251
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Lee J, Lee D. Association analysis of the perturbation of interactions in biological pathways and anticancer drug activity. Biochem Biophys Res Commun 2016; 470:137-143. [PMID: 26772881 DOI: 10.1016/j.bbrc.2016.01.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Accepted: 01/03/2016] [Indexed: 11/25/2022]
Abstract
Understanding how different genomic mutational landscapes in patients with cancer lead to different responses to anticancer drugs is an important challenge for realizing precision medicine for cancer. Many studies have analyzed the comprehensive anticancer drug-response profiles and genomic profiles of cancer cell lines to identify the relationship between the anticancer drug response and genomic alternations. However, few studies have focused on interpreting these profiles with a network perspective. In this work, we analyzed genomic alterations in cancer cell lines by considering which interactions in the signaling pathway were perturbed by mutations. With our interaction-centric approach, we identified novel interaction/drug response associations for two drugs (afatinib and ixabepilone) for which no gene-centric association could be found. When we compared the performance of classifiers for predicting the responses to 164 drugs, the classifiers trained with interaction-centric features outperformed the classifiers trained with gene-centric features, despite the smaller number of features (p-value = 2.0 × 10(-3)). By incorporating the interaction information from signaling pathways, we revealed associations between genomic alterations and drug responses that could be missed when using a gene-centric approach.
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Affiliation(s)
- Junehawk Lee
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea; Department of Convergence Technology Research, Korea Institute of Science and Technology Information, Daejeon, Republic of Korea
| | - Doheon Lee
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea; Bio-Synergy Research Center, Daejeon, Republic of Korea.
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252
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Vatter P, Schuhholz J, Koenig C, Pfreimer M, Moepps B. Ligand-dependent serum response factor activation by the human CC chemokine receptors CCR2a and CCR2b is mediated by G proteins of the Gqfamily. J Leukoc Biol 2016; 99:979-91. [DOI: 10.1189/jlb.2ma0815-386r] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2015] [Accepted: 01/13/2016] [Indexed: 12/31/2022] Open
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253
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Fujiwara S, Ohashi K, Mashiko T, Kondo H, Mizuno K. Interplay between Solo and keratin filaments is crucial for mechanical force-induced stress fiber reinforcement. Mol Biol Cell 2016; 27:954-66. [PMID: 26823019 PMCID: PMC4791139 DOI: 10.1091/mbc.e15-06-0417] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Accepted: 01/15/2016] [Indexed: 11/11/2022] Open
Abstract
Mechanical force-induced cytoskeletal reorganization is essential for cell and tissue remodeling and homeostasis; however, the underlying cellular mechanisms remain elusive. Solo (ARHGEF40) is a RhoA-targeting guanine nucleotide exchange factor (GEF) involved in cyclical stretch-induced human endothelial cell reorientation and convergent extension cell movement in zebrafish gastrula. In this study, we show that Solo binds to keratin-8/keratin-18 (K8/K18) intermediate filaments through multiple sites. Solo overexpression promotes the formation of thick actin stress fibers and keratin bundles, whereas knockdown of Solo, expression of a GEF-inactive mutant of Solo, or inhibition of ROCK suppresses stress fiber formation and leads to disorganized keratin networks, indicating that the Solo-RhoA-ROCK pathway serves to precisely organize keratin networks, as well as to promote stress fibers. Of importance, knockdown of Solo or K18 or overexpression of GEF-inactive or deletion mutants of Solo suppresses tensile force-induced stress fiber reinforcement. Furthermore, knockdown of Solo or K18 suppresses tensile force-induced RhoA activation. These results strongly suggest that the interplay between Solo and K8/K18 filaments plays a crucial role in tensile force-induced RhoA activation and consequent actin cytoskeletal reinforcement.
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Affiliation(s)
- Sachiko Fujiwara
- Department of Biomolecular Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8578, Japan
| | - Kazumasa Ohashi
- Department of Biomolecular Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8578, Japan
| | - Toshiya Mashiko
- Department of Biomolecular Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8578, Japan
| | - Hiroshi Kondo
- Department of Biomolecular Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8578, Japan
| | - Kensaku Mizuno
- Department of Biomolecular Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8578, Japan
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254
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Chávez-Vargas L, Adame-García SR, Cervantes-Villagrana RD, Castillo-Kauil A, Bruystens JGH, Fukuhara S, Taylor SS, Mochizuki N, Reyes-Cruz G, Vázquez-Prado J. Protein Kinase A (PKA) Type I Interacts with P-Rex1, a Rac Guanine Nucleotide Exchange Factor: EFFECT ON PKA LOCALIZATION AND P-Rex1 SIGNALING. J Biol Chem 2016; 291:6182-99. [PMID: 26797121 DOI: 10.1074/jbc.m115.712216] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Indexed: 12/15/2022] Open
Abstract
Morphology of migrating cells is regulated by Rho GTPases and fine-tuned by protein interactions and phosphorylation. PKA affects cell migration potentially through spatiotemporal interactions with regulators of Rho GTPases. Here we show that the endogenous regulatory (R) subunit of type I PKA interacts with P-Rex1, a Rac guanine nucleotide exchange factor that integrates chemotactic signals. Type I PKA holoenzyme interacts with P-Rex1 PDZ domains via the CNB B domain of RIα, which when expressed by itself facilitates endothelial cell migration. P-Rex1 activation localizes PKA to the cell periphery, whereas stimulation of PKA phosphorylates P-Rex1 and prevents its activation in cells responding to SDF-1 (stromal cell-derived factor 1). The P-Rex1 DEP1 domain is phosphorylated at Ser-436, which inhibits the DH-PH catalytic cassette by direct interaction. In addition, the P-Rex1 C terminus is indirectly targeted by PKA, promoting inhibitory interactions independently of the DEP1-PDZ2 region. A P-Rex1 S436A mutant construct shows increased RacGEF activity and prevents the inhibitory effect of forskolin on sphingosine 1-phosphate-dependent endothelial cell migration. Altogether, these results support the idea that P-Rex1 contributes to the spatiotemporal localization of type I PKA, which tightly regulates this guanine exchange factor by a multistep mechanism, initiated by interaction with the PDZ domains of P-Rex1 followed by direct phosphorylation at the first DEP domain and putatively indirect regulation of the C terminus, thus promoting inhibitory intramolecular interactions. This reciprocal regulation between PKA and P-Rex1 might represent a key node of integration by which chemotactic signaling is fine-tuned by PKA.
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Affiliation(s)
| | - Sendi Rafael Adame-García
- Cell Biology, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Mexico City, 07360 Mexico
| | | | - Alejandro Castillo-Kauil
- Cell Biology, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Mexico City, 07360 Mexico
| | | | - Shigetomo Fukuhara
- Department of Cell Biology, National Cerebral and Cardiovascular Center Research Institute (NCVC), Osaka, 565-8565 Japan, and
| | - Susan S Taylor
- Departments of Chemistry and Biochemistry and Pharmacology, University of California San Diego, La Jolla, California 92093
| | - Naoki Mochizuki
- Department of Cell Biology, National Cerebral and Cardiovascular Center Research Institute (NCVC), Osaka, 565-8565 Japan, and
| | - Guadalupe Reyes-Cruz
- Cell Biology, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Mexico City, 07360 Mexico
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255
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Redundant and nonredundant roles for Cdc42 and Rac1 in lymphomas developed in NPM-ALK transgenic mice. Blood 2016; 127:1297-306. [PMID: 26747246 DOI: 10.1182/blood-2015-11-683052] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Accepted: 12/14/2015] [Indexed: 01/24/2023] Open
Abstract
Increasing evidence suggests that Rho family GTPases could have a critical role in the biology of T-cell lymphoma. In ALK-rearranged anaplastic large cell lymphoma (ALCL), a specific subtype of T-cell lymphoma, the Rho family GTPases Cdc42 and Rac1 are activated by the ALK oncogenic activity. In vitro studies have shown that Cdc42 and Rac1 control rather similar phenotypes of ALCL biology such as the proliferation, survival, and migration of lymphoma cells. However, their role and possible redundancy in ALK-driven lymphoma development in vivo are still undetermined. We genetically deleted Cdc42 or Rac1 in a mouse model of ALK-rearranged ALCL to show that either Cdc42 or Rac1 deletion impaired lymphoma development, modified lymphoma morphology, actin filament distribution, and migration properties of lymphoma cells. Cdc42 or Rac1 deletion primarily affected survival rather than proliferation of lymphoma cells. Apoptosis of lymphoma cells was equally induced following Cdc42 or Rac1 deletion, was associated with upregulation of the proapoptotic molecule Bid, and was blocked by Bcl2 overexpression. Remarkably, Cdc42/Rac1 double deletion, but not Cdc42 or Rac1 single deletions, completely prevented NPM-ALK lymphoma dissemination in vivo. Thus, Cdc42 and Rac1 have nonredundant roles in controlling ALK-rearranged lymphoma survival and morphology but are redundant for lymphoma dissemination, suggesting that targeting both GTPases could represent a preferable therapeutic option for ALCL treatment.
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256
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Small GTPases in peroxisome dynamics. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1863:1006-13. [PMID: 26775587 DOI: 10.1016/j.bbamcr.2016.01.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Revised: 01/05/2016] [Accepted: 01/07/2016] [Indexed: 12/12/2022]
Abstract
In this review article, we summarize current knowledge on peroxisome biogenesis/functions and the role that small GTPases may play in these processes. Precise intracellular distribution of cell organelles requires their regulated association to microtubules and the actin cytoskeleton. In this respect, RhoGDP/RhoGTP favor binding of peroxisomes to microtubules and actin filaments. In its GTP-bound form, RhoA activates a regulatory cascade involving Rho kinaseII and non-muscle myosinIIA. Such interactions frequently depend on phosphoinositides (PIs) of which PI4P, PI(4,5)P2, and PI(3,5)P2 were found to be present in the peroxisomal membrane. PIs are pivotal determinants of intracellular signaling and known to regulate a wide range of cellular functions. In many of these functions, small GTPases are implicated. The small GTPase ADP-ribosylation factor 1 (Arf1), for example, is known to stimulate synthesis of PI4P and PI(4,5)P2 on the Golgi to regulate protein and lipid sorting. In vitro binding assays localized Arf1 and the COPI complex to peroxisomes. In light of the recent discussion of pre-peroxisomal vesicle generation at the ER, peroxisomal Arf1-COPI vesicles may serve retrograde transport of ER-resident components. A mass spectrometric screen localized various Rab proteins to peroxisomes. Overexpression of these proteins in combination with laser-scanning fluorescence microscopy co-localized Rab6, Rab8, Rab10, Rab14, and Rab18 with peroxisomal structures. By analogy to the role these proteins play in other organelle dynamics, we may envisage what the function of these proteins may be in relation to the peroxisomal compartment.
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257
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DeGeer J, Kaplan A, Mattar P, Morabito M, Stochaj U, Kennedy TE, Debant A, Cayouette M, Fournier AE, Lamarche-Vane N. Hsc70 chaperone activity underlies Trio GEF function in axon growth and guidance induced by netrin-1. J Cell Biol 2015; 210:817-32. [PMID: 26323693 PMCID: PMC4555821 DOI: 10.1083/jcb.201505084] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
During development, netrin-1 is both an attractive and repulsive axon guidance cue and mediates its attractive function through the receptor Deleted in Colorectal Cancer (DCC). The activation of Rho guanosine triphosphatases within the extending growth cone facilitates the dynamic reorganization of the cytoskeleton required to drive axon extension. The Rac1 guanine nucleotide exchange factor (GEF) Trio is essential for netrin-1-induced axon outgrowth and guidance. Here, we identify the molecular chaperone heat shock cognate protein 70 (Hsc70) as a novel Trio regulator. Hsc70 dynamically associated with the N-terminal region and Rac1 GEF domain of Trio. Whereas Hsc70 expression supported Trio-dependent Rac1 activation, adenosine triphosphatase-deficient Hsc70 (D10N) abrogated Trio Rac1 GEF activity and netrin-1-induced Rac1 activation. Hsc70 was required for netrin-1-mediated axon growth and attraction in vitro, whereas Hsc70 activity supported callosal projections and radial neuronal migration in the embryonic neocortex. These findings demonstrate that Hsc70 chaperone activity is required for Rac1 activation by Trio and this function underlies netrin-1/DCC-dependent axon outgrowth and guidance.
