1
|
Pitsava G, Pankratz N, Lane J, Yang W, Rigler S, Shaw GM, Mills JL. Exome sequencing findings in children with annular pancreas. Mol Genet Genomic Med 2023; 11:e2233. [PMID: 37635636 PMCID: PMC10568395 DOI: 10.1002/mgg3.2233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2022] [Accepted: 06/13/2023] [Indexed: 08/29/2023] Open
Abstract
BACKGROUND Annular pancreas (AP) is a congenital defect of unknown cause in which the pancreas encircles the duodenum. Theories include abnormal migration and rotation of the ventral bud, persistence of ectopic pancreatic tissue, and inappropriate fusion of the ventral and dorsal buds before rotation. The few reported familial cases suggest a genetic contribution. METHODS We conducted exome sequencing in 115 affected infants from the California birth defects registry. RESULTS Seven cases had a single heterozygous missense variant in IQGAP1, five of them with CADD scores >20; seven other infants had a single heterozygous missense variant in NRCAM, five of them with CADD scores >20. We also looked at genes previously associated with AP and found two rare heterozygous missense variants, one each in PDX1 and FOXF1. CONCLUSION IQGAP1 and NRCAM are crucial in cell polarization and migration. Mutations result in decreased motility which could possibly cause the ventral bud to not migrate normally. To our knowledge, this is the first study reporting a possible association for IQGAP1 and NRCAM with AP. Our findings of rare genetic variants involved in cell migration in 15% of our population raise the possibility that AP may be related to abnormal cell migration.
Collapse
Affiliation(s)
- Georgia Pitsava
- Division of Intramural Research, Division of Population Health Research, Eunice Kennedy Shriver National Institute of Child Health and Human DevelopmentNational Institutes of HealthBethesdaMarylandUSA
| | - Nathan Pankratz
- Department of Laboratory Medicine and PathologyUniversity of Minnesota Medical SchoolMinneapolisMinnesotaUSA
| | - John Lane
- Department of Laboratory Medicine and PathologyUniversity of Minnesota Medical SchoolMinneapolisMinnesotaUSA
| | - Wei Yang
- Department of PediatricsStanford University School of MedicineStanfordCaliforniaUSA
| | - Shannon Rigler
- Department of NeonatologyNaval Medical Center PortsmouthPortsmouthVirginiaUSA
| | - Gary M. Shaw
- Department of PediatricsStanford University School of MedicineStanfordCaliforniaUSA
| | - James L. Mills
- Division of Intramural Research, Division of Population Health Research, Eunice Kennedy Shriver National Institute of Child Health and Human DevelopmentNational Institutes of HealthBethesdaMarylandUSA
| |
Collapse
|
2
|
Ren X, Guo X, Liang Z, Guo R, Liang S, Liu H. Hax1 regulate focal adhesion dynamics through IQGAP1. Cell Commun Signal 2023; 21:182. [PMID: 37488602 PMCID: PMC10364419 DOI: 10.1186/s12964-023-01189-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Accepted: 06/07/2023] [Indexed: 07/26/2023] Open
Abstract
Cell migration is a highly orchestrated process requiring the coordination between the cytoskeleton, cell membrane and extracellular matrix adhesions. Our previous study demonstrated that Hax1 interacts with EB2, a microtubule end-binding protein, and this interaction regulate cell migration in keratinocytes. However, little is known about the underlying regulatory mechanism. Here, we show that Hax1 links dynamic focal adhesions to regulate cell migration via interacting with IQGAP1, a multidomain scaffolding protein, which was identified by affinity purification coupled with LC-MS/MS. Biochemical characterizations revealed that C-terminal region of Hax1 and RGCT domain of IQGAP1 are the most critical binding determinants for its interaction. IQGAP1/Hax1 interaction is essential for cell migration in MCF7 cells. Knockdown of HAX1 not only stabilizes focal adhesions, but also impairs the accumulation of IQGAP in focal adhesions. Further study indicates that this interaction is critical for maintaining efficient focal adhesion turnover. Perturbation of the IQGAP1/Hax1 interaction in vivo using a membrane-permeable TAT-RGCT peptide results in impaired focal adhesion turnover, thus leading to inhibition of directional cell migration. Together, our findings unravel a novel interaction between IQGAP1 and Hax1, suggesting that IQGAP1 association with Hax1 plays a significant role in focal adhesion turnover and directional cell migration. Video Abstract.
Collapse
Affiliation(s)
- Xinyi Ren
- School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, 325035, Zhejiang, China
| | - Xiaopu Guo
- School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, 325035, Zhejiang, China
| | - Zihan Liang
- School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, 325035, Zhejiang, China
| | - Renxian Guo
- School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, 325035, Zhejiang, China
| | - Shaohui Liang
- School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, 325035, Zhejiang, China.
| | - Han Liu
- School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, 325035, Zhejiang, China.
| |
Collapse
|
3
|
Song F, Dai Q, Grimm MO, Steinbach D. The Antithetic Roles of IQGAP2 and IQGAP3 in Cancers. Cancers (Basel) 2023; 15:cancers15041115. [PMID: 36831467 PMCID: PMC9953781 DOI: 10.3390/cancers15041115] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 02/02/2023] [Accepted: 02/08/2023] [Indexed: 02/12/2023] Open
Abstract
The scaffold protein family of IQ motif-containing GTPase-activating proteins (IQGAP1, 2, and 3) share a high degree of homology and comprise six functional domains. IQGAPs bind and regulate the cytoskeleton, interact with MAP kinases and calmodulin, and have GTPase-related activity, as well as a RasGAP domain. Thus, IQGAPs regulate multiple cellular processes and pathways, affecting cell division, growth, cell-cell interactions, migration, and invasion. In the past decade, significant evidence on the function of IQGAPs in signal transduction during carcinogenesis has emerged. Compared with IQGAP1, IQGAP2 and IQGAP3 were less analyzed. In this review, we summarize the different signaling pathways affected by IQGAP2 and IQGAP3, and the antithetic roles of IQGAP2 and IQGAP3 in different types of cancer. IQGAP2 expression is reduced and plays a tumor suppressor role in most solid cancer types, while IQGAP3 is overexpressed and acts as an oncogene. In lymphoma, for example, IQGAPs have partially opposite functions. There is considerable evidence that IQGAPs regulate a multitude of pathways to modulate cancer processes and chemoresistance, but some questions, such as how they trigger this signaling, through which domains, and why they play opposite roles on the same pathways, are still unanswered.
Collapse
Affiliation(s)
- Fei Song
- Department of Urology, Jena University Hospital, 07740 Jena, Germany
| | - Qingqing Dai
- Department of Internal Medicine IV (Gastroenterology, Hepatology, and Infectious Diseases), Jena University Hospital, 07740 Jena, Germany
| | - Marc-Oliver Grimm
- Department of Urology, Jena University Hospital, 07740 Jena, Germany
| | - Daniel Steinbach
- Department of Urology, Jena University Hospital, 07740 Jena, Germany
- Correspondence:
| |
Collapse
|
4
|
Dai Q, Song F, Li X, Huang F, Zhao H. Comprehensive analysis of the expression and prognosis for IQ motif-containing GTPase-activating proteins in hepatocellular carcinoma. BMC Cancer 2022; 22:1121. [PMID: 36320006 PMCID: PMC9628040 DOI: 10.1186/s12885-022-10204-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 10/20/2022] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND IQ motif-containing GTPase-activating proteins (IQGAPs) are a group of scaffold proteins which have been identified to be involved in tumor initiation and progression in diverse types of cancer. Clinical studies and experimental evidence suggest that IQGAPs play an essential role in hepatocellular carcinoma (HCC) progression and alterations in their expression are closely related to patient prognosis. However, the different expression patterns and prognostic values of all three IQGAP isoforms in HCC have not yet been analyzed simultaneously. METHODS We analyzed the transcriptional and survival data of IQGAPs in HCC patients using Oncomine, UALCAN, Kaplan-Meier Plotter, cBioPortal, and GeneMANIA. We further examined tumor and adjacent normal tissues from 250 HCC patients using immunohistochemistry to assess the relationship between IQGAPs expression and clinicopathological features and validate the prognostic value of IQGAPs. In addition, we analyzed transcriptional changes of IQGAPs with regards to survival data in HCC patients from the TCGA-LIHC (liver hepatocellular carcinoma) cohort to validate our results. RESULTS We found that the expression levels of IQGAP1 and 3 were significantly elevated in HCC tissues than in normal liver tissues, whereas the expression level of IQGAP2 was decreased in the former than in the latter. The clinical data showed that positive IQGAP1 expression was associated with larger tumor size, advanced tumor-node-metastasis (TNM) stage, poor relapse-free survival (RFS), and overall survival (OS), and positive IQGAP3 expression was associated with poorer tumor differentiation, RFS, and OS. Conversely, positive IQGAP2 expression predicted less tumor numbers and microvascular invasion, as well as higher RFS and OS in these patients. CONCLUSIONS IQGAPs may serve as new prognostic biomarkers and potential targets for precision therapy in HCC.
Collapse
Affiliation(s)
- Qingqing Dai
- grid.412679.f0000 0004 1771 3402Department of Hepatopancreatobiliary Surgery and Organ Transplantation Center, Department of General Surgery, The First Affiliated Hospital of Anhui Medical University, Anhui 230032 Hefei, People’s Republic of China ,grid.275559.90000 0000 8517 6224Department of Internal Medicine IV (Gastroenterology, Hepatology, and Infectious Diseases), Jena University Hospital, 07747 Jena, Germany
| | - Fei Song
- grid.275559.90000 0000 8517 6224Department of Urology, Jena University Hospital, 07747 Jena, Germany
| | - Xincheng Li
- grid.412679.f0000 0004 1771 3402Department of Hepatopancreatobiliary Surgery and Organ Transplantation Center, Department of General Surgery, The First Affiliated Hospital of Anhui Medical University, Anhui 230032 Hefei, People’s Republic of China
| | - Fan Huang
- grid.412679.f0000 0004 1771 3402Department of Hepatopancreatobiliary Surgery and Organ Transplantation Center, Department of General Surgery, The First Affiliated Hospital of Anhui Medical University, Anhui 230032 Hefei, People’s Republic of China
| | - Hongchuan Zhao
- grid.412679.f0000 0004 1771 3402Department of Hepatopancreatobiliary Surgery and Organ Transplantation Center, Department of General Surgery, The First Affiliated Hospital of Anhui Medical University, Anhui 230032 Hefei, People’s Republic of China
| |
Collapse
|
5
|
Javid H, Hashemian P, Yazdani S, Sharbaf Mashhad A, Karimi-Shahri M. The role of heat shock proteins in metastatic colorectal cancer: A review. J Cell Biochem 2022; 123:1704-1735. [PMID: 36063530 DOI: 10.1002/jcb.30326] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2022] [Revised: 08/20/2022] [Accepted: 08/24/2022] [Indexed: 01/18/2023]
Abstract
Heat shock proteins (HSPs) are a large molecular chaperone family classified by their molecular weights, including HSP27, HSP40, HSP60, HSP70, HSP90, and HSP110. HSPs are likely to have antiapoptotic properties and participate actively in various processes such as tumor cell proliferation, invasion, metastases, and death. In this review, we discuss comprehensively the functions of HSPs associated with the progression of colorectal cancer (CRC) and metastasis and resistance to cancer therapy. Taken together, HSPs have numerous clinical applications as biomarkers for cancer diagnosis and prognosis and potential therapeutic targets for CRC and its related metastases.
Collapse
Affiliation(s)
- Hossein Javid
- Department of Clinical Biochemistry, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.,Department of Medical Laboratory Sciences, Varastegan Institute for Medical Sciences, Mashhad, Iran
| | - Pedram Hashemian
- Jahad Daneshgahi Research Committee, Jahad Daneshgahi Institute, Mashhad, Iran
| | - Shaghayegh Yazdani
- Department of Medical Laboratory Sciences, Mashhad University of Medical Sciences, Mashhad, Iran.,Department of Medical Laboratory Sciences, Ilam University of Medical Sciences, Ilam, Iran
| | - Alireza Sharbaf Mashhad
- Department of Medical Laboratory Sciences, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Mehdi Karimi-Shahri
- Department of Pathology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.,Department of Pathology, School of Medicine, Gonabad University of Medical Sciences, Gonabad, Iran
| |
Collapse
|
6
|
Dai Q, Ain Q, Rooney M, Song F, Zipprich A. Role of IQ Motif-Containing GTPase-Activating Proteins in Hepatocellular Carcinoma. Front Oncol 2022; 12:920652. [PMID: 35785216 PMCID: PMC9243542 DOI: 10.3389/fonc.2022.920652] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 05/10/2022] [Indexed: 11/21/2022] Open
Abstract
IQ motif-containing GTPase-activating proteins (IQGAPs) are a class of scaffolding proteins, including IQGAP1, IQGAP2, and IQGAP3, which govern multiple cellular activities by facilitating cytoskeletal remodeling and cellular signal transduction. The role of IQGAPs in cancer initiation and progression has received increasing attention in recent years, especially in hepatocellular carcinoma (HCC), where the aberrant expression of IQGAPs is closely related to patient prognosis. IQGAP1 and 3 are upregulated and are considered oncogenes in HCC, while IQGAP2 is downregulated and functions as a tumor suppressor. This review details the three IQGAP isoforms and their respective structures. The expression and role of each protein in different liver diseases and mainly in HCC, as well as the underlying mechanisms, are also presented. This review also provides a reference for further studies on IQGAPs in HCC.
