scholarly journals Integrin αVβ6-mediated activation of latent TGF-β requires the latent TGF-β binding protein-1

2004 ◽  
Vol 165 (5) ◽  
pp. 723-734 ◽  
Author(s):  
Justin P. Annes ◽  
Yan Chen ◽  
John S. Munger ◽  
Daniel B. Rifkin
Keyword(s):  
Functional Role ◽  
Transforming Growth Factor ◽  
Binding Protein ◽  
Basic Amino Acid ◽  
Potential Interaction ◽  
Specific Function ◽  
Integrin Αvβ6 ◽  
The Matrix ◽  
Hinge Domain

Transforming growth factor-βs (TGF-β) are secreted as inactive complexes containing the TGF-β, the TGF-β propeptide, also called the latency-associated protein (LAP), and the latent TGF-β binding protein (LTBP). Extracellular activation of this complex is a critical but incompletely understood step in TGF-β regulation. We have investigated the role of LTBP in modulating TGF-β generation by the integrin αVβ6. We show that even though αvβ6 recognizes an RGD on LAP, LTBP-1 is required for αVβ6-mediated latent TGF-β activation. The domains of LTBP-1 necessary for activation include the TGF-β propeptide-binding domain and a basic amino acid sequence (hinge domain) with ECM targeting properties. Our results demonstrate an LTBP-1 isoform-specific function in αVβ6-mediated latent TGF-β activation; LTBP-3 is unable to substitute for LTBP-1 in this assay. The results reveal a functional role for LTBP-1 in latent TGF-β activation and suggest that activation of specific latent complexes is regulated by distinct mechanisms that may be determined by the LTBP isoform and its potential interaction with the matrix.

scholarly journals The major determinant of the heparin binding of glial cell-line-derived neurotrophic factor is near the N-terminus and is dispensable for receptor binding

2007 ◽  
Vol 404 (1) ◽  
pp. 131-140 ◽  
Author(s):  
Ivan Alfano ◽  
Parvez Vora ◽  
Rosemary S. Mummery ◽  
Barbara Mulloy ◽  
Christopher C. Rider
Keyword(s):  
Cell Line ◽  
Glial Cell ◽  
Neurotrophic Factor ◽  
Transforming Growth Factor ◽  
Basic Amino Acid ◽  
Transforming Growth Factor Β ◽  
Heparin Binding ◽  
Binding Sequence

GDNF (glial cell-line-derived neurotrophic factor), and the closely related cytokines artemin and neurturin, bind strongly to heparin. Deletion of a basic amino-acid-rich sequence of 16 residues N-terminal to the first cysteine of the transforming growth factor β domain of GDNF results in a marked reduction in heparin binding, whereas removal of a neighbouring sequence, and replacement of pairs of other basic residues with alanine had no effect. The heparin-binding sequence is quite distinct from the binding site for the high affinity GDNF polypeptide receptor, GFRα1 (GDNF family receptor α1), and heparin-bound GDNF is able to bind GFRα1 simultaneously. The heparin-binding sequence of GDNF is dispensable both for GFRα1 binding, and for activity for in vitro neurite outgrowth assay. Surprisingly, the observed inhibition of GDNF bioactivity with the wild-type protein in this assay was still found with the deletion mutant lacking the heparin-binding sequence. Heparin neither inhibits nor potentiates GDNF–GFRα1 interaction, and the extracellular domain of GFRα1 does not bind to heparin itself, precluding heparin cross-bridging of cytokine and receptor polypeptides. The role of heparin and heparan sulfate in GDNF signalling remains unclear, but the present study indicates that it does not occur in the first step of the pathway, namely GDNF–GFRα1 engagement.

scholarly journals Differential localization and functional role of calsequestrin in growing and differentiated myoblasts.

1995 ◽  
Vol 128 (3) ◽  
pp. 341-354 ◽  
Author(s):  
M Raichman ◽  
M C Panzeri ◽  
E Clementi ◽  
P Papazafiri ◽  
M Eckley ◽  
...  
Keyword(s):  
Functional Role ◽  
Heterologous Protein ◽  
Viral Vector ◽  
Binding Protein ◽  
High Capacity ◽  
Peptide Hormone ◽  
L6 Cells ◽  
Er Retention ◽  
Before And After

