| Structural highlights
Function
FERM2_HUMAN Scaffolding protein that enhances integrin activation mediated by TLN1 and/or TLN2, but activates integrins only weakly by itself. Binds to membranes enriched in phosphoinositides. Enhances integrin-mediated cell adhesion onto the extracellular matrix and cell spreading; this requires both its ability to interact with integrins and with phospholipid membranes. Required for the assembly of focal adhesions. Participates in the connection between extracellular matrix adhesion sites and the actin cytoskeleton and also in the orchestration of actin assembly and cell shape modulation. Recruits FBLIM1 to focal adhesions. Plays a role in the TGFB1 and integrin signaling pathways. Stabilizes active CTNNB1 and plays a role in the regulation of transcription mediated by CTNNB1 and TCF7L2/TCF4 and in Wnt signaling.[1] [2] [3] [4] [5] [6]
Publication Abstract from PubMed
ILK (integrin-linked kinase) is a distinct intracellular adaptor essential for integrin-mediated cell-extracellular matrix (ECM) adhesion, cell spreading, and migration. Acting as a major docking platform in focal adhesions (FAs), ILK engages many proteins to dynamically link integrins with cytoskeleton, but the underlying mechanism remains elusive. Here we have characterized the interaction of ILK with kindlin-2, a key regulator for integrin bi-directional signaling. We show that human kindlin-2 binds to human ILK with high affinity. Using systematic mapping approaches, we have identified a major ILK binding site involving a 20-residue (339-358) fragment in kindlin-2. NMR-based analysis reveals a helical conformation of this fragment which utilizes its leucine-rich surface to recognize the ILK pseudokinase domain in a mode that is distinct from another ILK pseudokinase domain binding protein, alpha-parvin. Structure-based mutational experiments further demonstrate that the kindlin-2 binding to ILK is crucial for the kindlin-2 localization to FAs and cell spreading (integrin outside-in signaling) but dispensable for the kindlin-2-mediated integrin activation (integrin inside-out signaling). These data define a specific mode of the kindlin-2/ILK interaction with mechanistic implications as to how it spatiotemporally mediates integrin signaling and cell adhesion.
Molecular basis of kindlin-2 binding to integrin-linked kinase (ILK) pseudokinase for regulating cell adhesion.,Fukuda K, Bledzka K, Yang J, Perera HD, Plow EF, Qin J J Biol Chem. 2014 Aug 25. pii: jbc.M114.596692. PMID:25160619[7]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Tu Y, Wu S, Shi X, Chen K, Wu C. Migfilin and Mig-2 link focal adhesions to filamin and the actin cytoskeleton and function in cell shape modulation. Cell. 2003 Apr 4;113(1):37-47. PMID:12679033
- ↑ Ma YQ, Qin J, Wu C, Plow EF. Kindlin-2 (Mig-2): a co-activator of beta3 integrins. J Cell Biol. 2008 May 5;181(3):439-46. doi: 10.1083/jcb.200710196. PMID:18458155 doi:http://dx.doi.org/10.1083/jcb.200710196
- ↑ Qu H, Tu Y, Shi X, Larjava H, Saleem MA, Shattil SJ, Fukuda K, Qin J, Kretzler M, Wu C. Kindlin-2 regulates podocyte adhesion and fibronectin matrix deposition through interactions with phosphoinositides and integrins. J Cell Sci. 2011 Mar 15;124(Pt 6):879-91. doi: 10.1242/jcs.076976. Epub 2011 Feb , 15. PMID:21325030 doi:http://dx.doi.org/10.1242/jcs.076976
- ↑ Yu Y, Wu J, Wang Y, Zhao T, Ma B, Liu Y, Fang W, Zhu WG, Zhang H. Kindlin 2 forms a transcriptional complex with beta-catenin and TCF4 to enhance Wnt signalling. EMBO Rep. 2012 Aug;13(8):750-8. doi: 10.1038/embor.2012.88. Epub 2012 Jun 15. PMID:22699938 doi:http://dx.doi.org/10.1038/embor.2012.88
- ↑ Liu J, Fukuda K, Xu Z, Ma YQ, Hirbawi J, Mao X, Wu C, Plow EF, Qin J. Structural basis of phosphoinositide binding to kindlin-2 protein pleckstrin homology domain in regulating integrin activation. J Biol Chem. 2011 Dec 16;286(50):43334-42. Epub 2011 Oct 26. PMID:22030399 doi:10.1074/jbc.M111.295352
- ↑ Perera HD, Ma YQ, Yang J, Hirbawi J, Plow EF, Qin J. Membrane Binding of the N-Terminal Ubiquitin-Like Domain of kindlin-2 Is Crucial for Its Regulation of Integrin Activation. Structure. 2011 Nov 9;19(11):1664-71. PMID:22078565 doi:10.1016/j.str.2011.08.012
- ↑ Fukuda K, Bledzka K, Yang J, Perera HD, Plow EF, Qin J. Molecular basis of kindlin-2 binding to integrin-linked kinase (ILK) pseudokinase for regulating cell adhesion. J Biol Chem. 2014 Aug 25. pii: jbc.M114.596692. PMID:25160619 doi:http://dx.doi.org/10.1074/jbc.M114.596692
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