Complete sequence, recombinant analysis and binding to laminins and sulphated ligands of the N-terminal domains of laminin α3B and α5 chains

2002 ◽  
Vol 362 (2) ◽  
pp. 213-221 ◽  
Author(s):  
Jörg H. O. GARBE ◽  
Walter GÖHRING ◽  
Karlheinz MANN ◽  
Rupert TIMPL ◽  
Takako SASAKI

The N-terminal sequences of mouse laminin α3B and α5 chains have been completed and demonstrate the presence of a signal peptide followed by a complete laminin N-terminal (LN) module (domain VI). These signal peptides were released after recombinant production of larger fragments comprising domains VI/V (45–65kDa) from this region yielding properly folded proteins, which were secreted from HEK-293—EBNA cells. Pepsin digestion of these fragments yielded products of 25–35kDa, which consisted only of domain V. The αVI/V fragments were able to inhibit self-assembly of laminin-1, with those from the α3B and α5 chains being more active than those from α1 and α2 chains. Domain V fragments, however, showed a reduced activity, indicating the major contribution of the LN module in inhibition. These interactions were confirmed by surface-plasmon-resonance assays demonstrating moderate affinities (Kd = 0.02 to > 6μM) for the binding to laminin-1. This indicated that laminins containing α3B or α5 chains should also be able to form non-covalent networks by polymerization. The LN modules also showed heparin binding in affinity chromatography, which was strongest for α1/α2, moderate for α3B, whereas no binding was observed for α5. They all bound to heparan sulphate chains of perlecan and to sulphatides, with a lower variability in binding activity. Specific antibodies were raised against α3BVI/V and α5VI/V and were shown to stain basement membrane zones in various mouse tissues. These antibodies also allowed the identification of a new laminin assembly form 5B consisting of α3B, β3 and γ2 chains.

2004 ◽  
Vol 382 (3) ◽  
pp. 933-943 ◽  
Author(s):  
Hironobu YAMASHITA ◽  
Akira GOTO ◽  
Tatsuhiko KADOWAKI ◽  
Yasuo KITAGAWA

We have previously shown that the LG4 (laminin G-like) domain of the laminin α4 chain is responsible for the significantly higher affinity of the α4 chain to heparin than found for other α chains [Yamaguchi, Yamashita, Mori, Okazaki, Nomizu, Beck and Kitagawa (2000) J. Biol. Chem. 275, 29458–29465]; four basic residues were identified to be essential for this activity [Yamashita, Beck and Kitagawa (2004) J. Mol. Biol. 335, 1145–1149]. By creating GST (glutathione S-transferase)-fused LG1, LG2, LG4 and LG5 proteins, we found that only LG4 is active for the adhesion of human HT1080 cells, human umbilical vein endothelial cells and Drosophila haemocytes Kc167 with a half-saturating concentration of 20 μg/ml. Adhesion was counteracted by treatment of the cells with heparin, heparan sulphate and heparitinase I. Upon mutating the four basic residues essential for heparin binding within LG4, the adhesion activity was abolished. Pull-down experiments using glutathione beads/GST-fusion proteins indicate a direct interaction of LG4 with syndecan-4, which might be the major receptor for cell adhesion. Neither the release of glypican-1 by treating human cells with phosphatidylinositol-specific phospholipase C nor targeted knockdown of dally or dally-like protein impaired the cell-adhesion activity. As the LG4–LG5 domain of the α4 chain is cleaved in vivo from the main body of laminin-8 (α4β1γ1), we suggest that the heparan sulphate proteoglycan-binding activity of LG4 is significant in modulating the signalling of Wnt, Decapentaplegic and fibroblast growth factors.


2003 ◽  
Vol 375 (2) ◽  
pp. 425-432 ◽  
Author(s):  
Timothy M. RITTY ◽  
Thomas J. BROEKELMANN ◽  
Claudio C. WERNECK ◽  
Robert P. MECHAM

Fibrillin-1 and −2 are large modular extracellular matrix glycoproteins found in many vertebrate organ systems and are known to be key components of the elastic fibre. In the present study, we identify a new heparin-binding region in fibrillin-2 between exons 18 and 24. Additionally, we have narrowed the location of heparin-binding activity previously identified in fibrillin-1 to the last 17 residues of the mature proteolytically processed protein. This domain demonstrated higher activity as a multimer than as a monomer. The fibrillin-1 C-terminal site supported cell attachment in each of nine cell types tested. Attachment was shown to be mediated by cell-surface heparan sulphate proteoglycans. Fibrillin-1 has been shown previously to have heparin-binding activity that is important for matrix deposition of the molecule by fibroblasts. This function in deposition was confirmed in two additional fibrillin-producing cell types (osteosarcoma and epithelial cells) for the deposition of both fibrillin-1 and −2 into the extracellular matrix.


