51
|
Endothelial Akt1 mediates angiogenesis by phosphorylating multiple angiogenic substrates. Proc Natl Acad Sci U S A 2014; 111:12865-70. [PMID: 25136137 DOI: 10.1073/pnas.1408472111] [Citation(s) in RCA: 109] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The PI3K/Akt pathway is necessary for several key endothelial cell (EC) functions, including cell growth, migration, survival, and vascular tone. However, existing literature supports the idea that Akt can be either pro- or antiangiogenic, possibly due to compensation by multiple isoforms in the EC when a single isoform is deleted. Thus, biochemical, genetic, and proteomic studies were conducted to examine isoform-substrate specificity for Akt1 vs. Akt2. In vitro, Akt1 preferentially phosphorylates endothelial nitric oxide synthase (eNOS) and promotes NO release, whereas nonphysiological overexpression of Akt2 can bypass the loss of Akt1. Conditional deletion of Akt1 in the EC, in the absence or presence of Akt2, retards retinal angiogenesis, implying that Akt1 exerts a nonredundant function during physiological angiogenesis. Finally, proteomic analysis of Akt substrates isolated from Akt1- or Akt2-deficient ECs documents that phosphorylation of multiple Akt substrates regulating angiogenic signaling is reduced in Akt1-deficient, but not Akt2-deficient, ECs, including eNOS and Forkhead box proteins. Therefore, Akt1 promotes angiogenesis largely due to phosphorylation and regulation of important downstream effectors that promote aspects of angiogenic signaling.
Collapse
|
52
|
Mojallal M, Zheng Y, Hultin S, Audebert S, van Harn T, Johnsson P, Lenander C, Fritz N, Mieth C, Corcoran M, Lembo F, Hallström M, Hartman J, Mazure NM, Weide T, Grandér D, Borg JP, Uhlén P, Holmgren L. AmotL2 disrupts apical-basal cell polarity and promotes tumour invasion. Nat Commun 2014; 5:4557. [PMID: 25080976 DOI: 10.1038/ncomms5557] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Accepted: 06/30/2014] [Indexed: 01/02/2023] Open
Abstract
The establishment and maintenance of apical-basal cell polarity is essential for the functionality of glandular epithelia. Cell polarity is often lost in advanced tumours correlating with acquisition of invasive and malignant properties. Despite extensive knowledge regarding the formation and maintenance of polarity, the mechanisms that deregulate polarity in metastasizing cells remain to be fully characterized. Here we show that AmotL2 expression correlates with loss of tissue architecture in tumours from human breast and colon cancer patients. We further show that hypoxic stress results in activation of c-Fos-dependent expression of AmotL2 leading to loss of polarity. c-Fos/hypoxia-induced p60 AmotL2 interacts with the Crb3 and Par3 polarity complexes retaining them in large vesicles and preventing them from reaching the apical membrane. The resulting loss of polarity potentiates the response to invasive cues in vitro and in vivo in mice. These data provide a molecular mechanism how hypoxic stress deregulates cell polarity during tumour progression.
Collapse
Affiliation(s)
- Mahdi Mojallal
- 1] Department of Oncology and Pathology, Cancer Centrum Karolinska, Karolinska Institutet, SE-17176 Stockholm, Sweden [2]
| | - Yujuan Zheng
- 1] Department of Oncology and Pathology, Cancer Centrum Karolinska, Karolinska Institutet, SE-17176 Stockholm, Sweden [2]
| | - Sara Hultin
- Department of Oncology and Pathology, Cancer Centrum Karolinska, Karolinska Institutet, SE-17176 Stockholm, Sweden
| | - Stéphane Audebert
- 1] Inserm U1068, CRCM, 13009 Marseille, France [2] CNRS UMR7258, CRCM, 13009 Marseille, France [3] Institut Paoli-Calmettes, 13009 Marseille, France [4] Aix-Marseille Université, 13009 Marseille, France
| | - Tanja van Harn
- Department of Oncology and Pathology, Cancer Centrum Karolinska, Karolinska Institutet, SE-17176 Stockholm, Sweden
| | - Per Johnsson
- Department of Oncology and Pathology, Cancer Centrum Karolinska, Karolinska Institutet, SE-17176 Stockholm, Sweden
| | - Claes Lenander
- Department of Oncology and Pathology, Cancer Centrum Karolinska, Karolinska Institutet, SE-17176 Stockholm, Sweden
| | - Nicolas Fritz
- Laboratory of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-17177 Stockholm, Sweden
| | - Christin Mieth
- Max-Delbrück-Center for Molecular Medicine (MDC), Robert-Rössle-Str. 10, 13125 Berlin, Germany
| | - Martin Corcoran
- Department of Oncology and Pathology, Cancer Centrum Karolinska, Karolinska Institutet, SE-17176 Stockholm, Sweden
| | - Frédérique Lembo
- 1] Inserm U1068, CRCM, 13009 Marseille, France [2] CNRS UMR7258, CRCM, 13009 Marseille, France [3] Institut Paoli-Calmettes, 13009 Marseille, France [4] Aix-Marseille Université, 13009 Marseille, France
| | - Marja Hallström
- Department of Oncology and Pathology, Cancer Centrum Karolinska, Karolinska Institutet, SE-17176 Stockholm, Sweden
| | - Johan Hartman
- Department of Oncology and Pathology, Cancer Centrum Karolinska, Karolinska Institutet, SE-17176 Stockholm, Sweden
| | - Nathalie M Mazure
- Institute for Research on Cancer and Ageing of Nice (IRCAN), UMR CNRS 7284-INSERM U1081-UNS, Université de Nice-Sophia-Antipolis, 33 avenue Valombrose, 06189 Nice cedex 2, France
| | - Thomas Weide
- Department of Internal Medicine D, Division of Molecular Nephrology, University Hospital Muenster, Albert-Schweitzer-Campus 1, A14 D-48149 Muenster, Germany
| | - Dan Grandér
- Department of Oncology and Pathology, Cancer Centrum Karolinska, Karolinska Institutet, SE-17176 Stockholm, Sweden
| | - Jean-Paul Borg
- 1] Inserm U1068, CRCM, 13009 Marseille, France [2] CNRS UMR7258, CRCM, 13009 Marseille, France [3] Institut Paoli-Calmettes, 13009 Marseille, France [4] Aix-Marseille Université, 13009 Marseille, France
| | - Per Uhlén
- Laboratory of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-17177 Stockholm, Sweden
| | - Lars Holmgren
- Department of Oncology and Pathology, Cancer Centrum Karolinska, Karolinska Institutet, SE-17176 Stockholm, Sweden
| |
Collapse
|
53
|
Microenvironment, oncoantigens, and antitumor vaccination: lessons learned from BALB-neuT mice. BIOMED RESEARCH INTERNATIONAL 2014; 2014:534969. [PMID: 25136593 PMCID: PMC4065702 DOI: 10.1155/2014/534969] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Accepted: 05/12/2014] [Indexed: 12/20/2022]
Abstract
The tyrosine kinase human epidermal growth factor receptor 2 (HER2) gene is amplified in approximately 20% of human breast cancers and is associated with an aggressive clinical course and the early development of metastasis. Its crucial role in tumor growth and progression makes HER2 a prototypic oncoantigen, the targeting of which may be critical for the development of effective anticancer therapies. The setup of anti-HER2 targeting strategies has revolutionized the clinical outcome of HER2+ breast cancer. However, their initial success has been overshadowed by the onset of pharmacological resistance that renders them ineffective. Since the tumor microenvironment (TME) plays a crucial role in drug resistance, the design of more effective anticancer therapies should depend on the targeting of both cancer cells and their TME as a whole. In this review, starting from the successful know-how obtained with a HER2+ mouse model of mammary carcinogenesis, the BALB-neuT mice, we discuss the role of TME in mammary tumor development. Indeed, a deeper knowledge of antigens critical for cancer outbreak and progression and of the mechanisms that regulate the interplay between cancer and stromal cell populations could advise promising ways for the development of the best anticancer strategy.
Collapse
|
54
|
AmotL2 links VE-cadherin to contractile actin fibres necessary for aortic lumen expansion. Nat Commun 2014; 5:3743. [PMID: 24806444 DOI: 10.1038/ncomms4743] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Accepted: 03/27/2014] [Indexed: 02/07/2023] Open
Abstract
The assembly of individual endothelial cells into multicellular tubes is a complex morphogenetic event in vascular development. Extracellular matrix cues and cell-cell junctional communication are fundamental to tube formation. Together they determine the shape of endothelial cells and the tubular structures that they ultimately form. Little is known regarding how mechanical signals are transmitted between cells to control cell shape changes during morphogenesis. Here we provide evidence that the scaffold protein amotL2 is needed for aortic vessel lumen expansion. Using gene inactivation strategies in zebrafish, mouse and endothelial cell culture systems, we show that amotL2 associates to the VE-cadherin adhesion complex where it couples adherens junctions to contractile actin fibres. Inactivation of amotL2 dissociates VE-cadherin from cytoskeletal tensile forces that affect endothelial cell shape. We propose that the VE-cadherin/amotL2 complex is responsible for transmitting mechanical force between endothelial cells for the coordination of cellular morphogenesis consistent with aortic lumen expansion and function.
Collapse
|
55
|
Leung CY, Zernicka-Goetz M. Angiomotin prevents pluripotent lineage differentiation in mouse embryos via Hippo pathway-dependent and -independent mechanisms. Nat Commun 2014; 4:2251. [PMID: 23903990 PMCID: PMC3741640 DOI: 10.1038/ncomms3251] [Citation(s) in RCA: 134] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2013] [Accepted: 07/03/2013] [Indexed: 01/04/2023] Open
Abstract
Cell identity is specified in the early mammalian embryo by the generation of precursors for two cell lineages: the pluripotent inner cell mass and differentiating trophectoderm. Here we identify Angiomotin as a key regulator of this process. We show that the loss of Angiomotin, together with Angiomotin-like 2, leads to differentiation of inner cell mass cells and compromised peri-implantation development. We show that Angiomotin regulates localization of Yap, and Yap-binding motifs are required for full activity of Angiomotin. Importantly, we also show that Angiomotin function can compensate for the absence of Lats1/2 kinases, indicating the ability of Angiomotin to bypass the classical Hippo pathway for Yap regulation. In polarized outside cells, Angiomotin localizes apically, pointing to the importance of cell polarity in regulating Yap to promote differentiation. We propose that both Hippo pathway-dependent and Hippo pathway-independent mechanisms regulate Yap localization to set apart pluripotent and differentiated lineages in the pre-implantation mouse embryo. Angiomotins retain the transcription co-activator YAP in the cytoplasm and thereby regulate the Hippo pathway in mammalian cultured cells. Here Leung and Zernicka-Goetz show that Angiomotin family members prevent the differentiation of inner cell mass cells in the mouse blastocyst, via both Hippo pathway-dependent and -independent mechanisms.
