Signaling of the direction-sensing FAK/RACK1/PDE4D5 complex to the small GTPase Rap1

We recently reported that a complex between focal adhesion kianse (FAK) and the molecular scaffold RACK1 controlled nascent integrin adhesion formation and cell polarization, via peripheral recruitment of the cAMP-degrading PDE4D5 isoform. Here we review and extend these studies by demonstrating that the FAK/RACK1/PDE4D5 ‘direction-sensing’ complex likely functions by signaling, via the guanine nucleotide exchange factor EPAC, to its small GTPase target Rap1. Specifically, activating EPAC suppresses polarization of squamous cancer cells, while, in contrast, modulating PKA, the other major cAMP effector, has no effect. Moreover, FAK-deficient malignant keratinocytes re-expressing a FAK mutant that cannot bind to RACK1, namely FAK-E139A,D140A, display elevated Rap1 that is linked to impaired polarization. Thus, it is likely that the FAK/RACK1/PDE4D5 complex signals to keep Rap1 low at appropriate times and in a spatially-regulated manner as cells first sense their environment and make decisions about nascent adhesion stabilization and polarization. RACK1 is abundantly expressed in both normal and malignant keratinocytes, while FAK and PDE4D5 are both elevated in the cancer cells, suggesting that the FAK/RACK1/PDE4D5/Rap1 signaling axis may contribute to FAK’s well documented role in tumor progression.

[1]  K. Anderson,et al.  A Complex between FAK, RACK1, and PDE4D5 Controls Spreading Initiation and Cancer Cell Polarity , 2010, Current Biology.

[2]  G. Baillie,et al.  Phosphorylation of RACK1 on Tyrosine 52 by c-Abl Is Required for Insulin-like Growth Factor I-mediated Regulation of Focal Adhesion Kinase* , 2009, The Journal of Biological Chemistry.

[3]  R. Gude,et al.  Pentoxifylline impedes migration in B16F10 melanoma by modulating Rho GTPase activity and actin organisation. , 2008, European journal of cancer.

[4]  R. Cardiff,et al.  Mammary epithelial-specific disruption of the focal adhesion kinase blocks mammary tumor progression , 2007, Proceedings of the National Academy of Sciences.

[5]  Gareth E. Jones,et al.  Focal adhesion kinase controls actin assembly via a FERM-mediated interaction with the Arp2/3 complex , 2007, Nature Cell Biology.

[6]  R. Cole,et al.  RACK1 Competes with HSP90 for Binding to HIF-1α and is Required for O2-independent and HSP90 Inhibitor-induced Degradation of HIF-1α , 2007 .

[7]  P. Hordijk,et al.  Epac1‐Rap1 signaling regulates monocyte adhesion and chemotaxis , 2006, Journal of leukocyte biology.

[8]  D. Schlaepfer,et al.  Integrin-regulated FAK-Src signaling in normal and cancer cells. , 2006, Current opinion in cell biology.

[9]  G. Baillie,et al.  Scanning peptide array analyses identify overlapping binding sites for the signalling scaffold proteins, beta-arrestin and RACK1, in cAMP-specific phosphodiesterase PDE4D5. , 2006, The Biochemical journal.

[10]  M. Houslay,et al.  In resting COS1 cells a dominant negative approach shows that specific, anchored PDE4 cAMP phosphodiesterase isoforms gate the activation, by basal cyclic AMP production, of AKAP-tethered protein kinase A type II located in the centrosomal region. , 2005, Cellular signalling.

[11]  J. Scott,et al.  Compartmentalisation of phosphodiesterases and protein kinase A: opposites attract , 2005, FEBS letters.

[12]  G. Baillie,et al.  Arrestin times for compartmentalised cAMP signalling and phosphodiesterase-4 enzymes. , 2005, Current opinion in cell biology.

[13]  S. Grant,et al.  Specific deletion of focal adhesion kinase suppresses tumor formation and blocks malignant progression. , 2004, Genes & development.

[14]  M. Mann,et al.  RNA and RNA Binding Proteins Participate in Early Stages of Cell Spreading through Spreading Initiation Centers , 2004, Cell.

[15]  S. Hanks,et al.  Focal adhesion kinase signaling activities and their implications in the control of cell survival and motility. , 2003, Frontiers in bioscience : a journal and virtual library.

[16]  T. Tsuruo,et al.  Rap1 translates chemokine signals to integrin activation, cell polarization, and motility across vascular endothelium under flow , 2003, The Journal of cell biology.

[17]  J. Parsons,et al.  Focal adhesion kinase: the first ten years , 2003, Journal of Cell Science.

[18]  A. Huttenlocher,et al.  RACK1 regulates integrin-mediated adhesion, protrusion, and chemotactic cell migration via its Src-binding site. , 2003, Molecular biology of the cell.

[19]  J. Warwicker,et al.  The RACK1 scaffold protein: a dynamic cog in cell response mechanisms. , 2002, Molecular pharmacology.

[20]  R. O'Connor,et al.  RACK1 Is an Insulin-like Growth Factor 1 (IGF-1) Receptor-interacting Protein That Can Regulate IGF-1-mediated Akt Activation and Protection from Cell Death* , 2002, The Journal of Biological Chemistry.