Collapse
Affiliation(s)
- Qingqing Dai
- Department of Internal Medicine IV (Gastroenterology, Hepatology, and Infectious Diseases), Jena University Hospital, Jena, Germany
- Else Kröner Graduate School for Medical Students “Jena School for Ageing Medicine (JSAM)”, Jena University Hospital, Jena, Germany
| | - Quratul Ain
- Department of Internal Medicine IV (Gastroenterology, Hepatology, and Infectious Diseases), Jena University Hospital, Jena, Germany
| | - Michael Rooney
- Department of Internal Medicine IV (Gastroenterology, Hepatology, and Infectious Diseases), Jena University Hospital, Jena, Germany
| | - Fei Song
- Department of Urology, Jena University Hospital, Jena, Germany
| | - Alexander Zipprich
- Department of Internal Medicine IV (Gastroenterology, Hepatology, and Infectious Diseases), Jena University Hospital, Jena, Germany
- *Correspondence: Alexander Zipprich,
| |
Collapse
|
7
|
Asgharzadeh F, Moradi-Marjaneh R, Marjaneh MM. The role of heat shock protein 40 in carcinogenesis and biology of colorectal cancer. Curr Pharm Des 2022; 28:1457-1465. [PMID: 35570564 DOI: 10.2174/1381612828666220513124603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 03/31/2022] [Indexed: 11/22/2022]
Abstract
Colorectal cancer (CRC) is the third most common cancer worldwide. Despite the enormous amount of effort in the diagnosis and treatment of CRC, the overall survival rate of patients remains low. The precise molecular and cellular basis underlying CRC has not been completely understood yet. Over time, new genes and molecular pathways involved in the pathogenesis of the disease are being identified. Accurate discovery of these genes and signaling pathways are important and urgent missions for the next generation of anticancer therapy research. Chaperone DnaJ, also known as Hsp40 (heat shock protein 40), has been of particular interest in CRC pathogenesis, as it is involved in the fundamental cell activities for maintaining cellular homeostasis. Evidence show that protein family members of DnaJ/Hsp40 play both roles; enhancing and reducing the growth of CRC cells. In the present review, we focus on the current knowledge on the molecular mechanisms responsible for the role of DnaJ/Hsp40 in CRC carcinogenesis and biology.
Collapse
Affiliation(s)
- Fereshteh Asgharzadeh
- Department of Physiology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Reyhaneh Moradi-Marjaneh
- Department of Physiology, School of Paramedical Sciences, Torbat Heydariyeh University of Medical Sciences, Torbat Heydariyeh, Iran
| | - Mahdi Moradi Marjaneh
- Department of Infectious Disease, Faculty of Medicine, Imperial College London, London, United Kingdom
| |
Collapse
|
8
|
Yerramilli VS, Ross AH, Scarlata S, Gericke A. IQGAP1 scaffolding links phosphoinositide kinases to cytoskeletal reorganization. Biophys J 2022; 121:793-807. [PMID: 35077666 PMCID: PMC8943696 DOI: 10.1016/j.bpj.2022.01.018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 09/24/2021] [Accepted: 01/21/2022] [Indexed: 11/02/2022] Open
Abstract
IQGAP1 is a multidomain scaffold protein that coordinates the direction and impact of multiple signaling pathways by scaffolding its various binding partners. However, the spatial and temporal resolution of IQGAP1 scaffolding remains unclear. Here, we use fluorescence imaging and correlation methods that allow for real-time live-cell changes in IQGAP1 localization and complex formation during signaling. We find that IQGAP1 and PIPKIγ interact on both the plasma membrane and in cytosol. Epidermal growth factor (EGF) stimulation, which can initiate cytoskeletal changes, drives the movement of the cytosolic pool toward the plasma membrane to promote cytoskeletal changes. We also observe that a significant population of cytosolic IQGAP1-PIPKIγ complexes localize to early endosomes, and in some instances form aggregated clusters which become highly mobile upon EGF stimulation. Our imaging studies show that PIPKIγ and PI3K bind simultaneously to IQGAP1, which may accelerate conversion of PI4P to PI(3,4,5)P3 that is required for cytoskeletal changes. Additionally, we find that IQGAP1 is responsible for PIPKIγ association with two proteins associated with cytoskeletal changes, talin and Cdc42, during EGF stimulation. These results directly show that IQGAP1 provides a physical link between phosphoinositides (through PIPKIγ), focal adhesion formation (through talin), and cytoskeletal reorganization (through Cdc42) upon EGF stimulation. Taken together, our results support the importance of IQGAP1 in regulating cell migration by linking phosphoinositide lipid signaling with cytoskeletal reorganization.
Collapse
Affiliation(s)
- V. Siddartha Yerramilli
- Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, Massachusetts
| | - Alonzo H. Ross
- Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, Massachusetts,Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Suzanne Scarlata
- Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, Massachusetts
| | - Arne Gericke
- Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, Massachusetts.
| |
Collapse
|
9
|
Li W, Li F, Zhang X, Lin HK, Xu C. Insights into the post-translational modification and its emerging role in shaping the tumor microenvironment. Signal Transduct Target Ther 2021; 6:422. [PMID: 34924561 PMCID: PMC8685280 DOI: 10.1038/s41392-021-00825-8] [Citation(s) in RCA: 57] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 11/02/2021] [Accepted: 11/05/2021] [Indexed: 12/11/2022] Open
Abstract
More and more in-depth studies have revealed that the occurrence and development of tumors depend on gene mutation and tumor heterogeneity. The most important manifestation of tumor heterogeneity is the dynamic change of tumor microenvironment (TME) heterogeneity. This depends not only on the tumor cells themselves in the microenvironment where the infiltrating immune cells and matrix together forming an antitumor and/or pro-tumor network. TME has resulted in novel therapeutic interventions as a place beyond tumor beds. The malignant cancer cells, tumor infiltrate immune cells, angiogenic vascular cells, lymphatic endothelial cells, cancer-associated fibroblastic cells, and the released factors including intracellular metabolites, hormonal signals and inflammatory mediators all contribute actively to cancer progression. Protein post-translational modification (PTM) is often regarded as a degradative mechanism in protein destruction or turnover to maintain physiological homeostasis. Advances in quantitative transcriptomics, proteomics, and nuclease-based gene editing are now paving the global ways for exploring PTMs. In this review, we focus on recent developments in the PTM area and speculate on their importance as a critical functional readout for the regulation of TME. A wealth of information has been emerging to prove useful in the search for conventional therapies and the development of global therapeutic strategies.
Collapse
Affiliation(s)
- Wen Li
- grid.54549.390000 0004 0369 4060Integrative Cancer Center & Cancer Clinical Research Center, Sichuan Cancer Hospital & Institute, Sichuan Cancer Center, School of Medicine, University of Electronic Science and Technology of China, 610042 Chengdu, P. R. China
| | - Feifei Li
- grid.54549.390000 0004 0369 4060Integrative Cancer Center & Cancer Clinical Research Center, Sichuan Cancer Hospital & Institute, Sichuan Cancer Center, School of Medicine, University of Electronic Science and Technology of China, 610042 Chengdu, P. R. China ,grid.256607.00000 0004 1798 2653Guangxi Collaborative Innovation Center for Biomedicine (Guangxi-ASEAN Collaborative Innovation Center for Major Disease Prevention and Treatment), Guangxi Medical University, 530021 Nanning, Guangxi China
| | - Xia Zhang
- grid.410570.70000 0004 1760 6682Institute of Pathology and Southwest Cancer Center, Southwest Hospital, Third Military Medical University (Army Medical University), 400038 Chongqing, China
| | - Hui-Kuan Lin
- grid.241167.70000 0001 2185 3318Department of Cancer Biology, Wake Forest Baptist Medical Center, Wake Forest University, Winston Salem, NC 27101 USA
| | - Chuan Xu
- Integrative Cancer Center & Cancer Clinical Research Center, Sichuan Cancer Hospital & Institute, Sichuan Cancer Center, School of Medicine, University of Electronic Science and Technology of China, 610042, Chengdu, P. R. China. .,Department of Cancer Biology, Wake Forest Baptist Medical Center, Wake Forest University, Winston Salem, NC, 27101, USA.
| |
Collapse
|
10
|
Mosaddeghzadeh N, Nouri K, Krumbach OHF, Amin E, Dvorsky R, Ahmadian MR. Selectivity Determinants of RHO GTPase Binding to IQGAPs. Int J Mol Sci 2021; 22:12596. [PMID: 34830479 PMCID: PMC8625570 DOI: 10.3390/ijms222212596] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 11/16/2021] [Accepted: 11/19/2021] [Indexed: 12/13/2022] Open
Abstract
IQ motif-containing GTPase-activating proteins (IQGAPs) modulate a wide range of cellular processes by acting as scaffolds and driving protein components into distinct signaling networks. Their functional states have been proposed to be controlled by members of the RHO family of GTPases, among other regulators. In this study, we show that IQGAP1 and IQGAP2 can associate with CDC42 and RAC1-like proteins but not with RIF, RHOD, or RHO-like proteins, including RHOA. This seems to be based on the distribution of charged surface residues, which varies significantly among RHO GTPases despite their high sequence homology. Although effector proteins bind first to the highly flexible switch regions of RHO GTPases, additional contacts outside are required for effector activation. Sequence alignment and structural, mutational, and competitive biochemical analyses revealed that RHO GTPases possess paralog-specific residues outside the two highly conserved switch regions that essentially determine the selectivity of RHO GTPase binding to IQGAPs. Amino acid substitution of these specific residues in RHOA to the corresponding residues in RAC1 resulted in RHOA association with IQGAP1. Thus, electrostatics most likely plays a decisive role in these interactions.
Collapse
Affiliation(s)
- Niloufar Mosaddeghzadeh
- Medical Faculty, Institute of Biochemistry and Molecular Biology II, University Hospital Düsseldorf, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany; (N.M.); (K.N.); (O.H.F.K.); (E.A.); (R.D.)
| | - Kazem Nouri
- Medical Faculty, Institute of Biochemistry and Molecular Biology II, University Hospital Düsseldorf, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany; (N.M.); (K.N.); (O.H.F.K.); (E.A.); (R.D.)
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON L8S 4L8, Canada
| | - Oliver H. F. Krumbach
- Medical Faculty, Institute of Biochemistry and Molecular Biology II, University Hospital Düsseldorf, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany; (N.M.); (K.N.); (O.H.F.K.); (E.A.); (R.D.)
| | - Ehsan Amin
- Medical Faculty, Institute of Biochemistry and Molecular Biology II, University Hospital Düsseldorf, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany; (N.M.); (K.N.); (O.H.F.K.); (E.A.); (R.D.)
- Medical Faculty, Institute of Neural and Sensory Physiology, University Hospital Düsseldorf, Heinrich Heine University, 40225 Düsseldorf, Germany
| | - Radovan Dvorsky
- Medical Faculty, Institute of Biochemistry and Molecular Biology II, University Hospital Düsseldorf, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany; (N.M.); (K.N.); (O.H.F.K.); (E.A.); (R.D.)
| | - Mohammad R. Ahmadian
- Medical Faculty, Institute of Biochemistry and Molecular Biology II, University Hospital Düsseldorf, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany; (N.M.); (K.N.); (O.H.F.K.); (E.A.); (R.D.)
| |
Collapse
|
11
|
Lou Y, Jiang Y, Liang Z, Liu B, Li T, Zhang D. Role of RhoC in cancer cell migration. Cancer Cell Int 2021; 21:527. [PMID: 34627249 PMCID: PMC8502390 DOI: 10.1186/s12935-021-02234-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 09/27/2021] [Indexed: 12/20/2022] Open
Abstract
Migration is one of the five major behaviors of cells. Although RhoC—a classic member of the Rho gene family—was first identified in 1985, functional RhoC data have only been widely reported in recent years. Cell migration involves highly complex signaling mechanisms, in which RhoC plays an essential role. Cell migration regulated by RhoC—of which the most well-known function is its role in cancer metastasis—has been widely reported in breast, gastric, colon, bladder, prostate, lung, pancreatic, liver, and other cancers. Our review describes the role of RhoC in various types of cell migration. The classic two-dimensional cell migration cycle constitutes cell polarization, adhesion regulation, cell contraction and tail retraction, most of which are modulated by RhoC. In the three-dimensional cell migration model, amoeboid migration is the most classic and well-studied model. Here, RhoC modulates the formation of membrane vesicles by regulating myosin II, thereby affecting the rate and persistence of amoeba-like migration. To the best of our knowledge, this review is the first to describe the role of RhoC in all cell migration processes. We believe that understanding the detail of RhoC-regulated migration processes will help us better comprehend the mechanism of cancer metastasis. This will contribute to the study of anti-metastatic treatment approaches, aiding in the identification of new intervention targets for therapeutic or genetic transformational purposes.
Collapse
Affiliation(s)
- Yingyue Lou
- Department of Plastic and Reconstructive Surgery, The First Hospital of Jilin University, Changchun, Jilin, China
| | - Yuhan Jiang
- Department of Plastic and Reconstructive Surgery, The First Hospital of Jilin University, Changchun, Jilin, China
| | - Zhen Liang
- Department of Neurology and Neuroscience Center, The First Hospital of Jilin University, Changchun, China
| | - Bingzhang Liu
- Department of Plastic and Reconstructive Surgery, The First Hospital of Jilin University, Changchun, Jilin, China
| | - Tian Li
- Department of Plastic and Reconstructive Surgery, The First Hospital of Jilin University, Changchun, Jilin, China.
| | - Duo Zhang
- Department of Plastic and Reconstructive Surgery, The First Hospital of Jilin University, Changchun, Jilin, China.
| |
Collapse
|
12
|
Zembroski AS, Andolino C, Buhman KK, Teegarden D. Proteomic Characterization of Cytoplasmic Lipid Droplets in Human Metastatic Breast Cancer Cells. Front Oncol 2021; 11:576326. [PMID: 34141606 PMCID: PMC8204105 DOI: 10.3389/fonc.2021.576326] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 05/10/2021] [Indexed: 12/19/2022] Open
Abstract
One of the characteristic features of metastatic breast cancer is increased cellular storage of neutral lipid in cytoplasmic lipid droplets (CLDs). CLD accumulation is associated with increased cancer aggressiveness, suggesting CLDs contribute to metastasis. However, how CLDs contribute to metastasis is not clear. CLDs are composed of a neutral lipid core, a phospholipid monolayer, and associated proteins. Proteins that associate with CLDs regulate both cellular and CLD metabolism; however, the proteome of CLDs in metastatic breast cancer and how these proteins may contribute to breast cancer progression is unknown. Therefore, the purpose of this study was to identify the proteome and assess the characteristics of CLDs in the MCF10CA1a human metastatic breast cancer cell line. Utilizing shotgun proteomics, we identified over 1500 proteins involved in a variety of cellular processes in the isolated CLD fraction. Interestingly, unlike other cell lines such as adipocytes or enterocytes, the most enriched protein categories were involved in cellular processes outside of lipid metabolism. For example, cell-cell adhesion was the most enriched category of proteins identified, and many of these proteins have been implicated in breast cancer metastasis. In addition, we characterized CLD size and area in MCF10CA1a cells using transmission electron microscopy. Our results provide a hypothesis-generating list of potential players in breast cancer progression and offers a new perspective on the role of CLDs in cancer.