1991 ◽  
Vol 66 (03) ◽  
pp. 310-314 ◽  
Author(s):  
David C Sane ◽  
Tammy L Moser ◽  
Charles S Greenberg

SummaryVitronectin (VN) stabilizes plasminogen activator inhibitor type 1 (PAI-1) activity and prevents the fibrin(ogen)-induced acceleration of plasminogen activation by t-PA. These antifibrinolytic activities as well as other functions are mediated by the glycosaminoglycan (GAG) binding domain of VN. Since the GAG binding region is rich in arginyl and lysyl residues, it is a potential target for enzymes such as plasmin. In this paper, the dose and time-dependent proteolysis of VN by plasmin is demonstrated. The addition of urokinase or streptokinase (200 units/ml) to plasma also produced proteolysis of VN. With minimal proteolysis, the 75 kDa band was degraded to a 62-65 kDa form of VN. This minimal proteolysis destroyed the binding of [3H]-heparin to VN and reversed the neutralization of heparin by VN.Thus, the plasmin-mediated proteolysis of the GAG binding activity of VN could destroy the antifibrinolytic activity of VN during physiologic conditions and during thrombolytic therapy. Furthermore, other functions of VN in complement and coagulation systems that are mediated by the GAG binding domain may be destroyed by plasmin proteolysis.


PLoS ONE ◽  
2013 ◽  
Vol 8 (2) ◽  
pp. e56839 ◽  
Author(s):  
Marina Klemenčič ◽  
Marko Novinec ◽  
Silke Maier ◽  
Ursula Hartmann ◽  
Brigita Lenarčič

1994 ◽  
Vol 107 (2) ◽  
pp. 401-411
Author(s):  
N. Flint ◽  
F.L. Cove ◽  
G.S. Evans

Heparin is a sulphated glycosaminoglycan derived from mast cells and has a number of functions including the inhibition of proliferation in several cell types and interactions with a range of heparin-binding growth factors. We report that heparin is a trophic factor in primary cultures of rat small intestinal epithelium. Heparin elicits a dose-dependent increase in epithelial proliferation and inhibits the growth of associated mesenchyme. The trophic effect of this molecule is not reproduced by other glycosaminoglycans including heparan sulphate but is dependent upon extensive molecular sulphation. Highly sulphated polysaccharides that are structurally unrelated to heparin (e.g. dextran sulphate and pentosan polysulphate) also stimulate epithelial proliferation in primary cultures. Heparin may act by the potentiation of mesenchyme-derived heparin-binding growth factors and these data suggest an in vivo role for mast cell-derived heparin in mucosal wound regeneration.


2005 ◽  
Vol 390 (2) ◽  
pp. 407-418 ◽  
Author(s):  
Catherine de Coupade ◽  
Antonio Fittipaldi ◽  
Vanessa Chagnas ◽  
Matthieu Michel ◽  
Sophie Carlier ◽  
...  

Short peptide sequences that are able to transport molecules across the cell membrane have been developed as tools for intracellular delivery of therapeutic molecules. This work describes a novel family of cell-penetrating peptides named Vectocell® peptides [also termed DPVs (Diatos peptide vectors)]. These peptides, originating from human heparin binding proteins and/or anti-DNA antibodies, once conjugated to a therapeutic molecule, can deliver the molecule to either the cytoplasm or the nucleus of mammalian cells. Vectocell® peptides can drive intracellular delivery of molecules of varying molecular mass, including full-length active immunoglobulins, with efficiency often greater than that of the well-characterized cell-penetrating peptide Tat. The internalization of Vectocell® peptides has been demonstrated to occur in both adherent and suspension cell lines as well as in primary cells through an energy-dependent endocytosis process, involving cell-membrane lipid rafts. This endocytosis occurs after binding of the cell-penetrating peptides to extracellular heparan sulphate proteoglycans, except for one particular peptide (DPV1047) that partially originates from an anti-DNA antibody and is internalized in a caveolar independent manner. These new therapeutic tools are currently being developed for intracellular delivery of a number of active molecules and their potentiality for in vivo transduction investigated.


1995 ◽  
Vol 270 (16) ◽  
pp. 9398-9406 ◽  
Author(s):  
Holly Colognato-Pyke ◽  
Julian J. O'Rear ◽  
Yoshihiko Yamada ◽  
Salvatore Carbonetto ◽  
Yi-Shan Cheng ◽  
...  

