crosslinked when LTBP-1 and tTgase interact at the cell surface. (J Histochem Cytochem 47:1417-1432, 1999)
Verderio
E
E
Department of Life Sciences, Nottingham Trent University, Nottingham, UK.
Gaudry
C
C
Gross
S
S
Smith
C
C
Downes
S
S
Griffin
M
M
D016475:3T3 Cells; D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism*; D003840:Deoxycholic Acid / Q000494:pharmacology; D004797:Enzyme-Linked Immunosorbent Assay; D005109:Extracellular Matrix / Q000378:metabolism* / Q000648:ultrastructure; D005353:Fibronectins / Q000032:analysis / Q000378:metabolism; D019084:Fluorescent Antibody Technique, Indirect; D019204:GTP-Binding Proteins / Q000235:genetics* / Q000378:metabolism*; D015971:Gene Expression Regulation, Enzymologic; D047908:Intracellular Signaling Peptides and Proteins; D007700:Kinetics; D053779:Latent TGF-beta Binding Proteins; D051379:Mice; D016253:Microscopy, Immunoelectron / Q000379:methods; D011401:Promoter Regions, Genetic; D000091345:Protein Glutamine gamma Glutamyltransferase 2; D011700:Putrescine / Q000494:pharmacology; D011994:Recombinant Proteins / Q000378:metabolism; D013752:Tetracycline / Q000494:pharmacology; D014162:Transfection; D016212:Transforming Growth Factor beta / Q000378:metabolism*; D011503:Transglutaminases / Q000235:genetics* / Q000378:metabolism*
D002352:Carrier Proteins; D005353:Fibronectins; D047908:Intracellular Signaling Peptides and Proteins; D053779:Latent TGF-beta Binding Proteins; C509033:Ltbp1 protein, mouse; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; D003840:Deoxycholic Acid; D000091345:Protein Glutamine gamma Glutamyltransferase 2; D011503:Transglutaminases; D019204:GTP-Binding Proteins; D013752:Tetracycline; D011700:Putrescine