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Affiliation(s)
- Jonathan DeGeer
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec H3A 0C7, Canada The Research Institute of McGill University Health Centre, Montreal, Quebec H4A 3J1, Canada
| | - Andrew Kaplan
- Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec H3A 2B4, Canada
| | - Pierre Mattar
- Cellular Neurobiology Research Unit, Institut de Recherches Cliniques de Montréal, Montreal, Quebec H2W 1R7, Canada
| | - Morgane Morabito
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec H3A 0C7, Canada The Research Institute of McGill University Health Centre, Montreal, Quebec H4A 3J1, Canada
| | - Ursula Stochaj
- Department of Physiology, McGill University, Montreal, Quebec H3G 1Y6, Canada
| | - Timothy E Kennedy
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec H3A 0C7, Canada Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec H3A 2B4, Canada
| | - Anne Debant
- Centre de Recherche de Biochimie Macromoléculaire, Centre National de la Recherche Scientifique, UMR5237, University of Montpellier, Montpellier 34293, France
| | - Michel Cayouette
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec H3A 0C7, Canada Cellular Neurobiology Research Unit, Institut de Recherches Cliniques de Montréal, Montreal, Quebec H2W 1R7, Canada Department of Medicine, Université de Montréal, Montreal, Quubec H3T 1J4, Canada
| | - Alyson E Fournier
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec H3A 0C7, Canada Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec H3A 2B4, Canada
| | - Nathalie Lamarche-Vane
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec H3A 0C7, Canada The Research Institute of McGill University Health Centre, Montreal, Quebec H4A 3J1, Canada
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258
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Novel Activities of Select NSAID R-Enantiomers against Rac1 and Cdc42 GTPases. PLoS One 2015; 10:e0142182. [PMID: 26558612 PMCID: PMC4641600 DOI: 10.1371/journal.pone.0142182] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Accepted: 10/19/2015] [Indexed: 01/02/2023] Open
Abstract
Rho family GTPases (including Rac, Rho and Cdc42) collectively control cell proliferation, adhesion and migration and are of interest as functional therapeutic targets in numerous epithelial cancers. Based on high throughput screening of the Prestwick Chemical Library® and cheminformatics we identified the R-enantiomers of two approved drugs (naproxen and ketorolac) as inhibitors of Rac1 and Cdc42. The corresponding S-enantiomers are considered the active component in racemic drug formulations, acting as non-steroidal anti-inflammatory drugs (NSAIDs) with selective activity against cyclooxygenases. Here, we show that the S-enantiomers of naproxen and ketorolac are inactive against the GTPases. Additionally, more than twenty other NSAIDs lacked inhibitory action against the GTPases, establishing the selectivity of the two identified NSAIDs. R-naproxen was first identified as a lead compound and tested in parallel with its S-enantiomer and the non-chiral 6-methoxy-naphthalene acetic acid (active metabolite of nabumetone, another NSAID) as a structural series. Cheminformatics-based substructure analyses—using the rotationally constrained carboxylate in R-naproxen—led to identification of racemic [R/S] ketorolac as a suitable FDA-approved candidate. Cell based measurement of GTPase activity (in animal and human cell lines) demonstrated that the R-enantiomers specifically inhibit epidermal growth factor stimulated Rac1 and Cdc42 activation. The GTPase inhibitory effects of the R-enantiomers in cells largely mimic those of established Rac1 (NSC23766) and Cdc42 (CID2950007/ML141) specific inhibitors. Docking predicts that rotational constraints position the carboxylate moieties of the R-enantiomers to preferentially coordinate the magnesium ion, thereby destabilizing nucleotide binding to Rac1 and Cdc42. The S-enantiomers can be docked but are less favorably positioned in proximity to the magnesium. R-naproxen and R-ketorolac have potential for rapid translation and efficacy in the treatment of several epithelial cancer types on account of established human toxicity profiles and novel activities against Rho-family GTPases.
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259
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ESRP2 controls an adult splicing programme in hepatocytes to support postnatal liver maturation. Nat Commun 2015; 6:8768. [PMID: 26531099 PMCID: PMC4635967 DOI: 10.1038/ncomms9768] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2015] [Accepted: 09/25/2015] [Indexed: 12/15/2022] Open
Abstract
Although major genetic networks controlling early liver specification and morphogenesis are known, the mechanisms responsible for postnatal hepatic maturation are poorly understood. Here we employ global analyses of the mouse liver transcriptome to demonstrate that postnatal remodelling of the liver is accompanied by large-scale transcriptional and post-transcriptional transitions that are cell-type-specific and temporally coordinated. Combining detailed expression analyses with gain- and loss-of-function studies, we identify epithelial splicing regulatory protein 2 (ESRP2) as a conserved regulatory factor that controls the neonatal-to-adult switch of ∼20% of splice isoforms in mouse and human hepatocytes. The normal shift in splicing coincides tightly with dramatic postnatal induction of ESRP2 in hepatocytes. We further demonstrate that forced expression of ESRP2 in immature mouse and human hepatocytes is sufficient to drive a reciprocal shift in splicing and causes various physiological abnormalities. These findings define a direct role for ESRP2 in the generation of conserved repertoires of adult splice isoforms that facilitate terminal differentiation and maturation of hepatocytes.
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260
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Semprucci E, Tocci P, Cianfrocca R, Sestito R, Caprara V, Veglione M, Castro VD, Spadaro F, Ferrandina G, Bagnato A, Rosanò L. Endothelin A receptor drives invadopodia function and cell motility through the β-arrestin/PDZ-RhoGEF pathway in ovarian carcinoma. Oncogene 2015; 35:3432-42. [PMID: 26522724 DOI: 10.1038/onc.2015.403] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Revised: 09/16/2015] [Accepted: 09/18/2015] [Indexed: 02/07/2023]
Abstract
The endothelin-1 (ET-1)/ET A receptor (ETAR) signalling pathway is a well-established driver of epithelial ovarian cancer (EOC) progression. One key process promoted by ET-1 is tumor cell invasion, which requires the scaffolding functions of β-arrestin-1 (β-arr1) downstream of the receptor; however, the potential role of ET-1 in inducing invadopodia, which are crucial for cellular invasion and tumor metastasis, is completely unknown. We describe here that ET-1/ETAR, through β-arr1, activates RhoA and RhoC GTPase and downstream ROCK (Rho-associated coiled coil-forming kinase) kinase activity, promoting actin-based dynamic remodelling and enhanced cell invasion. This is accomplished by the direct interaction of β-arr1 with PDZ-RhoGEF (postsynaptic density protein 95/disc-large/zonula occludens-RhoGEF). Interestingly, ETAR-mediated invasive properties are related to the regulation of invadopodia, as evaluated by colocalization of actin with cortactin, as well as with TKS5 and MT1-MMP (membrane type 1-matrix metalloproteinase) with areas of matrix degradation, and activation of cofilin pathway, which is crucial for regulating invadopodia activity. Depletion of PDZ-RhoGEF, or β-arr1, or RhoC, as well as the treatment with the dual ET-1 receptor antagonist macitentan, significantly impairs invadopodia function, MMP activity and invasion, demonstrating that β-arr1/PDZ-RhoGEF interaction mediates ETAR-driven ROCK-LIMK-cofilin pathway through the control of RhoC activity. In vivo, macitentan is able to inhibit metastatic dissemination and cofilin phosphorylation. Collectively, our data unveil a noncanonical activation of the RhoC/ROCK pathway through the β-arr1/PDZ-RhoGEF complex as a regulator of ETAR-induced motility and metastasis, establishing ET-1 axis as a novel regulator of invadopodia protrusions through the RhoC/ROCK/LIMK/cofilin pathway during the initial steps of EOC invasion.
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Affiliation(s)
- E Semprucci
- Regina Elena National Cancer Institute Rome, Rome, Italy
| | - P Tocci
- Regina Elena National Cancer Institute Rome, Rome, Italy
| | - R Cianfrocca
- Regina Elena National Cancer Institute Rome, Rome, Italy
| | - R Sestito
- Regina Elena National Cancer Institute Rome, Rome, Italy
| | - V Caprara
- Regina Elena National Cancer Institute Rome, Rome, Italy
| | - M Veglione
- Regina Elena National Cancer Institute Rome, Rome, Italy
| | - V Di Castro
- Regina Elena National Cancer Institute Rome, Rome, Italy
| | - F Spadaro
- Section of Experimental Immunotherapy, Department of Haematology, Oncology and Molecular Medicine, Istituto Superiore di Sanita', Rome, Italy
| | - G Ferrandina
- Gynecologic Oncology Unit, Catholic University of Rome, Rome, Italy
| | - A Bagnato
- Regina Elena National Cancer Institute Rome, Rome, Italy
| | - L Rosanò
- Regina Elena National Cancer Institute Rome, Rome, Italy
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261
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Veluthakal R, Tunduguru R, Arora DK, Sidarala V, Syeda K, Vlaar CP, Thurmond DC, Kowluru A. VAV2, a guanine nucleotide exchange factor for Rac1, regulates glucose-stimulated insulin secretion in pancreatic beta cells. Diabetologia 2015. [PMID: 26224100 PMCID: PMC4591202 DOI: 10.1007/s00125-015-3707-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
AIMS/HYPOTHESIS Rho GTPases (Ras-related C3 botulinum toxin substrate 1 [Rac1] and cell division cycle 42 [Cdc42]) have been shown to regulate glucose-stimulated insulin secretion (GSIS) via cytoskeletal remodelling, trafficking and fusion of insulin-secretory granules with the plasma membrane. GTP loading of these G proteins, which is facilitated by GDP/GTP exchange factors, is a requisite step in the regulation of downstream effector proteins. Guanine nucleotide exchange factor VAV2 (VAV2), a member of the Dbl family of proteins, has been identified as one of the GDP/GTP exchange factors for Rac1. Despite recent evidence on the regulatory roles of VAV2 in different cell types, roles of this guanine nucleotide exchange factor in the signalling events leading to GSIS remain undefined. Using immunological, short interfering RNA (siRNA), pharmacological and microscopic approaches we investigated the role of VAV2 in GSIS from islet beta cells. METHODS Co-localisation of Rac1 and VAV2 was determined by Triton X-114 phase partition and confocal microscopy. Glucose-induced actin remodelling was quantified by live cell imaging using the LifeAct-GFP fluorescent biosensor. Rac1 activation was determined by G protein linked immunosorbent assay (G-LISA). RESULTS Western blotting indicated that VAV2 is expressed in INS-1 832/13 beta cells, normal rat islets and human islets. Vav2 siRNA markedly attenuated GSIS in INS-1 832/13 cells. Ehop-016, a newly discovered small molecule inhibitor of the VAV2-Rac1 interaction, or siRNA-mediated knockdown of VAV2 markedly attenuated glucose-induced Rac1 activation and GSIS in INS-1 832/13 cells. Pharmacological findings were recapitulated in primary rat islets. A high glucose concentration promoted co-localisation of Rac1 and VAV2. Real-time imaging in live cells indicated a significant inhibition of glucose-induced cortical actin remodelling by Ehop-016. CONCLUSIONS/INTERPRETATION Our data provide the first evidence to implicate VAV2 in glucose-induced Rac1 activation, actin remodelling and GSIS in pancreatic beta cells.
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Affiliation(s)
- Rajakrishnan Veluthakal
- Beta Cell Biochemistry Laboratory, John D. Dingell VA Medical Center, 4646 John R, Detroit, MI, 48201, USA
- Department of Pediatrics, Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Ragadeepthi Tunduguru
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Daleep Kumar Arora
- Immunobiology and Cancer Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Vaibhav Sidarala
- Beta Cell Biochemistry Laboratory, John D. Dingell VA Medical Center, 4646 John R, Detroit, MI, 48201, USA
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy, Wayne State University, Detroit, MI, USA
| | - Khadija Syeda
- Beta Cell Biochemistry Laboratory, John D. Dingell VA Medical Center, 4646 John R, Detroit, MI, 48201, USA
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy, Wayne State University, Detroit, MI, USA
| | - Cornelis P Vlaar
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Puerto Rico, Medical Sciences Campus, San Juan, Puerto Rico
| | - Debbie C Thurmond
- Department of Pediatrics, Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN, USA
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Anjaneyulu Kowluru
- Beta Cell Biochemistry Laboratory, John D. Dingell VA Medical Center, 4646 John R, Detroit, MI, 48201, USA.
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy, Wayne State University, Detroit, MI, USA.
- B-4237 Research Service, John D. Dingell VA Medical Center, 4646 John R, Detroit, MI, 48201, USA.