Collapse
Affiliation(s)
- Alyssa S Zembroski
- Department of Nutrition Science, Purdue University, West Lafayette, IN, United States
| | - Chaylen Andolino
- Department of Nutrition Science, Purdue University, West Lafayette, IN, United States
| | - Kimberly K Buhman
- Department of Nutrition Science, Purdue University, West Lafayette, IN, United States
| | - Dorothy Teegarden
- Department of Nutrition Science, Purdue University, West Lafayette, IN, United States
| |
Collapse
|
13
|
Kumar D, Patel SA, Hassan MK, Mohapatra N, Pattanaik N, Dixit M. Reduced IQGAP2 expression promotes EMT and inhibits apoptosis by modulating the MEK-ERK and p38 signaling in breast cancer irrespective of ER status. Cell Death Dis 2021; 12:389. [PMID: 33846302 PMCID: PMC8041781 DOI: 10.1038/s41419-021-03673-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Revised: 03/27/2021] [Accepted: 03/29/2021] [Indexed: 12/29/2022]
Abstract
IQGAP2, a member of the IQGAP family, functions as a tumor suppressor in most of the cancers. Unlike IQGAP1 and IQGAP3, which function as oncogenes in breast cancer, the role of IQGAP2 is still unexplored. Here we report a reduced expression of IQGAP2, which was associated with lymph node positivity, lymphovascular invasion, and higher age in breast cancer patients. We found an inverse correlation of IQGAP2 expression levels with oncogenic properties of breast cancer cell lines in estrogen receptor (ER) independent manner. IQGAP2 expression enhanced apoptosis via reactive oxygen species (ROS)-P38-p53 pathway and reduced epithelial-mesenchymal transition (EMT) in a MEK-ERK-dependent manner. IQGAP2-IQGAP1 ratio correlated negatively with phospho-ERK levels in breast cancer patients. Pull-down assay showed interaction of IQGAP1 and IQGAP2. IQGAP2 overexpression rescued, IQGAP1-mediated ERK activation, suggesting the possibility of IQGAP1 sequestration by IQGAP2. IQGAP2 depletion, in a tumor xenograft model, increased tumor volume, tumor weight, and phospho-ERK expression. Overall, our findings suggest that IQGAP2 is negatively associated with proliferative and metastatic abilities of breast cancer cells. Suppression of IQGAP1-mediated ERK activation is a possible route via which IQGAP2 restricts oncogenic properties of breast cancer cells. Our study highlights the candidature of IQGAP2 as a potent target for therapeutic intervention.
Collapse
Affiliation(s)
- Dinesh Kumar
- School of Biological Sciences, National Institute of Science Education and Research Bhubaneswar, HBNI, P.O. Jatni, Khurda, Odisha, 752050, India
| | - Saket Awadesbhai Patel
- School of Biological Sciences, National Institute of Science Education and Research Bhubaneswar, HBNI, P.O. Jatni, Khurda, Odisha, 752050, India
| | - Md Khurshidul Hassan
- School of Biological Sciences, National Institute of Science Education and Research Bhubaneswar, HBNI, P.O. Jatni, Khurda, Odisha, 752050, India
| | - Nachiketa Mohapatra
- Apollo Hospitals, Plot No. 251, Old Sainik School Road, Bhubaneswar, Odisha, 750015, India
| | - Niharika Pattanaik
- AMRI Hospital, Plot No. 1, Near Jayadev Vatika Park, Khandagiri, Bhubaneswar, Odisha, 751019, India
| | - Manjusha Dixit
- School of Biological Sciences, National Institute of Science Education and Research Bhubaneswar, HBNI, P.O. Jatni, Khurda, Odisha, 752050, India.
| |
Collapse
|
14
|
Peng X, Wang T, Gao H, Yue X, Bian W, Mei J, Zhang Y. The interplay between IQGAP1 and small GTPases in cancer metastasis. Biomed Pharmacother 2021; 135:111243. [PMID: 33434854 DOI: 10.1016/j.biopha.2021.111243] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 12/27/2020] [Accepted: 12/31/2020] [Indexed: 01/07/2023] Open
Abstract
The metastatic spread of tumor cells to distant anatomical locations is a critical cause for disease progression and leads to more than 90 % of cancer-related deaths. IQ motif-containing GTPase-activating protein 1 (IQGAP1), a prominent regulator in the cancer metastasis process, is a scaffold protein that interacts with components of the cytoskeleton. As a critical node within the small GTPase network, IQGAP1 acts as a binding partner of several small GTPases, which in turn function as molecular switches to control most cellular processes, including cell migration and invasion. Given the significant interaction between IQGAP1 and small GTPases in cancer metastasis, we briefly elucidate the role of IQGAP1 in regulating cancer metastasis and the varied interactions existing between IQGAP1 and small GTPases. In addition, the potential regulators for IQGAP1 activity and its interaction with small GTPases are also incorporated in this review. Overall, we comprehensively summarize the role of IQGAP1 in cancer tumorigenicity and metastasis, which may be a potential anti-tumor target to restrain cancer progression.
Collapse
Affiliation(s)
- Xiafeng Peng
- Department of Gynecology and Obstetrics, Wuxi Maternal and Child Health Hospital, the Affiliated Hospital to Nanjing Medical University, Wuxi, 214023, China; First Clinical Medicine College, Nanjing Medical University, Nanjing, 211166, China.
| | - Tiejun Wang
- Department of Gynecology and Obstetrics, Wuxi Maternal and Child Health Hospital, the Affiliated Hospital to Nanjing Medical University, Wuxi, 214023, China.
| | - Han Gao
- School of Medicine, Jiangnan University, Wuxi, 214122, China.
| | - Xin Yue
- First Clinical Medicine College, Nanjing Medical University, Nanjing, 211166, China.
| | - Weiqi Bian
- First Clinical Medicine College, Nanjing Medical University, Nanjing, 211166, China.
| | - Jie Mei
- Department of Gynecology and Obstetrics, Wuxi Maternal and Child Health Hospital, the Affiliated Hospital to Nanjing Medical University, Wuxi, 214023, China; Wuxi Clinical Medical College, Nanjing Medical University, Wuxi, 214023, China.
| | - Yan Zhang
- Department of Gynecology and Obstetrics, Wuxi Maternal and Child Health Hospital, the Affiliated Hospital to Nanjing Medical University, Wuxi, 214023, China.
| |
Collapse
|
15
|
Humphries BA, Wang Z, Yang C. MicroRNA Regulation of the Small Rho GTPase Regulators-Complexities and Opportunities in Targeting Cancer Metastasis. Cancers (Basel) 2020; 12:E1092. [PMID: 32353968 PMCID: PMC7281527 DOI: 10.3390/cancers12051092] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 04/24/2020] [Accepted: 04/25/2020] [Indexed: 02/07/2023] Open
Abstract
The small Rho GTPases regulate important cellular processes that affect cancer metastasis, such as cell survival and proliferation, actin dynamics, adhesion, migration, invasion and transcriptional activation. The Rho GTPases function as molecular switches cycling between an active GTP-bound and inactive guanosine diphosphate (GDP)-bound conformation. It is known that Rho GTPase activities are mainly regulated by guanine nucleotide exchange factors (RhoGEFs), GTPase-activating proteins (RhoGAPs), GDP dissociation inhibitors (RhoGDIs) and guanine nucleotide exchange modifiers (GEMs). These Rho GTPase regulators are often dysregulated in cancer; however, the underlying mechanisms are not well understood. MicroRNAs (miRNAs), a large family of small non-coding RNAs that negatively regulate protein-coding gene expression, have been shown to play important roles in cancer metastasis. Recent studies showed that miRNAs are capable of directly targeting RhoGAPs, RhoGEFs, and RhoGDIs, and regulate the activities of Rho GTPases. This not only provides new evidence for the critical role of miRNA dysregulation in cancer metastasis, it also reveals novel mechanisms for Rho GTPase regulation. This review summarizes recent exciting findings showing that miRNAs play important roles in regulating Rho GTPase regulators (RhoGEFs, RhoGAPs, RhoGDIs), thus affecting Rho GTPase activities and cancer metastasis. The potential opportunities and challenges for targeting miRNAs and Rho GTPase regulators in treating cancer metastasis are also discussed. A comprehensive list of the currently validated miRNA-targeting of small Rho GTPase regulators is presented as a reference resource.
Collapse
Affiliation(s)
- Brock A. Humphries
- Center for Molecular Imaging, Department of Radiology, University of Michigan, 109 Zina Pitcher Place, Ann Arbor, MI 48109, USA
| | - Zhishan Wang
- Department of Toxicology and Cancer Biology, College of Medicine, University of Kentucky, 1095 V A Drive, Lexington, KY 40536, USA;
| | - Chengfeng Yang
- Department of Toxicology and Cancer Biology, College of Medicine, University of Kentucky, 1095 V A Drive, Lexington, KY 40536, USA;
| |
Collapse
|
16
|
The scaffold protein IQGAP1 is crucial for extravasation and metastasis. Sci Rep 2020; 10:2439. [PMID: 32051509 PMCID: PMC7015931 DOI: 10.1038/s41598-020-59438-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Accepted: 01/29/2020] [Indexed: 12/21/2022] Open
Abstract
IQGAP1 is a scaffold protein involved in a range of cellular activities, including migration, invasion, adhesion and proliferation. It is also oncogenic in a variety of cancers, promoting primary tumor growth and invasiveness. However, the role of IQGAP1 in tumor progression and metastasis remains unclear. In this study, we use both knockdown and knockout of IQGAP1 to investigate its role in the metastatic cascade of both melanoma and breast cancer cells in vivo. We find that reduction of IQGAP1 expression decreases the formation of both spontaneous and experimental metastases, without limiting primary or metastatic tumor growth. Furthermore, IQGAP1 knockout significantly inhibits extravasation of tumor cells from circulation, possibly involving invadopodial function. By expressing mutant forms of IQGAP1 in a knockout context, we also determine that IQGAP1’s pro-metastatic functions are dependent on multiple domains and functions. These data demonstrate that IQGAP1 is crucial for metastasis in vivo through regulation of extravasation and suggest that it may represent a valid therapeutic target for inhibiting metastasis.
Collapse
|
17
|
Akula MK, Ibrahim MX, Ivarsson EG, Khan OM, Kumar IT, Erlandsson M, Karlsson C, Xu X, Brisslert M, Brakebusch C, Wang D, Bokarewa M, Sayin VI, Bergo MO. Protein prenylation restrains innate immunity by inhibiting Rac1 effector interactions. Nat Commun 2019; 10:3975. [PMID: 31484924 PMCID: PMC6726657 DOI: 10.1038/s41467-019-11606-x] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Accepted: 07/23/2019] [Indexed: 12/18/2022] Open
Abstract
Rho family proteins are prenylated by geranylgeranyltransferase type I (GGTase-I), which normally target proteins to membranes for GTP-loading. However, conditional deletion of GGTase-I in mouse macrophages increases GTP-loading of Rho proteins, leading to enhanced inflammatory responses and severe rheumatoid arthritis. Here we show that heterozygous deletion of the Rho family gene Rac1, but not Rhoa and Cdc42, reverses inflammation and arthritis in GGTase-I-deficient mice. Non-prenylated Rac1 has a high affinity for the adaptor protein Ras GTPase-activating-like protein 1 (Iqgap1), which facilitates both GTP exchange and ubiquitination-mediated degradation of Rac1. Consistently, inactivating Iqgap1 normalizes Rac1 GTP-loading, and reduces inflammation and arthritis in GGTase-I-deficient mice, as well as prevents statins from increasing Rac1 GTP-loading and cytokine production in macrophages. We conclude that blocking prenylation stimulates Rac1 effector interactions and unleashes proinflammatory signaling. Our results thus suggest that prenylation normally restrains innate immune responses by preventing Rac1 effector interactions. Macrophage specific deletion of GGTase-I, a prenylation enzyme, in mice induces inflammatory response and rheumatoid arthritis. Here the authors show that GGTase-I deficiency and the resulting reduction of RAC1 prenylation increase RAC1 interaction with the adaptor protein IQGAP1, leading to GTP-loading of RAC1 and enhanced proinflammatory cytokine production.
Collapse
Affiliation(s)
- Murali K Akula
- Sahlgrenska Cancer Center, Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, SE-405 30, Gothenburg, Sweden.,Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, SE-405 30, Gothenburg, Sweden
| | - Mohamed X Ibrahim
- Sahlgrenska Cancer Center, Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, SE-405 30, Gothenburg, Sweden
| | - Emil G Ivarsson
- Sahlgrenska Cancer Center, Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, SE-405 30, Gothenburg, Sweden
| | - Omar M Khan
- Adult Stem Cell Laboratory, Francis Crick Research Institute, London, NW1 1AT, UK.,College of Health and Life Sciences, Hamad Bin Khalifa University, Education City, Qatar Foundation, Doha, 34110, Qatar
| | - Israiel T Kumar
- Sahlgrenska Cancer Center, Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, SE-405 30, Gothenburg, Sweden
| | - Malin Erlandsson
- Department of Rheumatology, Institute of Medicine, University of Gothenburg, SE-41345, Gothenburg, Sweden
| | - Christin Karlsson
- Sahlgrenska Cancer Center, Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, SE-405 30, Gothenburg, Sweden
| | - Xiufeng Xu
- Department of Biosciences and Nutrition, Karolinska Institutet, SE-141 83, Huddinge, Sweden
| | - Mikael Brisslert
- Department of Rheumatology, Institute of Medicine, University of Gothenburg, SE-41345, Gothenburg, Sweden
| | - Cord Brakebusch
- Biotech Research and Innovation Centre, University of Copenhagen, 2200, Copenhagen N, Denmark
| | - Donghai Wang
- Department of Immunology, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Maria Bokarewa
- Department of Rheumatology, Institute of Medicine, University of Gothenburg, SE-41345, Gothenburg, Sweden
| | - Volkan I Sayin
- Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, SE-405 30, Gothenburg, Sweden.,Sahlgrenska Cancer Center, Department of Surgery, Institute of Clinical Sciences, University of Gothenburg, SE-405 30, Gothenburg, Sweden
| | - Martin O Bergo
- Sahlgrenska Cancer Center, Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, SE-405 30, Gothenburg, Sweden. .,Department of Biosciences and Nutrition, Karolinska Institutet, SE-141 83, Huddinge, Sweden.
| |
Collapse
|
18
|
Müller MT, Schempp R, Lutz A, Felder T, Felder E, Miklavc P. Interaction of microtubules and actin during the post-fusion phase of exocytosis. Sci Rep 2019; 9:11973. [PMID: 31427591 PMCID: PMC6700138 DOI: 10.1038/s41598-019-47741-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Accepted: 07/09/2019] [Indexed: 01/24/2023] Open
Abstract
Exocytosis is the intracellular trafficking step where a secretory vesicle fuses with the plasma membrane to release vesicle content. Actin and microtubules both play a role in exocytosis; however, their interplay is not understood. Here we study the interaction of actin and microtubules during exocytosis in lung alveolar type II (ATII) cells that secrete surfactant from large secretory vesicles. Surfactant extrusion is facilitated by an actin coat that forms on the vesicle shortly after fusion pore opening. Actin coat compression allows hydrophobic surfactant to be released from the vesicle. We show that microtubules are localized close to actin coats and stay close to the coats during their compression. Inhibition of microtubule polymerization by colchicine and nocodazole affected the kinetics of actin coat formation and the extent of actin polymerisation on fused vesicles. In addition, microtubule and actin cross-linking protein IQGAP1 localized to fused secretory vesicles and IQGAP1 silencing influenced actin polymerisation after vesicle fusion. This study demonstrates that microtubules can influence actin coat formation and actin polymerization on secretory vesicles during exocytosis.
