Receptor-proximal protein kinase regulating integrin-mediated signal transduction. May act as a mediator of inside-out integrin signaling. Focal adhesion protein part of the complex ILK-PINCH. This complex is considered to be one of the convergence points of integrin- and growth factor-signaling pathway. Could be implicated in mediating cell architecture, adhesion to integrin substrates and anchorage-dependent growth in epithelial cells. Phosphorylates beta-1 and beta-3 integrin subunit on serine and threonine residues, but also AKT1 and GSK3B.
Interacting selectively and non-covalently with any protein or protein complex (a complex of two or more proteins that may include other nonprotein molecules).
Evidence
1:
Inferred from Physical InteractionIntAct
Myopodin is a tumor-suppressor gene that suppresses growth of prostate and urothelial carcinomas. However, the mechanism of myopodin tumor-suppressor activity or signaling that leads to activation of myopodin remains unclear. In this report, we showed that the N-terminus of myopodin binds integrin-linked kinase (ILK) both in vivo and in vitro. An ILK interaction motif of 78 amino acids (amino acids 82-157) was identified in the N-terminus region of myopodin. Induction of ILK-dependent kinase activity by integrin α7 led to phosphorylation of myopodin both in vivo and in vitro. Knocking down ILK dramatically reduced the inhibition of cell growth and motility mediated by myopodin. A mutant of myopodin lacking the ILK interaction motif is inactive in suppressing the growth and motility of PC3 cells. As a result, this study showed a novel and critical signaling pathway that leads to activation of myopodin.
Evidence
2:
Inferred from Physical InteractionIntAct
ILKAP, a protein serine/threonine (S/T) phosphatase of the PP2C family, was isolated in a yeast two-hybrid screen baited with integrin-linked kinase, ILK1. Association of ILK1 and ILKAP was independent of the catalytic activity of either partner, as assayed in co-precipitation and two-hybrid experiments. Condi tional expression of ILKAP in HEK 293 cells resulted in selective inhibition of ECM- and growth factor-stimulated ILK1 activity, but did not inhibit Raf-1 kinase activity. A catalytic mutant of ILKAP, H154D, did not inhibit ILK1 kinase activity. Two cellular targets of ILK1, glycogen synthase kinase 3 beta (GSK3beta) and protein kinase B (PKB)/AKT, were differentially affected by ILKAP-mediated inhibition of ILK1. Catalytically active, but not mutant ILKAP, strongly inhibited insulin-like growth factor-1-stimulated GSK3beta phosphorylation on Ser9, but did not affect phosphorylation of PKB on Ser473, suggesting that ILKAP selectively affects ILK-mediated GSK3beta signalling. Consistent with this, active, but not H154D mutant or the related PP2Calpha, selectively inhibited transactivation of a Tcf/Lef reporter gene, TOPFlash, in 293 cells. We propose that ILKAP regulates ILK1 activity, targeting ILK1 signalling of Wnt pathway components via modulation of GSK3beta phosphorylation.
Evidence
3:
Inferred from Physical InteractionIntAct
Integrin-mediated adhesion of leukemia cells to extracellular matrix proteins reduces apoptosis following radiation-induced genotoxic injury. To evaluate the role of integrin-linked kinase (ILK) in this process, HL60 human acute promyelocytic leukemia cells were stably transfected with ILK wild-type or kinase-hyperactive overexpression vectors. Suspension or fibronectin (FN) adhesion cultures were irradiated with X-rays and processed for measurement of apoptosis, mitochondrial transmembrane potential and caspase activation. Adhesion to FN pronouncedly reduced radiation-induced apoptosis of HL60 cells and vector controls. Intriguingly, overexpressed ILK enhanced apoptosis after irradiation by combined activation of caspase-3 through caspase-8 and -9 in irradiated FN cultures. Irradiation of ILK suspension cultures lacked caspase-8 activation, but showed serial cleavage of caspase-9, -3 and poly (ADP-ribose) polymerase. These findings further characterize the cell death-promoting function of ILK in DNA-damaged cells. Moreover, ILK might represent a potential therapeutic target for innovative chemo- and radiooncological approaches in hematological malignancies.