Collapse
Affiliation(s)
- Chuen Yan Leung
- The Wellcome Trust/Cancer Research UK Gurdon Institute, the Henry Wellcome Building of Cancer and Developmental Biology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK
| | | |
Collapse
|
56
|
Hirate Y, Sasaki H. The role of angiomotin phosphorylation in the Hippo pathway during preimplantation mouse development. Tissue Barriers 2014; 2:e28127. [PMID: 24843842 PMCID: PMC4022607 DOI: 10.4161/tisb.28127] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2014] [Revised: 02/01/2014] [Accepted: 02/05/2014] [Indexed: 11/19/2022] Open
Abstract
The Hippo signaling pathway regulates a number of cellular events, including the control of cell fates in preimplantation mouse embryos. The inner and outer cells of the embryo show high and low levels of Hippo signaling, respectively. This position-dependent Hippo signaling promotes the specification of distinct cell fates. In a recent paper, we identified the molecular mechanism that controls Hippo signaling in preimplantation embryos. The junction-associated scaffold protein Angiomotin (Amot) plays a key role in this mechanism. At the adherens junctions of the inner cells, Amot activates the Hippo pathway by recruiting and activating the protein kinase large tumor suppressor (Lats). In contrast, Amot at the apical membrane of the outer cells suppresses Hippo signaling by interacting with F-actin. The phosphorylation of Amot inhibits its interaction with F-actin and activates Hippo signaling. We propose that Amot acts as a molecular switch for the Hippo pathway and links F-actin with Lats activity.
Collapse
Affiliation(s)
- Yoshikazu Hirate
- Department of Cell Fate Control; Institute of Molecular Embryology and Genetics; Kumamoto University; Kumamoto, Japan
| | - Hiroshi Sasaki
- Department of Cell Fate Control; Institute of Molecular Embryology and Genetics; Kumamoto University; Kumamoto, Japan
| |
Collapse
|
57
|
Abu-Odeh M, Bar-Mag T, Huang H, Kim T, Salah Z, Abdeen SK, Sudol M, Reichmann D, Sidhu S, Kim PM, Aqeilan RI. Characterizing WW domain interactions of tumor suppressor WWOX reveals its association with multiprotein networks. J Biol Chem 2014; 289:8865-80. [PMID: 24550385 DOI: 10.1074/jbc.m113.506790] [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: 11/06/2022] Open
Abstract
WW domains are small modules present in regulatory and signaling proteins that mediate specific protein-protein interactions. The WW domain-containing oxidoreductase (WWOX) encodes a 46-kDa tumor suppressor that contains two N-terminal WW domains and a central short-chain dehydrogenase/reductase domain. Based on its ligand recognition motifs, the WW domain family is classified into four groups. The largest one, to which WWOX belongs, recognizes ligands with a PPXY motif. To pursue the functional properties of the WW domains of WWOX, we employed mass spectrometry and phage display experiments to identify putative WWOX-interacting partners. Our analysis revealed that the first WW (WW1) domain of WWOX is the main functional interacting domain. Furthermore, our study uncovered well known and new PPXY-WW1-interacting partners and shed light on novel LPXY-WW1-interacting partners of WWOX. Many of these proteins are components of multiprotein complexes involved in molecular processes, including transcription, RNA processing, tight junction, and metabolism. By utilizing GST pull-down and immunoprecipitation assays, we validated that WWOX is a substrate of the E3 ubiquitin ligase ITCH, which contains two LPXY motifs. We found that ITCH mediates Lys-63-linked polyubiquitination of WWOX, leading to its nuclear localization and increased cell death. Our data suggest that the WW1 domain of WWOX provides a versatile platform that links WWOX with individual proteins associated with physiologically important networks.
Collapse
Affiliation(s)
- Mohammad Abu-Odeh
- From the Lautenberg Center for Immunology and Cancer Research, IMRIC, Hebrew University-Hadassah Medical School, Jerusalem, Israel 91120
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
58
|
The Angiomotins--from discovery to function. FEBS Lett 2014; 588:2693-703. [PMID: 24548561 DOI: 10.1016/j.febslet.2014.02.006] [Citation(s) in RCA: 86] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Revised: 02/05/2014] [Accepted: 02/06/2014] [Indexed: 12/13/2022]
Abstract
Angiomotins were originally identified as angiostatin binding proteins and implicated in the regulation of endothelial cell migration. Recent studies have shed light on the role of Angiomotins and other members of the Motin protein family in epithelial cells and in pathways directly linked to the pathogenesis of cancer. In particular, Motins have been shown to play a role in signaling pathways regulated by small G-proteins and the Hippo-YAP pathway. In this review the role of the Motin protein family in these signaling pathways will be described and open questions will be discussed.
Collapse
|
59
|
Chan SW, Lim CJ, Guo F, Tan I, Leung T, Hong W. Actin-binding and cell proliferation activities of angiomotin family members are regulated by Hippo pathway-mediated phosphorylation. J Biol Chem 2013; 288:37296-307. [PMID: 24225952 DOI: 10.1074/jbc.m113.527598] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Whether the Hippo pathway has downstream targets other than YAP and TAZ is unknown. In this report, we have identified angiomotin (Amot) family members as novel substrates of Hippo core kinases. The N-terminal regions of Amot proteins contain a conserved HXRXXS consensus site for LATS1/2-mediated phosphorylation. Phospho-specific antibodies showed that Hippo core kinases could mediate phosphorylation of endogenous as well as exogenous Amot family members. Knockdown of LATS1 and LATS2 endogenously reduced the phosphorylation of Amots detected by the phospho-specific antibodies. Mutation of the serine to alanine within this HXRXXS site in Amot and AmotL2 established that this site was essential for Hippo core kinase-mediated phosphorylation. Wild-type and non-phosphorylated Amot (Amot-S175A) were targeted to actin filaments, whereas phospho-mimic Amot (Amot-S175D) failed to be localized with actin. Overexpression of LATS2 caused dissociation of Amot from actin but not Amot-S175A. Mapping of the actin-binding site of Amot showed that serine 175 of Amot was important for the actin-binding activity. Amot-S175A promoted, whereas Amot and Amot-S175D inhibited, cell proliferation. These results collectively suggest that the Hippo pathway negatively regulates the actin-binding activity of Amot family members through direct phosphorylation.
Collapse
Affiliation(s)
- Siew Wee Chan
- From the Institute of Molecular and Cell Biology, 61 Biopolis Drive, Singapore 138673 and
| | | | | | | | | | | |
Collapse
|
60
|
Schmouth JF, Castellarin M, Laprise S, Banks KG, Bonaguro RJ, McInerny SC, Borretta L, Amirabbasi M, Korecki AJ, Portales-Casamar E, Wilson G, Dreolini L, Jones SJM, Wasserman WW, Goldowitz D, Holt RA, Simpson EM. Non-coding-regulatory regions of human brain genes delineated by bacterial artificial chromosome knock-in mice. BMC Biol 2013; 11:106. [PMID: 24124870 PMCID: PMC4015596 DOI: 10.1186/1741-7007-11-106] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Accepted: 09/30/2013] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND The next big challenge in human genetics is understanding the 98% of the genome that comprises non-coding DNA. Hidden in this DNA are sequences critical for gene regulation, and new experimental strategies are needed to understand the functional role of gene-regulation sequences in health and disease. In this study, we build upon our HuGX ('high-throughput human genes on the X chromosome') strategy to expand our understanding of human gene regulation in vivo. RESULTS In all, ten human genes known to express in therapeutically important brain regions were chosen for study. For eight of these genes, human bacterial artificial chromosome clones were identified, retrofitted with a reporter, knocked single-copy into the Hprt locus in mouse embryonic stem cells, and mouse strains derived. Five of these human genes expressed in mouse, and all expressed in the adult brain region for which they were chosen. This defined the boundaries of the genomic DNA sufficient for brain expression, and refined our knowledge regarding the complexity of gene regulation. We also characterized for the first time the expression of human MAOA and NR2F2, two genes for which the mouse homologs have been extensively studied in the central nervous system (CNS), and AMOTL1 and NOV, for which roles in CNS have been unclear. CONCLUSIONS We have demonstrated the use of the HuGX strategy to functionally delineate non-coding-regulatory regions of therapeutically important human brain genes. Our results also show that a careful investigation, using publicly available resources and bioinformatics, can lead to accurate predictions of gene expression.
Collapse
Affiliation(s)
- Jean-François Schmouth
- Centre for Molecular Medicine and Therapeutics at the Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada
- Genetics Graduate Program, University of British Columbia, Vancouver, British Columbia V6T 1Z2, Canada
| | - Mauro Castellarin
- Canada’s Michael Smith Genome Sciences Centre, British Columbia Cancer Agency, Vancouver, British Columbia V5Z 4S6, Canada
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Stéphanie Laprise
- Centre for Molecular Medicine and Therapeutics at the Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada
| | - Kathleen G Banks
- Centre for Molecular Medicine and Therapeutics at the Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada
| | - Russell J Bonaguro
- Centre for Molecular Medicine and Therapeutics at the Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada
| | - Simone C McInerny
- Centre for Molecular Medicine and Therapeutics at the Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada
| | - Lisa Borretta
- Centre for Molecular Medicine and Therapeutics at the Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada
| | - Mahsa Amirabbasi
- Centre for Molecular Medicine and Therapeutics at the Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada
| | - Andrea J Korecki
- Centre for Molecular Medicine and Therapeutics at the Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada
| | - Elodie Portales-Casamar
- Centre for Molecular Medicine and Therapeutics at the Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada
| | - Gary Wilson
- Canada’s Michael Smith Genome Sciences Centre, British Columbia Cancer Agency, Vancouver, British Columbia V5Z 4S6, Canada
| | - Lisa Dreolini
- Canada’s Michael Smith Genome Sciences Centre, British Columbia Cancer Agency, Vancouver, British Columbia V5Z 4S6, Canada
| | - Steven JM Jones
- Genetics Graduate Program, University of British Columbia, Vancouver, British Columbia V6T 1Z2, Canada
- Canada’s Michael Smith Genome Sciences Centre, British Columbia Cancer Agency, Vancouver, British Columbia V5Z 4S6, Canada
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
- Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Wyeth W Wasserman
- Centre for Molecular Medicine and Therapeutics at the Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada
- Genetics Graduate Program, University of British Columbia, Vancouver, British Columbia V6T 1Z2, Canada
- Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Daniel Goldowitz
- Centre for Molecular Medicine and Therapeutics at the Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada
- Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Robert A Holt
- Genetics Graduate Program, University of British Columbia, Vancouver, British Columbia V6T 1Z2, Canada
- Canada’s Michael Smith Genome Sciences Centre, British Columbia Cancer Agency, Vancouver, British Columbia V5Z 4S6, Canada
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
- Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
- Department of Psychiatry, University of British Columbia, Vancouver, British Columbia V6T 2A1, Canada
| | - Elizabeth M Simpson
- Centre for Molecular Medicine and Therapeutics at the Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada
- Genetics Graduate Program, University of British Columbia, Vancouver, British Columbia V6T 1Z2, Canada
- Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
- Department of Psychiatry, University of British Columbia, Vancouver, British Columbia V6T 2A1, Canada
| |
Collapse
|
61
|
Hong W. Angiomotin'g YAP into the Nucleus for Cell Proliferation and Cancer Development. Sci Signal 2013; 6:pe27. [DOI: 10.1126/scisignal.2004573] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
|
62
|
Nakajima Y, Nakamura Y, Shigeeda W, Tomoyasu M, Deguchi H, Tanita T, Yamauchi K. The role of tumor necrosis factor-α and interferon-γ in regulating angiomotin-like protein 1 expression in lung microvascular endothelial cells. Allergol Int 2013; 62:309-22. [PMID: 23793505 DOI: 10.2332/allergolint.12-oa-0528] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Accepted: 02/19/2013] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Angiogenesis in the alveolar septa is thought be a critical factor in pulmonary emphysema. Angiomotin-like protein 1 (AmotL1) is involved in angiogenesis via regulating endothelial cell function. However, the role of AmotL1 in the pathogenesis of pulmonary emphysema has not been elucidated. The objective of this study is to evaluate the expression of AmotL1 in lung tissues from a murine model with emphysema, as well as from patients with chronic obstructive pulmonary disease (COPD). Furthermore, we analyzed the regulation of AmotL1 expression by TNF-α and IFN-γ in endothelial cells in vitro. METHODS Nrf2 knockout mice were exposed to cigarette smoke (CS) for 4 weeks, and the down-regulated genes affecting vascularity in the whole lung were identified by microarray analysis. This analysis revealed that the mRNA expression of AmotL1 decreased in response to CS when compared with air exposure. To confirm the protein levels that were indicated in the microarray data, we determined the expression of AmotL1 in lung tissues obtained from patients with COPD and also determined the expression of AmotL1, NFκB and IκBα in cultured normal human lung microvascular endothelial cells (HLMVECs) that were stimulated by TNF-α and IFN-γ. RESULTS We found that the number of AmotL1-positive vessels decreased in the emphysema lungs compared with the normal and bronchial asthmatic lungs. IFN-γ pretreatment diminished the TNF-α-induced AmotL1 in the cultured HLMVECs by blocking the degradation of IκBα. CONCLUSIONS These results suggested that IFN-γ exhibits anti-angiogenesis effects by regulating the expression of TNF-α-induced AmotL1 via NFκB in emphysema lungs.
