Proteoglycans, ion channels and cell–matrix adhesion

2017 ◽  
Vol 474 (12) ◽  
pp. 1965-1979 ◽  
Author(s):  
Ioli Mitsou ◽  
Hinke A.B. Multhaupt ◽  
John R. Couchman

Cell surface proteoglycans comprise a transmembrane or membrane-associated core protein to which one or more glycosaminoglycan chains are covalently attached. They are ubiquitous receptors on nearly all animal cell surfaces. In mammals, the cell surface proteoglycans include the six glypicans, CD44, NG2 (CSPG4), neuropilin-1 and four syndecans. A single syndecan is present in invertebrates such as nematodes and insects. Uniquely, syndecans are receptors for many classes of proteins that can bind to the heparan sulphate chains present on syndecan core proteins. These range from cytokines, chemokines, growth factors and morphogens to enzymes and extracellular matrix (ECM) glycoproteins and collagens. Extracellular interactions with other receptors, such as some integrins, are mediated by the core protein. This places syndecans at the nexus of many cellular responses to extracellular cues in development, maintenance, repair and disease. The cytoplasmic domains of syndecans, while having no intrinsic kinase activity, can nevertheless signal through binding proteins. All syndecans appear to be connected to the actin cytoskeleton and can therefore contribute to cell adhesion, notably to the ECM and migration. Recent data now suggest that syndecans can regulate stretch-activated ion channels. The structure and function of the syndecans and the ion channels are reviewed here, along with an analysis of ion channel functions in cell–matrix adhesion. This area sheds new light on the syndecans, not least since evidence suggests that this is an evolutionarily conserved relationship that is also potentially important in the progression of some common diseases where syndecans are implicated.

1997 ◽  
Vol 327 (1) ◽  
pp. 1-16 ◽  
Author(s):  
David J. CAREY

This review will summarize our current state of knowledge of the structure, biochemical properties and functions of syndecans, a family of transmembrane heparan sulphate proteoglycans. Syndecans bind a variety of extracellular ligands via their covalently attached heparan sulphate chains. Syndecans have been proposed to play a role in a variety of cellular functions, including cell proliferation and cell–matrix and cell–cell adhesion. Syndecan expression is highly regulated and is cell-type- and developmental-stage-specific. The main function of syndecans appears to be to modulate the ligand-dependent activation of primary signalling receptors at the cell surface. Principal functions of the syndecan core proteins are to target the heparan sulphate chains to the appropriate plasma-membrane compartment and to interact with components of the actin-based cytoskeleton. Several functions of the syndecans, including syndecan oligomerization and actin cytoskeleton association, have been localized to specific structural domains of syndecan core proteins.


2002 ◽  
Vol 82 (4) ◽  
pp. 1848-1857 ◽  
Author(s):  
Ella Zimmerman ◽  
Benjamin Geiger ◽  
Lia Addadi

2021 ◽  
Vol 22 (10) ◽  
pp. 5144
Author(s):  
Antonín Sedlář ◽  
Martina Trávníčková ◽  
Pavla Bojarová ◽  
Miluše Vlachová ◽  
Kristýna Slámová ◽  
...  

Galectin-3 (Gal-3) is a β-galactoside-binding protein that influences various cell functions, including cell adhesion. We focused on the role of Gal-3 as an extracellular ligand mediating cell-matrix adhesion. We used human adipose tissue-derived stem cells and human umbilical vein endothelial cells that are promising for vascular tissue engineering. We found that these cells naturally contained Gal-3 on their surface and inside the cells. Moreover, they were able to associate with exogenous Gal-3 added to the culture medium. This association was reduced with a β-galactoside LacdiNAc (GalNAcβ1,4GlcNAc), a selective ligand of Gal-3, which binds to the carbohydrate recognition domain (CRD) in the Gal-3 molecule. This ligand was also able to detach Gal-3 newly associated with cells but not Gal-3 naturally present on cells. In addition, Gal-3 preadsorbed on plastic surfaces acted as an adhesion ligand for both cell types, and the cell adhesion was resistant to blocking with LacdiNAc. This result suggests that the adhesion was mediated by a binding site different from the CRD. The blocking of integrin adhesion receptors on cells with specific antibodies revealed that the cell adhesion to the preadsorbed Gal-3 was mediated, at least partially, by β1 and αV integrins—namely α5β1, αVβ3, and αVβ1 integrins.


2007 ◽  
Vol 213 (3) ◽  
pp. 565-573 ◽  
Author(s):  
Allison L. Berrier ◽  
Kenneth M. Yamada

2018 ◽  
Author(s):  
Vibha Singh ◽  
Chaitanya Erady ◽  
Nagaraj Balasubramanian

AbstractCell-matrix adhesion regulates membrane trafficking to control anchorage-dependent signaling. While a dynamic Golgi complex can contribute to this pathway, its control by adhesion remains untested. We find the loss of adhesion rapidly disorganizes the Golgi in mouse and human fibroblast cells, its integrity restored rapidly on re-adhesion to fibronectin (but not poly-l-lysine coated beads) along the microtubule network. Adhesion regulates the trans-Golgi more prominently than the cis /cis-medial Golgi, though they show no fallback into the ER making this reorganization distinct from known Golgi fragmentation. This is controlled by an adhesion-dependent drop and recovery of Arf1 activation, mediated through the Arf1 GEF BIG1/2 over GBF1. Constitutively active Arf1 disrupts this regulation and prevents Golgi disorganization in non-adherent cells. Adhesion regulates active Arf1 binding to the microtubule minus-end motor protein dynein to control Golgi reorganization, which ciliobrevin blocks. This regulation by adhesion controls Golgi function, promoting cell surface glycosylation on the loss of adhesion that constitutively active Arf1 blocks. This study hence identifies cell-matrix adhesion to be a novel regulator of Arf1 activation, controlling Golgi organization and function in anchorage-dependent cells.Summary StatementThis study identifies a role for cell-matrix adhesion in regulating organelle (Golgi) architecture and function which could have implications for multiple cellular pathways and function.


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