Evidence
4:
Inferred from Physical InteractionUniProtKB
The heterotrimeric complex between integrin-linked kinase (ILK), PINCH, and parvin is an essential signaling platform, serving as a convergence point for integrin and growth-factor signaling and regulating cell adhesion, spreading, and migration. We report a 1.6-A crystal structure of the ILK ankyrin repeat domain bound to the PINCH1 LIM1 domain, revealing the molecular basis of ILK-PINCH interactions and providing a structural description of this region of ILK. This structure identifies 5 ankyrin repeats in ILK, explains previous deletion mutagenesis data, permits identification of ILK and PINCH1 point mutations that disrupt the interaction, shows how zincs are coordinated by PINCH1 LIM1, and suggests that conformational flexibility and twisting between the 2 zinc fingers within the LIM1 domain may be important for ILK binding. These data provide an atomic-resolution description of a key interaction in the ILK-PINCH-parvin scaffolding complex.
Evidence
5:
Inferred from Physical InteractionIntAct
Kidney anion exchanger 1 (kAE1) mediates chloride/bicarbonate exchange at the basolateral membrane of kidney alpha-intercalated cells, thereby facilitating bicarbonate reabsorption into the blood. Human kAE1 lacks the N-terminal 65 residues of the erythroid form (AE1, band 3), which are essential for binding of cytoskeletal and cytosolic proteins. Yeast two-hybrid screening identified integrin-linked kinase (ILK), a serine/threonine kinase, and an actin-binding protein as an interacting partner with the N-terminal domain of kAE1. Interaction between kAE1 and ILK was confirmed in co-expression experiments in HEK 293 cells and is mediated by a previously unidentified calponin homology domain in the kAE1 N-terminal region. The calponin homology domain of kAE1 binds the C-terminal catalytic domain of ILK to enhance association of kAE1 with the actin cytoskeleton. Overexpression of ILK increased kAE1 levels at the cell surface as shown by flow cytometry, cell surface biotinylation, and anion transport activity assays. Pulse-chase experiments revealed that ILK associates with kAE1 early in biosynthesis, likely in the endoplasmic reticulum. ILK co-localized with kAE1 at the basolateral membrane of polarized Madin-Darby canine kidney cells and in alpha-intercalated cells of human kidneys. Taken together these results suggest that ILK and kAE1 traffic together from the endoplasmic reticulum to the basolateral membrane. ILK may provide a linkage between kAE1 and the underlying actin cytoskeleton to stabilize kAE1 at the basolateral membrane, resulting in higher levels of cell surface expression.
Evidence
6:
Inferred from Physical InteractionIntAct
An unbiased proteomic screen to identify integrin-linked kinase (ILK) interactors revealed rictor as an ILK-binding protein. This finding was interesting because rictor, originally identified as a regulator of cytoskeletal dynamics, is also a component of mammalian target of rapamycin complex 2 (mTORC2), a complex implicated in Akt phosphorylation. These functions overlap with known ILK functions. Coimmunoprecipitation analyses confirmed this interaction, and ILK and rictor colocalized in membrane ruffles and leading edges of cancer cells. Yeast two-hybrid assays showed a direct interaction between the NH(2)- and COOH-terminal domains of rictor and the ILK kinase domain. Depletion of ILK and rictor in breast and prostate cancer cell lines resulted in inhibition of Akt Ser(473) phosphorylation and induction of apoptosis, whereas, in several cell lines, depletion of mTOR increased Akt phosphorylation. Akt and Ser(473)P-Akt were detected in ILK immunoprecipitates and small interfering RNA-mediated depletion of rictor, but not mTOR, inhibited the amount of Ser(473)P-Akt in the ILK complex. Expression of the NH(2)-terminal (1-398 amino acids) rictor domain also resulted in the inhibition of ILK-associated Akt Ser(473) phosphorylation. These data show that rictor regulates the ability of ILK to promote Akt phosphorylation and cancer cell survival.