Collapse
Affiliation(s)
- M Tabitha Müller
- Institute of General Physiology, Ulm University, Albert-Einstein Allee 11, 89081, Ulm, Germany
| | - Rebekka Schempp
- Institute of General Physiology, Ulm University, Albert-Einstein Allee 11, 89081, Ulm, Germany
| | - Anngrit Lutz
- Institute of General Physiology, Ulm University, Albert-Einstein Allee 11, 89081, Ulm, Germany
| | - Tatiana Felder
- Institute of General Physiology, Ulm University, Albert-Einstein Allee 11, 89081, Ulm, Germany
| | - Edward Felder
- Institute of General Physiology, Ulm University, Albert-Einstein Allee 11, 89081, Ulm, Germany
| | - Pika Miklavc
- School of Environment and Life Sciences, University of Salford, The Crescent, M54WT, Salford, United Kingdom.
| |
Collapse
|
19
|
Chellini L, Caprara V, Spadaro F, Sestito R, Bagnato A, Rosanò L. Regulation of extracellular matrix degradation and metastatic spread by IQGAP1 through endothelin-1 receptor signalling in ovarian cancer. Matrix Biol 2019; 81:17-33. [DOI: 10.1016/j.matbio.2018.10.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 10/22/2018] [Accepted: 10/22/2018] [Indexed: 12/25/2022]
|
20
|
Tanaka M, Osanai T, Homma Y, Hanada K, Okumura K, Tomita H. IQGAP1 activates PLC-δ1 by direct binding and moving along microtubule with DLC-1 to cell surface. FASEB Bioadv 2019; 1:465-480. [PMID: 32123844 PMCID: PMC6996382 DOI: 10.1096/fba.2019-00020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 03/05/2019] [Accepted: 05/31/2019] [Indexed: 01/08/2023] Open
Abstract
Phospholipase C (PLC)-δ1, activated by p122RhoGTPase-activating protein (GAP)/deleted in liver cancer-1 (p122RhoGAP/DLC-1), contributes to the coronary spastic angina (CSA) pathogenesis. The present study aims to further investigate the p122RhoGAP/DLC-1 protein. We examined molecules assisting this protein and identified a scaffold protein-IQ motif-containing GTPase-activating protein 1 (IQGAP1). IQGAP1-C binds to the steroidogenic acute regulatory-related lipid transfer (START) domain of p122RhoGAP/DLC-1, and PLC-δ1 binds to IQGAP1-N, forming a complex. In fluorescence microscopy, small dots of PLC-δ1 created fine linear arrays like microtubules, and IQGAP1 and p122RhoGAP/DLC-1 were colocated in the cytoplasm with PLC-δ1. Ionomycin induced the raft recruitment of the PLC-δ1, IQGAP1, and p122RhoGAP/DLC-1 complex by translocation to the plasma membrane (PM), indicating the movement of this complex is along microtubules with the motor protein kinesin. Moreover, the IQGAP1 protein was elevated in skin fibroblasts obtained from patients with CSA, and it enhanced the PLC activity and peak intracellular calcium concentration in response to acetylcholine. IQGAP1, a novel stimulating protein, forms a complex with p122RhoGAP/DLC-1 and PLC-δ1 that moves along microtubules and enhances the PLC activity.
Collapse
Affiliation(s)
- Makoto Tanaka
- Department of Stroke and Cerebrovascular MedicineHirosaki University Graduate School of MedicineHirosakiJapan
| | - Tomohiro Osanai
- Department of Nursing ScienceHirosaki University Graduate School of Health ScienceHirosakiJapan
| | - Yoshimi Homma
- Department of Biomolecular ScienceFukushima Medical University School of MedicineFukushimaJapan
| | - Kenji Hanada
- Department of CardiologyHirosaki University Graduate School of MedicineHirosakiJapan
| | - Ken Okumura
- Division of CardiologySaiseikai Kumamoto HospitalKumamotoJapan
| | - Hirofumi Tomita
- Department of Stroke and Cerebrovascular MedicineHirosaki University Graduate School of MedicineHirosakiJapan
- Department of CardiologyHirosaki University Graduate School of MedicineHirosakiJapan
| |
Collapse
|
21
|
Morgan CJ, Hedman AC, Li Z, Sacks DB. Endogenous IQGAP1 and IQGAP3 do not functionally interact with Ras. Sci Rep 2019; 9:11057. [PMID: 31363101 PMCID: PMC6667474 DOI: 10.1038/s41598-019-46677-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Accepted: 06/28/2019] [Indexed: 02/07/2023] Open
Abstract
The Ras family of small GTPases modulates numerous essential processes. Activating Ras mutations result in hyper-activation of selected signaling cascades, which leads to human diseases. The high frequency of Ras mutations in human malignant neoplasms has led to Ras being a desirable chemotherapeutic target. The IQGAP family of scaffold proteins binds to and regulates multiple signaling molecules, including the Rho family GTPases Rac1 and Cdc42. There are conflicting data in the published literature regarding interactions between IQGAP and Ras proteins. Initial reports showed no binding, but subsequent studies claim associations of IQGAP1 and IQGAP3 with K-Ras and H-Ras, respectively. Therefore, we set out to resolve this controversy. Here we demonstrate that neither endogenous IQGAP1 nor endogenous IQGAP3 binds to the major Ras isoforms, namely H-, K-, and N-Ras. Importantly, Ras activation by epidermal growth factor is not altered when IQGAP1 or IQGAP3 proteins are depleted from cells. These data strongly suggest that IQGAP proteins are not functional interactors of H-, K-, or N-Ras and challenge the rationale for targeting the interaction of Ras with IQGAP for the development of therapeutic agents.
Collapse
Affiliation(s)
- Chase J Morgan
- From the Department of Laboratory Medicine, National Institutes of Health, 10 Center Drive, Bethesda, Maryland, 20892, USA
| | - Andrew C Hedman
- From the Department of Laboratory Medicine, National Institutes of Health, 10 Center Drive, Bethesda, Maryland, 20892, USA
| | - Zhigang Li
- From the Department of Laboratory Medicine, National Institutes of Health, 10 Center Drive, Bethesda, Maryland, 20892, USA
| | - David B Sacks
- From the Department of Laboratory Medicine, National Institutes of Health, 10 Center Drive, Bethesda, Maryland, 20892, USA.
| |
Collapse
|
22
|
Chen M, Choi S, Jung O, Wen T, Baum C, Thapa N, Lambert PF, Rapraeger AC, Anderson RA. The Specificity of EGF-Stimulated IQGAP1 Scaffold Towards the PI3K-Akt Pathway is Defined by the IQ3 motif. Sci Rep 2019; 9:9126. [PMID: 31235839 PMCID: PMC6591252 DOI: 10.1038/s41598-019-45671-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Accepted: 05/22/2019] [Indexed: 12/13/2022] Open
Abstract
Epidermal growth factor receptor (EGFR) and its downstream phosphoinositide 3-kinase (PI3K) pathway are commonly deregulated in cancer. Recently, we have shown that the IQ motif-containing GTPase-activating protein 1 (IQGAP1) provides a molecular platform to scaffold all the components of the PI3K-Akt pathway and results in the sequential generation of phosphatidylinositol-3,4,5-trisphosphate (PI3,4,5P3). In addition to the PI3K-Akt pathway, IQGAP1 also scaffolds the Ras-ERK pathway. To define the specificity of IQGAP1 for the control of PI3K signaling, we have focused on the IQ3 motif in IQGAP1 as PIPKIα and PI3K enzymes bind this region. An IQ3 deletion mutant loses interactions with the PI3K-Akt components but retains binding to ERK and EGFR. Consistently, blocking the IQ3 motif of IQGAP1 using an IQ3 motif-derived peptide mirrors the effect of IQ3 deletion mutant by reducing Akt activation but has no impact on ERK activation. Also, the peptide disrupts the binding of IQGAP1 with PI3K-Akt pathway components, while IQGAP1 interactions with ERK and EGFR are not affected. Functionally, deleting or blocking the IQ3 motif inhibits cell proliferation, invasion, and migration in a non-additive manner to a PIPKIα inhibitor, establishing the functional specificity of IQ3 motif towards the PI3K-Akt pathway. Taken together, the IQ3 motif is a specific target for suppressing activation of the PI3K-Akt but not the Ras-ERK pathway. Although EGFR stimulates the IQGAP1-PI3K and -ERK pathways, here we show that IQGAP1-PI3K controls migration, invasion, and proliferation independent of ERK. These data illustrate that the IQ3 region of IQGAP1 is a promising therapeutic target for PI3K-driven cancer.
Collapse
Affiliation(s)
- Mo Chen
- University of Wisconsin-Madison, School of Medicine and Public Health, Madison, WI, USA
| | - Suyong Choi
- University of Wisconsin-Madison, School of Medicine and Public Health, Madison, WI, USA
| | - Oisun Jung
- University of Wisconsin-Madison, School of Medicine and Public Health, Madison, WI, USA
| | - Tianmu Wen
- University of Wisconsin-Madison, School of Medicine and Public Health, Madison, WI, USA
| | - Christina Baum
- University of Wisconsin-Madison, School of Medicine and Public Health, Madison, WI, USA
| | - Narendra Thapa
- University of Wisconsin-Madison, School of Medicine and Public Health, Madison, WI, USA
| | - Paul F Lambert
- University of Wisconsin-Madison, School of Medicine and Public Health, Madison, WI, USA
| | - Alan C Rapraeger
- University of Wisconsin-Madison, School of Medicine and Public Health, Madison, WI, USA
| | - Richard A Anderson
- University of Wisconsin-Madison, School of Medicine and Public Health, Madison, WI, USA.
| |
Collapse
|
23
|
Hu W, Wang Z, Zhang S, Lu X, Wu J, Yu K, Ji A, Lu W, Wang Z, Wu J, Jiang C. IQGAP1 promotes pancreatic cancer progression and epithelial-mesenchymal transition (EMT) through Wnt/β-catenin signaling. Sci Rep 2019; 9:7539. [PMID: 31101875 PMCID: PMC6525164 DOI: 10.1038/s41598-019-44048-y] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Accepted: 05/07/2019] [Indexed: 12/24/2022] Open
Abstract
IQ motif-containing GTPase-activating protein 1 (IQGAP1) is a scaffold protein that participates in several cellular functions, including cytoskeletal regulation, cell adhesion, gene transcription and cell polarization. IQGAP1 has been implicated in the tumorigenesis and progression of several human cancers. However, the role of IQGAP1 in pancreatic ductal adenocarcinoma (PDAC) is still unknown. We found that IQGAP1 expression was an independent prognostic factor for PDAC. IQGAP1 upregulation significantly promoted cell proliferation, migration, invasion and epithelial-mesenchymal transition (EMT), whereas IQGAP1 downregulation impaired its oncogenic functions. Overexpression of IQGAP1 increased the protein level of Dishevelled2 (DVL2) and enhanced canonical Wnt signaling as evidenced by increased DVL2 level, β-catenin transcriptional activity, β-catenin nuclear translocation and expression of the direct target genes of β-catenin (cyclin D1 and c-myc). In contrast, knockdown of IQGAP1 decreased the level of DVL2 and attenuated Wnt/β-catenin signaling. In vivo results revealed that IQGAP1 promoted tumor growth and metastasis. Co-immunoprecipitation studies demonstrated that IQGAP1 interacted with both DVL2 and β-catenin. Moreover, knockdown of DVL2 reversed IQGAP1-induced EMT. Our findings thus confirmed that IQGAP1 could be used as a potential target for PDAC treatment.
