Open AccessKindlin-2 interacts with a highly-conserved surface of ILK to regulate focal adhesion localization and cell spreading
Author(s) -
Yasmin A. Kadry,
Clotilde Huet-Calderwood,
Bertrand Simon,
David A. Calderwood
Publication year - 2018
Publication title -
journal of cell science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.384
H-Index - 278
eISSN - 1477-9137
pISSN - 0021-9533
DOI - 10.1242/jcs.221184
Subject(s) - integrin linked kinase , microbiology and biotechnology , biology , focal adhesion , integrin , signal transducing adaptor protein , cell adhesion , gene knockdown , plasma protein binding , protein kinase domain , signal transduction , mutant , kinase , cell , genetics , protein kinase a , cell culture , gene , cyclin dependent kinase 2
The integrin-associated adaptor proteins integrin-linked kinase (ILK) and kindlin-2 play central roles in integrin signaling and control of cell morphology. A direct ILK-kindlin-2 interaction is conserved across species and involves the kindlin-2 F2PH subdomain and the ILK pseudokinase domain. However, complete understanding of the ILK-kindlin-2 interaction and its role in integrin-mediated signaling has been impeded by difficulties identifying the binding site for kindlin-2 on ILK. We used conservation-guided mapping to dissect the interaction between ILK and kindlin-2 and identified a previously unknown binding site for kindlin-2 on the C-lobe of the pseudokinase domain of ILK. Mutations at this site inhibit binding to kindlin-2 while maintaining structural integrity of the ILK pseudokinase domain. Importantly, kindlin binding-defective ILK mutants exhibit impaired focal adhesion localization and fail to fully rescue the spreading defects seen in ILK knockdown cells. Furthermore, kindlin-2 mutants with impaired ILK binding are also unable to fully support cell spreading. Thus, the interaction between ILK and kindlin-2 is critical for cell spreading and focal adhesion localization, representing a key signaling axis downstream of integrins.