Collapse
Affiliation(s)
- Yoshio Nakajima
- Division of Pulmonary Medicine, Allergy, and Rheumatology, Department of Internal Medicine, Iwate Medical University School of Medicine, Iwate 020-8505, Japan
| | | | | | | | | | | | | |
Collapse
|
63
|
Hirate Y, Hirahara S, Inoue KI, Suzuki A, Alarcon VB, Akimoto K, Hirai T, Hara T, Adachi M, Chida K, Ohno S, Marikawa Y, Nakao K, Shimono A, Sasaki H. Polarity-dependent distribution of angiomotin localizes Hippo signaling in preimplantation embryos. Curr Biol 2013; 23:1181-94. [PMID: 23791731 DOI: 10.1016/j.cub.2013.05.014] [Citation(s) in RCA: 286] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2013] [Revised: 05/07/2013] [Accepted: 05/08/2013] [Indexed: 12/18/2022]
Abstract
BACKGROUND In preimplantation mouse embryos, the first cell fate specification to the trophectoderm or inner cell mass occurs by the early blastocyst stage. The cell fate is controlled by cell position-dependent Hippo signaling, although the mechanisms underlying position-dependent Hippo signaling are unknown. RESULTS We show that a combination of cell polarity and cell-cell adhesion establishes position-dependent Hippo signaling, where the outer and inner cells are polar and nonpolar, respectively. The junction-associated proteins angiomotin (Amot) and angiomotin-like 2 (Amotl2) are essential for Hippo pathway activation and appropriate cell fate specification. In the nonpolar inner cells, Amot localizes to adherens junctions (AJs), and cell-cell adhesion activates the Hippo pathway. In the outer cells, the cell polarity sequesters Amot from basolateral AJs to apical domains, thereby suppressing Hippo signaling. The N-terminal domain of Amot is required for actin binding, Nf2/Merlin-mediated association with the E-cadherin complex, and interaction with Lats protein kinase. In AJs, S176 in the N-terminal domain of Amot is phosphorylated by Lats, which inhibits the actin-binding activity, thereby stabilizing the Amot-Lats interaction to activate the Hippo pathway. CONCLUSIONS We propose that the phosphorylation of S176 in Amot is a critical step for activation of the Hippo pathway in AJs and that cell polarity disconnects the Hippo pathway from cell-cell adhesion by sequestering Amot from AJs. This mechanism converts positional information into differential Hippo signaling, thereby leading to differential cell fates.
Collapse
Affiliation(s)
- Yoshikazu Hirate
- Department of Cell Fate Control, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto 860-0811, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
64
|
Adler JJ, Heller BL, Bringman LR, Ranahan WP, Cocklin RR, Goebl MG, Oh M, Lim HS, Ingham RJ, Wells CD. Amot130 adapts atrophin-1 interacting protein 4 to inhibit yes-associated protein signaling and cell growth. J Biol Chem 2013; 288:15181-93. [PMID: 23564455 DOI: 10.1074/jbc.m112.446534] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The adaptor protein Amot130 scaffolds components of the Hippo pathway to promote the inhibition of cell growth. This study describes how Amot130 through binding and activating the ubiquitin ligase AIP4/Itch achieves these effects. AIP4 is found to bind and ubiquitinate Amot130 at residue Lys-481. This both stabilizes Amot130 and promotes its residence at the plasma membrane. Furthermore, Amot130 is shown to scaffold a complex containing overexpressed AIP4 and the transcriptional co-activator Yes-associated protein (YAP). Consequently, Amot130 promotes the ubiquitination of YAP by AIP4 and prevents AIP4 from binding to large tumor suppressor 1. Amot130 is found to reduce YAP stability. Importantly, Amot130 inhibition of YAP dependent transcription is reversed by AIP4 silencing, whereas Amot130 and AIP4 expression interdependently suppress cell growth. Thus, Amot130 repurposes AIP4 from its previously described role in degrading large tumor suppressor 1 to the inhibition of YAP and cell growth.
Collapse
Affiliation(s)
- Jacob J Adler
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana 46202, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
65
|
Proszynski TJ, Sanes JR. Amotl2 interacts with LL5β, localizes to podosomes and regulates postsynaptic differentiation in muscle. J Cell Sci 2013; 126:2225-35. [PMID: 23525008 DOI: 10.1242/jcs.121327] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Neuromuscular junctions (NMJs) in mammalian skeletal muscle undergo a postnatal topological transformation from a simple oval plaque to a complex branched structure. We previously showed that podosomes, actin-rich adhesive organelles, promote the remodeling process, and demonstrated a key role for one podosome component, LL5β. To further investigate molecular mechanisms of postsynaptic maturation, we purified LL5β-associated proteins from myotubes and showed that three regulators of the actin cytoskeleton--Amotl2, Asef2 and Flii--interact with LL5β. These and other LL5β-interacting proteins are associated with conventional podosomes in macrophages and podosome-like invadopodia in fibroblasts, strengthening the close relationship between synaptic and non-synaptic podosomes. We then focused on Amotl2, showing that it is associated with synaptic podosomes in cultured myotubes and with NMJs in vivo. Depletion of Amotl2 in myotubes leads to increased size of synaptic podosomes and corresponding alterations in postsynaptic topology. Depletion of Amotl2 from fibroblasts disrupts invadopodia in these cells. These results demonstrate a role for Amotl2 in synaptic maturation and support the involvement of podosomes in this process.
Collapse
Affiliation(s)
- Tomasz J Proszynski
- Department of Molecular and Cellular Biology and Center for Brain Science, Harvard University, Cambridge, MA 02138, USA
| | | |
Collapse
|
66
|
Stalin J, Harhouri K, Hubert L, Subrini C, Lafitte D, Lissitzky JC, Elganfoud N, Robert S, Foucault-Bertaud A, Kaspi E, Sabatier F, Aurrand-Lions M, Bardin N, Holmgren L, Dignat-George F, Blot-Chabaud M. Soluble melanoma cell adhesion molecule (sMCAM/sCD146) promotes angiogenic effects on endothelial progenitor cells through angiomotin. J Biol Chem 2013; 288:8991-9000. [PMID: 23389031 DOI: 10.1074/jbc.m112.446518] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The melanoma cell adhesion molecule (CD146) contains a circulating proteolytic variant (sCD146), which is involved in inflammation and angiogenesis. Its circulating level is modulated in different pathologies, but its intracellular transduction pathways are still largely unknown. Using peptide pulldown and mass spectrometry, we identified angiomotin as a sCD146-associated protein in endothelial progenitor cells (EPC). Interaction between angiomotin and sCD146 was confirmed by enzyme-linked immunosorbent assay (ELISA), homogeneous time-resolved fluorescence, and binding of sCD146 on both immobilized recombinant angiomotin and angiomotin-transfected cells. Silencing angiomotin in EPC inhibited sCD146 angiogenic effects, i.e. EPC migration, proliferation, and capacity to form capillary-like structures in Matrigel. In addition, sCD146 effects were inhibited by the angiomotin inhibitor angiostatin and competition with recombinant angiomotin. Finally, binding of sCD146 on angiomotin triggered the activation of several transduction pathways that were identified by antibody array. These results delineate a novel signaling pathway where sCD146 binds to angiomotin to stimulate a proangiogenic response. This result is important to find novel target cells of sCD146 and for the development of therapeutic strategies based on EPC in the treatment of ischemic diseases.
Collapse
Affiliation(s)
- Jimmy Stalin
- Inserm UMR-S 1076, Physiopathology of Endothelium, Aix-Marseille University, Formation and Research Unit of Pharmacy, 13005 Marseille, France
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
67
|
Kalozoumi G, Tzimas C, Sanoudou D. The expanding role of epigenetics. Glob Cardiol Sci Pract 2012; 2012:7. [PMID: 25610838 PMCID: PMC4239821 DOI: 10.5339/gcsp.2012.7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2012] [Accepted: 05/20/2012] [Indexed: 12/13/2022] Open
Affiliation(s)
- Georgia Kalozoumi
- Department of Pharmacology, Medical School, University of Athens, Greece
| | - Christos Tzimas
- Molecular Biology Division, Biomedical Research Foundation of the Academy of Athens, Greece
| | - Despina Sanoudou
- Department of Pharmacology, Medical School, University of Athens, Greece ; Molecular Biology Division, Biomedical Research Foundation of the Academy of Athens, Greece
| |
Collapse
|
68
|
Skouloudaki K, Walz G. YAP1 recruits c-Abl to protect angiomotin-like 1 from Nedd4-mediated degradation. PLoS One 2012; 7:e35735. [PMID: 22558212 PMCID: PMC3338797 DOI: 10.1371/journal.pone.0035735] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2011] [Accepted: 03/21/2012] [Indexed: 11/29/2022] Open
Abstract
Background Tissue development and organ growth require constant remodeling of cell-cell contacts formed between epithelial cells. The Hippo signaling cascade curtails organ growth by excluding the transcriptional co-activator Yes Associated Protein 1 (YAP1) from the nucleus. Angiomotin family members recruit YAP1 to tight junctions [1], but whether YAP1 plays a specific role outside of the nucleus is currently unknown. Methodology/Principal Findings The present study demonstrates that the E3 ubiquitin ligase Nedd4.2 targets Angiomotin-like 1 (AMOTL1), a family member that promotes the formation of epithelial tight junctions, for ubiquitin-dependent degradation. Unexpectedly, YAP1 antagonizes the function of Nedd4.2, and protects AMOTL1 against Nedd4.2-mediated degradation. YAP1 recruits c-Abl, a tyrosine kinase that binds and phosphorylates Nedd4.2 on tyrosine residues, thereby modifying its ubiquitin-ligase activity. Conclusions/Significance Our results uncover a novel function for cytoplasmic YAP1. YAP1 recruits c-Abl to protect AMOTL1 against Nedd4.2-mediated degradation. Thus, YAP1, excluded from the nucleus, contributes to the maintenance of tight junctions.