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262
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Huang H, Fan L, Zhan R, Wu S, Niu W. Expression of microRNA-10a, microRNA-342-3p and their predicted target gene TIAM1 in extranodal NK/T-cell lymphoma, nasal type. Oncol Lett 2015; 11:345-351. [PMID: 26870215 DOI: 10.3892/ol.2015.3831] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2014] [Accepted: 09/14/2015] [Indexed: 01/09/2023] Open
Abstract
MicroRNAs (miRNAs) may act as oncogenes or tumor suppressor genes in different types of human cancer. T-lymphoma invasion and metastasis inducing factor 1 (TIAM1) participates in the development of several types of human cancer. However, the expression of miRNAs and TIAM1 in extranodal natural killer (NK)/T-cell lymphoma, nasal type (ENKTCL) remains poorly understood. In the present study, the association between the expression levels of miR-10a and miR-342-3p and the protein expression levels of TIAM1 was examined in ENKTCL tissues. The expression levels of miR-10a, miR-22, miR-340, miR-342-3p and miR-590-5p in 15 primary ENKTCL tissues were analyzed using quantitative polymerase chain reaction, and the protein expression levels of TIAM1 in 21 primary ENKTCL tissues were analyzed using immunohistochemistry. The expression levels of miR-10a and miR-342-3p were lower in ENKTCL tissues than in normal NK cells, but no significant differences were observed in the expression levels of miR-22, miR-340 and miR-590-5p in ENKTCL tissues, compared with normal NK cells. The low expression levels of miR-10a detected in the tissues of patients with ENKTCL were inversely correlated with the age of the patients, whereas the low expression levels of miR-342-3p measured in these samples were not correlated with any demographic or clinical features of the patients. The protein expression levels of TIAM1 were higher in ENKTCL tissues than in normal and reactive lymph node hyperplasia tissues, and positively correlated with the Ann Arbor stage and international prognostic index score of the tumors. Furthermore, the expression levels of miRNA-10a and miRNA-342-3p were inversely correlated with the protein expression levels of TIAM1 in ENKTCL tissues. These data suggest that TIAM1 may contribute to the pathogenesis of ENKTCL, and miRNA-10a and miRNA-342-3p may be involved in the development of ENKTCL via the TIAM1 pathway.
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Affiliation(s)
- Haobo Huang
- Department of Blood Transfusion, Fujian Medical University Union Hospital, Fuzhou, Fujian 350001, P.R. China
| | - Liping Fan
- Department of Blood Transfusion, Fujian Medical University Union Hospital, Fuzhou, Fujian 350001, P.R. China
| | - Rong Zhan
- Department of Hematology, Fujian Medical University Union Hospital and Fujian Institute of Hematology, Fuzhou, Fujian 350001, P.R. China
| | - Shunquan Wu
- Department of Hematology, Fujian Medical University Union Hospital and Fujian Institute of Hematology, Fuzhou, Fujian 350001, P.R. China
| | - Wenyan Niu
- Department of Hematology, Fujian Medical University Union Hospital and Fujian Institute of Hematology, Fuzhou, Fujian 350001, P.R. China
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263
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Hernández-García R, Iruela-Arispe ML, Reyes-Cruz G, Vázquez-Prado J. Endothelial RhoGEFs: A systematic analysis of their expression profiles in VEGF-stimulated and tumor endothelial cells. Vascul Pharmacol 2015; 74:60-72. [PMID: 26471833 DOI: 10.1016/j.vph.2015.10.003] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Revised: 10/08/2015] [Accepted: 10/09/2015] [Indexed: 12/18/2022]
Abstract
Rho guanine nucleotide exchange factors (RhoGEFs) integrate cell signaling inputs into morphological and functional responses. However, little is known about the endothelial repertoire of RhoGEFs and their regulation. Thus, we assessed the expression of 81 RhoGEFs (70 homologous to Dbl and 11 of the DOCK family) in endothelial cells. Further, in the case of DH-RhoGEFs, we also determined their responses to VEGF exposure in vitro and in the context of tumors. A phylogenetic analysis revealed the existence of four groups of DH-RhoGEFs and two of the DOCK family. Among them, we found that the most abundant endothelial RhoGEFs were: Tuba, FGD5, Farp1, ARHGEF17, TRIO, P-Rex1, ARHGEF15, ARHGEF11, ABR, Farp2, ARHGEF40, ALS, DOCK1, DOCK7 and DOCK6. Expression of RASGRF2 and PREX2 increased significantly in response to VEGF, but most other RhoGEFs were unaffected. Interestingly murine endothelial cells isolated from tumors showed that all four phylogenetic subgroups of DH-RhoGEFs were altered when compared to non-tumor endothelial cells. In summary, our results provide a detailed assessment of RhoGEFs expression profiles in the endothelium and set the basis to systematically address their regulation in vascular signaling.
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Affiliation(s)
| | - M Luisa Iruela-Arispe
- Department of Molecular, Cell, and Developmental Biology and Molecular Biology Institute,University of California,Los Angeles, CA,USA
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264
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van Unen J, Reinhard NR, Yin T, Wu YI, Postma M, Gadella TWJ, Goedhart J. Plasma membrane restricted RhoGEF activity is sufficient for RhoA-mediated actin polymerization. Sci Rep 2015; 5:14693. [PMID: 26435194 PMCID: PMC4592971 DOI: 10.1038/srep14693] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2015] [Accepted: 09/04/2015] [Indexed: 01/08/2023] Open
Abstract
The small GTPase RhoA is involved in cell morphology and migration. RhoA activity is tightly regulated in time and space and depends on guanine exchange factors (GEFs). However, the kinetics and subcellular localization of GEF activity towards RhoA are poorly defined. To study the mechanism underlying the spatiotemporal control of RhoA activity by GEFs, we performed single cell imaging with an improved FRET sensor reporting on the nucleotide loading state of RhoA. By employing the FRET sensor we show that a plasma membrane located RhoGEF, p63RhoGEF, can rapidly activate RhoA through endogenous GPCRs and that localized RhoA activity at the cell periphery correlates with actin polymerization. Moreover, synthetic recruitment of the catalytic domain derived from p63RhoGEF to the plasma membrane, but not to the Golgi apparatus, is sufficient to activate RhoA. The synthetic system enables local activation of endogenous RhoA and effectively induces actin polymerization and changes in cellular morphology. Together, our data demonstrate that GEF activity at the plasma membrane is sufficient for actin polymerization via local RhoA signaling.
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Affiliation(s)
- Jakobus van Unen
- Swammerdam Institute for Life Sciences, Section of Molecular Cytology, van Leeuwenhoek Centre for Advanced Microscopy, University of Amsterdam, P.O. Box 94215, NL-1090 GE Amsterdam, The Netherlands
| | - Nathalie R Reinhard
- Swammerdam Institute for Life Sciences, Section of Molecular Cytology, van Leeuwenhoek Centre for Advanced Microscopy, University of Amsterdam, P.O. Box 94215, NL-1090 GE Amsterdam, The Netherlands
| | - Taofei Yin
- Center for Cell Analysis and Modeling, University of Connecticut Health Center, 400 Farmington Avenue, Farmington, CT 06032-6406
| | - Yi I Wu
- Center for Cell Analysis and Modeling, University of Connecticut Health Center, 400 Farmington Avenue, Farmington, CT 06032-6406
| | - Marten Postma
- Swammerdam Institute for Life Sciences, Section of Molecular Cytology, van Leeuwenhoek Centre for Advanced Microscopy, University of Amsterdam, P.O. Box 94215, NL-1090 GE Amsterdam, The Netherlands
| | - Theodorus W J Gadella
- Swammerdam Institute for Life Sciences, Section of Molecular Cytology, van Leeuwenhoek Centre for Advanced Microscopy, University of Amsterdam, P.O. Box 94215, NL-1090 GE Amsterdam, The Netherlands
| | - Joachim Goedhart
- Swammerdam Institute for Life Sciences, Section of Molecular Cytology, van Leeuwenhoek Centre for Advanced Microscopy, University of Amsterdam, P.O. Box 94215, NL-1090 GE Amsterdam, The Netherlands
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265
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Raimondi F, Felline A, Fanelli F. Catching Functional Modes and Structural Communication in Dbl Family Rho Guanine Nucleotide Exchange Factors. J Chem Inf Model 2015; 55:1878-93. [PMID: 26322553 DOI: 10.1021/acs.jcim.5b00122] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Computational approaches such as Principal Component Analysis (PCA) and Elastic Network Model-Normal Mode Analysis (ENM-NMA) are proving to be of great value in investigating relevant biological problems linked to slow motions with no demand in computer power. In this study, these approaches have been coupled to the graph theory-based Protein Structure Network (PSN) analysis to dissect functional dynamics and structural communication in the Dbl family of Rho Guanine Nucleotide Exchange Factors (RhoGEFs). They are multidomain proteins whose common structural feature is a DH-PH tandem domain deputed to the GEF activity that makes them play a central role in cell and cancer biology. While their common GEF action is accomplished by the DH domain, their regulatory mechanisms are highly variegate and depend on the PH and the additional domains as well as on interacting proteins. Major evolutionary-driven deformations as inferred from PCA concern the α6 helix of DH that dictates the orientation of the PH domain. Such deformations seem to depend on the mechanisms adopted by the GEF to prevent Rho binding, i.e. functional specialization linked to autoinhibition. In line with PCA, ENM-NMA indicates α6 and the linked PH domain as the portions of the tandem domain holding almost the totality of intrinsic and functional dynamics, with the α6/β1 junction acting as a hinge point for the collective motions of PH. In contrast, the DH domain holds a static scaffolding and hub behavior, with structural communication playing a central role in the regulatory actions by other domains/proteins. Possible allosteric communication pathways involving essentially DH were indeed found in those RhoGEFs acting as effectors of small or heterotrimeric RasGTPases. The employed methodology is suitable for deciphering structure/dynamics relationships in large sets of homologous or analogous proteins.
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Affiliation(s)
- Francesco Raimondi
- Department of Life Sciences, University of Modena and Reggio Emilia , via Campi 103, 41125 Modena, Modena, Italy
| | - Angelo Felline
- Department of Life Sciences, University of Modena and Reggio Emilia , via Campi 103, 41125 Modena, Modena, Italy
| | - Francesca Fanelli
- Department of Life Sciences, University of Modena and Reggio Emilia , via Campi 103, 41125 Modena, Modena, Italy
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266
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Morishita Y, Tsutsumi K, Ohta Y. Phosphorylation of Serine 402 Regulates RacGAP Protein Activity of FilGAP Protein. J Biol Chem 2015; 290:26328-38. [PMID: 26359494 DOI: 10.1074/jbc.m115.666875] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Indexed: 11/06/2022] Open
Abstract
FilGAP is a Rho GTPase-activating protein (GAP) that specifically regulates Rac. FilGAP is phosphorylated by ROCK, and this phosphorylation stimulates its RacGAP activity. However, it is unclear how phosphorylation regulates cellular functions and localization of FilGAP. We found that non-phosphorylatable FilGAP (ST/A) mutant is predominantly localized to the cytoskeleton along actin filaments and partially co-localized with vinculin around cell periphery, whereas phosphomimetic FilGAP (ST/D) mutant is diffusely cytoplasmic. Moreover, phosphorylated FilGAP detected by Phos-tag is also mainly localized in the cytoplasm. Of the six potential phosphorylation sites in FilGAP tested, only mutation of serine 402 to alanine (S402A) resulted in decreased cell spreading on fibronectin. FilGAP phosphorylated at Ser-402 is localized to the cytoplasm but not at the cytoskeleton. Although Ser-402 is highly phosphorylated in serum-starved quiescent cells, dephosphorylation of Ser-402 is accompanied with the cell spreading on fibronectin. Treatment of the cells expressing wild-type FilGAP with calyculin A, a Ser/Thr phosphatase inhibitor, suppressed cell spreading on fibronectin, whereas cells transfected with FilGAP S402A mutant were not affected by calyculin A. Expression of constitutively activate Arf6 Q67L mutant stimulated membrane blebbing activity of both non-phosphorylatable (ST/A) and phosphomimetic (ST/D) FilGAP mutants. Conversely, depletion of endogenous Arf6 suppressed membrane blebbing induced by FilGAP (ST/A) and (ST/D) mutants. Our study suggests that Arf6 and phosphorylation of FilGAP may regulate FilGAP, and phosphorylation of Ser-402 may play a role in the regulation of cell spreading on fibronectin.