Calsequestrin (CSQ) is the low affinity, high capacity Ca(2+)-binding protein concentrated within specialized areas of the muscle fiber sarcoplasmic reticulum (a part of the ER) where it is believed to buffer large amounts of Ca2+. Upon activation of intracellular channels this Ca2+ pool is released, giving rise to the [Ca2+]i increases that sustain contraction. In order to investigate the ER retention and the functional role of the protein, L6 rat myoblasts were infected with a viral vector with or without the cDNA of chicken CSQ, and stable clones were investigated before and after differentiation to myotubes. In the undifferentiated L6 cells, expression of considerable amounts of heterologous CSQ occurred with no major changes of other ER components. Ca2+ release from the ER, induced by the peptide hormone vasopressin, remained however unchanged, and the same occurred when other treatments were given in sequence to deplete the ER and other intracellular stores: with the Ca2+ pump blocker, thapsigargin; and with the Ca2+ ionophore, ionomycin, followed by the Na+/H+ ionophore, monensin. The lack of effect of CSQ expression on the vasopressin-induced [Ca2+]i responses was explained by immunocytochemistry showing the heterologous protein to be localized not in the ER but in large vacuoles of acidic content, positive also for the lysosomal enzyme, cathepsin D, corresponding to a lysosomal subpopulation. After differentiation, all L6 cells expressed small amounts of homologous CSQ. In the infected cells the heterologous protein progressively decreased, yet the [Ca2+]i responses to vasopressin were now larger with respect to both control and undifferentiated cells. This change correlated with the drop of the vacuoles and with the accumulation of CSQ within the ER lumen, where a clustered distribution was observed as recently shown in developing muscle fibers. These results provide direct evidence for the contribution of CSQ, when appropriately retained, to the Ca2+ capacity of the rapidly exchanging, ER-located Ca2+ stores; and for the existence of specific mechanism(s) (that in L6 cells develop in the course of differentiation) for the ER retention of the protein. In the growing L6 myoblasts the Ca(2+)-binding protein appears in contrast to travel along the exocytic pathway, down to post-Golgi, lysosome-related vacuoles which, based on the lack of [Ca2+]i response to ionomycin-monensin, appear to be incompetent for Ca2+ accumulation.

Functional role of oppA encoding an oligopeptide-binding protein from Lactobacillus salivarius Ren in bile tolerance

2015 ◽  
Vol 42 (8) ◽  
pp. 1167-1174 ◽  
Author(s):  
Guohong Wang ◽  
Dan Li ◽  
Xiayin Ma ◽  
Haoran An ◽  
Zhengyuan Zhai ◽  
...  
Keyword(s):  
Functional Role ◽  
Binding Protein ◽  
Lactobacillus Salivarius ◽  
Bile Tolerance

Role of Transforming Growth Factor-β1 and its Latent Form Binding Protein in Pseudoexfoliation Syndrome

2001 ◽  
Vol 73 (6) ◽  
pp. 765-780 ◽  
Author(s):  
Ursula Schlötzer-Schrehardt ◽  
Matthias Zenkel ◽  
Michael Küchle ◽  
Lynn Y. Sakai ◽  
Gottfried O.H. Naumann
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor ◽  
Binding Protein ◽  
Transforming Growth Factor Β1 ◽  
Pseudoexfoliation Syndrome ◽  
Latent Form

scholarly journals Role of the Latent Transforming Growth Factor β-Binding Protein 1 in Fibrillin-Containing Microfibrils in Bone Cells In Vitro and In Vivo

2000 ◽  
Vol 15 (1) ◽  
pp. 68-81 ◽  
Author(s):  
Sarah L. Dallas ◽  
Douglas R. Keene ◽  
Scott P. Bruder ◽  
Juha Saharinen ◽  
Lynn Y. Sakai ◽  
...  
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor ◽  
Bone Cells ◽  
Binding Protein ◽  
Transforming Growth Factor Β

scholarly journals Techno-Functional Role of Exopolysaccharides in Cereal-Based, Yogurt-Like Beverages

Beverages ◽  
2019 ◽  
Vol 5 (1) ◽  
pp. 16 ◽  
Author(s):  
Valery Ripari
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Functional Role ◽  
Current Knowledge ◽  
Starter Cultures ◽  
Solid Surfaces ◽  
Functional Roles ◽  
The Matrix

This review describes the technical and functional role of exopolysaccharides (EPSs) in cereal-based, yogurt-like beverages. Many microorganisms produce EPSs as a strategy for growing, adhering to solid surfaces, and surviving under adverse conditions. In several food and beverages, EPSs play technical and functional roles. Therefore, EPSs can be isolated, purified, and added to the product, or appropriate bacteria can be employed as starter cultures to produce the EPSs in situ within the matrix. The exploitation of in situ production of EPSs is of particular interest to manufacturers of cereal-base beverages aiming to mimic dairy products. In this review, traditional and innovative or experimental cereal-based beverages, and in particular, yogurt-like beverages are described with a particular focus in lactic acid bacteria (LAB’s) EPS production. The aim of this review is to present an overview of the current knowledge of exopolysaccharides produced by lactic acid bacteria, and their presence in cereal-based, yogurt-like beverages.

Functional role of transforming growth factor-β type III receptor during palatal fusion

2007 ◽  
Vol 236 (3) ◽  
pp. 791-801 ◽  
Author(s):  
Akira Nakajima ◽  
Yoshihiro Ito ◽  
Masatake Asano ◽  
Masao Maeno ◽  
Koichi Iwata ◽  
...  
Keyword(s):  
Growth Factor ◽  
Functional Role ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Type Iii ◽  
Palatal Fusion
Sign in / Sign up

Export Citation Format

Share Document