Evidence
7:
Inferred from Physical InteractionIntAct
Systematic mapping of protein-protein interactions, or 'interactome' mapping, was initiated in model organisms, starting with defined biological processes and then expanding to the scale of the proteome. Although far from complete, such maps have revealed global topological and dynamic features of interactome networks that relate to known biological properties, suggesting that a human interactome map will provide insight into development and disease mechanisms at a systems level. Here we describe an initial version of a proteome-scale map of human binary protein-protein interactions. Using a stringent, high-throughput yeast two-hybrid system, we tested pairwise interactions among the products of approximately 8,100 currently available Gateway-cloned open reading frames and detected approximately 2,800 interactions. This data set, called CCSB-HI1, has a verification rate of approximately 78% as revealed by an independent co-affinity purification assay, and correlates significantly with other biological attributes. The CCSB-HI1 data set increases by approximately 70% the set of available binary interactions within the tested space and reveals more than 300 new connections to over 100 disease-associated proteins. This work represents an important step towards a systematic and comprehensive human interactome project.
Interacting selectively and non-covalently with a protein kinase, any enzyme that catalyzes the transfer of a phosphate group, usually from ATP, to a protein substrate.
Evidence
1:
Inferred from Physical InteractionUniProtKB
The Eph-ephrin receptor-ligand system is implicated in cell behavior and morphology. EphA1 is the founding member of the Eph receptors, but little is known about its function. Here, we show that activation of EphA1 kinase inhibits cell spreading and migration in a RhoA-ROCK-dependent manner. We also describe a novel interaction between EphA1 and integrin-linked kinase (ILK), a mediator of interactions between integrin and the actin cytoskeleton. The C-terminal sterile alpha motif (SAM) domain of EphA1 is required and the ankyrin region of ILK is sufficient for the interaction between EphA1 and ILK. The interaction is independent of EphA1 kinase activity but dependent on stimulation of the EphA1 ligand ephrin-A1. Activation of EphA1 kinase resulted in a decrease of ILK activity. Finally, we demonstrated that expression of a kinase-active form of ILK (S343D) rescued the EphA1-mediated spreading defect, and attenuated RhoA activation. These results suggest that EphA1 regulates cell morphology and motility through the ILK-RhoA-ROCK pathway.
We have shown previously that integrin-linked kinase (ILK) is upregulated in human HT-144 melanoma cells following TGF-beta1 stimulation. Using mRNA from TGF-beta1 stimulated HT-144 cells and reverse transcriptase polymerase chain reaction, we have isolated a cDNA encoding a protein highly homologous to ILK. Sequencing of the full-length 1359 base pair cDNA and polypeptide translation revealed that this protein, designated ILK-2, differs from the known ILK (hereafter called ILK-1) by only four amino acids, while the cDNA sequence diverges by 102 nucleotides, thus excluding that ILK-2 is an allelic variant of ILK-1. Expression of ILK-2 mRNA was observed in metastatic human HT-144 melanoma and HT-1080 fibrosarcoma cell lines, but not in normal human tissues. Moreover, stimulation of HT-144 cells with TGF-beta1, but not with EGF, PDGF-AB or insulin, induced a selective overexpression of ILK-2 mRNA as compared to ILK-1 mRNA. Bacterially-expressed GST/ILK-2 autophosphorylated and labeled myelin basic protein as well as a recombinant GST/beta3 integrin cytoplasmic tail peptide. Transfection of either ILK-2 or ILK-1 cDNA into the non-metastatic melanoma cell line SK-Mel-2, expressing exclusively ILK-1, induced anchorage independent cell growth and cell proliferation, as demonstrated by growth in soft agar. Our data provide evidence that ILK-2 is a new isoform of ILK-1 that is expressed in some highly invasive tumor cell lines but not in normal adult human tissues and whose expression is regulated by TGF-beta1.