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Affiliation(s)
- Yuji Morishita
- From the Division of Cell Biology, Department of Biosciences, School of Science, Kitasato University, 1-15-1 Kitasato, Sagamihara, Minami-ku, Kanagawa 252-0373, Japan
| | - Koji Tsutsumi
- From the Division of Cell Biology, Department of Biosciences, School of Science, Kitasato University, 1-15-1 Kitasato, Sagamihara, Minami-ku, Kanagawa 252-0373, Japan
| | - Yasutaka Ohta
- From the Division of Cell Biology, Department of Biosciences, School of Science, Kitasato University, 1-15-1 Kitasato, Sagamihara, Minami-ku, Kanagawa 252-0373, Japan
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267
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Chang GHK, Lay AJ, Ting KK, Zhao Y, Coleman PR, Powter EE, Formaz-Preston A, Jolly CJ, Bower NI, Hogan BM, Rinkwitz S, Becker TS, Vadas MA, Gamble JR. ARHGAP18: an endogenous inhibitor of angiogenesis, limiting tip formation and stabilizing junctions. Small GTPases 2015; 5:1-15. [PMID: 25425145 DOI: 10.4161/21541248.2014.975002] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The formation of the vascular network requires a tightly controlled balance of pro-angiogenic and stabilizing signals. Perturbation of this balance can result in dysregulated blood vessel morphogenesis and drive pathologies including cancer. Here, we have identified a novel gene, ARHGAP18, as an endogenous negative regulator of angiogenesis, limiting pro-angiogenic signaling and promoting vascular stability. Loss of ARHGAP18 promotes EC hypersprouting during zebrafish and murine retinal vessel development and enhances tumor vascularization and growth. Endogenous ARHGAP18 acts specifically on RhoC and relocalizes to the angiogenic and destabilized EC junctions in a ROCK dependent manner, where it is important in reaffirming stable EC junctions and suppressing tip cell behavior, at least partially through regulation of tip cell genes, Dll4, Flk-1 and Flt-4. These findings highlight ARHGAP18 as a specific RhoGAP to fine tune vascular morphogenesis, limiting tip cell formation and promoting junctional integrity to stabilize the angiogenic architecture.
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Key Words
- AJ, Adherens junctions
- ARHGAP18
- DLL4, Delta-like ligand 4
- EC, Endothelial cell
- GAP, GTPase activating protein
- GDI, Guanine nucleotide dissociation inhibitor
- GEF, Guanine nucleotide exchange factor
- HUVEC, Human umbilical vein endothelial cell
- ISV, Intersegmental vessel
- MO, Morpholino
- SC, Stalk cell
- SENEX
- Sp, Splice
- TC, Tip cell
- Tr, Translational
- WT, Wildtype
- angiogenesis
- cell junctions
- hpf, Hours post fertilization
- sprouting
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Affiliation(s)
- Garry H K Chang
- a Centre for the Endothelium; Vascular Biology Program; Centenary Institute ; Newtown , NSW , Australia
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268
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A High-Throughput Assay for Rho Guanine Nucleotide Exchange Factors Based on the Transcreener GDP Assay. ACTA ACUST UNITED AC 2015. [DOI: 10.1177/1087057115596326] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Ras homologous (Rho) family GTPases act as molecular switches controlling cell growth, movement, and gene expression by cycling between inactive guanosine diphosphate (GDP)- and active guanosine triphosphate (GTP)-bound conformations. Guanine nucleotide exchange factors (GEFs) positively regulate Rho GTPases by accelerating GDP dissociation to allow formation of the active, GTP-bound complex. Rho proteins are directly involved in cancer pathways, especially cell migration and invasion, and inhibiting GEFs holds potential as a therapeutic strategy to diminish Rho-dependent oncogenesis. Methods for measuring GEF activity suitable for high-throughput screening (HTS) are limited. We developed a simple, generic biochemical assay method for measuring GEF activity based on the fact that GDP dissociation is generally the rate-limiting step in the Rho GTPase catalytic cycle, and thus addition of a GEF causes an increase in steady-state GTPase activity. We used the Transcreener GDP Assay, which relies on selective immunodetection of GDP, to measure the GEF-dependent stimulation of steady-state GTP hydrolysis by small GTPases using Dbs (Dbl’s big sister) as a GEF for Cdc42, RhoA, and RhoB. The assay is well suited for HTS, with a homogenous format and far red fluorescence polarization (FP) readout, and it should be broadly applicable to diverse Rho GEF/GTPase pairs.
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269
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Goodwin JF, Kothari V, Drake JM, Zhao S, Dylgjeri E, Dean JL, Schiewer MJ, McNair C, Jones JK, Aytes A, Magee MS, Snook AE, Zhu Z, Den RB, Birbe RC, Gomella LG, Graham NA, Vashisht AA, Wohlschlegel JA, Graeber TG, Karnes RJ, Takhar M, Davicioni E, Tomlins SA, Abate-Shen C, Sharifi N, Witte ON, Feng FY, Knudsen KE. DNA-PKcs-Mediated Transcriptional Regulation Drives Prostate Cancer Progression and Metastasis. Cancer Cell 2015; 28:97-113. [PMID: 26175416 PMCID: PMC4531387 DOI: 10.1016/j.ccell.2015.06.004] [Citation(s) in RCA: 140] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Revised: 04/02/2015] [Accepted: 06/12/2015] [Indexed: 01/06/2023]
Abstract
Emerging evidence demonstrates that the DNA repair kinase DNA-PKcs exerts divergent roles in transcriptional regulation of unsolved consequence. Here, in vitro and in vivo interrogation demonstrate that DNA-PKcs functions as a selective modulator of transcriptional networks that induce cell migration, invasion, and metastasis. Accordingly, suppression of DNA-PKcs inhibits tumor metastases. Clinical assessment revealed that DNA-PKcs is significantly elevated in advanced disease and independently predicts for metastases, recurrence, and reduced overall survival. Further investigation demonstrated that DNA-PKcs in advanced tumors is highly activated, independent of DNA damage indicators. Combined, these findings reveal unexpected DNA-PKcs functions, identify DNA-PKcs as a potent driver of tumor progression and metastases, and nominate DNA-PKcs as a therapeutic target for advanced malignancies.
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Affiliation(s)
- Jonathan F Goodwin
- Department of Cancer Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Vishal Kothari
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Justin M Drake
- Departments of Microbiology, Immunology, & Molecular Genetics, UCLA, Los Angeles, CA 90095, USA
| | - Shuang Zhao
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Emanuela Dylgjeri
- Department of Cancer Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Jeffry L Dean
- Department of Cancer Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Matthew J Schiewer
- Department of Cancer Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Christopher McNair
- Department of Cancer Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Jennifer K Jones
- Department of Cancer Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Alvaro Aytes
- Departments of Urology, Pathology & Cell Biology, Systems Biology, Institute for Cancer Genetics, Herbert Irving Comprehensive Cancer Center, Columbia University Medical Center, New York, NY 10032, USA
| | - Michael S Magee
- Department of Pharmacology & Experimental Therapeutics, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Adam E Snook
- Department of Pharmacology & Experimental Therapeutics, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Ziqi Zhu
- Department of Cancer Biology, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Robert B Den
- Department of Cancer Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA; Department of Radiation Oncology, Thomas Jefferson University, Philadelphia, PA 19107, USA; Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Ruth C Birbe
- Department of Pathology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Leonard G Gomella
- Department of Urology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Nicholas A Graham
- Crump Institute for Molecular Imaging, UCLA, Los Angeles, CA 90095, USA; Department of Molecular & Medical Pharmacology, UCLA, Los Angeles, CA 90095, USA
| | - Ajay A Vashisht
- Department of Biological Chemistry, UCLA, Los Angeles, CA 90095, USA
| | | | - Thomas G Graeber
- Crump Institute for Molecular Imaging, UCLA, Los Angeles, CA 90095, USA; Department of Molecular & Medical Pharmacology, UCLA, Los Angeles, CA 90095, USA; Jonsson Comprehensive Cancer Center, UCLA, Los Angeles, CA 90095, USA; California NanoSystems Institute, UCLA, Los Angeles, CA 90095, USA
| | | | | | | | - Scott A Tomlins
- Michigan Center for Translational Pathology, University of Michigan, Ann Arbor, MI 48109, USA; Department of Urology, University of Michigan, Ann Arbor, MI 48109, USA; Comprehensive Cancer Center, University of Michigan, Ann Arbor, MI 48109, USA
| | - Cory Abate-Shen
- Departments of Urology, Pathology & Cell Biology, Systems Biology, Institute for Cancer Genetics, Herbert Irving Comprehensive Cancer Center, Columbia University Medical Center, New York, NY 10032, USA
| | - Nima Sharifi
- Department of Cancer Biology, Cleveland Clinic, Cleveland, OH 44195, USA; Department of Urology, Cleveland Clinic, Cleveland, OH 44195, USA; Solid Tumor Oncology, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Owen N Witte
- Departments of Microbiology, Immunology, & Molecular Genetics, UCLA, Los Angeles, CA 90095, USA; Department of Molecular & Medical Pharmacology, UCLA, Los Angeles, CA 90095, USA; Howard Hughes Medical Institute, UCLA, Los Angeles, CA 90095, USA; Eli & Edythe Broad Center of Regenerative Medicine and Stem Cell Research, UCLA, Los Angeles, CA 90095, USA
| | - Felix Y Feng
- Michigan Center for Translational Pathology, University of Michigan, Ann Arbor, MI 48109, USA; Department of Radiation Oncology, University of Michigan, Ann Arbor, MI 48109, USA; Comprehensive Cancer Center, University of Michigan, Ann Arbor, MI 48109, USA
| | - Karen E Knudsen
- Department of Cancer Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA; Department of Urology, Thomas Jefferson University, Philadelphia, PA 19107, USA; Department of Radiation Oncology, Thomas Jefferson University, Philadelphia, PA 19107, USA; Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA 19107, USA.
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270
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Abstract
INTRODUCTION Rho GTPases are master regulators of actomyosin structure and dynamics and play pivotal roles in a variety of cellular processes including cell morphology, gene transcription, cell cycle progression, and cell adhesion. Because aberrant Rho GTPase signaling activities are widely associated with human cancer, key components of Rho GTPase signaling pathways have attracted increasing interest as potential therapeutic targets. Similar to Ras, Rho GTPases themselves were, until recently, deemed "undruggable" because of structure-function considerations. Several approaches to interfere with Rho GTPase signaling have been explored and show promise as new ways for tackling cancer cells. AREAS COVERED This review focuses on the recent progress in targeting the signaling activities of three prototypical Rho GTPases, that is, RhoA, Rac1, and Cdc42. The authors describe the involvement of these Rho GTPases, their key regulators and effectors in cancer. Furthermore, the authors discuss the current approaches for rationally targeting aberrant Rho GTPases along their signaling cascades, upstream and downstream of Rho GTPases, and posttranslational modifications at a molecular level. EXPERT OPINION To date, while no clinically effective drugs targeting Rho GTPase signaling for cancer treatment are available, tool compounds and lead drugs that pharmacologically inhibit Rho GTPase pathways have shown promise. Small-molecule inhibitors targeting Rho GTPase signaling may add new treatment options for future precision cancer therapy, particularly in combination with other anti-cancer agents.
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Affiliation(s)
- Yuan Lin
- Division of Experimental Hematology and Cancer Biology, Children’s Hospital Medical Center, University of Cincinnati, Cincinnati, Ohio 45229, USA
| | - Yi Zheng
- Division of Experimental Hematology and Cancer Biology, Children’s Hospital Medical Center, University of Cincinnati, Cincinnati, Ohio 45229, USA
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271
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Yan HC, Wang HB. Significance of expression of ECT2 in gastric cancer. Shijie Huaren Xiaohua Zazhi 2015; 23:2215-2220. [DOI: 10.11569/wcjd.v23.i14.2215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate the expression of epithelial cell transforming sequence 2 (ECT2) in gastric cancer (GC) and to analyze its correlation with clinicopathological characteristics.
METHODS: Immunohistochemistry (IHC) and RT-PCR were used to examine the expression of ECT2 protein and mRNA in GC tissues and paired adjacent normal tissues. The correlation between ECT2 expression and clinicopathological characteristics was then analyzed.
RESULTS: In comparison with adjacent normal tissues (36.0%), the expression of ECT2 protein in GC tissues (76.0%) was significantly higher (P < 0.01), and the expression of ECT2 mRNA in GC tissues was also significantly higher in GC tissues than in adjacent normal tissues. The expression of ECT2 protein and mRNA was related to histologic differentiation, TNM stage and lymph node metastasis in GC (P < 0.05), but not to gender, age or tumor size (P > 0.05).
CONCLUSION: Both ECT2 protein and mRNA are overexpressed in GC, and ECT2 expression correlates with the histologic differentiation, TNM stage and lymph node metastasis in GC. ECT2 may play an important role during GC progression, and may serve as a good factor to indicate biologic behavior of GC.
