1. Department of Pharmacology, Program in Molecular and Cellular Pharmacology, University of Wisconsin-Madison, 1300 University Avenue, University of Wisconsin Medical School, Madison, Wisconsin 53706, USA
2. These authors contributed equally to this work

Correspondence to: Richard A. Anderson¹ Correspondence and requests for materials should be addressed to R.A.A. (e-mail: Email: raanders@facstaff.wisc.edu).

Abstract

The ability of cells to form cell contacts, adhere to the extracellular matrix, change morphology, and migrate is essential for development, wound healing, metastasis, cell survival and the immune response. These events depend on the binding of integrin to the extracellular matrix, and assembly of focal adhesions, which are complexes comprising scaffolding and signalling proteins organized by adhesion to the extracellular matrix^{1, 2, 3}. Phosphatidylinositol-4,5-bisphosphate (PtdIns(4,5)P₂) regulates interactions between these proteins, including the interaction of vinculin with actin and talin^{4, 5, 6, 7, 8, 9}. The binding of talin to -integrin is strengthened by PtdIns(4,5)P₂, suggesting that the basis of focal adhesion assembly is regulated by this lipid mediator^{9, 10}. Here we show that the type I phosphatidylinositol phosphate kinase isoform- 661 (PIPKI661), an enzyme that makes PtdIns(4,5)P₂, is targeted to focal adhesions by an association with talin. PIPKI661 is tyrosine phosphorylated by focal adhesion associated kinase signalling, increasing both the activity of phosphatidylinositol phosphate kinase and its association with talin. This defines a mechanism for spatial generation of PtdIns(4,5)P₂ at focal adhesions.