Matrix proteins, extracellular

Oberhauser et al., 1998] Oberhauser, A. F., Marszalek, P. E., Erickson, H., and Fernandez, J. The molecular elasticity of tenascin, an extracellular matrix protein. Nature. In Press. 

Cathepsins are intracellular proteinases that reside within lysosomes or specific intracellular granules. Cathepsins are used to degrade proteins or pqffides that are internalised from the extracellular space. Some cathepsins such as cathepsin-G or cathepsin-K may be released from the cell to degrade specific extracellular matrix proteins. All cathepsins except cathepsin-G (serine) and cathepsin-D (aspartyl) are cysteine proteinases. 

Reelin is an extracellular matrix protein, which is secreted by neuronal cells and binds to two lipoprotein receptors (VLDLR and ApoER2) that relay the Reelin signal inside target neurons by docking the tyrosine kinase adapter disabled-1 (Dabl). This allows neurons to complete migration and adopt their ultimate positions in laminar structures in the central nervous system. In... 

The secretion of extracellular matrix proteins is also a function of smooth muscle cells but, since it occurs concurrently with other activities, it does not seem to constitute a physiological state. However, the fraction of the cellular resources which are devoted to it must be regulated these regulatory mechanisms are virtually unknown. In addition, it should be anticipated that autocrine activity occurs as well, involving peptides, prostaglandins, cytokines, and nitric oxide. 

Matrix metalloproteinases Zinc-dependent enzymes capable of degrading extracellular matrix proteins, including connective tissue. 

There are various angiotensin II-dependent pathways of NADPH oxidase activation. Xie et al. [116] have found that angiotensin II induced the stimulation of osteopontin, an extracellular matrix protein, in cardiac microvascular endothelial... 

TGF-Ps are pleiotrophic cytokines. They are capable of inhibiting the cell cycle and, hence, cell growth of several cell types, most notably epithelial and haematopoietic cells. These factors, however, stimulate the growth of other cell types, most notably cells that give rise to connective tissue, cartilage and bone. They induce the synthesis of extracellular matrix proteins and modulate the expression of matrix proteases. They also serve as a powerful chemoattractant for monocytes... 

Usher II is caused by mutations in at least four genes only one, usherin, has been identified. Usherin is an extracellular matrix protein of unknown function it is found in basement membranes in the eye and ear (and in other tissues as well). Similarly, at least two genes underlie Usher III, but only one (clarin-1) has been cloned. The function of clarin-1 is unknown. 

Fibronectin is an extracellular matrix protein that mediates a variety of cellular effects. It is important in cell-cell and cell-substratum interactions ( 3.9), mediates reticuloendothelial cell activity and binds both to Clq (the first component of complement) and to bacteria. It also increases the tu-mouricidal activity of macrophages and activates complement receptors, by regulating the binding of C3b-coated particles to neutrophils. It may mediate attachment of Staphylococcus aureus to neutrophils and may also play a role as an adhesion factor, promoting the adhesion of neutrophils to surfaces. Fibronectin mRNA (8.7-8.8 kb) is detected only at low levels in... 

Matrix metalloproteinases (MMPs) are a class of zinc- and calcium-dependent enzymes that are responsible for the metabolism of extracellular matrix proteins [27]. Increased activity of MMPs has been associated with pathological diseases such as arthritis, cancer, multiple sclerosis and Alzheimer s disease [28-31]. Therefore, they constitute an important group of drug targets. Their inhibition is accomplished by blocking the active site of the catalytic domain with ligands that contain hydroxamic or carboxylic acids to chelate the Zn metal. The identification of low molecular weight compounds that contain different scaffolds may lead to the development of a new class of specific inhibitors. 

Pakianathan DR. Extracellular-matrix proteins and leukocyte function. J Leukocyte Biol 1995 57 699-702. 

Collagen is the most abundant extracellular matrix protein family in vertebrates. Proteins in the collagen superfamily all have three polypeptide chains with the required -Gly-Xaa-Yaa- repeated sequence, where Xaa and Yaa are frequently proline and 4-hydroxyproline, respectively. At present, more than 30 molecular species of vertebrate proteins called collagen are classified into 28 types as type I, II, III,..., XXVIII. They are typically called type N collagen , or collagen N . In addition, there are many more collagen-like proteins that... 

Most types of collagen are extracellular matrix proteins but four of the vertebrate collagens (XIII, XVII, XXIII, and XXV) are classified as type II membrane proteins. They contain an N-terminal cytoplasmic domain, a transmembrane domain, and an extracellular collagenous domain. Also, a membrane-bound protein, ectodys-plasin-A, is a membrane protein with 19 -Gly-Xaa-Yaa- repeat. Macrophage scavenger receptor, ... 

Figure. 4. Principle of the cell adhesion to artificial materials. In cell culture media or body fluids, the material is spontaneously adsorbed with cell adhesion-mediating extracellular matrix proteins (e g., vitronectin, fibronectin). The cells then adhere to specific amino acid sequences of these proteins by their adhesion receptors of integrin or non-integrin type [38-41].

Gateau E, Levasseur P, Borgonovi M, Imbert C. (2007) The effect of aminocandin (HMR 3270) on the in vitro adherence of Candida Albicans to polystyrene surfaces coated with extracellular matrix proteins or fibronectin. Clin Microbiol Infec 13 311-315. 

Heparin has been found to bind a large number of proteins (Table 3). The biological activity of heparin and related polysaccharides is usually ascribed to their interaction with heparin-binding proteins. These proteins can be classified into classes including (1) enzymes, (2) protease inhibitors, (3) lipoproteins, (4) growth factors, (5) chemokines, (6) selectins, (7) extracellular matrix proteins, (8) receptor proteins, (9) viral coat proteins, (10) nuclear proteins, and (11) other proteins (1). Many heparin-binding proteins are enzymes and enzyme inhibitors. For example, proteases in the coagulation cascade, such as factors Ha, IXa, Xa, Xlla, and Villa, are heparin-... 

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