Collapse
Affiliation(s)
| | - Gerd Walz
- Renal Division, University Hospital Freiburg, Freiburg, Germany
- Center for Biological Signaling Studies (bioss), Freiburg, Germany
- * E-mail:
| |
Collapse
|
69
|
Arigoni M, Barutello G, Lanzardo S, Longo D, Aime S, Curcio C, Iezzi M, Zheng Y, Barkefors I, Holmgren L, Cavallo F. A vaccine targeting angiomotin induces an antibody response which alters tumor vessel permeability and hampers the growth of established tumors. Angiogenesis 2012; 15:305-16. [PMID: 22426512 PMCID: PMC3338916 DOI: 10.1007/s10456-012-9263-3] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2011] [Accepted: 02/21/2012] [Indexed: 12/21/2022]
Abstract
Angiomotin (Amot) is one of several identified angiostatin receptors expressed by the endothelia of angiogenic tissues. We have shown that a DNA vaccine targeting Amot overcome immune tolerance and induce an antibody response that hampers the progression of incipient tumors. Following our observation of increased Amot expression on tumor endothelia concomitant with the progression from pre-neoplastic lesions to full-fledged carcinoma, we evaluated the effect of anti-Amot vaccination on clinically evident tumors. Electroporation of plasmid coding for the human Amot (pAmot) significantly delayed the progression both of autochthonous tumors in cancer prone BALB-neuT and PyMT genetically engineered mice and transplantable TUBO tumor in wild-type BALB/c mice. The intensity of the inhibition directly correlated with the titer of anti-Amot antibodies induced by the vaccine. Tumor inhibition was associated with an increase of vessels diameter with the formation of lacunar spaces, increase in vessel permeability, massive tumor perivascular necrosis and an effective epitope spreading that induces an immune response against other tumor associated antigens. Greater tumor vessel permeability also markedly enhances the antitumor effect of doxorubicin. These data provide a rationale for the development of novel anticancer treatments based on anti-Amot vaccination in conjunction with chemotherapy regimens.
Collapse
|
70
|
Li Z, Wang Y, Zhang M, Xu P, Huang H, Wu D, Meng A. The Amotl2 gene inhibits Wnt/β-catenin signaling and regulates embryonic development in zebrafish. J Biol Chem 2012; 287:13005-15. [PMID: 22362771 DOI: 10.1074/jbc.m112.347419] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The Motin family proteins can regulate cell polarity, cell mobility, and proliferation during embryonic development by controlling distinct signaling pathways. In this study, we demonstrate that amotl2 knockdown in zebrafish wild-type embryos results in embryonic dorsalization, and this effect can be antagonized by co-knockdown of the dorsal inducer β-catenin2. Overexpression of amotl2 in masterblind (mbl) homozygous embryos, in which canonical Wnt signaling is up-regulated due to an axin1 mutation, transforms eyeless phenotype into smaller eyes, whereas co-knockdown of amot, amotl1, and amotl2 leads to development of smaller eyes in mbl heterozygotes. In cultured mammalian cells, Motin family members all possess the ability to attenuate Wnt/β-catenin signaling. Focusing on Amotl2, we show that Amotl2 can associate with and trap β-catenin in the Rab11-positive recycling endosomes, and as a result, the amount of β-catenin in the cytosol and nucleus is reduced. Thus, our findings provide novel insights into functions of Motin family members and regulation of Wnt/β-catenin signaling.
Collapse
Affiliation(s)
- Zhiqiang Li
- State-Key Laboratory of Biomembrane and Membrane Engineering, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | | | | | | | | | | | | |
Collapse
|
71
|
Jiang H, Schwertz H, Schmid DI, Jones BB, Kriesel J, Martinez ML, Weyrich AS, Zimmerman GA, Kraiss LW. Different mechanisms preserve translation of programmed cell death 8 and JunB in virus-infected endothelial cells. Arterioscler Thromb Vasc Biol 2012; 32:997-1004. [PMID: 22328780 DOI: 10.1161/atvbaha.112.245324] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
OBJECTIVE Translation initiation of eukaryotic mRNAs typically occurs by cap-dependent ribosome scanning mechanism. However, certain mRNAs are translated by ribosome assembly at internal ribosome entry sites (IRESs). Whether IRES-mediated translation occurs in stressed primary human endothelial cells (ECs) is unknown. METHODS AND RESULTS We performed microarray analysis of polyribosomal mRNA from ECs to identify IRES-containing mRNAs. Cap-dependent translation was disabled by poliovirus (PV) infection and confirmed by loss of polysome peaks, detection of eukaryotic initiation factor (eIF) 4G cleavage, and decreased protein synthesis. We found that 87.4% of mRNAs were dissociated from polysomes in virus-infected ECs. Twelve percent of mRNAs remained associated with polysomes, and 0.6% were enriched ≥2-fold in polysome fractions from infected ECs. Quantitative reverse transcription-polymerase chain reaction confirmed the microarray findings for 31 selected mRNAs. We found that enriched polysome associations of programmed cell death 8 (PDCD8) and JunB mRNA resulted in increased protein expression in PV-infected ECs. The presence of IRESs in the 5' untranslated region of PDCD8 mRNA, but not of JunB mRNA, was confirmed by dicistronic analysis. CONCLUSIONS We show that microarray profiling of polyribosomal mRNA transcripts from PV-infected ECs successfully identifies mRNAs whose translation is preserved in the face of stress-induced, near complete cessation of cap-dependent initiation. Nevertheless, internal ribosome entry is not the only mechanism responsible for this privileged translation.
Collapse
Affiliation(s)
- Huimiao Jiang
- Division of Vascular Surgery, University of Utah, Salt Lake City, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
72
|
Wang Y, Li Z, Xu P, Huang L, Tong J, Huang H, Meng A. Angiomotin-like2 gene (amotl2) is required for migration and proliferation of endothelial cells during angiogenesis. J Biol Chem 2011; 286:41095-104. [PMID: 21937427 DOI: 10.1074/jbc.m111.296806] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Angiogenesis involves sprouting, migration, and proliferation of endothelial cells. The angiomotin-like2 gene (amotl2) has been found in blood vessels in zebrafish embryos, but its function in angiogenesis and underlying mechanisms remain unknown. In this study, we demonstrate that knockdown of amotl2 in zebrafish Tg(fli1:EGFP)(y1) and Tg(fli1:nEGFP)(y7) transgenic embryos impairs the intersegmental vessel growth and suppresses proliferation of endothelial cells. Transplantation experiments indicate that function of amotl2 in intersegmental vessel growth is cell-autonomous. AMOTL2 knockdown in cultured human umbilical vein endothelial cells also inhibits cell proliferation and migration and disrupts cell polarity, ultimately interrupting the formation of vascular tube-like structures. Amotl2 promotes MAPK/ERK activation via c-Src, which is dependent on phosphorylation of tyrosine residue at position 103 but independent of the C-terminal PDZ-binding domain. Taking together, our data indicate that Amotl2 plays a pivotal role in polarity, migration and proliferation of angiogenic endothelial cells.
Collapse
Affiliation(s)
- Yeqi Wang
- State-key Laboratory of Biomembrane and Membrane Engineering, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | | | | | | | | | | | | |
Collapse
|
73
|
Paramasivam M, Sarkeshik A, Yates JR, Fernandes MJG, McCollum D. Angiomotin family proteins are novel activators of the LATS2 kinase tumor suppressor. Mol Biol Cell 2011; 22:3725-33. [PMID: 21832154 PMCID: PMC3183025 DOI: 10.1091/mbc.e11-04-0300] [Citation(s) in RCA: 157] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The Hippo pathway kinase LATS2 promotes contact inhibition of growth. How LATS2 is activated in response to changes in cell density is unknown. It is found that tight junction protein AMOTL2 is a novel activator of LATS2, raising the possibility that tight junction assembly promotes LATS2-dependent inhibition of cell proliferation. LATS2 kinase functions as part of the Hippo pathway to promote contact inhibition of growth and tumor suppression by phosphorylating and inhibiting the transcriptional coactivator YAP. LATS2 is activated by the MST2 kinase. How LATS2 is activated by MST2 in response to changes in cell density is unknown. Here we identify the angiomotin-family tight junction protein AMOTL2 as a novel activator of LATS2. Like AMOTL2, the other angiomotin-family proteins AMOT and AMOTL1 also activate LATS2 through a novel conserved domain that binds and activates LATS2. AMOTL2 binds MST2, LATS2, and YAP, suggesting that AMOTL2 might serve as a scaffold protein. We show that LATS2, AMOTL2, and YAP all localize to tight junctions, raising the possibility that clustering of Hippo pathway components at tight junctions might function to trigger LATS2 activation and growth inhibition in response to increased cell density.
Collapse
Affiliation(s)
- Murugan Paramasivam
- Department of Microbial and Physiological Systems and Program in Cell Dynamics, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | | | | | | | | |
Collapse
|
74
|
Citi S, Spadaro D, Schneider Y, Stutz J, Pulimeno P. Regulation of small GTPases at epithelial cell-cell junctions. Mol Membr Biol 2011; 28:427-44. [DOI: 10.3109/09687688.2011.603101] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
|
75
|
Opposing roles of angiomotin-like-1 and zona occludens-2 on pro-apoptotic function of YAP. Oncogene 2011; 31:128-34. [PMID: 21685940 DOI: 10.1038/onc.2011.216] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
YAP (Yes-associated protein) oncogene has been found to form a stable complex with members of the Angiomotin (Amot) family of proteins, which bind WW domains of YAP and sequester the protein in the cytoplasm and junctional complexes. The Amot-mediated retention of YAP in the cytoplasm results in the inhibition of its proliferative function. Using apoptotic 'read-out' of YAP in HEK293 cells, we confirmed the molecular mode by which Amot regulates YAP. We showed that a representative member of the Amot family, AmotL1 (Angiomotin-like-1), uses its PPxY motifs to bind WW domains of YAP and inhibit YAP's nuclear translocation and pro-apoptotic function. Recently we also showed that YAP uses its PDZ-binding motif to interact with zona occludens-2 (ZO-2) protein, which promotes YAP's translocation to the nucleus. We also asked if AmotL1, YAP and ZO-2 signal together. We report here that AmotL1 and ZO-2 form a tripartite complex with YAP and regulate its function in HEK293 cells in opposite directions. AmotL1 inhibits pro-apoptotic function of YAP, whereas ZO-2 enhances it. As YAP is a potent oncogene, the identification and characterization of its regulators is important. AmotL1 and ZO-2 are two candidates that could be harnessed to control the oncogenic function of YAP.