Integrin-linked kinase (ILK) is a recently identified human protein kinase that has been implicated in integrin-mediated signal transduction and tumorigenesis. We have identified a mouse molecule that is highly homologous to human ILK. The mouse ILK homologue protein is readily recognized by antibodies raised against the human ILK protein, and the gene encoding the mouse ILK homologue is widely expressed in mouse tissues. The mouse ILK homologue gene has been mapped to chromosome 7E1 band. A second locus in the mouse chromosome 9E1-3 region has also been detected with a mouse ILK homologue cDNA probe by fluorescence in situ hybridization, suggesting the possible existence of an ILK pseudo-gene or a family of ILK genes in the mouse.
Interacting selectively and non-covalently with a SH3 domain (Src homology 3) of a protein, small protein modules containing approximately 50 amino acid residues found in a great variety of intracellular or membrane-associated proteins.
Conveys a signal across a cell to trigger a change in cell function or state. A signal is a physical entity or change in state that is used to transfer information in order to trigger a response.
The process in which the branching structure of the ureteric bud is generated and organized. The ureteric bud is an epithelial tube that grows out from the metanephric duct. The bud elongates and branches to give rise to the ureter and kidney collecting tubules.
An aging process that has as participant a cell after a cell has stopped dividing. Cell aging may occur when a cell has temporarily stopped dividing through cell cycle arrest (GO:0007050) or when a cell has permanently stopped dividing, in which case it is undergoing cellular senescence (GO:0090398). May precede cell death (GO:0008219) and succeed cell maturation (GO:0048469).
We have shown previously that integrin-linked kinase (ILK) is upregulated in human HT-144 melanoma cells following TGF-beta1 stimulation. Using mRNA from TGF-beta1 stimulated HT-144 cells and reverse transcriptase polymerase chain reaction, we have isolated a cDNA encoding a protein highly homologous to ILK. Sequencing of the full-length 1359 base pair cDNA and polypeptide translation revealed that this protein, designated ILK-2, differs from the known ILK (hereafter called ILK-1) by only four amino acids, while the cDNA sequence diverges by 102 nucleotides, thus excluding that ILK-2 is an allelic variant of ILK-1. Expression of ILK-2 mRNA was observed in metastatic human HT-144 melanoma and HT-1080 fibrosarcoma cell lines, but not in normal human tissues. Moreover, stimulation of HT-144 cells with TGF-beta1, but not with EGF, PDGF-AB or insulin, induced a selective overexpression of ILK-2 mRNA as compared to ILK-1 mRNA. Bacterially-expressed GST/ILK-2 autophosphorylated and labeled myelin basic protein as well as a recombinant GST/beta3 integrin cytoplasmic tail peptide. Transfection of either ILK-2 or ILK-1 cDNA into the non-metastatic melanoma cell line SK-Mel-2, expressing exclusively ILK-1, induced anchorage independent cell growth and cell proliferation, as demonstrated by growth in soft agar. Our data provide evidence that ILK-2 is a new isoform of ILK-1 that is expressed in some highly invasive tumor cell lines but not in normal adult human tissues and whose expression is regulated by TGF-beta1.
A process that is carried out at the cellular level which results in the assembly, arrangement of constituent parts, or disassembly of extracellular fibrils, extracellular matrix material consisting of polysaccharides and/or proteins.
A series of molecular signals initiated by the binding of extracellular ligand to an integrin on the surface of a target cell, and ending with regulation of a downstream cellular process, e.g. transcription.
Integrin-linked kinase (ILK) is a recently identified human protein kinase that has been implicated in integrin-mediated signal transduction and tumorigenesis. We have identified a mouse molecule that is highly homologous to human ILK. The mouse ILK homologue protein is readily recognized by antibodies raised against the human ILK protein, and the gene encoding the mouse ILK homologue is widely expressed in mouse tissues. The mouse ILK homologue gene has been mapped to chromosome 7E1 band. A second locus in the mouse chromosome 9E1-3 region has also been detected with a mouse ILK homologue cDNA probe by fluorescence in situ hybridization, suggesting the possible existence of an ILK pseudo-gene or a family of ILK genes in the mouse.