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272
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Abstract
The P-Rex family are Dbl-type guanine-nucleotide exchange factors for Rac family small G proteins. They are distinguished from other Rac-GEFs through their synergistic mode of activation by the lipid second messenger phosphatidyl inositol (3,4,5) trisphosphate and the Gβγ subunits of heterotrimeric G proteins, thus acting as coincidence detectors for phosphoinositide 3-kinase and G protein coupled receptor signaling. Work in genetically-modified mice has shown that P-Rex1 has physiological importance in the inflammatory response and the migration of melanoblasts during development, whereas P-Rex2 controls the dendrite morphology of cerebellar Purkinje neurons as well as glucose homeostasis in liver and adipose tissue. Deregulation of P-Rex1 and P-Rex2 expression occurs in many types of cancer, and P-Rex2 is frequently mutated in melanoma. Both GEFs promote tumor growth or metastasis. This review critically evaluates the P-Rex literature and tools available and highlights exciting recent developments and open questions.
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273
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Fine-Tuning of the Actin Cytoskeleton and Cell Adhesion During Drosophila Development by the Unconventional Guanine Nucleotide Exchange Factors Myoblast City and Sponge. Genetics 2015; 200:551-67. [PMID: 25908317 DOI: 10.1534/genetics.115.177063] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Accepted: 04/18/2015] [Indexed: 01/03/2023] Open
Abstract
The evolutionarily conserved Dock proteins function as unconventional guanine nucleotide exchange factors (GEFs). Upon binding to engulfment and cell motility (ELMO) proteins, Dock-ELMO complexes activate the Rho family of small GTPases to mediate a diverse array of biological processes, including cell motility, apoptotic cell clearance, and axon guidance. Overlapping expression patterns and functional redundancy among the 11 vertebrate Dock family members, which are subdivided into four families (Dock A, B, C, and D), complicate genetic analysis. In both vertebrate and invertebrate systems, the actin dynamics regulator, Rac, is the target GTPase of the Dock-A subfamily. However, it remains unclear whether Rac or Rap1 are the in vivo downstream GTPases of the Dock-B subfamily. Drosophila melanogaster is an excellent genetic model organism for understanding Dock protein function as its genome encodes one ortholog per subfamily: Myoblast city (Mbc; Dock A) and Sponge (Spg; Dock B). Here we show that the roles of Spg and Mbc are not redundant in the Drosophila somatic muscle or the dorsal vessel. Moreover, we confirm the in vivo role of Mbc upstream of Rac and provide evidence that Spg functions in concert with Rap1, possibly to regulate aspects of cell adhesion. Together these data show that Mbc and Spg can have different downstream GTPase targets. Our findings predict that the ability to regulate downstream GTPases is dependent on cellular context and allows for the fine-tuning of actin cytoskeletal or cell adhesion events in biological processes that undergo cell morphogenesis.
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274
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Collins SR, Yang HW, Bonger KM, Guignet EG, Wandless TJ, Meyer T. Using light to shape chemical gradients for parallel and automated analysis of chemotaxis. Mol Syst Biol 2015; 11:804. [PMID: 25908733 PMCID: PMC4422560 DOI: 10.15252/msb.20156027] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Revised: 03/25/2015] [Accepted: 03/27/2015] [Indexed: 12/19/2022] Open
Abstract
Numerous molecular components have been identified that regulate the directed migration of eukaryotic cells toward sources of chemoattractant. However, how the components of this system are wired together to coordinate multiple aspects of the response, such as directionality, speed, and sensitivity to stimulus, remains poorly understood. Here we developed a method to shape chemoattractant gradients optically and analyze cellular chemotaxis responses of hundreds of living cells per well in 96-well format by measuring speed changes and directional accuracy. We then systematically characterized migration and chemotaxis phenotypes for 285 siRNA perturbations. A key finding was that the G-protein Giα subunit selectively controls the direction of migration while the receptor and Gβ subunit proportionally control both speed and direction. Furthermore, we demonstrate that neutrophils chemotax persistently in response to gradients of fMLF but only transiently in response to gradients of ATP. The method we introduce is applicable for diverse chemical cues and systematic perturbations, can be used to measure multiple cell migration and signaling parameters, and is compatible with low- and high-resolution fluorescence microscopy.
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Affiliation(s)
- Sean R Collins
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA, USA
| | - Hee Won Yang
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA, USA
| | - Kimberly M Bonger
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA, USA
| | - Emmanuel G Guignet
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA, USA
| | - Thomas J Wandless
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA, USA
| | - Tobias Meyer
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA, USA
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275
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Lian G, Sheen VL. Cytoskeletal proteins in cortical development and disease: actin associated proteins in periventricular heterotopia. Front Cell Neurosci 2015; 9:99. [PMID: 25883548 PMCID: PMC4381626 DOI: 10.3389/fncel.2015.00099] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Accepted: 03/07/2015] [Indexed: 01/28/2023] Open
Abstract
The actin cytoskeleton regulates many important cellular processes in the brain, including cell division and proliferation, migration, and cytokinesis and differentiation. These developmental processes can be regulated through actin dependent vesicle and organelle movement, cell signaling, and the establishment and maintenance of cell junctions and cell shape. Many of these processes are mediated by extensive and intimate interactions of actin with cellular membranes and proteins. Disruption in the actin cytoskeleton in the brain gives rise to periventricular heterotopia (PH), a malformation of cortical development, characterized by abnormal neurons clustered deep in the brain along the lateral ventricles. This disorder can give rise to seizures, dyslexia and psychiatric disturbances. Anatomically, PH is characterized by a smaller brain (impaired proliferation), heterotopia (impaired initial migration) and disruption along the neuroependymal lining (impaired cell-cell adhesion). Genes causal for PH have also been implicated in actin-dependent processes. The current review provides mechanistic insight into actin cytoskeletal regulation of cortical development in the context of this malformation of cortical development.
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Affiliation(s)
- Gewei Lian
- Department of Neurology, Beth Israel Deaconess Medical Center and Harvard Medical School Boston, MA, USA
| | - Volney L Sheen
- Department of Neurology, Beth Israel Deaconess Medical Center and Harvard Medical School Boston, MA, USA
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276
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Ha BG, Park JE, Cho HJ, Lim YB, Shon YH. Inhibitory effects of proton beam irradiation on integrin expression and signaling pathway in human colon carcinoma HT29 cells. Int J Oncol 2015; 46:2621-8. [PMID: 25845382 DOI: 10.3892/ijo.2015.2942] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 03/12/2015] [Indexed: 11/05/2022] Open
Abstract
Proton radiotherapy has been established as a highly effective modality used in the local control of tumor growth. Although proton radiotherapy is used worldwide to treat several types of cancer clinically with great success due to superior targeting and energy deposition, the detailed regulatory mechanisms underlying the functions of proton radiation are not yet well understood. Accordingly, in the present study, to assess the effects of proton beam on integrin-mediated signaling pathways, we investigated the expression of integrins related to tumor progression and integrin trafficking, and key molecules related to cell adhesion, as well as examining phosphorylation of signaling molecules involved in integrin-mediated signaling pathways. Proton beam irradiation inhibited the increase in 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced integrin β1 protein expression and the gene expression of members of the integrin family, such as α5β1, α6β4, αvβ3, and αvβ6 in human colorectal adenocarcinoma HT-29 cells. Simultaneously, the gene expression of cell adhesion molecules, such as FAK and CDH1, and integrin trafficking regulators, such as RAB4, RAB11, and HAX1, was decreased by proton beam irradiation. Moreover, proton beam irradiation decreased the phosphorylation of key molecules involved in integrin signaling, such as FAK, Src, and p130Cas, as well as PKC and MAPK, which are known as promoters of cell migration, while increased the phosphorylation of AMPK and the gene expression of Rab IP4 involved in the inhibition of cell adhesion and cell spreading. Taken together, our findings suggest that proton beam irradiation can inhibit metastatic potential, including cell adhesion and migration, by modulating the gene expression of molecules involved in integrin trafficking and integrin-mediated signaling, which are necessary for tumor progression.
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Affiliation(s)
- Byung Geun Ha
- Bio-Medical Research Institute, Kyungpook National University Hospital, Daegu, Republic of Korea
| | - Jung-Eun Park
- Bio-Medical Research Institute, Kyungpook National University Hospital, Daegu, Republic of Korea
| | - Hyun-Jung Cho
- Bio-Medical Research Institute, Kyungpook National University Hospital, Daegu, Republic of Korea
| | - Young-Bin Lim
- Division of Radiation Effects, Korea Institute of Radiological and Medical Sciences, Seoul, Republic of Korea
| | - Yun Hee Shon
- Bio-Medical Research Institute, Kyungpook National University Hospital, Daegu, Republic of Korea
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277
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Abiko H, Fujiwara S, Ohashi K, Hiatari R, Mashiko T, Sakamoto N, Sato M, Mizuno K. Rho guanine nucleotide exchange factors involved in cyclic-stretch-induced reorientation of vascular endothelial cells. J Cell Sci 2015; 128:1683-95. [PMID: 25795300 DOI: 10.1242/jcs.157503] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Accepted: 03/13/2015] [Indexed: 12/31/2022] Open
Abstract
Cyclic stretch is an artificial model of mechanical force loading, which induces the reorientation of vascular endothelial cells and their stress fibers in a direction perpendicular to the stretch axis. Rho family GTPases are crucial for cyclic-stretch-induced endothelial cell reorientation; however, the mechanism underlying stretch-induced activation of Rho family GTPases is unknown. A screen of short hairpin RNAs targeting 63 Rho guanine nucleotide exchange factors (Rho-GEFs) revealed that at least 11 Rho-GEFs – Abr, alsin, ARHGEF10, Bcr, GEF-H1 (also known as ARHGEF2), LARG (also known as ARHGEF12), p190RhoGEF (also known as ARHGEF28), PLEKHG1, P-REX2, Solo (also known as ARHGEF40) and α-PIX (also known as ARHGEF6) – which specifically or broadly target RhoA, Rac1 and/or Cdc42, are involved in cyclic-stretch-induced perpendicular reorientation of endothelial cells. Overexpression of Solo induced RhoA activation and F-actin accumulation at cell-cell and cell-substrate adhesion sites. Knockdown of Solo suppressed cyclic-stretch- or tensile-force-induced RhoA activation. Moreover, knockdown of Solo significantly reduced cyclic-stretch-induced perpendicular reorientation of endothelial cells when cells were cultured at high density, but not when they were cultured at low density or pretreated with EGTA or VE-cadherin-targeting small interfering RNAs. These results suggest that Solo is involved in cell-cell-adhesion-mediated mechanical signal transduction during cyclic-stretch-induced endothelial cell reorientation.
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Affiliation(s)
- Hiyori Abiko
- Department of Biomolecular Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8578, Japan
| | - Sachiko Fujiwara
- Department of Biomolecular Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8578, Japan
| | - Kazumasa Ohashi
- Department of Biomolecular Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8578, Japan
| | - Ryuichi Hiatari
- Department of Biomolecular Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8578, Japan
| | - Toshiya Mashiko
- Department of Biomolecular Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8578, Japan
| | - Naoya Sakamoto
- Department of Biomedical Engineering, Graduate School of Biomedical Engineering, Tohoku University, Sendai, Miyagi 980-8579, Japan
| | - Masaaki Sato
- Department of Biomedical Engineering, Graduate School of Biomedical Engineering, Tohoku University, Sendai, Miyagi 980-8579, Japan
| | - Kensaku Mizuno
- Department of Biomolecular Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8578, Japan
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278
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Abstract
The RhoGEF (Rho GTPase guanine-nucleotide-exchange factor) domain of AKAP-Lbc (A-kinase-anchoring protein-Lbc, also known as AKAP13) catalyses nucleotide exchange on RhoA and is involved in the development of cardiac hypertrophy. The RhoGEF activity of AKAP-Lbc has also been implicated in cancer. We have determined the X-ray crystal structure of the complex between RhoA–GDP and the AKAP-Lbc RhoGEF [DH (Dbl-homologous)–PH (pleckstrin homology)] domain to 2.1 Å (1 Å=0.1 nm) resolution. The structure reveals important differences compared with related RhoGEF proteins such as leukaemia-associated RhoGEF. Nucleotide-exchange assays comparing the activity of the DH–PH domain to the DH domain alone showed no role for the PH domain in nucleotide exchange, which is explained by the RhoA–AKAP-Lbc structure. Comparison with a structure of the isolated AKAP-Lbc DH domain revealed a change in conformation of the N-terminal ‘GEF switch’ region upon binding to RhoA. Isothermal titration calorimetry showed that AKAP-Lbc has only micromolar affinity for RhoA, which combined with the presence of potential binding pockets for small molecules on AKAP-Lbc, raises the possibility of targeting AKAP-Lbc with GEF inhibitors. The crystal structure of the RhoGEF domain of AKAP-Lbc in complex with RhoA combined with nucleotide exchange assays explain differences to related RhoGEF proteins and allow the possibility of targeting the AKAP-Lbc RhoGEF domain with small molecules.