Collapse
Affiliation(s)
- Wei Hu
- Department of Hepatobiliary Surgery, Lianyungang Clinical College of Nanjing Medical University, Lianyungang, 222001, Jiangsu, China.,Department of Hepatobiliary Surgery, Drum Tower Clinical College of Nanjing Medical University, Nanjing, 210008, Jiangsu, China
| | - Zhongxia Wang
- Department of Hepatobiliary Surgery, Drum Tower Clinical College of Nanjing Medical University, Nanjing, 210008, Jiangsu, China
| | - Shan Zhang
- Department of Hepatobiliary Surgery, Drum Tower Clinical College of Nanjing Medical University, Nanjing, 210008, Jiangsu, China
| | - Xian Lu
- Department of Hepatobiliary Surgery, Drum Tower Clinical College of Nanjing Medical University, Nanjing, 210008, Jiangsu, China
| | - Junyi Wu
- Department of Hepatobiliary Surgery, Drum Tower Clinical College of Nanjing Medical University, Nanjing, 210008, Jiangsu, China
| | - Kuanyong Yu
- Department of Hepatobiliary Surgery, Drum Tower Clinical College of Nanjing Medical University, Nanjing, 210008, Jiangsu, China
| | - Anlai Ji
- Department of Hepatobiliary Surgery, Drum Tower Clinical College of Nanjing Medical University, Nanjing, 210008, Jiangsu, China
| | - Wei Lu
- Jiangsu Province Hospital of Traditional Chinese Medicine, Nanjing, 210029, Jiangsu, China
| | - Zhong Wang
- Department of Hepatobiliary Surgery, Lianyungang Clinical College of Nanjing Medical University, Lianyungang, 222001, Jiangsu, China.
| | - Junhua Wu
- Jiangsu Key Laboratory of Molecular Medicine, Medical School, Nanjing University, Nanjing, 210093, Jiangsu, China.
| | - Chunping Jiang
- Department of Hepatobiliary Surgery, Drum Tower Clinical College of Nanjing Medical University, Nanjing, 210008, Jiangsu, China.
| |
Collapse
|
24
|
Mullin BH, Zhu K, Xu J, Brown SJ, Mullin S, Tickner J, Pavlos NJ, Dudbridge F, Walsh JP, Wilson SG. Expression Quantitative Trait Locus Study of Bone Mineral Density GWAS Variants in Human Osteoclasts. J Bone Miner Res 2018; 33:1044-1051. [PMID: 29473973 DOI: 10.1002/jbmr.3412] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2017] [Revised: 02/15/2018] [Accepted: 02/20/2018] [Indexed: 12/23/2022]
Abstract
Osteoporosis is a complex disease with a strong genetic component. Genomewide association studies (GWAS) have been very successful at identifying common genetic variants associated with bone parameters. A recently published study documented the results of the largest GWAS for bone mineral density (BMD) performed to date (n = 142,487), identifying 307 conditionally independent single-nucleotide polymorphisms (SNPs) as associated with estimated BMD (eBMD) at the genomewide significance level. The vast majority of these variants are non-coding SNPs. Expression quantitative trait locus (eQTL) studies using disease-specific cell types have increasingly been integrated with the results from GWAS to identify genes through which the observed GWAS associations are likely mediated. We generated a unique human osteoclast-specific eQTL data set using cells differentiated in vitro from 158 participants. We then used this resource to characterize the 307 recently identified BMD GWAS SNPs for association with nearby genes (±500 kb). After correction for multiple testing, 24 variants were found to be significantly associated with the expression of 32 genes in the osteoclast-like cells. Bioinformatics analysis suggested that these variants and those in strong linkage disequilibrium with them are enriched in regulatory regions. Several of the eQTL associations identified are relevant to genes that present strongly as having a role in bone, particularly IQGAP1, CYP19A1, CTNNB1, and COL6A3. Supporting evidence for many of the associations was obtained from publicly available eQTL data sets. We have also generated strong evidence for the presence of a regulatory region on chromosome 15q21.2 relevant to both the GLDN and CYP19A1 genes. In conclusion, we have generated a unique osteoclast-specific eQTL resource and have used this to identify 32 eQTL associations for recently identified BMD GWAS loci, which should inform functional studies of osteoclast biology. © 2018 American Society for Bone and Mineral Research.
Collapse
Affiliation(s)
- Benjamin H Mullin
- Department of Endocrinology and Diabetes, Sir Charles Gairdner Hospital, Nedlands, Australia.,School of Biomedical Sciences, University of Western Australia, Crawley, Australia
| | - Kun Zhu
- Department of Endocrinology and Diabetes, Sir Charles Gairdner Hospital, Nedlands, Australia.,School of Biomedical Sciences, University of Western Australia, Crawley, Australia
| | - Jiake Xu
- School of Biomedical Sciences, University of Western Australia, Crawley, Australia
| | - Suzanne J Brown
- Department of Endocrinology and Diabetes, Sir Charles Gairdner Hospital, Nedlands, Australia
| | - Shelby Mullin
- Department of Endocrinology and Diabetes, Sir Charles Gairdner Hospital, Nedlands, Australia.,School of Biomedical Sciences, University of Western Australia, Crawley, Australia
| | - Jennifer Tickner
- School of Biomedical Sciences, University of Western Australia, Crawley, Australia
| | - Nathan J Pavlos
- School of Biomedical Sciences, University of Western Australia, Crawley, Australia
| | - Frank Dudbridge
- Department of Health Sciences, University of Leicester, Leicester, UK
| | - John P Walsh
- Department of Endocrinology and Diabetes, Sir Charles Gairdner Hospital, Nedlands, Australia.,Medical School, University of Western Australia, Crawley, Australia
| | - Scott G Wilson
- Department of Endocrinology and Diabetes, Sir Charles Gairdner Hospital, Nedlands, Australia.,School of Biomedical Sciences, University of Western Australia, Crawley, Australia.,Department of Twin Research and Genetic Epidemiology, King's College London, London, UK
| |
Collapse
|
25
|
Lu B, Lian R, Wu Z, Miao W, Li X, Li J, Shi Y, Yu W. MTA1 promotes viability and motility in nasopharyngeal carcinoma by modulating IQGAP1 expression. J Cell Biochem 2018; 119:3864-3872. [PMID: 29125886 DOI: 10.1002/jcb.26494] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Accepted: 11/09/2017] [Indexed: 12/14/2022]
Abstract
Nasopharyngeal carcinoma (NPC) is frequently seen in Chinese, especially the population that resides in southeast China. Metastasis-associated protein 1 (MTA1) is a chromatin modifier and plays a role in tumor cell metastasis. IQGAP1 is a ubiquitously expressed protein that contributes to cytoskeleton remodeling. This study aimed to investigate the role of MTA1 and IQGAP1 in NPC malignant transformation. MTA1 and IQGAP1 expression in NPC (n = 43) and control tissues (n = 31) were detected using qRT-PCR, immunoblot, and immunohistochemistry. MTA1 was overexpressed in CNE-1 and CNE-2 cell line by pcDNA3.1/MTA1 transfection. Dominant-negative p53 was transfected to inhibit p53 activity. si-IQGAP1 or dominant-negative IQGAP1 (IQGAP1ΔGRD) was used to suppress IQGAP1 activity. Cell proliferation was measured by CKK-8 assay. Cell migration was evaluated by Transwell assay. The results showed that MTA1 and IQGAP1 were highly expressed in NPC tissues compared with the controls. Forced expression of MTA1 accelerated cell proliferation and migration and upregulated IQGAP1 expression in a p53-independent way. Knockdown of IQGAP1 or transfection of dominant-negative IQGAP1 impeded tumor cell proliferation and migration as well as PI3K/Akt signaling induced by MTA1. In conclusion, MTA1 participates in NPC malignant transformation via regulating IQGAP1 expression and PI3K/Akt signaling pathway.
Collapse
Affiliation(s)
- Baocai Lu
- Department of Otolaryngology, The First Affiliated Hospital of Xinxiang Medical University, Xinxiang, Henan Province, China
| | - Rong Lian
- Department of Otolaryngology, The First Affiliated Hospital of Xinxiang Medical University, Xinxiang, Henan Province, China
| | - Zhiyan Wu
- Department of Otolaryngology, The First Affiliated Hospital of Xinxiang Medical University, Xinxiang, Henan Province, China
| | - Wenjie Miao
- Department of Otolaryngology, The First Affiliated Hospital of Xinxiang Medical University, Xinxiang, Henan Province, China
| | - Xiao Li
- Department of Otolaryngology, The First Affiliated Hospital of Xinxiang Medical University, Xinxiang, Henan Province, China
| | - Jin Li
- Department of Otolaryngology, The First Affiliated Hospital of Xinxiang Medical University, Xinxiang, Henan Province, China
| | - Yongjuan Shi
- Department of Anesthesiology, The First Affiliated Hospital of Xinxiang Medical University, Xinxiang, Henan Province, China
| | - Wenfa Yu
- Department of Otolaryngology, The First Affiliated Hospital of Xinxiang Medical University, Xinxiang, Henan Province, China
| |
Collapse
|
26
|
Sema4C/PlexinB2 signaling controls breast cancer cell growth, hormonal dependence and tumorigenic potential. Cell Death Differ 2018; 25:1259-1275. [PMID: 29555978 DOI: 10.1038/s41418-018-0097-4] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Revised: 02/21/2018] [Accepted: 02/27/2018] [Indexed: 11/09/2022] Open
Abstract
Semaphorin 4C (Sema4C) expression in human breast cancers correlates with poor disease outcome. Surprisingly, upon knock-down of Sema4C or its receptor PlexinB2 in diverse mammary carcinoma cells (but not their normal counterparts), we observed dramatic growth inhibition associated with impairment of G2/M phase transition, cytokinesis defects and the onset of cell senescence. Mechanistically, we demonstrated a Sema4C/PlexinB2/LARG-dependent signaling cascade that is required to maintain critical RhoA-GTP levels in cancer cells. Interestingly, we also found that Sema4C upregulation in luminal-type breast cancer cells drives a dramatic phenotypic change, with disassembly of polarity complexes, mitotic spindle misorientation, cell-cell dissociation and increased migration and invasiveness. We found that this signaling cascade is dependent on the PlexinB2 effectors ErbB2 and RhoA-dependent kinases. Moreover, Sema4C-overexpressing luminal breast cancer cells upregulated the transcription factors Snail, Slug and SOX-2, and formed estrogen-independent metastatic tumors in mice. In sum, our data indicate that Sema4C/PlexinB2 signaling is essential for the growth of breast carcinoma cells, featuring a novel potential therapeutic target. In addition, elevated Sema4C expression enables indolent luminal-type tumors to become resistant to estrogen deprivation, invasive and metastatic in vivo, which could account for its association with a subset of human breast cancers with poor prognosis.
Collapse
|
27
|
Ozdemir ES, Jang H, Gursoy A, Keskin O, Li Z, Sacks DB, Nussinov R. Unraveling the molecular mechanism of interactions of the Rho GTPases Cdc42 and Rac1 with the scaffolding protein IQGAP2. J Biol Chem 2018; 293:3685-3699. [PMID: 29358323 PMCID: PMC5846150 DOI: 10.1074/jbc.ra117.001596] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 01/12/2018] [Indexed: 12/22/2022] Open
Abstract
IQ motif-containing GTPase-activating proteins (IQGAPs) are scaffolding proteins playing central roles in cell-cell adhesion, polarity, and motility. The Rho GTPases Cdc42 and Rac1, in their GTP-bound active forms, interact with all three human IQGAPs. The IQGAP-Cdc42 interaction promotes metastasis by enhancing actin polymerization. However, despite their high sequence identity, Cdc42 and Rac1 differ in their interactions with IQGAP. Two Cdc42 molecules can bind to the Ex-domain and the RasGAP site of the GTPase-activating protein (GAP)-related domain (GRD) of IQGAP and promote IQGAP dimerization. Only one Rac1 molecule might bind to the RasGAP site of GRD and may not facilitate the dimerization, and the exact mechanism of Cdc42 and Rac1 binding to IQGAP is unclear. Using all-atom molecular dynamics simulations, site-directed mutagenesis, and Western blotting, we unraveled the detailed mechanisms of Cdc42 and Rac1 interactions with IQGAP2. We observed that Cdc42 binding to the Ex-domain of GRD of IQGAP2 (GRD2) releases the Ex-domain at the C-terminal region of GRD2, facilitating IQGAP2 dimerization. Cdc42 binding to the Ex-domain promoted allosteric changes in the RasGAP site, providing a binding site for the second Cdc42 in the RasGAP site. Of note, the Cdc42 "insert loop" was important for the interaction of the first Cdc42 with the Ex-domain. By contrast, differences in Rac1 insert-loop sequence and structure precluded its interaction with the Ex-domain. Rac1 could bind only to the RasGAP site of apo-GRD2 and could not facilitate IQGAP2 dimerization. Our detailed mechanistic insights help decipher how Cdc42 can stimulate actin polymerization in metastasis.
Collapse
Affiliation(s)
- E Sila Ozdemir
- From the Departments of Chemical and Biological Engineering and
| | - Hyunbum Jang
- the Cancer and Inflammation Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, NCI-Frederick, Frederick, Maryland 21702
| | - Attila Gursoy
- Computer Engineering, Koc University, Istanbul 34450, Turkey,
| | - Ozlem Keskin
- From the Departments of Chemical and Biological Engineering and
| | - Zhigang Li
- the Department of Laboratory Medicine, National Institutes of Health, Bethesda, Maryland 20892, and
| | - David B Sacks
- the Department of Laboratory Medicine, National Institutes of Health, Bethesda, Maryland 20892, and
| | - Ruth Nussinov
- the Cancer and Inflammation Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, NCI-Frederick, Frederick, Maryland 21702,
- the Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| |
Collapse
|
28
|
Orr K, Buckley NE, Haddock P, James C, Parent JL, McQuaid S, Mullan PB. Thromboxane A2 receptor (TBXA2R) is a potent survival factor for triple negative breast cancers (TNBCs). Oncotarget 2018; 7:55458-55472. [PMID: 27487152 PMCID: PMC5342429 DOI: 10.18632/oncotarget.10969] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 06/12/2016] [Indexed: 12/19/2022] Open
Abstract
Triple Negative Breast Cancer (TNBC) is defined by the lack of ERα, PR expression and HER2 overexpression and is the breast cancer subtype with the poorest clinical outcomes. Our aim was to identify genes driving TNBC proliferation and/or survival which could represent novel therapeutic targets. We performed microarray profiling of primary TNBCs and generated differential genelists based on clinical outcomes following the chemotherapy regimen FEC (5-Fluorouracil/Epirubicin/Cyclophosphamide -‘good’ outcome no relapse > 3 years; ‘poor’ outcome relapse < 3 years). Elevated expression of thromboxane A2 receptor (TBXA2R) was observed in ‘good’ outcome TNBCs. TBXA2R expression was higher specifically in TNBC cell lines and TBXA2R knockdowns consistently showed dramatic cell killing in TNBC cells. TBXA2R mRNA and promoter activities were up-regulated following BRCA1 knockdown, with c-Myc being required for BRCA1-mediated transcriptional repression. We demonstrated that TBXA2R enhanced TNBC cell migration, invasion and activated Rho signalling, phenotypes which could be reversed using Rho-associated Kinase (ROCK) inhibitors. TBXA2R also protected TNBC cells from DNA damage by negatively regulating reactive oxygen species levels. In summary, TBXA2R is a novel breast cancer-associated gene required for the survival and migratory behaviour of a subset of TNBCs and could provide opportunities to develop novel, more effective treatments.