The process in which the wraps of cell membrane that constitute myelin are laid down around an axon in the central or peripheral nervous system.
IEAOrtholog Compara
Negative regulation of cardiac muscle cell apoptotic processdefinition[GO:0010667]‹silver
Any process that decreases the rate or extent of cardiac cell apoptotic process, a form of programmed cell death induced by external or internal signals that trigger the activity of proteolytic caspases whose actions dismantle a cardiac muscle cell and result in its death.
The process in which the anatomical structures of a neuron projection are generated and organized. A neuron projection is any process extending from a neural cell, such as axons or dendrites.
Any process that increases the rate, frequency, or extent of the Wnt receptor signaling pathway through beta-catenin, the series of molecular signals initiated by binding of a Wnt protein to a frizzled family receptor on the surface of the target cell, followed by propagation of the signal via beta-catenin, and ending with a change in transcription of target genes.
Evidence
1:
Inferred from Mutant PhenotypeUniProtKB
Collagen I has been shown to promote epithelial-mesenchymal transition (EMT), a critical process of embryonic development and disease progression. However, little is known about the signaling mechanisms by which collagen I induces this cellular transformation. Here we show that collagen I causes ILK-dependent phosphorylation of IkappaB and subsequent nuclear translocation of active NF-kappaB, which in turn promotes increased expression of the Snail and LEF-1 transcription factors. ILK also causes inhibitory phosphorylation of GSK-3beta, a kinase that prevents functional activation of both Snail and LEF-1. These transcription factors alter expression of epithelial and mesenchymal markers to initiate EMT and stimulate cell migration. These data provide a foundation for understanding the mechanisms by which collagen I stimulates EMT and identify potential therapeutic targets for suppressing this transition in pathological conditions.
Any process that activates or increases the frequency, rate or extent of myoblast differentiation. A myoblast is a mononucleate cell type that, by fusion with other myoblasts, gives rise to the myotubes that eventually develop into skeletal muscle fibers.
Collagen I has been shown to promote epithelial-mesenchymal transition (EMT), a critical process of embryonic development and disease progression. However, little is known about the signaling mechanisms by which collagen I induces this cellular transformation. Here we show that collagen I causes ILK-dependent phosphorylation of IkappaB and subsequent nuclear translocation of active NF-kappaB, which in turn promotes increased expression of the Snail and LEF-1 transcription factors. ILK also causes inhibitory phosphorylation of GSK-3beta, a kinase that prevents functional activation of both Snail and LEF-1. These transcription factors alter expression of epithelial and mesenchymal markers to initiate EMT and stimulate cell migration. These data provide a foundation for understanding the mechanisms by which collagen I stimulates EMT and identify potential therapeutic targets for suppressing this transition in pathological conditions.
Any process that activates or increases the frequency, rate or extent of the protein kinase B signaling cascade, a series of reactions mediated by the intracellular serine/threonine kinase protein kinase B.
Collagen I has been shown to promote epithelial-mesenchymal transition (EMT), a critical process of embryonic development and disease progression. However, little is known about the signaling mechanisms by which collagen I induces this cellular transformation. Here we show that collagen I causes ILK-dependent phosphorylation of IkappaB and subsequent nuclear translocation of active NF-kappaB, which in turn promotes increased expression of the Snail and LEF-1 transcription factors. ILK also causes inhibitory phosphorylation of GSK-3beta, a kinase that prevents functional activation of both Snail and LEF-1. These transcription factors alter expression of epithelial and mesenchymal markers to initiate EMT and stimulate cell migration. These data provide a foundation for understanding the mechanisms by which collagen I stimulates EMT and identify potential therapeutic targets for suppressing this transition in pathological conditions.
