Integrins domain

A. Overall Picture of Integrin Heterodimers and Integrin Domains. 31... 

R 315 JJ. Calvete, Structures of Integrin Domains and Concerted Conformational Changes in the Bidirectional Signaling Mechanism of oinbpa , Exp.Biol.Med., 2004,229,732... 

The leukocyte integrin a 4(3 1 (also known as VLA-4 and CD49d/CD29) is a cell adhesion receptor, which is predominantly expressed on lymphocytes, monocytes and eosinophils. VLA-4 is generally selective for the CS1 domain within fibronectin, with an essential requirement for LDV sequence for binding. VLA-4 also binds to VCAM-1 as a counter receptor. 

The integrin a 4(3 7 is restricted to leukocytes and can bind not only to VCAM1 and fibronectin, but also to MAdCAM the mucosal addressin or homing receptor, which contains immunoglobulin-like domains related to VCAM-1. 

The Sema domain consisting of about 500 amino acids is characterized by highly conserved cysteine residues that form intramolecular disulfide bonds. Crystal structures have revealed that the Sema domain folds in the manner of the (3 propeller topology which is also found in integrins or the low-density lipoprotein (LDL) receptors. Sema domains are found in semaphorins, plexins and in the receptor tyrosine kinases Met and Ron. 

Kim J. Han L Kim Y. et al. C-terminal heparin-binding domain of fibronectin regulates integrin-mediated cell spreading but not the activation of mitogen-activated protein kinase / / Biochem. J. 2001. V. 360. P. 239-245. 

Mi LX, Fischer S, Chung B et al (2006) Self-assembling protein hydrogels with modular integrin binding domains. Biomacromolecules 7 38 7... 

Figure 48-3. Schematic representation of fibronectin. Seven functional domains of fibronectin are represented two different types of domain for heparin, cell-binding, and fibrin are shown. The domains are composed of various combinations of three structural motifs (I, II, and III), not depicted in the figure. Also not shown is the fact that fibronectin is a dimer joined by disulfide bridges near the carboxyl terminals of the monomers. The approximate location of the RGD sequence of fibronectin, which interacts with a variety of fibronectin integrin receptors on cell surfaces, is indicated by the arrow. (Redrawn after Yamada KM Adhesive recognition sequences.

FIGURE 7-3 Integrins are heterodimers. Integrins consist of a and 3 subunits noncovalently linked, which interact via their cytoplasmic domains with a number of cytoplasmic proteins. The axpi integrin complex on the left binds to a complex which includes focal adhesion kinase (FAK). The a6P4 integrin complex contains fibronectin (FN) III repeats, which mediate binding to intermediate filaments. 

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