[21]  K. Mostov.  Faculty Opinions recommendation of Integrin-mediated activation of Cdc42 controls cell polarity in migrating astrocytes through PKCzeta. , 2001 .

[22]  Daria Mochly-Rosen,et al.  Adaptor proteins in protein kinase C-mediated signal transduction , 2001, Oncogene.

[23]  A. Hall,et al.  Integrin-Mediated Activation of Cdc42 Controls Cell Polarity in Migrating Astrocytes through PKCζ , 2001, Cell.

[24]  M. Schaller.  Biochemical signals and biological responses elicited by the focal adhesion kinase. , 2001, Biochimica et biophysica acta.

[25]  C. Cartwright,et al.  The Interaction of Src and RACK1 Is Enhanced by Activation of Protein Kinase C and Tyrosine Phosphorylation of RACK1* , 2001, The Journal of Biological Chemistry.

[26]  M. Moran,et al.  RACK1, a protein kinase C scaffolding protein, interacts with the PH domain of p120GAP. , 2001, Biochemical and biophysical research communications.

[27]  S. M. Burden-Gulley,et al.  The PTPμ Protein-tyrosine Phosphatase Binds and Recruits the Scaffolding Protein RACK1 to Cell-Cell Contacts* , 2001, The Journal of Biological Chemistry.

[28]  G. Plopper,et al.  The WD protein Rack1 mediates protein kinase C and integrin-dependent cell migration. , 2001, Journal of cell science.

[29]  T. Pawson,et al.  A mammalian PAR-3–PAR-6 complex implicated in Cdc42/Rac1 and aPKC signalling and cell polarity , 2000, Nature Cell Biology.

[30]  Haigen Huang,et al.  Stimulation of erythropoiesis by inhibiting a new hematopoietic death receptor in transgenic zebrafish , 2000, Nature Cell Biology.

[31]  D. Mochly‐Rosen,et al.  RACK1, a protein kinase C anchoring protein, coordinates the binding of activated protein kinase C and select pleckstrin homology domains in vitro. , 1999, Biochemistry.

[32]  M. Houslay,et al.  The RACK1 Signaling Scaffold Protein Selectively Interacts with the cAMP-specific Phosphodiesterase PDE4D5 Isoform* , 1999, The Journal of Biological Chemistry.

[33]  L. Shaw,et al.  Release of cAMP Gating by the α6β4 Integrin Stimulates Lamellae Formation and the Chemotactic Migration of Invasive Carcinoma Cells , 1998, The Journal of cell biology.

[34]  A. Wittinghofer,et al.  Epac is a Rap1 guanine-nucleotide-exchange factor directly activated by cyclic AMP , 1998, Nature.

[35]  D. Chang,et al.  Rack1, a Receptor for Activated Protein Kinase C, Interacts with Integrin β Subunit* , 1998, The Journal of Biological Chemistry.

[36]  J. Parsons,et al.  Inhibition of cell spreading by expression of the C-terminal domain of focal adhesion kinase (FAK) is rescued by coexpression of Src or catalytically inactive FAK: a role for paxillin tyrosine phosphorylation , 1997, Molecular and cellular biology.

[37]  S. Aizawa,et al.  Reduced cell motility and enhanced focal adhesion contact formation in cells from FAK-deficient mice , 1995, Nature.

[38]  M. Disatnik,et al.  Interaction of protein kinase C with RACK1, a receptor for activated C-kinase: a role in beta protein kinase C mediated signal transduction. , 1995, Biochemical Society transactions.

[39]  T. Hunter,et al.  Integrin-mediated signal transduction linked to Ras pathway by GRB2 binding to focal adhesion kinase , 1994, Nature.

[40]  J. Caldwell,et al.  Cloning of an intracellular receptor for protein kinase C: a homolog of the beta subunit of G proteins. , 1994, Proceedings of the National Academy of Sciences of the United States of America.

[41]  G. Carpenter,et al.  Phospholipase C-gamma 1 binding to intracellular receptors for activated protein kinase C. , 1994, Proceedings of the National Academy of Sciences of the United States of America.

[42]  G. Baillie,et al.  Phosphorylation of RACK 1 on Tyrosine 52 by c-Abl Is Required for Insulin-like Growth Factor I-mediated Regulation of Focal Adhesion Kinase * , 2009 .

[43]  Chia-Hao Liu,et al.  An enhanced association of RACK1 with Abl in cells transfected with oncogenic ras. , 2008, The international journal of biochemistry & cell biology.

[44]  R. Cole,et al.  RACK1 competes with HSP90 for binding to HIF-1alpha and is required for O(2)-independent and HSP90 inhibitor-induced degradation of HIF-1alpha. , 2007, Molecular cell.

[45]  Y. Doki,et al.  Cyclic AMP specific phosphodiesterase activity and colon cancer cell motility , 2004, Clinical & Experimental Metastasis.

[46]  G. Dorn,et al.  Intracellular transport mechanisms of signal transducers. , 2002, Annual review of physiology.