The process of creating protein oligomers, compounds composed of a small number, usually between three and ten, of component monomers that are not all identical. Oligomers may be formed by the polymerization of a number of monomers or the depolymerization of a large protein polymer.
We have shown previously that integrin-linked kinase (ILK) is upregulated in human HT-144 melanoma cells following TGF-beta1 stimulation. Using mRNA from TGF-beta1 stimulated HT-144 cells and reverse transcriptase polymerase chain reaction, we have isolated a cDNA encoding a protein highly homologous to ILK. Sequencing of the full-length 1359 base pair cDNA and polypeptide translation revealed that this protein, designated ILK-2, differs from the known ILK (hereafter called ILK-1) by only four amino acids, while the cDNA sequence diverges by 102 nucleotides, thus excluding that ILK-2 is an allelic variant of ILK-1. Expression of ILK-2 mRNA was observed in metastatic human HT-144 melanoma and HT-1080 fibrosarcoma cell lines, but not in normal human tissues. Moreover, stimulation of HT-144 cells with TGF-beta1, but not with EGF, PDGF-AB or insulin, induced a selective overexpression of ILK-2 mRNA as compared to ILK-1 mRNA. Bacterially-expressed GST/ILK-2 autophosphorylated and labeled myelin basic protein as well as a recombinant GST/beta3 integrin cytoplasmic tail peptide. Transfection of either ILK-2 or ILK-1 cDNA into the non-metastatic melanoma cell line SK-Mel-2, expressing exclusively ILK-1, induced anchorage independent cell growth and cell proliferation, as demonstrated by growth in soft agar. Our data provide evidence that ILK-2 is a new isoform of ILK-1 that is expressed in some highly invasive tumor cell lines but not in normal adult human tissues and whose expression is regulated by TGF-beta1.
Any process that modulates the frequency, rate or extent of the formation, arrangement of constituent parts, or disassembly of cytoskeletal structures comprising actin filaments and their associated proteins.
The Eph-ephrin receptor-ligand system is implicated in cell behavior and morphology. EphA1 is the founding member of the Eph receptors, but little is known about its function. Here, we show that activation of EphA1 kinase inhibits cell spreading and migration in a RhoA-ROCK-dependent manner. We also describe a novel interaction between EphA1 and integrin-linked kinase (ILK), a mediator of interactions between integrin and the actin cytoskeleton. The C-terminal sterile alpha motif (SAM) domain of EphA1 is required and the ankyrin region of ILK is sufficient for the interaction between EphA1 and ILK. The interaction is independent of EphA1 kinase activity but dependent on stimulation of the EphA1 ligand ephrin-A1. Activation of EphA1 kinase resulted in a decrease of ILK activity. Finally, we demonstrated that expression of a kinase-active form of ILK (S343D) rescued the EphA1-mediated spreading defect, and attenuated RhoA activation. These results suggest that EphA1 regulates cell morphology and motility through the ILK-RhoA-ROCK pathway.
This protein acts as an enzyme. It is known to catalyze the following reaction
EC 2.7.11.1: ATP + a protein ⇄ ADP + a phosphoprotein.
CuratedUniProtKB
It is regulated in the following manner
Stimulated rapidly but transiently by both cell fibronectin interactions, as well as by insulin, in a PI3-K-dependent manner, likely via the binding of PtdIns(3,4,5)P3 with a PH-like domain of ILK.
Protein which catalyzes the phosphorylation of serine or threonine residues on target proteins by using ATP as phosphate donor. Such phosphorylation may cause changes in the function of the target protein. Protein kinases share a conserved catalytic core common to both serine/ threonine and tyrosine protein kinases.
A reference proteome is a set of protein sequences derived from a complete proteome which constitutes a defined standard for a particular user community. Reference proteomes are manually defined according to a number of criteria. They cover the proteomes of well- studied model organisms and other proteomes of interest for biomedical and biotechnological research. Reference proteomes have been selected to provide broad coverage of the tree of life, and constitute a representative cross-section of the taxonomic diversity to be found within UniProtKB.