Collapse
Affiliation(s)
- Katy Orr
- Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, UK
| | - Niamh E Buckley
- Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, UK
| | - Paula Haddock
- Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, UK
| | - Colin James
- Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, UK
| | | | - Stephen McQuaid
- Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, UK
| | - Paul B Mullan
- Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, UK
| |
Collapse
|
29
|
Jiang H, Zhang X, Chen X, Aramsangtienchai P, Tong Z, Lin H. Protein Lipidation: Occurrence, Mechanisms, Biological Functions, and Enabling Technologies. Chem Rev 2018; 118:919-988. [PMID: 29292991 DOI: 10.1021/acs.chemrev.6b00750] [Citation(s) in RCA: 274] [Impact Index Per Article: 45.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Protein lipidation, including cysteine prenylation, N-terminal glycine myristoylation, cysteine palmitoylation, and serine and lysine fatty acylation, occurs in many proteins in eukaryotic cells and regulates numerous biological pathways, such as membrane trafficking, protein secretion, signal transduction, and apoptosis. We provide a comprehensive review of protein lipidation, including descriptions of proteins known to be modified and the functions of the modifications, the enzymes that control them, and the tools and technologies developed to study them. We also highlight key questions about protein lipidation that remain to be answered, the challenges associated with answering such questions, and possible solutions to overcome these challenges.
Collapse
Affiliation(s)
- Hong Jiang
- Howard Hughes Medical Institute, Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States
| | - Xiaoyu Zhang
- Howard Hughes Medical Institute, Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States
| | - Xiao Chen
- Howard Hughes Medical Institute, Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States
| | - Pornpun Aramsangtienchai
- Howard Hughes Medical Institute, Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States
| | - Zhen Tong
- Howard Hughes Medical Institute, Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States
| | - Hening Lin
- Howard Hughes Medical Institute, Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States
| |
Collapse
|
30
|
Reimer M, Denby E, Zustiak SP, Schober JM. Ras GAP-related and C-terminal domain-dependent localization and tumorigenic activities of IQGAP1 in melanoma cells. PLoS One 2017; 12:e0189589. [PMID: 29240845 PMCID: PMC5730206 DOI: 10.1371/journal.pone.0189589] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 11/29/2017] [Indexed: 12/19/2022] Open
Abstract
IQGAP1 interacts with a number of binding partners through a calponin homology domain (CHD), a WW motif, IQ repeats, a Ras GAP-related domain (GRD), and a conserved C-terminal (CT) domain. Among various biological and cellular functions, IQGAP1 is known to play a role in actin cytoskeleton dynamics during membrane ruffling and lamellipodium protrusion. In addition, phosphorylation near the CT domain is thought to control IQGAP1 activity through regulation of intramolecular interaction. In a previous study, we discovered that IQGAP1 preferentially localizes to retracting areas in B16F10 mouse melanoma cells, not areas of membrane ruffling and lamellipodium protrusion. Nothing is known of the domains needed for retraction localization and very little is known of IQGAP1 function in the actin cytoskeleton of melanoma cells. Thus, we examined localization of IQGAP1 mutants to retracting areas, and characterized knock down phenotypes on tissue culture plastic and physiologic-stiffness hydrogels. Localization of IQGAP1 mutants (S1441E/S1443D, S1441A/S1443A, ΔCHD, ΔGRD or ΔCT) to retracting and protruding cell edges were measured. In retracting areas there was a decrease in S1441A/S1443A, ΔGRD and ΔCT localization, a minor decrease in ΔCHD localization, and normal localization of the S1441E/S1443D mutant. In areas of cell protrusion just behind the lamellipodium leading edge, we surprisingly observed both ΔGRD and ΔCT localization, and increased number of microtubules. IQGAP1 knock down caused loss of cell polarity on laminin-coated glass, decreased proliferation on tissue culture polystyrene, and abnormal spheroid growth on laminin-coated hydrogels. We propose that the GRD and CT domains regulate IQGAP1 localization to retracting actin networks to promote a tumorigenic role in melanoma cells.
Collapse
Affiliation(s)
- Michael Reimer
- Department of Pharmaceutical Sciences, Southern Illinois University Edwardsville, Edwardsville, Illinois, United States of America
| | - Elisabeth Denby
- Department of Pharmaceutical Sciences, Southern Illinois University Edwardsville, Edwardsville, Illinois, United States of America
| | - Silviya P. Zustiak
- Department of Biomedical Engineering, Saint Louis University, Saint Louis, Missouri, United States of America
| | - Joseph M. Schober
- Department of Pharmaceutical Sciences, Southern Illinois University Edwardsville, Edwardsville, Illinois, United States of America
- * E-mail:
| |
Collapse
|
31
|
Kalyanaraman H, Zhuang S, Pilz RB, Casteel DE. The activity of cGMP-dependent protein kinase Iα is not directly regulated by oxidation-induced disulfide formation at cysteine 43. J Biol Chem 2017; 292:8262-8268. [PMID: 28360102 DOI: 10.1074/jbc.c117.787358] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Revised: 03/28/2017] [Indexed: 12/20/2022] Open
Abstract
The type I cGMP-dependent protein kinases (PKGs) are key regulators of smooth muscle tone, cardiac hypertrophy, and other physiological processes. The two isoforms PKGIα and PKGIβ are thought to have unique functions because of their tissue-specific expression, different cGMP affinities, and isoform-specific protein-protein interactions. Recently, a non-canonical pathway of PKGIα activation has been proposed, in which PKGIα is activated in a cGMP-independent fashion via oxidation of Cys43, resulting in disulfide formation within the PKGIα N-terminal dimerization domain. A "redox-dead" knock-in mouse containing a C43S mutation exhibits phenotypes consistent with decreased PKGIα signaling, but the detailed mechanism of oxidation-induced PKGIα activation is unknown. Therefore, we examined oxidation-induced activation of PKGIα, and in contrast to previous findings, we observed that disulfide formation at Cys43 does not directly activate PKGIα in vitro or in intact cells. In transfected cells, phosphorylation of Ras homolog gene family member A (RhoA) and vasodilator-stimulated phosphoprotein was increased in response to 8-CPT-cGMP treatment, but not when disulfide formation in PKGIα was induced by H2O2 Using purified enzymes, we found that the Cys43 oxidation had no effect on basal kinase activity or Km and Vmax values; however, PKGIα containing the C43S mutation was less responsive to cGMP-induced activation. This reduction in cGMP affinity may in part explain the PKGIα loss-of-function phenotype of the C43S knock-in mouse. In conclusion, disulfide formation at Cys43 does not directly activate PKGIα, and the C43S-mutant PKGIα has a higher Ka for cGMP. Our results highlight that mutant enzymes should be carefully biochemically characterized before making in vivo inferences.
Collapse
Affiliation(s)
- Hema Kalyanaraman
- Department of Medicine, University of California, San Diego, La Jolla, California 92093
| | - Shunhui Zhuang
- Department of Medicine, University of California, San Diego, La Jolla, California 92093
| | - Renate B Pilz
- Department of Medicine, University of California, San Diego, La Jolla, California 92093
| | - Darren E Casteel
- Department of Medicine, University of California, San Diego, La Jolla, California 92093.
| |
Collapse
|
32
|
Cui X, Song L, Bai Y, Wang Y, Wang B, Wang W. Elevated IQGAP1 and CDC42 levels correlate with tumor malignancy of human glioma. Oncol Rep 2016; 37:768-776. [PMID: 28035419 PMCID: PMC5355752 DOI: 10.3892/or.2016.5341] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 12/12/2016] [Indexed: 01/03/2023] Open
Abstract
IQGAP1 is a multifunctional scaffold protein involved in cell adhesion and cell migration. The abnormal expression of IQGAP1 widely exists in many cancers, but the combined biological roles of IQGAP1 and CDC42 in human glioma remain to be clarified. In this study, we investigated the associated expression level of IQGAP1, CDC42 and clinical significances in human glioma, as well as its biological functions in glioma progression. Our results revealed that IQGAP1 and CDC42 are frequently elevated in glioma tissues compared with their noncancerous counterparts, and a high expression of IQGAP1 and CDC42 correlates with tumor grades and poor overall survival of glioma patients. Moreover, the overexpression of IQGAP1 improves cell proliferation and migration ability of human glioma cells, whereas the knockdown of IQGAP1 by siRNA reduces cell growth and cell migration in vitro. These results suggest that IQGAP1, CDC42 and their interactions play important roles in human glioma carcinogenesis and progression.
Collapse
Affiliation(s)
- Xiaobo Cui
- Inner Mongolia Medical University Affiliated Hospital, Hohhot, Inner Mongolia 010050, P.R. China
| | - Laixiao Song
- Inner Mongolia Medical University Affiliated Hospital, Hohhot, Inner Mongolia 010050, P.R. China
| | - Yunfei Bai
- Inner Mongolia Medical University Affiliated Hospital, Hohhot, Inner Mongolia 010050, P.R. China
| | - Yaping Wang
- Inner Mongolia Medical University Affiliated Hospital, Hohhot, Inner Mongolia 010050, P.R. China
| | - Boqian Wang
- Inner Mongolia Medical University Affiliated Hospital, Hohhot, Inner Mongolia 010050, P.R. China
| | - Wei Wang
- Inner Mongolia Medical University Affiliated Hospital, Hohhot, Inner Mongolia 010050, P.R. China
| |
Collapse
|
33
|
Nouri K, Fansa EK, Amin E, Dvorsky R, Gremer L, Willbold D, Schmitt L, Timson DJ, Ahmadian MR. IQGAP1 Interaction with RHO Family Proteins Revisited: KINETIC AND EQUILIBRIUM EVIDENCE FOR MULTIPLE DISTINCT BINDING SITES. J Biol Chem 2016; 291:26364-26376. [PMID: 27815503 PMCID: PMC5159498 DOI: 10.1074/jbc.m116.752121] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 10/27/2016] [Indexed: 11/16/2022] Open
Abstract
IQ motif-containing GTPase activating protein 1 (IQGAP1) plays a central role in the physical assembly of relevant signaling networks that are responsible for various cellular processes, including cell adhesion, polarity, and transmigration. The RHO family proteins CDC42 and RAC1 have been shown to mainly interact with the GAP-related domain (GRD) of IQGAP1. However, the role of its RASGAP C-terminal (RGCT) and C-terminal domains in the interactions with RHO proteins has remained obscure. Here, we demonstrate that IQGAP1 interactions with RHO proteins underlie a multiple-step binding mechanism: (i) a high affinity, GTP-dependent binding of RGCT to the switch regions of CDC42 or RAC1 and (ii) a very low affinity binding of GRD and a C terminus adjacent to the switch regions. These data were confirmed by phosphomimetic mutation of serine 1443 to glutamate within RGCT, which led to a significant reduction of IQGAP1 affinity for CDC42 and RAC1, clearly disclosing the critical role of RGCT for these interactions. Unlike CDC42, an extremely low affinity was determined for the RAC1-GRD interaction, suggesting that the molecular nature of IQGAP1 interaction with CDC42 partially differs from that of RAC1. Our study provides new insights into the interaction characteristics of IQGAP1 with RHO family proteins and highlights the complementary importance of kinetic and equilibrium analyses. We propose that the ability of IQGAP1 to interact with RHO proteins is based on a multiple-step binding process, which is a prerequisite for the dynamic functions of IQGAP1 as a scaffolding protein and a critical mechanism in temporal regulation and integration of IQGAP1-mediated cellular responses.
Collapse
Affiliation(s)
- Kazem Nouri
- From the Institute of Biochemistry and Molecular Biology II, Medical Faculty of the Heinrich-Heine University, 40225 Düsseldorf, Germany
| | - Eyad K Fansa
- From the Institute of Biochemistry and Molecular Biology II, Medical Faculty of the Heinrich-Heine University, 40225 Düsseldorf, Germany
| | - Ehsan Amin
- From the Institute of Biochemistry and Molecular Biology II, Medical Faculty of the Heinrich-Heine University, 40225 Düsseldorf, Germany
| | - Radovan Dvorsky
- From the Institute of Biochemistry and Molecular Biology II, Medical Faculty of the Heinrich-Heine University, 40225 Düsseldorf, Germany
| | - Lothar Gremer
- the Institute of Physical Biology, Heinrich-Heine University, 40225 Düsseldorf, Germany.,Forschungszentrum Jülich, ICS-6, 52428 Jülich, Germany
| | - Dieter Willbold
- the Institute of Physical Biology, Heinrich-Heine University, 40225 Düsseldorf, Germany.,Forschungszentrum Jülich, ICS-6, 52428 Jülich, Germany
| | - Lutz Schmitt
- the Institute of Biochemistry, Heinrich-Heine University, 40225 Düsseldorf, Germany, and
| | - David J Timson
- the School of Pharmacy and Biomolecular Sciences, University of Brighton, Huxley Building, Lewes Road, Brighton BN2 4GJ, United Kingdom
| | - Mohammad R Ahmadian
- From the Institute of Biochemistry and Molecular Biology II, Medical Faculty of the Heinrich-Heine University, 40225 Düsseldorf, Germany,
| |
Collapse
|
34
|
The Structural Basis for Cdc42-Induced Dimerization of IQGAPs. Structure 2016; 24:1499-508. [PMID: 27524202 DOI: 10.1016/j.str.2016.06.016] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Revised: 06/18/2016] [Accepted: 06/20/2016] [Indexed: 01/18/2023]
Abstract
In signaling, Rho-family GTPases bind effector proteins and alter their behavior. Here we present the crystal structure of Cdc42·GTP bound to the GTPase-activating protein (GAP)-related domain (GRD) of IQGAP2. Four molecules of Cdc42 are bound to two GRD molecules, which bind each other in a parallel dimer. Two Cdc42s bind very similarly to the Ras/RasGAP interaction, while the other two bind primarily to "extra domain" sequences from both GRDs, tying the GRDs together. Calorimetry confirms two-site binding of Cdc42·GTP for the GRDs of both IQGAP2 and IQGAP1. Mutation of important extra domain residues reduces binding to single-site and abrogates Cdc42 binding to a much larger IQGAP1 fragment. Importantly, Rac1·GTP displays only single-site binding to the GRDs, indicating that only Cdc42 promotes IQGAP dimerization. The structure identifies an unexpected role for Cdc42 in protein dimerization, thus expanding the repertoire of interactions of Ras family proteins with their targets.
