Laminins

Vasostatin Inhibits EC proliferation, adhesion to laminin and induces EC apoptosis... 

Several nonconventional cadherins that contain cadherin repeats have been described but they have specific features not found in the classical cadherins [1]. The cadherin Flamingo, originally detected in Drosophila, contains seven transmembrane segments and in this respect resembles G protein-coupled receptors. The extracellular domain of Flamingo and its mammalian homologs is composed of cadherin repeats as well as EGF-like and laminin motifs. The seven transmembrane span cadherins have a role in homotypic cell interactions and in the establishment of cell polarity. The FAT-related cadherins are characterized by a large number of cadherin repeats (34 in FAT and 27 in dachsous). Their cytoplasmic domains can bind to catenins. T- (=truncated-)cadherin differs from other cadherins in that it has no transmembrane domain but is attached to the cell membrane via a glycosylpho-sphatidylinositol anchor. 

It is of interest that proteins termed motility factors (55-70 kD) are secreted by fetal cells and some tumor cells. These proteins act as autocrine factors and stimulate rapid movement by these cells. Motility factors induce the formation of cell processes that are packed with actin filaments and have an increased number of receptors for the matrix proteins laminin and fibronectin. The latter enhance the ability of the cells to bind to the extracellular matrix. Thus, it is likely that motility factors influence the organization of the cytoskeleton through changes taking place at the cell surface (reviewed by Warn and Dowrick, 1989). 

Martin, G.R. Timpl, R. (1987). Laminin and other basement membrane components. Ann. Rev. Cell. Biol. 3, 57-85. 

LAMININ IS A MAJOR PROTEIN COMPONENT OF RENAL GLOMERULAR OTHER BASAL LAMINAS... 

Basal laminas are specialized areas of the ECM that surround epithelial and some other cells (eg, muscle cells) here we discuss only the laminas found in the renal glomerulus. In that strucmre, the basal lamina is contributed by two separate sheets of cells (one endothelial and one epithelial), each disposed on opposite sides of the lamina these three layers make up the glomerular membrane. The primary components of the basal lamina are three proteins—laminin, entactin, and type IV collagen—and the GAG heparin or heparan sulfate. These components are synthesized by the underlying cells. 

Figure 48-4. Schematic representation of a cell interacting through various integrin receptors with collagen, fibronectin, and laminin present in the ECM. (Specific subunits are not indicated.) (Redrawn after Yamada KM Adhesive recognition sequences. J Biol Chem 1991 266 12809.)...

Certain proteoglycans (eg, heparan sulfate) are associated with the plasma membrane of cells, with their core proteins acmally spanning that membrane. In it they may act as receptors and may also participate in the mediation of cell growth and cell-cell communication. The attachment of cells to their substramm in cul-mre is mediated at least in part by heparan sulfate. This proteoglycan is also found in the basement membrane of the kidney along with type IV collagen and laminin... 

Have specific interactions with collagen, elastin, fibronectin, laminin, and other proteins such as growth factors... 

The major components of the ECM are the structural proteins collagen, elastin, and fibrihin a number of specialized proteins (eg, fibronectin and laminin) and various proteoglycans. 

VLA-1 (CD49a) WBCs, others aipi Collagen, laminin Cell-ECM adhesion... 

Integrins themselves are found on nearly all cells and mediate several physiological responses, such as cell-cell and cell-matrix interactions. Three families of integrins, each family with a common beta subunit in combination with distinct alpha subunits, have been recognized. The beta 1 family, also called very late lymphocyte-activation antigen or VLA, has receptors mediating extracellular matrix interactions with molecules such as collagen, laminin, and fibronectin. Naturally, platelets contain many of the receptors of the beta 1 family. 

Thus, while glycoprotein Ia/IIa (a2Pj) binds to collagen, glycoprotein Ic/IIa (a ) binds to fibronectin (5). The other integrin belonging to the beta 1 family that is involved in platelet adhesion is ct6P, which binds laminin. 

Cytoplasmic serine/threonine protein kinases catalyze the transfer of phosphate groups to serine and threonine residues of target proteins. Serine/threonine kinases have been recognized as the products of protooncogenes (e.g., c-mos, c-raj) or as kinases intimately involved with the regulation of serine/threonine kinase activity by cAMP. Some of these kinases specifically phosphorylate cellular structural proteins, such as histone, laminins, etc. Others phosphorylate still more kinases, resulting in either the activation or deactivation of downstream protein kinases. Specific examples in which serine/threonine kinases elicit specific cellular responses are discussed in this chapter. 

Jucker M, Tian M, Ingram DK. Laminins in the adult and aged brain. Mol Chem Neuropathol 1996 28 209-218. Bernstein JJ, Karps SM. Migrating fetal astrocytes do not intravasate since they are excluded from blood vessels by vital basement membrane. Int J Dev Neuroscience 1996 14 177-180. 

Laminine-containing metastable calcium phosphate solution... 

Fig. 11.22 Preparation of hydroxyapatite-laminine nano-hybrid layer.

Uchida, M., Oyane, A., Kim, H.-M., Kokubo, T. and Ito, A. (2004) Biomimetic coating of laminin-apatite composite on titanium metal and its excellent cell-adhesive properties. Advanced Materials, 16, 1071-1074. 

Oyane, A., Uchida, M. and Ito, A. (2005) Laminin-apatite composite coating to enhance cell adhesion to ethylene-vinyl alcohol copolymer. Journal of Biomedical Materials Research, 72A, 168-174. 

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