Collapse
|
76
|
Zhao B, Li L, Lu Q, Wang LH, Liu CY, Lei Q, Guan KL. Angiomotin is a novel Hippo pathway component that inhibits YAP oncoprotein. Genes Dev 2011; 25:51-63. [PMID: 21205866 DOI: 10.1101/gad.2000111] [Citation(s) in RCA: 517] [Impact Index Per Article: 39.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The Yes-associated protein (YAP) is a transcription coactivator that plays a crucial role in organ size control by promoting cell proliferation and inhibiting apoptosis. The Hippo tumor suppressor pathway inhibits YAP through phosphorylation-induced cytoplasmic retention and degradation. Here we report a novel mechanism of YAP regulation by angiomotin (AMOT) family proteins via a direct interaction. Knockdown of AMOT family protein AMOTL2 in polarized Madin-Darby canine kidney (MDCK) cells leads to YAP activation, as indicated by decreased YAP tight junction localization, attenuated YAP phosphorylation, accumulation of nuclear YAP, and induction of YAP target gene expression. Transcriptional coactivator with PDZ-binding motif (TAZ), the YAP paralog, is also regulated by AMOT in a similar fashion. Furthermore, AMOTL2 knockdown results in loss of cell contact inhibition in a manner dependent on the functions of YAP and TAZ. Our results indicate a potential tumor-suppressing role of AMOT family proteins as components of the Hippo pathway, and demonstrate a novel mechanism of YAP and TAZ inhibition by AMOT-mediated tight junction localization. These observations provide a potential link between the Hippo pathway and cell contact inhibition.
Collapse
Affiliation(s)
- Bin Zhao
- Department of Pharmacology, University of California at San Diego, La Jolla, California 92093, USA
| | | | | | | | | | | | | |
Collapse
|
77
|
Wang W, Huang J, Chen J. Angiomotin-like proteins associate with and negatively regulate YAP1. J Biol Chem 2010; 286:4364-70. [PMID: 21187284 DOI: 10.1074/jbc.c110.205401] [Citation(s) in RCA: 210] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
In both Drosophila and mammalian systems, the Hippo pathway plays an important role in controlling organ size, mainly through its ability to regulate cell proliferation and apoptosis. The key component in the Hippo pathway is the Yes-associated protein YAP1, which localizes in nucleus, functions as a transcriptional coactivator, and regulates the expression of several proliferation- and apoptosis-related genes. The Hippo pathway negatively regulates YAP1 transcriptional activity by modulating its nuclear-cytoplasmic localization in a phosphorylation-dependent manner. Here, we describe the identification of several new PY motif-containing proteins, including angiomotin-like protein 1 (AMOTL1) and 2 (AMOTL2), as YAP1-associated proteins. We demonstrate that AMOTL1 and AMOTL2 can regulate YAP1 cytoplasm-to-nucleus translocation through direct protein-protein interaction, which can occur independent of YAP1 phosphorylation status. Moreover, down-regulation of AMOTL2 in MCF10A cells promotes epithelial-mesenchymal transition, a phenotype that is also observed in MCF10A cells with YAP1 overexpression. Together, these data support a new mechanism for YAP1 regulation, which is mediated via its direct interactions with angiomotin-like proteins.
Collapse
Affiliation(s)
- Wenqi Wang
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | | | | |
Collapse
|
78
|
Song MG, Li Y, Kiledjian M. Multiple mRNA decapping enzymes in mammalian cells. Mol Cell 2010; 40:423-32. [PMID: 21070968 DOI: 10.1016/j.molcel.2010.10.010] [Citation(s) in RCA: 119] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2010] [Revised: 07/10/2010] [Accepted: 08/25/2010] [Indexed: 01/18/2023]
Abstract
Regulation of RNA degradation plays an important role in the control of gene expression. One mechanism of eukaryotic mRNA decay proceeds through an initial deadenylation followed by 5' end decapping and exonucleolytic decay. Dcp2 is currently believed to be the only cytoplasmic decapping enzyme responsible for decapping of all mRNAs. Here we report that Dcp2 protein modestly contributes to bulk mRNA decay and surprisingly is not detectable in a subset of mouse and human tissues. Consistent with these findings, a hypomorphic knockout of Dcp2 had no adverse consequences in mice. In contrast, the previously reported Xenopus nucleolar decapping enzyme, Nudt16, is an ubiquitous cytoplasmic decapping enzyme in mammalian cells. Like Dcp2, Nudt16 also regulates the stability of a subset of mRNAs including a member of the motin family of proteins involved in angiogenesis, Angiomotin-like 2. These data demonstrate mammalian cells possess multiple mRNA decapping enzymes, including Nudt16 to regulate mRNA turnover.
Collapse
Affiliation(s)
- Man-Gen Song
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ 08854, USA
| | | | | |
Collapse
|
79
|
Sudol M. Newcomers to the WW Domain-Mediated Network of the Hippo Tumor Suppressor Pathway. Genes Cancer 2010; 1:1115-8. [PMID: 21779434 PMCID: PMC3092277 DOI: 10.1177/1947601911401911] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The Hippo tumor suppressor pathway regulates the size of organs by controlling 2 opposing processes: proliferation and apoptosis. The pathway was originally defined in Drosophila, but it is well conserved in mammals. One of the unique features of Hippo signaling is the unusually wide occurrence of WW domains and its cognate PPxY ligand motifs within components of this pathway. Recently, it was proposed that the prevalence of WW domain-mediated complexes in the Hippo signaling pathway should facilitate its molecular analysis and help in the identification of new components of the Hippo-centered network. Indeed, several new members of the Hippo pathway, which form functional complexes with WW domains of YAP and TAZ effectors, were recently described. We focus here on 2 families of such proteins, angiomotins and SMADs, plus 1 regulatory factor, WBP-2, which together shed new light on the rapidly expanding Hippo network. Since the Hippo pathway acts as a tumor suppressor pathway, the complexes described here, which assemble on WW domains of YAP and TAZ, represent potential targets of cancer therapy.
Collapse
Affiliation(s)
- Marius Sudol
- Weis Center for Research, Geisinger Clinic, Danville, PA, USA
| |
Collapse
|
80
|
Differential DNA methylation correlates with differential expression of angiogenic factors in human heart failure. PLoS One 2010; 5:e8564. [PMID: 20084101 PMCID: PMC2797324 DOI: 10.1371/journal.pone.0008564] [Citation(s) in RCA: 146] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2009] [Accepted: 11/30/2009] [Indexed: 11/19/2022] Open
Abstract
Epigenetic mechanisms such as microRNA and histone modification are crucially responsible for dysregulated gene expression in heart failure. In contrast, the role of DNA methylation, another well-characterized epigenetic mark, is unknown. In order to examine whether human cardiomyopathy of different etiologies are connected by a unifying pattern of DNA methylation pattern, we undertook profiling with ischaemic and idiopathic end-stage cardiomyopathic left ventricular (LV) explants from patients who had undergone cardiac transplantation compared to normal control. We performed a preliminary analysis using methylated-DNA immunoprecipitation-chip (MeDIP-chip), validated differential methylation loci by bisulfite-(BS) PCR and high throughput sequencing, and identified 3 angiogenesis-related genetic loci that were differentially methylated. Using quantitative RT-PCR, we found that the expression of these genes differed significantly between CM hearts and normal control (p<0.01). Moreover, for each individual LV tissue, differential methylation showed a predicted correlation to differential expression of the corresponding gene. Thus, differential DNA methylation exists in human cardiomyopathy. In this series of heterogenous cardiomyopathic LV explants, differential DNA methylation was found in at least 3 angiogenesis-related genes. While in other systems, changes in DNA methylation at specific genomic loci usually precede changes in the expression of corresponding genes, our current findings in cardiomyopathy merit further investigation to determine whether DNA methylation changes play a causative role in the progression of heart failure.
Collapse
|
81
|
PIV5 M protein interaction with host protein angiomotin-like 1. Virology 2009; 397:155-66. [PMID: 19932912 DOI: 10.1016/j.virol.2009.11.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2009] [Revised: 09/29/2009] [Accepted: 11/02/2009] [Indexed: 12/14/2022]
Abstract
Paramyxovirus matrix (M) proteins organize virus assembly, functioning as adapters that link together viral ribonucleoprotein complexes and viral glycoproteins at infected cell plasma membranes. M proteins may also function to recruit and manipulate host factors to assist virus budding, similar to retroviral Gag proteins. By yeast two-hybrid screening, angiomotin-like 1 (AmotL1) was identified as a host factor that interacts with the M protein of parainfluenza virus 5 (PIV5). AmotL1-M protein interaction was observed in yeast, in transfected mammalian cells, and in virus-infected cells. Binding was mapped to a 83-amino acid region derived from the C-terminal portion of AmotL1. Overexpression of M-binding AmotL1-derived polypeptides potently inhibited production of PIV5 VLPs and impaired virus budding. Expression of these polypeptides moderately inhibited production of mumps VLPs, but had no effect on production of Nipah VLPs. siRNA-mediated depletion of AmotL1 protein reduced PIV5 budding, suggesting that this interaction is beneficial to paramyxovirus infection.
Collapse
|
82
|
Tight junctions: a barrier to the initiation and progression of breast cancer? J Biomed Biotechnol 2009; 2010:460607. [PMID: 19920867 PMCID: PMC2777242 DOI: 10.1155/2010/460607] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2009] [Accepted: 08/27/2009] [Indexed: 12/11/2022] Open
Abstract
Breast cancer is a complex and heterogeneous disease that arises from epithelial cells lining the breast ducts and lobules. Correct adhesion between adjacent epithelial cells is important in determining the normal structure and function of epithelial tissues, and there is accumulating evidence that dysregulated cell-cell adhesion is associated with many cancers. This review will focus on one cell-cell adhesion complex, the tight junction (TJ), and summarize recent evidence that TJs may participate in breast cancer development or progression. We will first outline the protein composition of TJs and discuss the functions of the TJ complex. Secondly we will examine how alterations in these functions might facilitate breast cancer initiation or progression; by focussing on the regulatory influence of TJs on cell polarity, cell fate and cell migration. Finally we will outline how pharmacological targeting of TJ proteins may be useful in limiting breast cancer progression. Overall we hope to illustrate that the relationship between TJ alterations and breast cancer is a complex one; but that this area offers promise in uncovering fundamental mechanisms linked to breast cancer progression.
Collapse
|
83
|
Gagné V, Moreau J, Plourde M, Lapointe M, Lord M, Gagnon É, Fernandes MJG. Human angiomotin-like 1 associates with an angiomotin protein complex through its coiled-coil domain and induces the remodeling of the actin cytoskeleton. ACTA ACUST UNITED AC 2009; 66:754-68. [DOI: 10.1002/cm.20405] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
|
84
|
Zheng Y, Vertuani S, Nyström S, Audebert S, Meijer I, Tegnebratt T, Borg JP, Uhlén P, Majumdar A, Holmgren L. Angiomotin-Like Protein 1 Controls Endothelial Polarity and Junction Stability During Sprouting Angiogenesis. Circ Res 2009; 105:260-70. [DOI: 10.1161/circresaha.109.195156] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Rationale:
We have previously shown that angiomotin (Amot) is essential for endothelial cell migration during mouse embryogenesis. However, ≈5% of Amot knockout mice survived without any detectable vascular defects. Angiomotin-like protein 1 (AmotL1) potentially compensates for the absence of Amot as it is 62% homologous to Amot and exhibits similar expression pattern in endothelial cells.