Collapse
|
35
|
Győrffy B, Stelniec-Klotz I, Sigler C, Kasack K, Redmer T, Qian Y, Schäfer R. Effects of RAL signal transduction in KRAS- and BRAF-mutated cells and prognostic potential of the RAL signature in colorectal cancer. Oncotarget 2016; 6:13334-46. [PMID: 26033452 PMCID: PMC4537018 DOI: 10.18632/oncotarget.3871] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Accepted: 04/02/2015] [Indexed: 01/16/2023] Open
Abstract
Our understanding of oncogenic signaling pathways has strongly fostered current concepts for targeted therapies in metastatic colorectal cancer. The RALA pathway is novel candidate due to its independent role in controlling expression of genes downstream of RAS. We compared RALA GTPase activities in three colorectal cancer cell lines by GTPase pull-down assay and analyzed the transcriptional and phenotypic effects of transient RALA silencing. Knocking-down RALA expression strongly diminished the active GTP-bound form of the protein. Proliferation of KRAS mutated cell lines was significantly reduced, while BRAF mutated cells were mostly unaffected. By microarray analysis we identified common genes showing altered expression upon RALA silencing in all cell lines. None of these genes were affected when the RAF/MAPK or PI3K pathways were blocked. To investigate the potential clinical relevance of the RALA pathway and its associated transcriptome, we performed a meta-analysis interrogating progression-free survival of colorectal cancer patients of five independent data sets using Cox regression. In each dataset, the RALA-responsive signature correlated with worse outcome. In summary, we uncovered the impact of the RAL signal transduction on genetic program and growth control in KRAS- and BRAF-mutated colorectal cells and demonstrated prognostic potential of the pathway-responsive gene signature in cancer patients.
Collapse
Affiliation(s)
- Balázs Győrffy
- MTA TTK Lendület Cancer Biomarker Research Group, Budapest, Hungary.,Semmelweis University, 2nd Department of Pediatrics, Budapest, Hungary.,MTA-SE Pediatrics and Nephrology Research Group, Budapest, Hungary
| | - Iwona Stelniec-Klotz
- Laboratories of Functional Genomics and Molecular Tumor Pathology, Charité Universitätsmedizin Berlin, Germany
| | - Christian Sigler
- Laboratories of Functional Genomics and Molecular Tumor Pathology, Charité Universitätsmedizin Berlin, Germany
| | - Katharina Kasack
- Laboratories of Functional Genomics and Molecular Tumor Pathology, Charité Universitätsmedizin Berlin, Germany.,German Cancer Consortium (DKTK), German Cancer Research Center, Heidelberg, Germany
| | - Torben Redmer
- Laboratories of Functional Genomics and Molecular Tumor Pathology, Charité Universitätsmedizin Berlin, Germany.,German Cancer Consortium (DKTK), German Cancer Research Center, Heidelberg, Germany
| | - Yu Qian
- Laboratories of Functional Genomics and Molecular Tumor Pathology, Charité Universitätsmedizin Berlin, Germany
| | - Reinhold Schäfer
- Laboratories of Functional Genomics and Molecular Tumor Pathology, Charité Universitätsmedizin Berlin, Germany.,German Cancer Consortium (DKTK), German Cancer Research Center, Heidelberg, Germany
| |
Collapse
|
36
|
Jin X, Liu Y, Liu J, Lu W, Liang Z, Zhang D, Liu G, Zhu H, Xu N, Liang S. The Overexpression of IQGAP1 and β-Catenin Is Associated with Tumor Progression in Hepatocellular Carcinoma In Vitro and In Vivo. PLoS One 2015; 10:e0133770. [PMID: 26252773 PMCID: PMC4529304 DOI: 10.1371/journal.pone.0133770] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2015] [Accepted: 07/01/2015] [Indexed: 02/05/2023] Open
Abstract
The IQ-domain GTPase-activating protein 1 (IQGAP1) is a multifunctional scaffold protein, which interacts with diverse proteins to regulate cell adhesion and cell migration. The abnormal expression of IQGAP1 widely exists in many cancers, but biological roles of IQGAP1 cooperation with its interacting proteins to involve in tumorigenesis remain to clarify. In this study, we have found that IQGAP1 interacts with β-catenin and regulates β-catenin expression in hepatocellular carcinoma (HCC) cells. The expression levels of IQGAP1 and β-catenin and their associations have a positive correlation with cell metastasis ability in several HCC cell lines. The up-regulation of IQGAP1 and β-catenin improves cell proliferation and migration ability of HCC cells, whereas the knockdown of IQGAP1 by small interfering RNA can decrease β-catenin expression, which results in the reduction of cell proliferation and migration ability in vitro. In addition, a significantly higher expression of IQGAP1 and β-catenin also usually exists in human HCC tissues, especially their overexpression is clinicopathologically associated with tumor malignancy. Generally the overexpression and interactions of IQGAP1 and β-catenin contribute to HCC progression by promoting cell proliferation and migration.
Collapse
Affiliation(s)
- Xuewen Jin
- State Key Laboratory of Biotherapy and Cancer Center/Collaborative Innovation Center for Biotherapy, West China Hospital, Sichuan University, No.17, 3rd Section of People's South Road, Chengdu, 610041, P. R. China
| | - Yuling Liu
- State Key Laboratory of Biotherapy and Cancer Center/Collaborative Innovation Center for Biotherapy, West China Hospital, Sichuan University, No.17, 3rd Section of People's South Road, Chengdu, 610041, P. R. China
| | - Jingjing Liu
- State Key Laboratory of Biotherapy and Cancer Center/Collaborative Innovation Center for Biotherapy, West China Hospital, Sichuan University, No.17, 3rd Section of People's South Road, Chengdu, 610041, P. R. China
| | - Weiliang Lu
- State Key Laboratory of Biotherapy and Cancer Center/Collaborative Innovation Center for Biotherapy, West China Hospital, Sichuan University, No.17, 3rd Section of People's South Road, Chengdu, 610041, P. R. China
| | - Ziwei Liang
- State Key Laboratory of Biotherapy and Cancer Center/Collaborative Innovation Center for Biotherapy, West China Hospital, Sichuan University, No.17, 3rd Section of People's South Road, Chengdu, 610041, P. R. China
| | - Dan Zhang
- State Key Laboratory of Biotherapy and Cancer Center/Collaborative Innovation Center for Biotherapy, West China Hospital, Sichuan University, No.17, 3rd Section of People's South Road, Chengdu, 610041, P. R. China
| | - Gang Liu
- Department of Rheumatology, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, P. R. China
| | - Hongxia Zhu
- Laboratory of Cell and Molecular Biology & State Key Laboratory of Molecular Oncology, Cancer Institute & Cancer Hospital, Chinese Academy of Medical Sciences, Beijing,100034, P. R. China
| | - Ningzhi Xu
- Laboratory of Cell and Molecular Biology & State Key Laboratory of Molecular Oncology, Cancer Institute & Cancer Hospital, Chinese Academy of Medical Sciences, Beijing,100034, P. R. China
| | - Shufang Liang
- State Key Laboratory of Biotherapy and Cancer Center/Collaborative Innovation Center for Biotherapy, West China Hospital, Sichuan University, No.17, 3rd Section of People's South Road, Chengdu, 610041, P. R. China
- * E-mail:
| |
Collapse
|
37
|
Gao C, Liang C, Nie Z, Liu Y, Wang J, Zhang D. Alkannin inhibits growth and invasion of glioma cells C6 through IQGAP/mTOR signal pathway. Int J Clin Exp Med 2015; 8:5287-5294. [PMID: 26131103 PMCID: PMC4483937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Accepted: 03/27/2015] [Indexed: 06/04/2023]
Abstract
OBJECTIVE This study aims to explore the effect of alkannin on the growth and invasion of glioma cells and its mechanism. METHODS The effects of alkannin on the growth and invasion of glioma cells were detected with MTT assay, clone forming test and transwell assay. The effects of alkannin on the cell cycle were detected with flow cytometry assay. The changes of cyclin, MMPs and IQGAP/mTOR signal pathway related proteins were detected with western blotting methods. RESULTS Alkannin (1 μM, 3 μM and 10 μM) can significantly inhibit the growth, proliferation, migration and invasion of glioma cells C6 with dose dependent. Alkannin can block cell cycle in G1 phase with the increased concentration, which was related with the down-regulation of cyclinA1, cyclinA2 and cyclinD1 expression. Alkannin can also down-regulate the expression of MMP 2, MMP 9 and IQGAP. Alkannin has no effect on mTOR but can inhibit the phosphorylation of mTOR. CONCLUSIONS Alkannin can inhibit the growth and invasion of glioma cells C6 through IQGAP/mTOR signal pathway.
Collapse
Affiliation(s)
- Chunyan Gao
- Yanjing Medical School, Capital University of Medical Sciences Beijing 101300, China
| | - Cunyin Liang
- Yanjing Medical School, Capital University of Medical Sciences Beijing 101300, China
| | - Zhengui Nie
- Yanjing Medical School, Capital University of Medical Sciences Beijing 101300, China
| | - Ying Liu
- Yanjing Medical School, Capital University of Medical Sciences Beijing 101300, China
| | - Junya Wang
- Yanjing Medical School, Capital University of Medical Sciences Beijing 101300, China
| | - Dongmei Zhang
- Yanjing Medical School, Capital University of Medical Sciences Beijing 101300, China
| |
Collapse
|
38
|
Xia FD, Wang ZL, Chen HX, Huang Y, Li JD, Wang ZM, Li XY. Differential expression of IQGAP1/2 in Hepatocellular carcinoma and its relationship with clinical outcomes. Asian Pac J Cancer Prev 2015; 15:4951-6. [PMID: 24998570 DOI: 10.7314/apjcp.2014.15.12.4951] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
PURPOSE To investigate IQGAP1 and IQGAP2 expression in hepatocellular carcinoma (HCC) and itsassociation with HCC clinicopathological characteristics and survival outcomes. METHODS IQGAP1 and IQGAP2 mRNA and protein were measured in HCC tissues, para-tumor tissues and normal tissues by RT-PCR and Western blotting. We further examined 150 HCC samples with adjacent para-tumor tissues and 11 normal specimens by immunohistochemistry to evaluate the correlation of IQGAP1 and IQGAP2 with clinicopathological features and prognosis. RESULTS IQGAP1 mRNA and protein were up-regulated while IQGAP2 mRNA and protein were down-regulated in human HCC tissues compared with para-tumor and normal liver tissues (p<0.05). IQGAP1 expression was higher in primary HCC (122/150, 81.3%) than matched adjacent tissues (30/150, 20%, p<0.001), whereas IQGAP2 was lower (31/150, 20.7% as compared to 112/150, 74.7%, P<0.001). Positive IQGAP1 expression correlated with larger tumor size (p=0.002), advanced TNM stage (p=0.002) and tumor differentiation (III and IV, p=0.034). Negative IQGAP2 expression was significantly associated with larger tumor size (p=0.009), multicentric tumor occurrence (p=0.01), advanced TNM stage (0.009) and tumor differentiation (III and IV, p=0.020). Survival analysis revealed that patients with either IQGAP1+ or IQGAP2- tumors had significantly reduced disease-free survival (p<0.001 and 0.006 respectively) and overall survival (p<0.001 for both). Multivariate analysis showed that IQGAP1/2 switch was an independent prognosis factor for disease-free survival (HR=2.824) and overall survival (HR=2.189). CONCLUSION Positive IQGAP1 and negative IQGAP2 expression were closely correlated with tumor progression and could be used as adjunctive biomarkers to improve prognostication for HCC patients.
Collapse
Affiliation(s)
- Fa-Da Xia
- Department of General Surgery, Xiangya Hospital, Central South University, Changsha, China E-mail :
| | | | | | | | | | | | | |
Collapse
|
39
|
Hedman AC, Smith JM, Sacks DB. The biology of IQGAP proteins: beyond the cytoskeleton. EMBO Rep 2015; 16:427-46. [PMID: 25722290 DOI: 10.15252/embr.201439834] [Citation(s) in RCA: 145] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Accepted: 01/07/2015] [Indexed: 01/02/2023] Open
Abstract
IQGAP scaffold proteins are evolutionarily conserved in eukaryotes and facilitate the formation of complexes that regulate cytoskeletal dynamics, intracellular signaling, and intercellular interactions. Fungal and mammalian IQGAPs are implicated in cytokinesis. IQGAP1, IQGAP2, and IQGAP3 have diverse roles in vertebrate physiology, operating in the kidney, nervous system, cardio-vascular system, pancreas, and lung. The functions of IQGAPs can be corrupted during oncogenesis and are usurped by microbial pathogens. Therefore, IQGAPs represent intriguing candidates for novel therapeutic agents. While modulation of the cytoskeletal architecture was initially thought to be the primary function of IQGAPs, it is now clear that they have roles beyond the cytoskeleton. This review describes contributions of IQGAPs to physiology at the organism level.
Collapse
Affiliation(s)
- Andrew C Hedman
- Department of Laboratory Medicine, National Institutes of Health, Bethesda, MD, USA
| | - Jessica M Smith
- Department of Laboratory Medicine, National Institutes of Health, Bethesda, MD, USA
| | - David B Sacks
- Department of Laboratory Medicine, National Institutes of Health, Bethesda, MD, USA
| |
Collapse
|
40
|
IQGAPs choreograph cellular signaling from the membrane to the nucleus. Trends Cell Biol 2015; 25:171-84. [PMID: 25618329 DOI: 10.1016/j.tcb.2014.12.005] [Citation(s) in RCA: 106] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Revised: 12/02/2014] [Accepted: 12/03/2014] [Indexed: 12/18/2022]
Abstract
Since its discovery in 1994, recognized cellular functions for the scaffold protein IQGAP1 have expanded immensely. Over 100 unique IQGAP1-interacting proteins have been identified, implicating IQGAP1 as a critical integrator of cellular signaling pathways. Initial research established functions for IQGAP1 in cell-cell adhesion, cell migration, and cell signaling. Recent studies have revealed additional IQGAP1 binding partners, expanding the biological roles of IQGAP1. These include crosstalk between signaling cascades, regulation of nuclear function, and Wnt pathway potentiation. Investigation of the IQGAP2 and IQGAP3 homologs demonstrates unique functions, some of which differ from those of IQGAP1. Summarized here are recent observations that enhance our understanding of IQGAP proteins in the integration of diverse signaling pathways.