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279
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Juin A, Di Martino J, Leitinger B, Henriet E, Gary AS, Paysan L, Bomo J, Baffet G, Gauthier-Rouvière C, Rosenbaum J, Moreau V, Saltel F. Discoidin domain receptor 1 controls linear invadosome formation via a Cdc42-Tuba pathway. ACTA ACUST UNITED AC 2015; 207:517-33. [PMID: 25422375 PMCID: PMC4242841 DOI: 10.1083/jcb.201404079] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
In tumor cells, the collagen receptor DDR1 collaborates with Cdc42 and its guanine exchange factor Tuba to promote linear invadosome formation and increase their matrix-invading activity. Accumulation of type I collagen fibrils in tumors is associated with an increased risk of metastasis. Invadosomes are F-actin structures able to degrade the extracellular matrix. We previously found that collagen I fibrils induced the formation of peculiar linear invadosomes in an unexpected integrin-independent manner. Here, we show that Discoidin Domain Receptor 1 (DDR1), a collagen receptor overexpressed in cancer, colocalizes with linear invadosomes in tumor cells and is required for their formation and matrix degradation ability. Unexpectedly, DDR1 kinase activity is not required for invadosome formation or activity, nor is Src tyrosine kinase. We show that the RhoGTPase Cdc42 is activated on collagen in a DDR1-dependent manner. Cdc42 and its specific guanine nucleotide-exchange factor (GEF), Tuba, localize to linear invadosomes, and both are required for linear invadosome formation. Finally, DDR1 depletion blocked cell invasion in a collagen gel. Altogether, our data uncover an important role for DDR1, acting through Tuba and Cdc42, in proteolysis-based cell invasion in a collagen-rich environment.
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Affiliation(s)
- Amélie Juin
- Institut National de la Santé et de la Recherche Médicale, U1053, F-33076 Bordeaux, France Université de Bordeaux, F-33076 Bordeaux, France
| | - Julie Di Martino
- Institut National de la Santé et de la Recherche Médicale, U1053, F-33076 Bordeaux, France Université de Bordeaux, F-33076 Bordeaux, France
| | - Birgit Leitinger
- National Heart and Lung Institute, Imperial College London, London SW7 2AZ, England, UK
| | - Elodie Henriet
- Institut National de la Santé et de la Recherche Médicale, U1053, F-33076 Bordeaux, France Université de Bordeaux, F-33076 Bordeaux, France
| | - Anne-Sophie Gary
- Institut National de la Santé et de la Recherche Médicale, U1053, F-33076 Bordeaux, France Université de Bordeaux, F-33076 Bordeaux, France
| | - Lisa Paysan
- Institut National de la Santé et de la Recherche Médicale, U1053, F-33076 Bordeaux, France Université de Bordeaux, F-33076 Bordeaux, France
| | - Jeremy Bomo
- Institut National de la Santé et de la Recherche Médicale, U1085, Institut de Recherche sur la Santé l'Environnement et le Travail (IRSET), Université de Rennes 1, 35043 Rennes, France
| | - Georges Baffet
- Institut National de la Santé et de la Recherche Médicale, U1085, Institut de Recherche sur la Santé l'Environnement et le Travail (IRSET), Université de Rennes 1, 35043 Rennes, France
| | - Cécile Gauthier-Rouvière
- Universités Montpellier 2 et 1, Centre de Recherche de Biochimie Macromoléculaire, Centre National de la Recherche Scientifique, UMR 5237, 34293 Montpellier, France
| | - Jean Rosenbaum
- Institut National de la Santé et de la Recherche Médicale, U1053, F-33076 Bordeaux, France Université de Bordeaux, F-33076 Bordeaux, France
| | - Violaine Moreau
- Institut National de la Santé et de la Recherche Médicale, U1053, F-33076 Bordeaux, France Université de Bordeaux, F-33076 Bordeaux, France
| | - Frédéric Saltel
- Institut National de la Santé et de la Recherche Médicale, U1053, F-33076 Bordeaux, France Université de Bordeaux, F-33076 Bordeaux, France
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280
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Schmitz HP, Jendretzki A, Wittland J, Wiechert J, Heinisch JJ. Identification of Dck1 and Lmo1 as upstream regulators of the small GTPase Rho5 inSaccharomyces cerevisiae. Mol Microbiol 2015; 96:306-24. [DOI: 10.1111/mmi.12937] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/14/2015] [Indexed: 12/29/2022]
Affiliation(s)
- Hans-Peter Schmitz
- Faculty of Biology/Chemistry, Department of Genetics Barbarastr. 11; University of Osnabrueck; Osnabrueck D-49076 Germany
| | - Arne Jendretzki
- Faculty of Biology/Chemistry, Department of Genetics Barbarastr. 11; University of Osnabrueck; Osnabrueck D-49076 Germany
| | - Janina Wittland
- Faculty of Biology/Chemistry, Department of Genetics Barbarastr. 11; University of Osnabrueck; Osnabrueck D-49076 Germany
| | - Johanna Wiechert
- Faculty of Biology/Chemistry, Department of Genetics Barbarastr. 11; University of Osnabrueck; Osnabrueck D-49076 Germany
| | - Jürgen J. Heinisch
- Faculty of Biology/Chemistry, Department of Genetics Barbarastr. 11; University of Osnabrueck; Osnabrueck D-49076 Germany
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281
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Bodman JAR, Yang Y, Logan MR, Eitzen G. Yeast translation elongation factor-1A binds vacuole-localized Rho1p to facilitate membrane integrity through F-actin remodeling. J Biol Chem 2015; 290:4705-4716. [PMID: 25561732 DOI: 10.1074/jbc.m114.630764] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Rho GTPases are molecular switches that modulate a variety of cellular processes, most notably those involving actin dynamics. We have previously shown that yeast vacuolar membrane fusion requires re-organization of actin filaments mediated by two Rho GTPases, Rho1p and Cdc42p. Cdc42p initiates actin polymerization to facilitate membrane tethering; Rho1p has a role in the late stages of vacuolar fusion, but its mode of action is unknown. Here, we identified eEF1A as a vacuolar Rho1p-interacting protein. eEF1A (encoded by the TEF1 and TEF2 genes in yeast) is an aminoacyl-tRNA transferase needed during protein translation. eEF1A also has a second function that is independent of translation; it binds and organizes actin filaments into ordered cable structures. Here, we report that eEF1A interacts with Rho1p via a C-terminal subdomain. This interaction occurs predominantly when both proteins are in the GDP-bound state. Therefore, eEF1A is an atypical downstream effector of Rho1p. eEF1A does not promote vacuolar fusion; however, overexpression of the Rho1p-interacting subdomain affects vacuolar morphology. Vacuoles were destabilized and prone to leakage when treated with the eEF1A inhibitor narciclasine. We propose a model whereby eEF1A binds to Rho1p-GDP on the vacuolar membrane; it is released upon Rho1p activation and then bundles actin filaments to stabilize fused vacuoles. Therefore, the Rho1p-eEF1A complex acts to spatially localize a pool of eEF1A to vacuoles where it can readily organize F-actin.
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Affiliation(s)
- James A R Bodman
- From the Department of Cell Biology, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
| | - Yang Yang
- From the Department of Cell Biology, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
| | - Michael R Logan
- From the Department of Cell Biology, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
| | - Gary Eitzen
- From the Department of Cell Biology, University of Alberta, Edmonton, Alberta T6G 2H7, Canada.
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282
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Janus-faces of NME-oncoprotein interactions. Naunyn Schmiedebergs Arch Pharmacol 2014; 388:175-87. [PMID: 25366701 DOI: 10.1007/s00210-014-1062-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Accepted: 10/15/2014] [Indexed: 12/26/2022]
Abstract
Since the identification of Nm23 (NME1, NME/NM23 nucleoside diphosphate kinase 1) as the first non-metastatic protein, a great deal of research on members of the NME family of proteins has focused on roles in processes implicated in carcinogenesis and particularly their regulation of cellular motility and the process of metastatic spread. To date, there are ten identified members of this family of genes, and these can be dichotomized into groups both taxonomically and by the presence or absence of their nucleoside diphosphate kinase activity with NMEs 1-4 encoding nucleoside diphosphate kinases (NDPKs) and NMEs 5-9 plus RP2 displaying little if any NDPK activity. NMEs are relatively small proteins that can form hetero-oligomers (typically hexamers), and given the apparent genetic redundancy of some NMEs and the number of different isoforms, it is perhaps not surprising that there remains a great deal of uncertainty regarding their function and even more regarding cellular mechanisms of action. Since residues that contribute to NDPK activity span much of the protein, it seems likely that the consequences of NME expression must be mediated through their NDPK activity, through interactions with other structures in cells including protein-protein interactions or through combinations of these. Our goal in this review is to focus on some of the protein-protein interactions that have been identified and to highlight some of the challenges that face this area of research.
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283
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Goicoechea SM, Awadia S, Garcia-Mata R. I'm coming to GEF you: Regulation of RhoGEFs during cell migration. Cell Adh Migr 2014; 8:535-49. [PMID: 25482524 PMCID: PMC4594598 DOI: 10.4161/cam.28721] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Cell migration is a highly regulated multistep process that requires the coordinated regulation of cell adhesion, protrusion, and contraction. These processes require numerous protein–protein interactions and the activation of specific signaling pathways. The Rho family of GTPases plays a key role in virtually every aspect of the cell migration cycle. The activation of Rho GTPases is mediated by a large and diverse family of proteins; the guanine nucleotide exchange factors (RhoGEFs). GEFs work immediately upstream of Rho proteins to provide a direct link between Rho activation and cell–surface receptors for various cytokines, growth factors, adhesion molecules, and G protein-coupled receptors. The regulated targeting and activation of RhoGEFs is essential to coordinate the migratory process. In this review, we summarize the recent advances in our understanding of the role of RhoGEFs in the regulation of cell migration.
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Key Words
- DH, Dbl-homology
- DHR, DOCK homology region
- DOCK, dedicator of cytokinesis
- ECM, extracellular matrix
- EGF, epidermal growth factor
- FA, focal adhesion
- FN, fibronectin
- GAP, GTPase activating protein
- GDI, guanine nucleotide dissociation inhibitor
- GEF, guanine nucleotide exchange factor
- GPCR, G protein-coupled receptor
- HGF, hepatocyte growth factor
- LPA, lysophosphatidic acid
- MII, myosin II
- PA, phosphatidic acid
- PDGF, platelet-derived growth factor
- PH, pleckstrin-homology
- PIP2, phosphatidylinositol 4, 5-bisphosphate
- PIP3, phosphatidylinositol (3, 4, 5)-trisphosphate.
- Rho GEFs
- Rho GTPases
- bFGF, basic fibroblast growth factor
- cell migration
- cell polarization
- focal adhesions
- guanine nucleotide exchange factors
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Affiliation(s)
- Silvia M Goicoechea
- a Department of Biological Sciences ; University of Toledo ; Toledo , OH USA
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284
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Castillo-Pichardo L, Humphries-Bickley T, De La Parra C, Forestier-Roman I, Martinez-Ferrer M, Hernandez E, Vlaar C, Ferrer-Acosta Y, Washington AV, Cubano LA, Rodriguez-Orengo J, Dharmawardhane S. The Rac Inhibitor EHop-016 Inhibits Mammary Tumor Growth and Metastasis in a Nude Mouse Model. Transl Oncol 2014; 7:546-55. [PMID: 25389450 PMCID: PMC4225654 DOI: 10.1016/j.tranon.2014.07.004] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 07/14/2014] [Accepted: 07/18/2014] [Indexed: 01/19/2023] Open
Abstract
Metastatic disease still lacks effective treatments, and remains the primary cause of cancer mortality. Therefore, there is a critical need to develop better strategies to inhibit metastatic cancer. The Rho family GTPase Rac is an ideal target for anti-metastatic cancer therapy, because Rac is a key molecular switch that is activated by a myriad of cell surface receptors to promote cancer cell migration/invasion and survival. Previously, we reported the design and development of EHop-016, a small molecule compound, which inhibits Rac activity of metastatic cancer cells with an IC50 of 1 μM. EHop-016 also inhibits the activity of the Rac downstream effector p21-activated kinase (PAK), lamellipodia extension, and cell migration in metastatic cancer cells. Herein, we tested the efficacy of EHop-016 in a nude mouse model of experimental metastasis, where EHop-016 administration at 25 mg/kg body weight (BW) significantly reduced mammary fat pad tumor growth, metastasis, and angiogenesis. As quantified by UPLC MS/MS, EHop-016 was detectable in the plasma of nude mice at 17 to 23 ng/ml levels at 12 h following intraperitoneal (i.p.) administration of 10 to 25 mg/kg BW EHop-016. The EHop-016 mediated inhibition of angiogenesis In Vivo was confirmed by immunohistochemistry of excised tumors and by In Vitro tube formation assays of endothelial cells. Moreover, EHop-016 affected cell viability by down-regulating Akt and Jun kinase activities and c-Myc and Cyclin D expression, as well as increasing caspase 3/7 activities in metastatic cancer cells. In conclusion, EHop-016 has potential as an anticancer compound to block cancer progression via multiple Rac-directed mechanisms.