Objective:
Here, we report the identification of a novel isoform of AmotL1 that controls endothelial cell polarization and directional migration.
Methods and Results:
Small interfering RNA–mediated silencing of AmotL1 in mouse aortic endothelial cells caused a significant reduction in migration. In confluent mouse pancreatic islet endothelial cells (MS-1), AmotL1 colocalized with Amot to tight junctions. Small interfering RNA knockdown of both Amot and AmotL1 in MS-1 cells exhibited an additive effect on increasing paracellular permeability compared to that of knocking down either Amot or AmotL1, indicating both proteins were required for proper tight junction activity. Moreover, as visualized using high-resolution 2-photon microscopy, the morpholino-mediated knockdown of
amotl1
during zebrafish embryogenesis resulted in vascular migratory defect of intersegmental vessels with strikingly decreased junction stability between the stalk cells and the aorta. However, the phenotype was quite distinct from that of
amot
knockdown which affected polarization of the tip cells of intersegmental vessels. Double knockdown resulted in an additive phenotype of depolarized tip cells with no or decreased connection of the stalk cells to the dorsal aorta.
Conclusions:
These results cumulatively validate that Amot and AmotL1 have similar effects on endothelial migration and tight junction formation in vitro. However, in vivo Amot appears to control the polarity of vascular tip cells whereas AmotL1 mainly affects the stability of cell–cell junctions of the stalk cells.
Collapse
Affiliation(s)
- Yujuan Zheng
- From the Department of Oncology and Pathology (Y.Z., S.V., S.N., I.M., T.T., L.H.), Cancer Centrum Karolinska; and Laboratory of Molecular Neurobiology (P.U.) and Division of Matrix Biology (A.M.), Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden; and Institut National de la Santé et de la Recherche Médicale (S.A., J.-P.B.), U891, Centre de Recherche en Cancérologie de Marseille, Institut Paoli-Calmettes, Univ Méditerranée, Marseille, France
| | - Simona Vertuani
- From the Department of Oncology and Pathology (Y.Z., S.V., S.N., I.M., T.T., L.H.), Cancer Centrum Karolinska; and Laboratory of Molecular Neurobiology (P.U.) and Division of Matrix Biology (A.M.), Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden; and Institut National de la Santé et de la Recherche Médicale (S.A., J.-P.B.), U891, Centre de Recherche en Cancérologie de Marseille, Institut Paoli-Calmettes, Univ Méditerranée, Marseille, France
| | - Staffan Nyström
- From the Department of Oncology and Pathology (Y.Z., S.V., S.N., I.M., T.T., L.H.), Cancer Centrum Karolinska; and Laboratory of Molecular Neurobiology (P.U.) and Division of Matrix Biology (A.M.), Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden; and Institut National de la Santé et de la Recherche Médicale (S.A., J.-P.B.), U891, Centre de Recherche en Cancérologie de Marseille, Institut Paoli-Calmettes, Univ Méditerranée, Marseille, France
| | - Stéphane Audebert
- From the Department of Oncology and Pathology (Y.Z., S.V., S.N., I.M., T.T., L.H.), Cancer Centrum Karolinska; and Laboratory of Molecular Neurobiology (P.U.) and Division of Matrix Biology (A.M.), Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden; and Institut National de la Santé et de la Recherche Médicale (S.A., J.-P.B.), U891, Centre de Recherche en Cancérologie de Marseille, Institut Paoli-Calmettes, Univ Méditerranée, Marseille, France
| | - Inèz Meijer
- From the Department of Oncology and Pathology (Y.Z., S.V., S.N., I.M., T.T., L.H.), Cancer Centrum Karolinska; and Laboratory of Molecular Neurobiology (P.U.) and Division of Matrix Biology (A.M.), Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden; and Institut National de la Santé et de la Recherche Médicale (S.A., J.-P.B.), U891, Centre de Recherche en Cancérologie de Marseille, Institut Paoli-Calmettes, Univ Méditerranée, Marseille, France
| | - Tetyana Tegnebratt
- From the Department of Oncology and Pathology (Y.Z., S.V., S.N., I.M., T.T., L.H.), Cancer Centrum Karolinska; and Laboratory of Molecular Neurobiology (P.U.) and Division of Matrix Biology (A.M.), Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden; and Institut National de la Santé et de la Recherche Médicale (S.A., J.-P.B.), U891, Centre de Recherche en Cancérologie de Marseille, Institut Paoli-Calmettes, Univ Méditerranée, Marseille, France
| | - Jean-Paul Borg
- From the Department of Oncology and Pathology (Y.Z., S.V., S.N., I.M., T.T., L.H.), Cancer Centrum Karolinska; and Laboratory of Molecular Neurobiology (P.U.) and Division of Matrix Biology (A.M.), Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden; and Institut National de la Santé et de la Recherche Médicale (S.A., J.-P.B.), U891, Centre de Recherche en Cancérologie de Marseille, Institut Paoli-Calmettes, Univ Méditerranée, Marseille, France
| | - Per Uhlén
- From the Department of Oncology and Pathology (Y.Z., S.V., S.N., I.M., T.T., L.H.), Cancer Centrum Karolinska; and Laboratory of Molecular Neurobiology (P.U.) and Division of Matrix Biology (A.M.), Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden; and Institut National de la Santé et de la Recherche Médicale (S.A., J.-P.B.), U891, Centre de Recherche en Cancérologie de Marseille, Institut Paoli-Calmettes, Univ Méditerranée, Marseille, France
| | - Arindam Majumdar
- From the Department of Oncology and Pathology (Y.Z., S.V., S.N., I.M., T.T., L.H.), Cancer Centrum Karolinska; and Laboratory of Molecular Neurobiology (P.U.) and Division of Matrix Biology (A.M.), Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden; and Institut National de la Santé et de la Recherche Médicale (S.A., J.-P.B.), U891, Centre de Recherche en Cancérologie de Marseille, Institut Paoli-Calmettes, Univ Méditerranée, Marseille, France
| | - Lars Holmgren
- From the Department of Oncology and Pathology (Y.Z., S.V., S.N., I.M., T.T., L.H.), Cancer Centrum Karolinska; and Laboratory of Molecular Neurobiology (P.U.) and Division of Matrix Biology (A.M.), Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden; and Institut National de la Santé et de la Recherche Médicale (S.A., J.-P.B.), U891, Centre de Recherche en Cancérologie de Marseille, Institut Paoli-Calmettes, Univ Méditerranée, Marseille, France
| |
Collapse
|
85
|
Roudier E, Chapados N, Decary S, Gineste C, Le Bel C, Lavoie JM, Bergeron R, Birot O. Angiomotin p80/p130 ratio: a new indicator of exercise-induced angiogenic activity in skeletal muscles from obese and non-obese rats? J Physiol 2009; 587:4105-19. [PMID: 19546164 DOI: 10.1113/jphysiol.2009.175554] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Skeletal muscle capillarisation responds to physiological and pathological conditions with a remarkable plasticity. Angiomotin was recently identified as a new pro-angiogenic molecule. Angiomotin is expressed as two protein isoforms, p80 and p130. Whereas p80 stimulates endothelial cell migration and angiogenesis, p130 is rather characteristic of stabilized and matured vessels. To date, how angiomotin expression is physiologically regulated in vivo remains largely unknown. We thus investigated (1) whether angiomotin was physiologically expressed in skeletal muscle; (2) whether exercise training, known to stimulate muscle angiogenesis, affected angiomotin expression; and (3) whether such regulation was altered in obesity, a pathological situation often associated with an impaired angiogenic activity and some capillary rarefaction in skeletal muscle. Two models of obesity were used: a high fat diet regime and Zucker Diabetic Fatty rats (ZDF). Our results provide evidence that angiomotin was expressed both in capillaries and myofibres. In non-obese rats, the p80 isoform was increased in plantaris muscle in response to endurance training whereas p130 was unaffected. In obese animals, no change was observed for p80 whereas training significantly decreased p130 expression. Exercise training induced angiogenesis in plantaris from both obese and non-obese rats, possibly through the modulation of angiomotin level and its consequences on RhoA-ROCK signalling. In conclusion, any increase in p80 or decrease in p130, as respectively observed in non-obese and obese animals, led to an increased ratio between p80 and p130 isoforms. This increased angiomotin p80/p130 ratio might then directly reflect the enhanced angiogenic ability of skeletal muscle in response to exercise training.
Collapse
Affiliation(s)
- Emilie Roudier
- York University, Muscle Health Research Center, School of Kinesiology and Health Science, Norman Bethune College (Room 353), 4700 Keele Street, Toronto, ON, M3J 1P3, Canada
| | | | | | | | | | | | | | | |
Collapse
|
86
|
Almog N, Ma L, Raychowdhury R, Schwager C, Erber R, Short S, Hlatky L, Vajkoczy P, Huber PE, Folkman J, Abdollahi A. Transcriptional Switch of Dormant Tumors to Fast-Growing Angiogenic Phenotype. Cancer Res 2009; 69:836-44. [DOI: 10.1158/0008-5472.can-08-2590] [Citation(s) in RCA: 203] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
87
|
The Amot/Patj/Syx signaling complex spatially controls RhoA GTPase activity in migrating endothelial cells. Blood 2008; 113:244-53. [PMID: 18824598 DOI: 10.1182/blood-2008-04-153874] [Citation(s) in RCA: 107] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Controlled regulation of Rho GTPase activity is an essential component mediating growth factor-stimulated migration. We have previously shown that angiomotin (Amot), a membrane-associated scaffold protein, plays a critical role during vascular patterning and endothelial migration during embryogenesis. However, the signaling pathways by which Amot controls directional migration are not known. Here we have used peptide pull-down and yeast 2-hybrid (Y2H) screening to identify proteins that interact with the C-terminal PDZ-binding motifs of Amot and its related proteins AmotL1 and 2. We report that Amot and its related proteins bind to the RhoA GTPase exchange factor (RhoGEF) protein Syx. We show that Amot forms a ternary complex together with Patj (or its paralogue Mupp1) and Syx. Using FRET analysis, we provide evidence that Amot controls targeting of RhoA activity to lamellipodia in vitro. We also report that, similar to Amot, morpholino knockdown of Syx in zebrafish results in inhibition of migration of intersegmental arteries. Taken together, our results indicate that the directional migration of capillaries in the embryo is governed by the Amot:Patj/Mupp1:Syx signaling that controls local GTPase activity.
Collapse
|
88
|
Abstract
The formation of stable cell–cell contacts is required for the generation of barrier-forming sheets of epithelial and endothelial cells. During various physiological processes like tissue development, wound healing or tumorigenesis, cellular junctions are reorganized to allow the release or the incorporation of individual cells. Cell–cell contact formation is regulated by multiprotein complexes which are localized at specific structures along the lateral cell junctions like the tight junctions and adherens junctions and which are targeted to these site through their association with cell adhesion molecules. Recent evidence indicates that several major protein complexes exist which have distinct functions during junction formation. However, this evidence also indicates that their composition is dynamic and subject to changes depending on the state of junction maturation. Thus, cell–cell contact formation and integrity is regulated by a complex network of protein complexes. Imbalancing this network by oncogenic proteins or pathogens results in barrier breakdown and eventually in cancer. Here, I will review the molecular organization of the major multiprotein complexes at junctions of epithelial cells and discuss their function in cell–cell contact formation and maintenance.
