Integrins activation

Shimonaka M, Katagiri K, Nakayama T, et al. Rapl translates chemokine signals to integrin activation, cell polarization, and motility across vascular endothelium under flow. J Cell Biol 2003 161 (2) 417 427. 

As a consequence of ligand binding and clustering of integrins, activation of different signaling pathways is initiated ... 

Additional information <1, 2, 3, 4, 38> (<2>, in cells loaded with protein-tyrosine phosphatase antibody, phosphatidylinositol 3 -kinase activity is increased by 38%, respectively, compared with control cells loaded with preim-mune IgG [11] <4>, b2-integrins activate the tyrosine kinases p58c-fgr and p59/61hck and causes them to associate with the p85 subunit of Ptdins 3-... 

Fig. 1 Downstream effects of integrin activation during outside-in signalling. The ECM properties and the growth factor environment regulate assembly of the ECM-integrin-adhesome-F-actin system, which controls cell activity. The long-term effects of the outside-in signalling (10-60 min) are indicated in italics...

Numerous and diverse biological functions are regulated by chemokines. In addition to the well characterized proinflammatory activities such as integrin activation, chemotaxis, lipid mediator biosynthesis, superoxide radical production, and granule enzyme release (reviewed in refs. 1-4), chemokines have been shown to suppress and stimulate angiogenesis (5-7), suppress hematopoiesis (8-10), suppress apoptosis (11), control viral infection (12,13), and effect leukocyte differentiation (14). Among the proinflammatory activities, chemotaxis in particular has received considerable attention as a target for novel antiinflammatory therapeutics (reviewed in ref. 15). 

Fig. 3. Conformational states for integrins. A-C. Model for a l3 integrin activation, with at least three conformations of the extracellular domain (Takagi et al, 2002). (A) Bent, low affinity conformation. (B) Extended conformation with closed headpiece. (C) Extended conformation with open headpiece shown with bound RGD-mimetic peptide (green CPK). D-H. Model for aiJ3 integrin activation. (D) Bent conformation with low affinity. (E) and (F) with a closed headpiece and closed I domain in...

A small GTPase involved in integrin activation and cell adhesion Randomly amplified polymorphic DNA RecA-assisted restriction endonuclease GTP-binding signal transducers... 

The conserved membrane-proximal portions of integrin a and 3 cytoplasmic tails control integrin activation. Mutation or tmn-cation of this region results in constitutive integrin activation... 

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