title: PDK1 regulates focal adhesion disassembly by modulating endocytosis of αvβ3 integrin.
abstract: Non-amoeboid cell migration is characterised by dynamic competition among multiple protrusions to establish new adhesion sites at the cell's leading edge. However, the mechanisms that regulate the decision to disassemble or to grow nascent adhesions are not fully understood. Here we show that, in endothelial cells, 3-phosphoinositide-dependent protein kinase 1 (PDK1) promotes focal adhesion (FA) turnover by controlling endocytosis of integrin αvβ3 in a PI3K-dependent manner. We demonstrate that PDK1 binds and phosphorylates integrin αvβ3. Downregulation of PDK1 increases FA size and slows down their disassembly. This process requires both PDK1 kinase activity and PI3K activation but does not involve Akt. Moreover, PDK1 silencing stabilises FA in membrane protrusions decreasing migration of endothelial cells on vitronectin. These results indicate that modulation of integrin endocytosis by PDK1 hampers endothelial cell adhesion and migration on extracellular matrix, thus unveiling a novel role for this kinase.
authors.affiliation: Candiolo Cancer Institute FPO-IRCCS, Candiolo, 10060 Turin, Italy Department of Oncology, University of Torino, 10126 Turin, Italy laura.diblasio@ircc.it luca.primo@ircc.it.
authors.forename: Laura
authors.initials: L
authors.lastname: di Blasio
authors.affiliation: Candiolo Cancer Institute FPO-IRCCS, Candiolo, 10060 Turin, Italy Department of Oncology, University of Torino, 10126 Turin, Italy.
authors.forename: Paolo Armando
authors.initials: PA
authors.lastname: Gagliardi
authors.affiliation: Candiolo Cancer Institute FPO-IRCCS, Candiolo, 10060 Turin, Italy Department of Oncology, University of Torino, 10126 Turin, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Puliafito
authors.affiliation: Candiolo Cancer Institute FPO-IRCCS, Candiolo, 10060 Turin, Italy Department of Oncology, University of Torino, 10126 Turin, Italy Present address: UC Berkeley, 689 Minor Hall, Berkeley, CA 94720, USA.
authors.forename: Roberto
authors.initials: R
authors.lastname: Sessa
authors.affiliation: Candiolo Cancer Institute FPO-IRCCS, Candiolo, 10060 Turin, Italy Department of Oncology, University of Torino, 10126 Turin, Italy Present address: Edwin Steele Laboratory for Tumor Biology, Harvard Medical School, Massachusetts General Hospital, Boston, MA 02114, USA.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Seano
authors.affiliation: Candiolo Cancer Institute FPO-IRCCS, Candiolo, 10060 Turin, Italy Department of Oncology, University of Torino, 10126 Turin, Italy.
authors.forename: Federico
authors.initials: F
authors.lastname: Bussolino
authors.affiliation: Candiolo Cancer Institute FPO-IRCCS, Candiolo, 10060 Turin, Italy Department of Oncology, University of Torino, 10126 Turin, Italy laura.diblasio@ircc.it luca.primo@ircc.it.
authors.forename: Luca
authors.initials: L
authors.lastname: Primo
mesh_terms: D002465:Cell Movement / Q000502:physiology*; D004705:Endocytosis / Q000502:physiology*; D022001:Focal Adhesions / Q000235:genetics / Q000378:metabolism*; D057809:HEK293 Cells; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D039302:Integrin alphaVbeta3 / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation / Q000502:physiology; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D000081382:Pyruvate Dehydrogenase Acetyl-Transferring Kinase
chemical_list: D039302:Integrin alphaVbeta3; C000631429:PDK1 protein, human; D000081382:Pyruvate Dehydrogenase Acetyl-Transferring Kinase; D017346:Protein Serine-Threonine Kinases
keywords: Endothelial cells; Focal adhesion; Integrin endocytosis; PDK1; PI3K