Collapse
Affiliation(s)
- Klaus Ebnet
- Institute of Medical Biochemistry, Center of Molecular Biology of Inflammation, University Münster, Münster, Germany.
| |
Collapse
|
89
|
Ernkvist M, Birot O, Sinha I, Veitonmaki N, Nyström S, Aase K, Holmgren L. Differential roles of p80- and p130-angiomotin in the switch between migration and stabilization of endothelial cells. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2008; 1783:429-37. [DOI: 10.1016/j.bbamcr.2007.11.018] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2007] [Revised: 11/21/2007] [Accepted: 11/26/2007] [Indexed: 10/22/2022]
|
90
|
Immunotherapy of Angiogenesis with DNA Vaccines. Angiogenesis 2008. [DOI: 10.1007/978-0-387-71518-6_39] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
91
|
Aase K, Ernkvist M, Ebarasi L, Jakobsson L, Majumdar A, Yi C, Birot O, Ming Y, Kvanta A, Edholm D, Aspenström P, Kissil J, Claesson-Welsh L, Shimono A, Holmgren L. Angiomotin regulates endothelial cell migration during embryonic angiogenesis. Genes Dev 2007; 21:2055-68. [PMID: 17699752 PMCID: PMC1948860 DOI: 10.1101/gad.432007] [Citation(s) in RCA: 113] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The development of the embryonic vascular system into a highly ordered network requires precise control over the migration and branching of endothelial cells (ECs). We have previously identified angiomotin (Amot) as a receptor for the angiogenesis inhibitor angiostatin. Furthermore, DNA vaccination targeting Amot inhibits angiogenesis and tumor growth. However, little is known regarding the role of Amot in physiological angiogenesis. We therefore investigated the role of Amot in embryonic neovascularization during zebrafish and mouse embryogenesis. Here we report that knockdown of Amot in zebrafish reduced the number of filopodia of endothelial tip cells and severely impaired the migration of intersegmental vessels. We further show that 75% of Amot knockout mice die between embryonic day 11 (E11) and E11.5 and exhibit severe vascular insufficiency in the intersomitic region as well as dilated vessels in the brain. Furthermore, using ECs differentiated from embryonic stem (ES) cells, we demonstrate that Amot-deficient cells have intact response to vascular endothelial growth factor (VEGF) in regard to differentiation and proliferation. However, the chemotactic response to VEGF was abolished in Amot-deficient cells. We provide evidence that Amot is important for endothelial polarization during migration and that Amot controls Rac1 activity in endothelial and epithelial cells. Our data demonstrate a critical role for Amot during vascular patterning and endothelial polarization.
Collapse
Affiliation(s)
- Karin Aase
- Department of Oncology-Pathology, Cancer Center Karolinska, Karolinska Institutet, SE-17176 Stockholm, Sweden
| | - Mira Ernkvist
- Department of Oncology-Pathology, Cancer Center Karolinska, Karolinska Institutet, SE-17176 Stockholm, Sweden
| | - Lwaki Ebarasi
- Division of Matrix Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-17177 Stockholm, Sweden
| | - Lars Jakobsson
- Department of Genetics and Pathology, Rudbeck Laboratory, Uppsala University, Dag Hammarskjölds väg 20, SE-751 85 Uppsala, Sweden
| | - Arindam Majumdar
- Division of Matrix Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-17177 Stockholm, Sweden
| | - Chunling Yi
- Molecular and Cellular Oncogenesis Program, The Wistar Institute, Philadelphia, Pennsylvania 19104, USA
| | - Olivier Birot
- Department of Oncology-Pathology, Cancer Center Karolinska, Karolinska Institutet, SE-17176 Stockholm, Sweden
| | - Yue Ming
- Department of Clinical Neuroscience, Section of Ophthalmology and Vision, Karolinska Institutet, St Erik’s Hospital, SE-11284 Stockholm, Sweden
| | - Anders Kvanta
- Department of Clinical Neuroscience, Section of Ophthalmology and Vision, Karolinska Institutet, St Erik’s Hospital, SE-11284 Stockholm, Sweden
| | - Dan Edholm
- Department of Genetics and Pathology, Rudbeck Laboratory, Uppsala University, Dag Hammarskjölds väg 20, SE-751 85 Uppsala, Sweden
| | - Pontus Aspenström
- Ludwig Institute for Cancer Research, Biomedical Centre, SE-75124 Uppsala, Sweden
| | - Joseph Kissil
- Molecular and Cellular Oncogenesis Program, The Wistar Institute, Philadelphia, Pennsylvania 19104, USA
| | - Lena Claesson-Welsh
- Department of Genetics and Pathology, Rudbeck Laboratory, Uppsala University, Dag Hammarskjölds väg 20, SE-751 85 Uppsala, Sweden
| | - Akihiko Shimono
- Vertebrate Body Plan, Center for Developmental Biology, RIKEN Kobe, Chuou-ku, Kobe 650-0047, Japan
| | - Lars Holmgren
- Department of Oncology-Pathology, Cancer Center Karolinska, Karolinska Institutet, SE-17176 Stockholm, Sweden
- Corresponding author.E-MAIL ; FAX 46-8-339031
| |
Collapse
|
92
|
Guillemot L, Paschoud S, Pulimeno P, Foglia A, Citi S. The cytoplasmic plaque of tight junctions: a scaffolding and signalling center. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2007; 1778:601-13. [PMID: 18339298 DOI: 10.1016/j.bbamem.2007.09.032] [Citation(s) in RCA: 146] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2007] [Revised: 09/25/2007] [Accepted: 09/26/2007] [Indexed: 01/19/2023]
Abstract
The region of cytoplasm underlying the tight junction (TJ) contains several multimolecular protein complexes, which are involved in scaffolding of membrane proteins, regulation of cytoskeletal organization, establishment of polarity, and signalling to and from the nucleus. In this review, we summarize some of the most recent advances in understanding the identity of these proteins, their domain organization, their protein interactions, and their functions in vertebrate organisms. Analysis of knockdown and knockout model systems shows that several TJ proteins are essential for the formation of epithelial tissues and early embryonic development, whereas others appear to have redundant functions.
Collapse
|
93
|
Sugihara-Mizuno Y, Adachi M, Kobayashi Y, Hamazaki Y, Nishimura M, Imai T, Furuse M, Tsukita S. Molecular characterization of angiomotin/JEAP family proteins: interaction with MUPP1/Patj and their endogenous properties. Genes Cells 2007; 12:473-86. [PMID: 17397395 DOI: 10.1111/j.1365-2443.2007.01066.x] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
We have previously shown that MUPP1, which has an MRE domain and 13 PDZ domains, is expressed in epithelial cells and localize at tight junctions (TJs) and apical membranes. Using yeast two-hybrid screening, we found here that MUPP1 interacts with angiomotin (Amot), JEAP/Amot-like 1 and MASCOT/Amot-like 2, which we refer to as Amot/JEAP family proteins. PDZ2 and -3 were responsible for MUPP1's interaction with Amot and MASCOT, whereas only PDZ3 was responsible for its interaction with JEAP. All the Amot/JEAP family proteins also interacted with Patj, a close relative of MUPP1. The C-terminal PDZ-binding motives of the Amot/JEAP family were required for these interactions. We successfully generated specific antibodies for these proteins and analyzed the endogenous molecular properties of the family in parallel. Immunofluorescence microscopy of cultured epithelial cells showed that in subcellular distribution, the Amot/JEAP family proteins were indistinguishable; they were apparent at TJs as well as apical membranes, and mostly co-localized with MUPP1. They were also located at TJs in several mouse tissues, but each protein showed a distinct tissue distribution. In biochemical fractionation assays, the Amot/JEAP family behaved not as transmembrane but as peripheral membrane proteins. Unexpectedly, the PDZ-binding motives were not necessarily required for their localization to TJs, and dominant negative MUPP1 or Patj did not affect the localization of Amot/JEAP family proteins, suggesting that the interaction with MUPP1/Patj is not necessarily responsible for their proper subcellular distribution.
Collapse
Affiliation(s)
- Yuko Sugihara-Mizuno
- Department of Cell Biology, Kyoto University, Yoshida-konoe-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | | | | | | | | | | | | | | |
Collapse
|
94
|
Huang H, Lu FI, Jia S, Meng S, Cao Y, Wang Y, Ma W, Yin K, Wen Z, Peng J, Thisse C, Thisse B, Meng A. Amotl2 is essential for cell movements in zebrafish embryo and regulates c-Src translocation. Development 2007; 134:979-88. [PMID: 17293535 DOI: 10.1242/dev.02782] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Angiomotin (Amot), the founding member of the Motin family, is involved in angiogenesis by regulating endothelial cell motility, and is required for visceral endoderm movement in mice. However, little is known about biological functions of the other two members of the Motin family, Angiomotin-like1(Amotl1) and Angiomotin-like2 (Amotl2). Here, we have identified zebrafish amotl2 as an Fgf-responsive gene. Zebrafish amotl2 is expressed maternally and in restricted cell types zygotically. Knockdown of amotl2 expression delays epiboly and impairs convergence and extension movement, and amotl2-deficient cells in mosaic embryos fail to migrate properly. This coincides with loss of membrane protrusions and disorder of F-actin. Amotl2 partially co-localizes with RhoB-or EEA1-positive endosomes and the non-receptor tyrosine kinase c-Src. We further demonstrate that Amotl2 interacts preferentially with and facilitates outward translocation of the phosphorylated c-Src, which may in turn regulate the membrane architecture. These data provide the first evidence that amotl2 is essential for cell movements in vertebrate embryos.
Collapse
Affiliation(s)
- Huizhe Huang
- State Key Laboratory of Biomembrane and Membrane Biotechnology, Department of Biological Sciences and Biotechnology, Tsinghua University, Beijing 100084, China
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
95
|
Hjortsberg L, Lindvall C, Corcoran M, Arulampalam V, Chan D, Thyrell L, Nordenskjold M, Grandér D, Pokrovskaja K. Phosphoinositide 3-kinase regulates a subset of interferon-alpha-stimulated genes. Exp Cell Res 2006; 313:404-14. [PMID: 17141757 DOI: 10.1016/j.yexcr.2006.10.022] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2006] [Revised: 10/18/2006] [Accepted: 10/24/2006] [Indexed: 10/24/2022]
Abstract
IFNalpha activates JAK-STAT signaling, followed by up-regulation of a cohort of genes. Also the PI3K pathway is activated by IFNalpha, but the significance of this activation for IFN-induced gene expression and biological functions remains unclear. We used a cDNA microarray to identify IFNalpha target genes whose expression is dependent on PI3K signaling. cDNAs from U266-1984 cells, untreated and IFNalpha-treated with or without PI3K inhibitor, Ly294002, was used in hybridization to a microarray representing 7000 genes. Among the 260 genes stimulated by IFNalpha, the expression of 95.4% was not affected by the presence of Ly294002. Luciferase reporter assays using consensus IFN-stimulated sequences confirmed that general regulation of transcription by IFNalpha is not altered by Ly294002. Up-regulation of 10 genes (3.8%) was affected in the presence of Ly294002. Bioinformatic analysis revealed the presence of consensus sequences of both STAT-specific and the PI3K pathway-regulated transcription factors, further suggesting that these genes are regulated by both pathways. We have recently shown that IFNalpha-induced apoptosis in the myeloma cell line U266-1984 was efficiently blocked by inhibition of PI3K. Therefore we suggest that the genes that are regulated by both the STAT and the PI3K pathways by IFNalpha in these cells may be specifically involved in the induction of apoptosis.