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Affiliation(s)
- Linette Castillo-Pichardo
- Department of Biochemistry, School of Medicine, University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico ; Department of Pathology and Laboratory Medicine, Universidad Central del Caribe, School of Medicine, Bayamón, Puerto Rico
| | - Tessa Humphries-Bickley
- Department of Biochemistry, School of Medicine, University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico
| | - Columba De La Parra
- Department of Biochemistry, School of Medicine, University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico
| | - Ingrid Forestier-Roman
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico
| | - Magaly Martinez-Ferrer
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico
| | - Eliud Hernandez
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico
| | - Cornelis Vlaar
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico
| | | | | | - Luis A Cubano
- Department of Anatomy and Cell Biology, Universidad Central del Caribe, School of Medicine, Bayamón, Puerto Rico
| | - Jose Rodriguez-Orengo
- Department of Biochemistry, School of Medicine, University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico
| | - Suranganie Dharmawardhane
- Department of Biochemistry, School of Medicine, University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico
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285
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Goto A, Kamioka Y, Matsuda M. PKA modulation of Rac in neuronal cells. Front Cell Neurosci 2014; 8:321. [PMID: 25352782 PMCID: PMC4196561 DOI: 10.3389/fncel.2014.00321] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Accepted: 09/24/2014] [Indexed: 12/20/2022] Open
Affiliation(s)
- Akihiro Goto
- Department of Pathology and Biology of Diseases, Graduate School of Medicine, Kyoto University Kyoto, Japan
| | - Yuji Kamioka
- Department of Pathology and Biology of Diseases, Graduate School of Medicine, Kyoto University Kyoto, Japan
| | - Michiyuki Matsuda
- Department of Pathology and Biology of Diseases, Graduate School of Medicine, Kyoto University Kyoto, Japan
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286
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Barrio-Real L, Benedetti LG, Engel N, Tu Y, Cho S, Sukumar S, Kazanietz MG. Subtype-specific overexpression of the Rac-GEF P-REX1 in breast cancer is associated with promoter hypomethylation. Breast Cancer Res 2014; 16:441. [PMID: 25248717 PMCID: PMC4303123 DOI: 10.1186/s13058-014-0441-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Accepted: 09/01/2014] [Indexed: 01/30/2023] Open
Abstract
Introduction The Rac-GEF P-REX1 is a key mediator of ErbB signaling in breast cancer recently implicated in mammary tumorigenesis and metastatic dissemination. Although P-REX1 is essentially undetectable in normal human mammary epithelial tissue, this Rac-GEF is markedly upregulated in human breast carcinomas, particularly of the luminal subtype. The mechanisms underlying P-REX1 upregulation in breast cancer are unknown. Toward the goal of dissecting the mechanistic basis of P-REX1 overexpression in breast cancer, in this study we focused on the analysis of methylation of the PREX1 gene promoter. Methods To determine the methylation status of the PREX1 promoter region, we used bisulfite genomic sequencing and pyrosequencing approaches. Re-expression studies in cell lines were carried out by treatment of breast cancer cells with the demethylating agent 5-aza-2′-deoxycitidine. PREX1 gene methylation in different human breast cancer subtypes was analyzed from the TCGA database. Results We found that the human PREX1 gene promoter has a CpG island located between -1.2 kb and +1.4 kb, and that DNA methylation in this region inversely correlates with P-REX1 expression in human breast cancer cell lines. A comprehensive analysis of human breast cancer cell lines and tumors revealed significant hypomethylation of the PREX1 promoter in ER-positive, luminal subtype, whereas hypermethylation occurs in basal-like breast cancer. Treatment of normal MCF-10A or basal-like cancer cells, MDA-MB-231 with the demethylating agent 5-aza-2′-deoxycitidine in combination with the histone deacetylase inhibitor trichostatin A restores P-REX1 levels to those observed in luminal breast cancer cell lines, suggesting that aberrant expression of P-REX1 in luminal breast cancer is a consequence of PREX1 promoter demethylation. Unlike PREX1, the pro-metastatic Rho/Rac-GEF, VAV3, is not regulated by methylation. Notably, PREX1 gene promoter hypomethylation is a prognostic marker of poor patient survival. Conclusions Our study identified for the first time gene promoter hypomethylation as a distinctive subtype-specific mechanism for controlling the expression of a key regulator of Rac-mediated motility and metastasis in breast cancer. Electronic supplementary material The online version of this article (doi:10.1186/s13058-014-0441-7) contains supplementary material, which is available to authorized users.
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287
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Sheshachalam A, Srivastava N, Mitchell T, Lacy P, Eitzen G. Granule protein processing and regulated secretion in neutrophils. Front Immunol 2014; 5:448. [PMID: 25285096 PMCID: PMC4168738 DOI: 10.3389/fimmu.2014.00448] [Citation(s) in RCA: 148] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Accepted: 09/03/2014] [Indexed: 12/31/2022] Open
Abstract
Neutrophils are part of a family of granulocytes that, together with eosinophils and basophils, play an essential role in innate immunity. Neutrophils are the most abundant circulating leukocytes and are vital for rapid immune responses, being recruited to sites of injury or infection within minutes, where they can act as specialized phagocytic cells. However, another prominent function of neutrophils is the release of pro-inflammatory compounds, including cytokines, chemokines, and digestive enzymes, which are stored in intracellular compartments and released through regulated exocytosis. Hence, an important feature that contributes to rapid immune responses is capacity of neutrophils to synthesize and store pre-formed pro-inflammatory mediators in specialized intracellular vesicles and thus no new synthesis is required. This review will focus on advancement in three topics relevant to neutrophil secretion. First, we will examine what is known about basal level pro-inflammatory mediator synthesis, trafficking, and storage in secretory compartments. Second, we will review recent advancements in the mechanisms that control vesicle mobilization and the release of pre-formed mediators. Third, we will examine the upregulation and de novo synthesis of pro-inflammatory mediators by neutrophils engaged at sites of infection.
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Affiliation(s)
| | - Nutan Srivastava
- Pulmonary Research Group, University of Alberta , Edmonton, AB , Canada ; Department of Medicine, University of Alberta , Edmonton, AB , Canada
| | - Troy Mitchell
- Department of Medicine, University of Alberta , Edmonton, AB , Canada
| | - Paige Lacy
- Pulmonary Research Group, University of Alberta , Edmonton, AB , Canada ; Department of Medicine, University of Alberta , Edmonton, AB , Canada
| | - Gary Eitzen
- Department of Cell Biology, University of Alberta , Edmonton, AB , Canada
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288
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Schmidt S, Debant A. Function and regulation of the Rho guanine nucleotide exchange factor Trio. Small GTPases 2014; 5:e29769. [PMID: 24987837 DOI: 10.4161/sgtp.29769] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Rho GTPases oscillate between an inactive GDP-bound state and an active GTP-bound state. They are activated by Rho Guanine nucleotide Exchange Factors (GEF), which accelerate the GDP to GTP exchange. RhoGEFs fall into two different classes: the Dbl family and the DOCK family of proteins. In this review, we focus on the function and regulation of the Dbl family RhoGEF Trio. Trio and its paralog Kalirin are unique within this family in that they display two GEF domains of distinct specificity. Trio is a major regulator of neuronal development, and its function is conserved through evolution. Moreover, Trio plays an important role in cell adhesion and in signaling pathways elicited by Gαq protein-coupled receptors. Combined, these observations suggest that Trio has a major role in cellular physiology. Of note, Trio is an essential gene for mouse development, with a prominent role in the development of the nervous system. Finally, Trio expression is significantly increased in different types of tumors and it has been proposed that it could participate in oncogenesis.
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Affiliation(s)
- Susanne Schmidt
- Centre de Recherche en Biochimie Macromoléculaire; CNRS - UMR 5237; Université de Montpellier; Montpellier, France
| | - Anne Debant
- Centre de Recherche en Biochimie Macromoléculaire; CNRS - UMR 5237; Université de Montpellier; Montpellier, France
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289
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Ngok SP, Lin WH, Anastasiadis PZ. Establishment of epithelial polarity--GEF who's minding the GAP? J Cell Sci 2014; 127:3205-15. [PMID: 24994932 DOI: 10.1242/jcs.153197] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Cell polarization is a fundamental process that underlies epithelial morphogenesis, cell motility, cell division and organogenesis. Loss of polarity predisposes tissues to developmental disorders and contributes to cancer progression. The formation and establishment of epithelial cell polarity is mediated by the cooperation of polarity protein complexes, namely the Crumbs, partitioning defective (Par) and Scribble complexes, with Rho family GTPases, including RhoA, Rac1 and Cdc42. The activation of different GTPases triggers distinct downstream signaling pathways to modulate protein-protein interactions and cytoskeletal remodeling. The spatio-temporal activation and inactivation of these small GTPases is tightly controlled by a complex interconnected network of different regulatory proteins, including guanine-nucleotide-exchange factors (GEFs), GTPase-activating proteins (GAPs), and guanine-nucleotide-dissociation inhibitors (GDIs). In this Commentary, we focus on current understanding on how polarity complexes interact with GEFs and GAPs to control the precise location and activation of Rho GTPases (Crumbs for RhoA, Par for Rac1, and Scribble for Cdc42) to promote apical-basal polarization in mammalian epithelial cells. The mutual exclusion of GTPase activities, especially that of RhoA and Rac1, which is well established, provides a mechanism through which polarity complexes that act through distinct Rho GTPases function as cellular rheostats to fine-tune specific downstream pathways to differentiate and preserve the apical and basolateral domains. This article is part of a Minifocus on Establishing polarity.
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Affiliation(s)
- Siu P Ngok
- Department of Cancer Biology, Mayo Clinic Comprehensive Cancer Center, Griffin Cancer Research Building, Room 307, 4500 San Pablo Road, Jacksonville, FL 32224, USA
| | - Wan-Hsin Lin
- Department of Cancer Biology, Mayo Clinic Comprehensive Cancer Center, Griffin Cancer Research Building, Room 307, 4500 San Pablo Road, Jacksonville, FL 32224, USA
| | - Panos Z Anastasiadis
- Department of Cancer Biology, Mayo Clinic Comprehensive Cancer Center, Griffin Cancer Research Building, Room 307, 4500 San Pablo Road, Jacksonville, FL 32224, USA
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290
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A Ca(2+)-dependent signalling circuit regulates influenza A virus internalization and infection. Nat Commun 2014; 4:2763. [PMID: 24434940 DOI: 10.1038/ncomms3763] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Accepted: 10/11/2013] [Indexed: 12/12/2022] Open
Abstract
Various viruses enter host cells via endocytosis, but the molecular mechanisms underlying the specific internalization pathways remain unclear. Here we show that influenza A viruses (IAVs) enter cells via redundant pathways of clathrin-mediated and clathrin-independent endocytosis, with intracellular Ca(2+) having a central role in regulation of both pathways by activating a signalling axis comprising RhoA, Rho-kinase, phosphatidylinositol 4-phosphate 5-kinase (PIP5K) and phospholipase C (PLC). IAV infection induces oscillations in the cytosolic Ca(2+) concentration of host cells, the prevention of which markedly attenuates virus internalization and infection. The small GTPase RhoA is found both to function downstream of the virus-induced Ca(2+) response and itself to induce Ca(2+) oscillations in a manner dependent on Rho-kinase and subsequent PIP5K-PLC signalling. This signalling circuit regulates both clathrin-mediated and clathrin-independent endocytosis during virus infection and seems to constitute a key mechanism for regulation of IAV internalization and infection.