2000 ◽  
Vol 24 (1) ◽  
pp. 43-51 ◽  
Author(s):  
H Song ◽  
J Beattie ◽  
IW Campbell ◽  
GJ Allan

Using site-directed mutagenesis, we have undertaken a study of a potential IGF-binding site in the C-terminal domain of rat IGFBP-5, lying close to or within a previously described heparin-binding domain (residues 201-218) in this protein. After analysis of binding activity using three different methods - ligand blotting, solution phase equilibrium binding and biosensor measurement of real-time on- and off-rates - we report that the mutation of two highly conserved residues within this region (glycine 203 and glutamine 209) reduces the affinity of the binding protein for both IGF-I and IGF-II, while having no effect on heparin binding. In addition, we confirm that mutation of basic residues within the heparin-binding domain (R201L, K202E, K206Q and R214A) results in a protein that has attenuated heparin binding but shows only a small reduction in affinity for IGF-I and -II. Previous findings have described the reduction in affinity of IGFBP-5 for IGFs that occurs after complexation of the binding protein with heparin or other components of the extracellular matrix (ECM) and have postulated that such an interaction may result in conformational changes in protein structure, affecting subsequent IGF interaction. Our data suggesting potential overlap of heparin- and IGF-binding domains argue for a more direct effect of ECM modulation of the affinity of IGFBP-5 for ligand by partial occlusion of the IGF-binding site after interaction with ECM.


2001 ◽  
Vol 276 (50) ◽  
pp. 46722-46728 ◽  
Author(s):  
Nanyue Chen ◽  
Wei-Ya Ma ◽  
Qing-Bai She ◽  
Erxi Wu ◽  
Guangming Liu ◽  
...  

The mechanism of 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced tumor promotion is still not well understood even though it is thought to be related to the protein kinase C/mitogen-activated protein kinase/AP-1 pathway. Recently, TPA was also found to induce epidermal growth factor receptor (EGFR) activity. Here, we investigated whether the EGFR is a necessary component for TPA-induced signal transduction associated with tumor promotion. We demonstrated that potent inhibitors of the EGFR, PD153035 and AG1478, blocked TPA-induced phosphorylation of extracellular signal-regulated kinases (ERKs), AP-1 activity, and cell transformation.Egfrgene deficiency blocked TPA-induced ERK activity and AP-1 binding activity. The blocking of the ectodomain of the EGFR by a monoclonal antibody depressed TPA-induced ERK activity and AP-1 DNA binding activity. The use of a neutralizing antibody for heparin-binding EGF, one of the ligands of EGFR, blocked TPA-induced phosphorylation of ERKs. BB-94, a potent inhibitor of matrix metalloproteinases, which are activators of ectodomain shedding of EGFR ligands, also blocked TPA-induced ERK activity, AP-1 DNA binding, and cell transformation but had no effect on EGF-induced signal transduction. Anti-EGFR, anti-heparin-binding EGF, and BB-94 each blocked TPA-induced EGFR phosphorylation, but only anti-EGFR could block EGF-induced EGFR phosphorylation. Based on these results, we conclude that the EGFR is required for mediating TPA-induced signal transduction. EGFR transactivation induced by TPA is a mechanism by which the EGFR mediates TPA-induced tumor promotion-related signal transduction.


1993 ◽  
Vol 290 (2) ◽  
pp. 623-626 ◽  
Author(s):  
K Karlsson ◽  
A Edlund ◽  
J Sandström ◽  
S L Marklund

The heparin-binding affinity of the tetrameric extracellular superoxide dismutase (EC-SOD) is a result of the cooperative effect of the heparin-binding domains of the subunits, located in the hydrophilic, strongly positively charged C-terminal ends. EC-SOD C, the high-heparin-affinity type, exposed to immobilized trypsin and plasmin was found to rapidly lose its affinity for heparin, without any loss of enzymic activity or major change in molecular mass as judged by size-exclusion chromatography. Heparin and dextran sulphate 5000 inhibited the proteolysis, suggesting that EC-SOD C sequestered by heparan sulphate proteoglycan in vivo is partially protected against proteolysis. The loss of heparin-affinity occurred with the stepwise formation of intermediates, and the pattern upon chromatography on heparin-Sepharose and subsequent immunoblotting was compatible with the notion that the changes are due to sequential truncations of heparin-binding domains from subunits composing the EC-SOD tetramers. A similar pattern with intermediates and apparent truncations has previously been found with EC-SOD of human plasma. The findings show that the unique design of the heparin-binding domain of EC-SOD allows easy modification of the heparin-affinity by means of limited proteolysis, and suggest that such proteolysis is a major contributor to the heterogeneity in heparin-affinity of EC-SOD in mammalian plasma.


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