Collapse
Affiliation(s)
- Linn Hjortsberg
- Department of Oncology and Pathology, Cancer Center Karolinska (CCK), Karolinska University Hospital and Institute, S-171 76 Stockholm, Sweden
| | | | | | | | | | | | | | | | | |
Collapse
|
96
|
Neeson P, Paterson Y. Effects of the tumor microenvironment on the efficacy of tumor immunotherapy. Immunol Invest 2006; 35:359-94. [PMID: 16916758 DOI: 10.1080/08820130600755009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Cancer immunotherapy utilizes vaccines targeting tumor antigens or tumor endothelium to prevent or regress tumors. Many cancer vaccines are designed to induce antigen-specific effector T cells that migrate to the tumor site. In an optimal situation, the effector T cells penetrate the tumor, release their effector molecules, induce tumor cell death and tumor regression. However, the tumor microenvironment is frequently immunosuppressive and contributes to a state of immune ignorance, impacting on the vaccine's ability to break tolerance to tumor antigen/s. This review discusses the factors in the tumor microenvironment that can affect the efficacy of cancer vaccines. In particular, the review focuses on pathways leading to effector T cell penetration of tumors or the inhibition of this process.
Collapse
Affiliation(s)
- Paul Neeson
- Microbiology Department, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6076, USA
| | | |
Collapse
|
97
|
Liu T, Laurell C, Selivanova G, Lundeberg J, Nilsson P, Wiman KG. Hypoxia induces p53-dependent transactivation and Fas/CD95-dependent apoptosis. Cell Death Differ 2006; 14:411-21. [PMID: 16917513 DOI: 10.1038/sj.cdd.4402022] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
p53 triggers apoptosis in response to cellular stress. We analyzed p53-dependent gene and protein expression in response to hypoxia using wild-type p53-carrying or p53 null HCT116 colon carcinoma cells. Hypoxia induced p53 protein levels and p53-dependent apoptosis in these cells. cDNA microarray analysis revealed that only a limited number of genes were regulated by p53 upon hypoxia. Most classical p53 target genes were not upregulated. However, we found that Fas/CD95 was significantly induced in response to hypoxia in a p53-dependent manner, along with several novel p53 target genes including ANXA1, DDIT3/GADD153 (CHOP), SEL1L and SMURF1. Disruption of Fas/CD95 signalling using anti-Fas-blocking antibody or a caspase 8 inhibitor abrogated p53-induced apoptosis in response to hypoxia. We conclude that hypoxia triggers a p53-dependent gene expression pattern distinct from that induced by other stress agents and that Fas/CD95 is a critical regulator of p53-dependent apoptosis upon hypoxia.
Collapse
Affiliation(s)
- T Liu
- Department of Oncology-Pathology, Cancer Center Karolinska, Karolinska Institute, Stockholm, Sweden
| | | | | | | | | | | |
Collapse
|
98
|
Holmgren L, Ambrosino E, Birot O, Tullus C, Veitonmäki N, Levchenko T, Carlson LM, Musiani P, Iezzi M, Curcio C, Forni G, Cavallo F, Kiessling R. A DNA vaccine targeting angiomotin inhibits angiogenesis and suppresses tumor growth. Proc Natl Acad Sci U S A 2006; 103:9208-13. [PMID: 16754857 PMCID: PMC1482591 DOI: 10.1073/pnas.0603110103] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Endogenous angiogenesis inhibitors have shown promise in preclinical trials, but clinical use has been hindered by low half-life in circulation and high production costs. Here, we describe a strategy that targets the angiostatin receptor angiomotin (Amot) by DNA vaccination. The vaccination procedure generated antibodies that detected Amot on the endothelial cell surface. Purified Ig bound to the endothelial cell membrane and inhibited endothelial cell migration. In vivo, DNA vaccination blocked angiogenesis in the matrigel plug assay and prevented growth of transplanted tumors for up to 150 days. We further demonstrate that a combination of DNA vaccines encoding Amot and the extracellular and transmembrane domains of the human EGF receptor 2 (Her-2)/neu oncogene inhibited breast cancer progression and impaired tumor vascularization in Her-2/neu transgenic mice. No toxicity or impairment of normal blood vessels could be detected. This work shows that DNA vaccination targeting Amot may be used to mimic the effect of angiostatin.
Collapse
Affiliation(s)
- Lars Holmgren
- *Department of Oncology and Pathology, Cancer Centre Karolinska, Karolinska Institutet, SE171 76 Stockholm, Sweden
| | - Elena Ambrosino
- Department of Clinical and Biological Sciences, University of Turin, I-10043 Orbassano, Italy
| | - Olivier Birot
- *Department of Oncology and Pathology, Cancer Centre Karolinska, Karolinska Institutet, SE171 76 Stockholm, Sweden
| | - Carl Tullus
- *Department of Oncology and Pathology, Cancer Centre Karolinska, Karolinska Institutet, SE171 76 Stockholm, Sweden
| | - Niina Veitonmäki
- *Department of Oncology and Pathology, Cancer Centre Karolinska, Karolinska Institutet, SE171 76 Stockholm, Sweden
| | - Tetyana Levchenko
- *Department of Oncology and Pathology, Cancer Centre Karolinska, Karolinska Institutet, SE171 76 Stockholm, Sweden
| | - Lena-Maria Carlson
- *Department of Oncology and Pathology, Cancer Centre Karolinska, Karolinska Institutet, SE171 76 Stockholm, Sweden
| | - Piero Musiani
- Aging Research Center, “Gabriele d’Annunzio” University Foundation, I-66013 Chieti, Italy; and
| | - Manuela Iezzi
- Aging Research Center, “Gabriele d’Annunzio” University Foundation, I-66013 Chieti, Italy; and
| | - Claudia Curcio
- Department of Clinical and Biological Sciences, University of Turin, I-10043 Orbassano, Italy
| | - Guido Forni
- Department of Clinical and Biological Sciences, University of Turin, I-10043 Orbassano, Italy
- Molecular Biotechnology Center, University of Turin, I-10123 Turino, Italy
| | - Federica Cavallo
- Department of Clinical and Biological Sciences, University of Turin, I-10043 Orbassano, Italy
- To whom correspondence should be addressed. E-mail:
| | - Rolf Kiessling
- *Department of Oncology and Pathology, Cancer Centre Karolinska, Karolinska Institutet, SE171 76 Stockholm, Sweden
| |
Collapse
|
99
|
Ernkvist M, Aase K, Ukomadu C, Wohlschlegel J, Blackman R, Veitonmäki N, Bratt A, Dutta A, Holmgren L. p130-Angiomotin associates to actin and controls endothelial cell shape. FEBS J 2006; 273:2000-11. [PMID: 16640563 DOI: 10.1111/j.1742-4658.2006.05216.x] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Angiomotin, an 80 kDa protein expressed in endothelial cells, promotes cell migration and invasion, and stabilizes tube formation in vitro. Angiomotin belongs to a new protein family with two additional members, Amotl-1 and Amotl-2, which are characterized by conserved coiled-coil domains and C-terminal PDZ binding motifs. Here, we report the identification of a 130 kDa splice isoform of angiomotin that is expressed in different cell types including vascular endothelial cells, as well as cytotrophoblasts of the placenta. p130-Angiomotin consists of a cytoplasmic N-terminal extension that mediates its association with F-actin. Transfection of p130-angiomotin into endothelial cells induces actin fiber formation and changes cell shape. The p130-angiomotin protein remained associated with actin after destabilization of actin fibers with cytochalasin B. In contrast to p80-angiomotin, p130-angiomotin does not promote cell migration and did not respond to angiostatin. We propose that p80- and p130-angiomotin play coordinating roles in tube formation by affecting cell migration and cell shape, respectively.
Collapse
Affiliation(s)
- Mira Ernkvist
- Department of Oncology-Pathology, Cancer Centre Karolinska Institute, Stockholm, Sweden
| | | | | | | | | | | | | | | | | |
Collapse
|
100
|
Jiang WG, Watkins G, Douglas-Jones A, Holmgren L, Mansel RE. Angiomotin and angiomotin like proteins, their expression and correlation with angiogenesis and clinical outcome in human breast cancer. BMC Cancer 2006; 6:16. [PMID: 16430777 PMCID: PMC1386688 DOI: 10.1186/1471-2407-6-16] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2005] [Accepted: 01/23/2006] [Indexed: 12/02/2022] Open
Abstract
Backgound Angiomotin is a newly discovered molecule that regulates the migration and tubule formation of endothelial cells. It therefore has been implicated in the control of angiogenesis under physiological and pathological conditions. This study examined the expression of angiomotin and its analogues, angiomotin-like 1 (L1) and -like 2 (L2) in breast tumour tissues, and analysed their correlation with angiogenesis and clinical outcomes. Methods Human breast tissues (normal n = 32 and tumours n = 120) were used. The levels of expression of angiomotin, L1 and L2 were determined using reverse transcription PCR. Microvessels were stained using antibodies against PECAM, von Willebrand factor (factor 8, or vWF) and VE-cadherin. The transcript levels of angiomotin and its analogues were assessed against the clinical and pathological background, including long term survival (120 months). Results Breast cancer tissues expressed significantly higher levels of angiomotin transcript, compared with normal mammary tissues (33.1 ± 11 in normal versus 86.5 ± 13.7 in tumour tissues, p = 0.003). Both L1 and L2 were seen at marginally higher levels in tumour than normal tissues but the difference was not statistically significant. Levels of angiomotin were at significantly higher levels in grade 2 and grade 3 tumours compared with grade 1 (p < 0.01 and p = 0.05 respectively). The levels of angiomotin in tumours from patients who had metastatic disease were also significantly higher than those patients who remained disease free (p = 0.03). Multivariate analysis indicated that angiomotin transcript was an independent prognostic factor (p = 0.031). No significant correlations were seen between angiomotin-L1 and L2 with the clinical outcome. Furthermore, high levels of angiomotin transcript were associated with shorter overall survival (p < 0.05). There was a high degree of correlation between levels of vW factor and that of angiomotin (p < 0.05), but not angiomotin-L1 and angiomotin-L2. Conclusion Angiomotin, a putative endothelial motility factor, is highly expressed in human breast tumour tissues and linked to angiogenesis. It links to the aggressive nature of breast tumours and the long term survival of the patients. These data point angiomotin as being a potential therapeutic target.
Collapse
Affiliation(s)
- Wen G Jiang
- Metastasis and Angiogenesis Research Group, Wales College of Medicine, Cardiff University, Cardiff, UK
| | - Gareth Watkins
- Metastasis and Angiogenesis Research Group, Wales College of Medicine, Cardiff University, Cardiff, UK
| | | | - Lars Holmgren
- Department of Oncology, Karolinska Institutet, Stockholm, Sweden
| | - Robert E Mansel
- Metastasis and Angiogenesis Research Group, Wales College of Medicine, Cardiff University, Cardiff, UK
| |
Collapse
|