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291
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Phosphatidylinositol 5-phosphate regulates invasion through binding and activation of Tiam1. Nat Commun 2014; 5:4080. [PMID: 24905281 DOI: 10.1038/ncomms5080] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Accepted: 05/09/2014] [Indexed: 12/13/2022] Open
Abstract
PtdIns5P is a lipid messenger acting as a stress-response mediator in the nucleus, and known to maintain cell activation through traffic alterations upon bacterial infection. Here, we show that PtdIns5P regulates actin dynamics and invasion via recruitment and activation of the exchange factor Tiam1 and Rac1. Restricted Rac1 activation results from the binding of Tiam1 DH-PH domains to PtdIns5P. Using an assay that mimics Rac1 membrane anchoring by using Rac1-His and liposomes containing Ni(2+)-NTA modified lipids, we demonstrate that intrinsic Tiam1 DH-PH activity increases when Rac1 is anchored in a PtdIns5P-enriched environment. This pathway appears to be general since it is valid in different pathophysiological models: receptor tyrosine kinase activation, bacterial phosphatase IpgD expression and the invasive NPM-ALK(+) lymphomas. The discovery that PtdIns5P could be a keystone of GTPases and cytoskeleton spatiotemporal regulation opens important research avenues towards unravelling new strategies counteracting cell invasion.
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292
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Britton D, Zen Y, Quaglia A, Selzer S, Mitra V, Lößner C, Jung S, Böhm G, Schmid P, Prefot P, Hoehle C, Koncarevic S, Gee J, Nicholson R, Ward M, Castellano L, Stebbing J, Zucht HD, Sarker D, Heaton N, Pike I. Quantification of pancreatic cancer proteome and phosphorylome: indicates molecular events likely contributing to cancer and activity of drug targets. PLoS One 2014; 9:e90948. [PMID: 24670416 PMCID: PMC3966770 DOI: 10.1371/journal.pone.0090948] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Accepted: 02/05/2014] [Indexed: 12/15/2022] Open
Abstract
OBJECTIVE LC-MS/MS phospho-proteomics is an essential technology to help unravel the complex molecular events that lead to and propagate cancer. We have developed a global phospho-proteomic workflow to determine activity of signaling pathways and drug targets in pancreatic cancer tissue for clinical application. METHODS Peptides resulting from tryptic digestion of proteins extracted from frozen tissue of pancreatic ductal adenocarcinoma and background pancreas (n = 12), were labelled with tandem mass tags (TMT 8-plex), separated by strong cation exchange chromatography, then were analysed by LC-MS/MS directly or first enriched for phosphopeptides using IMAC and TiO2, prior to analysis. In-house, commercial and freeware bioinformatic platforms were used to identify relevant biological events from the complex dataset. RESULTS Of 2,101 proteins identified, 152 demonstrated significant difference in abundance between tumor and non-tumor tissue. They included proteins that are known to be up-regulated in pancreatic cancer (e.g. Mucin-1), but the majority were new candidate markers such as HIPK1 & MLCK. Of the 6,543 unique phosphopeptides identified (6,284 unique phosphorylation sites), 635 showed significant regulation, particularly those from proteins involved in cell migration (Rho guanine nucleotide exchange factors & MRCKα) and formation of focal adhesions. Activator phosphorylation sites on FYN, AKT1, ERK2, HDAC1 and other drug targets were found to be highly modulated (≥2 fold) in different cases highlighting their predictive power. CONCLUSION Here we provided critical information enabling us to identify the common and unique molecular events likely contributing to cancer in each case. Such information may be used to help predict more bespoke therapy suitable for an individual case.
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Affiliation(s)
| | - Yoh Zen
- Institute of Liver Studies, King's College Hospital, London, United Kingdom
| | - Alberto Quaglia
- Institute of Liver Studies, King's College Hospital, London, United Kingdom
| | | | | | | | | | - Gitte Böhm
- Proteome Sciences plc, Cobham, United Kingdom
| | | | | | | | | | - Julia Gee
- Cardiff School of Pharmacy & Pharmaceutical Sciences, Cardiff University, Cardiff, United Kingdom
| | - Robert Nicholson
- Cardiff School of Pharmacy & Pharmaceutical Sciences, Cardiff University, Cardiff, United Kingdom
| | | | - Leandro Castellano
- Faculty of Medicine, Department of Surgery & Cancer, Imperial College, London, United Kingdom
| | - Justin Stebbing
- Faculty of Medicine, Department of Surgery & Cancer, Imperial College, London, United Kingdom
| | | | - Debashis Sarker
- Institute of Liver Studies, King's College Hospital, London, United Kingdom
| | - Nigel Heaton
- Institute of Liver Studies, King's College Hospital, London, United Kingdom
| | - Ian Pike
- Proteome Sciences plc, Cobham, United Kingdom
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293
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Sun C, Liu C, Li S, Li H, Wang Y, Xie Y, Li B, Cui X, Chen Y, Zhang W, Li F. Overexpression of GEFT, a Rho family guanine nucleotide exchange factor, predicts poor prognosis in patients with rhabdomyosarcoma. INTERNATIONAL JOURNAL OF CLINICAL AND EXPERIMENTAL PATHOLOGY 2014; 7:1606-1615. [PMID: 24817957 PMCID: PMC4014241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 01/11/2014] [Accepted: 02/15/2014] [Indexed: 06/03/2023]
Abstract
Rhabdomyosarcoma (RMS) is one of the most common soft-tissue sarcomas in children and adolescents with poor prognosis. Yet, there is lack of effective prognostic biomarkers for RMS. The present study, therefore, aimed to explore potential biomarkers for RMS based on our previous findings using array comparative genomic hybridization. We investigated guanine nucleotide exchange factor, GEFT, at expression level in 45 RMS patients and 36 normal striated muscle controls using immunohistochemistry using tissue microarrays. The expression rate of GEFT in RMS samples (42/45, 93.33%) was significantly higher (P<0.05) than that in normal controls (5/36, 13.89%). Moreover, the overexpression rate of GEFT in RMS (31/45, 68.89%) was also significantly higher (P<0.05) than that in normal controls (0/36, 0.00%). Increased expression of GEFT correlated significantly with advanced disease stages (stages III/IV) (P=0.001), lymph node metastasis (P=0.019), and distant metastasis (P=0.004), respectively, in RMS patients. In addition, RMS patients having overexpressed GEFT experienced worse overall survival (OS) than those having low levels of GEFT (P=0.001). GEFT overexpression was determined to be an independent prognostic factor for poor OS in RMS patients (hazard ratio: 3.491, 95% confidence interval: 1.121-10.871, P=0.004). In conclusion, these observations provide the first evidence of GEFT overexpression in RMS and its correlations with disease aggressiveness and metastasis. These findings suggest that GEFT may serve as a promising biomarker predicting poor prognosis in RMS patients, thus implying its potential as a therapeutic target.
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Affiliation(s)
- Chao Sun
- Department of Pathology, Shihezi University School of MedicineShihezi, Xinjiang 832002, China
- Key Laboratories for Xinjiang Endemic and Ethnic Diseases, Shihezi University and Chinese Ministry of EducationShihezi, Xinjiang 832002, China
| | - Chunxia Liu
- Department of Pathology, Shihezi University School of MedicineShihezi, Xinjiang 832002, China
- Key Laboratories for Xinjiang Endemic and Ethnic Diseases, Shihezi University and Chinese Ministry of EducationShihezi, Xinjiang 832002, China
| | - Shugang Li
- Department of Preventive Medicine, Shihezi University School of MedicineShihezi, Xinjiang 832002, China
| | - Hongan Li
- Department of Pathology, Shihezi University School of MedicineShihezi, Xinjiang 832002, China
| | - Yuanyuan Wang
- Department of Pathology, Shihezi University School of MedicineShihezi, Xinjiang 832002, China
| | - Yuwen Xie
- Department of Pathology, Shihezi University School of MedicineShihezi, Xinjiang 832002, China
| | - Bingcheng Li
- Department of Pathology, Shihezi University School of MedicineShihezi, Xinjiang 832002, China
| | - Xiaobin Cui
- Department of Pathology, Shihezi University School of MedicineShihezi, Xinjiang 832002, China
| | - Yunzhao Chen
- Department of Pathology, Shihezi University School of MedicineShihezi, Xinjiang 832002, China
| | - Wenjie Zhang
- Department of Pathology, Shihezi University School of MedicineShihezi, Xinjiang 832002, China
- Key Laboratories for Xinjiang Endemic and Ethnic Diseases, Shihezi University and Chinese Ministry of EducationShihezi, Xinjiang 832002, China
| | - Feng Li
- Department of Pathology, Shihezi University School of MedicineShihezi, Xinjiang 832002, China
- Key Laboratories for Xinjiang Endemic and Ethnic Diseases, Shihezi University and Chinese Ministry of EducationShihezi, Xinjiang 832002, China
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294
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Lawson CD, Burridge K. The on-off relationship of Rho and Rac during integrin-mediated adhesion and cell migration. Small GTPases 2014; 5:e27958. [PMID: 24607953 DOI: 10.4161/sgtp.27958] [Citation(s) in RCA: 218] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Rho GTPases play an essential role in regulating cell spreading, adhesion, and migration downstream of integrin engagement with the extracellular matrix. In this review, we focus on RhoA and Rac1--2 Rho GTPases that are required for efficient adhesion and migration--and describe how specific guanine nucleotide exchange factors (GEFs) and GTPase-activating proteins (GAPs) regulate the extensive crosstalk that exists between them. In particular, we assess the role of GEFs and GAPs in light of recent, unexpected evidence concerning the spatiotemporal relationship between RhoA and Rac1 at the leading edge of migrating cells. Force is increasingly recognized as a key regulator of cell adhesion and we highlight the role of GEFs and GAPs in mechanotransduction, before debating the controversial role of tension in focal adhesion maturation.
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Affiliation(s)
- Campbell D Lawson
- Department of Cell Biology and Physiology; Lineberger Comprehensive Cancer Center; University of North Carolina at Chapel Hill; Chapel Hill, NC USA
| | - Keith Burridge
- Department of Cell Biology and Physiology; Lineberger Comprehensive Cancer Center; University of North Carolina at Chapel Hill; Chapel Hill, NC USA
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295
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Saxena M, Dykes SS, Malyarchuk S, Wang AE, Cardelli JA, Pruitt K. The sirtuins promote Dishevelled-1 scaffolding of TIAM1, Rac activation and cell migration. Oncogene 2013; 34:188-98. [PMID: 24362520 PMCID: PMC4067478 DOI: 10.1038/onc.2013.549] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Revised: 11/02/2013] [Accepted: 11/15/2013] [Indexed: 12/18/2022]
Abstract
Rac1-GTPases serve as intermediary cellular switches which conduct transient and constitutive signals from upstream cues, including those from Ras oncoproteins. While the sirtuin1 (SIRT1) deacetylase is overexpressed in several human cancers and has recently been linked to cancer cell motility as a context-dependent regulator of multiple pathways, its role in Rac1 activation has not been reported. Likewise, SIRT2 has been demonstrated to be upregulated in some cancers; however, studies have also reported its role in tumor suppression. Here, we demonstrate that SIRT1 and SIRT2 positively regulate the levels of Rac1-GTP and the activity of T-cell lymphoma invasion and metastasis 1 (TIAM1), a Rac guanine nucleotide exchange factor (GEF). Transient inhibition of SIRT1 and SIRT2 resulted in increased acetylation of TIAM1 whereas chronic SIRT2 knockdown resulted in enhanced acetylation of TIAM1. SIRT1 regulates Dishevelled (DVL) protein levels in cancer cells and DVL along with TIAM1 are known to augment Rac activation; however, SIRT1 or 2 have not been previously linked with TIAM1. We found that diminished sirtuin activity led to the disruption of the DVL1-TIAM1 interaction. We hence propose a model for Rac activation where SIRT1/2 positively modulate the DVL/TIAM1/Rac axis and promote sustained pathway activation.
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Affiliation(s)
- M Saxena
- Department of Molecular and Cellular Physiology, LSU Health Shreveport, Shreveport, LA, USA
| | - S S Dykes
- Department of Microbiology and Immunology, LSU Health Shreveport, Shreveport, LA, USA
| | - S Malyarchuk
- Department of Molecular and Cellular Physiology, LSU Health Shreveport, Shreveport, LA, USA
| | - A E Wang
- Department of Molecular and Cellular Physiology, LSU Health Shreveport, Shreveport, LA, USA
| | - J A Cardelli
- 1] Department of Microbiology and Immunology, LSU Health Shreveport, Shreveport, LA, USA [2] Feist-Weiller Cancer Center, LSU Health Shreveport, Shreveport, LA, USA
| | - K Pruitt
- 1] Department of Molecular and Cellular Physiology, LSU Health Shreveport, Shreveport, LA, USA [2] Feist-Weiller Cancer Center, LSU Health Shreveport, Shreveport, LA, USA
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