Collapse
|
41
|
Bhattacharya M, Sundaram A, Kudo M, Farmer J, Ganesan P, Khalifeh-Soltani A, Arjomandi M, Atabai K, Huang X, Sheppard D. IQGAP1-dependent scaffold suppresses RhoA and inhibits airway smooth muscle contraction. J Clin Invest 2014; 124:4895-8. [PMID: 25271629 DOI: 10.1172/jci76658] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Accepted: 08/26/2014] [Indexed: 11/17/2022] Open
Abstract
The intracellular scaffold protein IQGAP1 supports protein complexes in conjunction with numerous binding partners involved in multiple cellular processes. Here, we determined that IQGAP1 modulates airway smooth muscle contractility. Compared with WT controls, at baseline as well as after immune sensitization and challenge, Iqgap1-/- mice had higher airway responsiveness. Tracheal rings from Iqgap1-/- mice generated greater agonist-induced contractile force, even after removal of the epithelium. RhoA, a regulator of airway smooth muscle contractility, was activated in airway smooth muscle lysates from Iqgap1-/- mice. Likewise, knockdown of IQGAP1 in primary human airway smooth muscle cells increased RhoA activity. Immunoprecipitation studies indicated that IQGAP1 binds to both RhoA and p190A-RhoGAP, a GTPase-activating protein that normally inhibits RhoA activation. Proximity ligation assays in primary airway human smooth muscle cells and mouse tracheal sections revealed colocalization of p190A-RhoGAP and RhoA; however, these proteins did not colocalize in IQGAP1 knockdown cells or in Iqgap1-/- trachea. Compared with healthy controls, human subjects with asthma had decreased IQGAP1 expression in airway biopsies. Together, these data demonstrate that IQGAP1 acts as a scaffold that colocalizes p190A-RhoGAP and RhoA, inactivating RhoA and suppressing airway smooth muscle contraction. Furthermore, our results suggest that IQGAP1 has the potential to modulate airway contraction severity in acute asthma.
Collapse
|
42
|
Zhang TT, Jiang YY, Shang L, Shi ZZ, Liang JW, Wang Z, Zhang Y, Hao JJ, Jia XM, Xu X, Cai Y, Zhan QM, Wang MR. Overexpression of DNAJB6 promotes colorectal cancer cell invasion through an IQGAP1/ERK-dependent signaling pathway. Mol Carcinog 2014; 54:1205-13. [PMID: 25044025 DOI: 10.1002/mc.22194] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2013] [Revised: 05/18/2014] [Accepted: 05/22/2014] [Indexed: 12/16/2022]
Affiliation(s)
- Tong-Tong Zhang
- State Key Laboratory of Molecular Oncology; Cancer Institute (Hospital), Peking Union Medical College and Chinese Academy of Medical Sciences; Beijing China
| | - Yan-Yi Jiang
- State Key Laboratory of Molecular Oncology; Cancer Institute (Hospital), Peking Union Medical College and Chinese Academy of Medical Sciences; Beijing China
| | - Li Shang
- State Key Laboratory of Molecular Oncology; Cancer Institute (Hospital), Peking Union Medical College and Chinese Academy of Medical Sciences; Beijing China
| | - Zhi-Zhou Shi
- State Key Laboratory of Molecular Oncology; Cancer Institute (Hospital), Peking Union Medical College and Chinese Academy of Medical Sciences; Beijing China
| | - Jian-Wei Liang
- State Key Laboratory of Molecular Oncology; Cancer Institute (Hospital), Peking Union Medical College and Chinese Academy of Medical Sciences; Beijing China
| | - Zheng Wang
- State Key Laboratory of Molecular Oncology; Cancer Institute (Hospital), Peking Union Medical College and Chinese Academy of Medical Sciences; Beijing China
| | - Yu Zhang
- State Key Laboratory of Molecular Oncology; Cancer Institute (Hospital), Peking Union Medical College and Chinese Academy of Medical Sciences; Beijing China
| | - Jia-Jie Hao
- State Key Laboratory of Molecular Oncology; Cancer Institute (Hospital), Peking Union Medical College and Chinese Academy of Medical Sciences; Beijing China
| | - Xue-Mei Jia
- Department of Histology and Embryology; Anhui Medical University; Hefei China
| | - Xin Xu
- State Key Laboratory of Molecular Oncology; Cancer Institute (Hospital), Peking Union Medical College and Chinese Academy of Medical Sciences; Beijing China
| | - Yan Cai
- State Key Laboratory of Molecular Oncology; Cancer Institute (Hospital), Peking Union Medical College and Chinese Academy of Medical Sciences; Beijing China
| | - Qi-Min Zhan
- State Key Laboratory of Molecular Oncology; Cancer Institute (Hospital), Peking Union Medical College and Chinese Academy of Medical Sciences; Beijing China
| | - Ming-Rong Wang
- State Key Laboratory of Molecular Oncology; Cancer Institute (Hospital), Peking Union Medical College and Chinese Academy of Medical Sciences; Beijing China
| |
Collapse
|
43
|
Foroutannejad S, Rohner N, Reimer M, Kwon G, Schober JM. A novel role for IQGAP1 protein in cell motility through cell retraction. Biochem Biophys Res Commun 2014; 448:39-44. [PMID: 24747073 DOI: 10.1016/j.bbrc.2014.04.038] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Accepted: 04/08/2014] [Indexed: 11/28/2022]
Abstract
IQGAP1 has emerged as a key component in the regulation of cytoskeleton dynamics during cell migration, maintenance of adherens junctions, microbial pathogenesis and intracellular trafficking. IQGAP1 is known to localize to the protruding edge of lamellipodia in a variety of cell types and interact with regulators of actin dynamics. Here, we provide evidence suggesting a novel role of IQGAP1 in cell motility through cell edge retraction. In some of the cell lines examined, IQGAP1 was markedly separated from WAVE localization suggesting IQGAP1 may localize to retracting edges. B16F10 mouse melanoma cells exhibited the most restricted separation in which the appearance of GFP-IQGAP1 correlated with cell edge retraction velocity and the disappearance of mCherry-Arp3. These results demonstrate that in some cell types IQGAP1 may function to promote cell retraction not lamellipodium edge protrusion. In addition, we examined co-localization of IQGAP1 with adhesion site markers, myosin IIA, calmodulin and IQGAP2. In areas rich in IQGAP1 there was decreased immunofluorescence staining of vinculin, paxillin and phosphorylated-tyrosine indicating adhesion site disassembly. Interestingly, calmodulin, but not myosin IIA or IQGAP2, co-localized with IQGAP1 in areas of cell retraction. Overall these results suggest a new role of IQGAP1, distinct form IQGAP2, in cell migration through up regulation of contractility and downregulation of adhesion sites potentially through calmodulin interaction.
Collapse
Affiliation(s)
- Sahar Foroutannejad
- Department of Pharmaceutical Sciences, Southern Illinois University School of Pharmacy, Edwardsville, IL 62026, USA
| | - Nathan Rohner
- Department of Pharmaceutical Sciences, Southern Illinois University School of Pharmacy, Edwardsville, IL 62026, USA
| | - Michael Reimer
- Department of Pharmaceutical Sciences, Southern Illinois University School of Pharmacy, Edwardsville, IL 62026, USA
| | - Guim Kwon
- Department of Pharmaceutical Sciences, Southern Illinois University School of Pharmacy, Edwardsville, IL 62026, USA
| | - Joseph M Schober
- Department of Pharmaceutical Sciences, Southern Illinois University School of Pharmacy, Edwardsville, IL 62026, USA.
| |
Collapse
|
44
|
Matsunaga H, Kubota K, Inoue T, Isono F, Ando O. IQGAP1 selectively interacts with K-Ras but not with H-Ras and modulates K-Ras function. Biochem Biophys Res Commun 2014; 444:360-4. [PMID: 24462863 DOI: 10.1016/j.bbrc.2014.01.041] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Accepted: 01/14/2014] [Indexed: 12/26/2022]
Abstract
K-Ras is frequently mutated and activated especially in pancreatic cancers. To analyze K-Ras function, we have searched for K-Ras interacting proteins and found IQ motif containing GTPase activating protein 1 (IQGAP1) as a novel K-Ras binding protein. IQGAP1 has been known as a scaffold protein for B-Raf, MEK1/2 and ERK1/2. Here we showed that IQGAP1 selectively formed a complex with K-Ras but not with H-Ras, and recruited B-Raf to K-Ras. We found that IQ motif region of IQGAP1 interacted with K-Ras. Both active and inactive K-Ras interacted with IQGAP1, and effector domain mutants of K-Ras also associated with IQGAP1, indicating that IQGAP1 interacts with K-Ras irrespective of Ras-effectors like B-Raf. We also found that overexpression or knock-down of IQGAP1 affected the interaction between K-Ras and B-Raf, and IQGAP1 overexpression increased ERK1/2 phosphorylation in K-Ras dependent manner in PANC1 cells. Our data suggest that IQGAP1 has a novel mechanism to modulate K-Ras pathway.
Collapse
Affiliation(s)
- Hironori Matsunaga
- Oncology Research Laboratories, R&D Division, Daiichi Sankyo Co., Ltd., 1-2-58, Hiromachi, Shinagawa-ku, Tokyo, Japan
| | - Kazuishi Kubota
- Discovery Science and Technology Department, Daiichi Sankyo RD Novare Co., Ltd., 1-16-13, Kitakasai, Edogawa-ku, Tokyo, Japan
| | - Tatsuya Inoue
- Discovery Science and Technology Department, Daiichi Sankyo RD Novare Co., Ltd., 1-16-13, Kitakasai, Edogawa-ku, Tokyo, Japan
| | - Fujio Isono
- Frontier Research Laboratories, R&D Division, Daiichi Sankyo Co., Ltd., 1-2-58, Hiromachi, Shinagawa-ku, Tokyo, Japan
| | - Osamu Ando
- Oncology Research Laboratories, R&D Division, Daiichi Sankyo Co., Ltd., 1-2-58, Hiromachi, Shinagawa-ku, Tokyo, Japan; U3 Pharma GmbH, Fraunhoferstr. 22, Martinsried, Planegg, Germany.
| |
Collapse
|
45
|
Abstract
Coordination of the activity of multiple small GTPases is required for the regulation of many physiological processes, including cell migration. There are now several examples of functional interplay between small GTPase pairs, but the mechanisms that control GTPase activity in time and space are only partially understood. Here, we build on the hypothesis that small GTPases are part of a large, integrated network and propose that key proteins within this network integrate multiple signaling events and coordinate multiple small GTPase activities. Specifically, we identify the scaffolding protein IQGAP1 as a master regulator of multiple small GTPases, including Cdc42, Rac1, Rap1, and RhoA. In addition, we demonstrate that IQGAP1 promotes Arf6 activation downstream of β1 integrin engagement. Furthermore, following literature-curated searches and recent mass spectrometric analysis of IQGAP1-binding partners, we report that IQGAP1 recruits other small GTPases, including RhoC, Rac2, M-Ras, RhoQ, Rab10, and Rab5, small GTPase regulators, including Tiam1, RacGAP1, srGAP2 and HERC1, and small GTPase effectors, including PAK6, N-WASP, several sub-units of the Arp2/3 complex and the formin mDia1. Therefore, we propose that IQGAP1 acts as a small GTPase scaffolding platform within the small GTPase network, and recruits and/or regulates small GTPases, small GTPase regulators and effectors to orchestrate cell behavior. Finally, to identify other putative key regulators of small GTPase crosstalk, we have assembled a small GTPase network using protein-protein interaction databases.
Collapse
Affiliation(s)
- Guillaume Jacquemet
- Wellcome Trust Centre for Cell-Matrix Research; Faculty of Life Sciences; University of Manchester; Manchester, UK
| | - Martin J Humphries
- Wellcome Trust Centre for Cell-Matrix Research; Faculty of Life Sciences; University of Manchester; Manchester, UK
| |
Collapse
|
46
|
Robinson TJW, Pai M, Liu JC, Vizeacoumar F, Sun T, Egan SE, Datti A, Huang J, Zacksenhaus E. High-throughput screen identifies disulfiram as a potential therapeutic for triple-negative breast cancer cells: interaction with IQ motif-containing factors. Cell Cycle 2013; 12:3013-24. [PMID: 23974104 PMCID: PMC3875676 DOI: 10.4161/cc.26063] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Triple-negative breast cancer (TNBC) represents an aggressive subtype, for which radiation and chemotherapy are the only options. Here we describe the identification of disulfiram, an FDA-approved drug used to treat alcoholism, as well as the related compound thiram, as the most potent growth inhibitors following high-throughput screens of 3185 compounds against multiple TNBC cell lines. The average IC50 for disulfiram was ~300 nM. Drug affinity responsive target stability (DARTS) analysis identified IQ motif-containing factors IQGAP1 and MYH9 as direct binding targets of disulfiram. Indeed, knockdown of these factors reduced, though did not completely abolish, cell growth. Combination treatment with 4 different drugs commonly used to treat TNBC revealed that disulfiram synergizes most effectively with doxorubicin to inhibit cell growth of TNBC cells. Disulfiram and doxorubicin cooperated to induce cell death as well as cellular senescence, and targeted the ESA+/CD24-/low/CD44+ cancer stem cell population. Our results suggest that disulfiram may be repurposed to treat TNBC in combination with doxorubicin.
Collapse
Affiliation(s)
- Tyler J W Robinson
- Department of Laboratory Medicine and Pathobiology; University of Toronto; Toronto, Ontario, Canada
| | | | | | | | | | | | | | | | | |
Collapse
|
47
|
Jacquemet G, Morgan MR, Byron A, Humphries JD, Choi CK, Chen CS, Caswell PT, Humphries MJ. Rac1 is deactivated at integrin activation sites through an IQGAP1-filamin-A-RacGAP1 pathway. J Cell Sci 2013; 126:4121-35. [PMID: 23843620 DOI: 10.1242/jcs.121988] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Cell migration makes a fundamental contribution to both normal physiology and disease pathogenesis. Integrin engagement with extracellular ligands spatially controls, via the cyclical activation and deactivation of the small GTPase Rac1, the dynamic membrane protrusion and cytoskeletal reorganization events that are required for directional migration. Although the pathways that control integrin-mediated Rac1 activation are reasonably well defined, the mechanisms that are responsible for switching off activity are poorly understood. Here, proteomic analysis of activated integrin-associated complexes suggests filamin-A and IQ-motif-containing GTPase-activating protein 1 (IQGAP1) as candidates that link β1 integrin to Rac1. siRNA-mediated knockdown of either filamin-A or IQGAP1 induced high, dysregulated Rac1 activity during cell spreading on fibronectin. Using immunoprecipitation and immunocytochemistry, filamin-A and IQGAP1 were shown to be part of a complex that is recruited to active β1 integrin. Mass spectrometric analysis of individual filamin-A, IQGAP1 and Rac1 pull-downs and biochemical analysis, identified RacGAP1 as a novel IQGAP1 binding partner. Further immunoprecipitation and immunocytochemistry analyses demonstrated that RacGAP1 is recruited to IQGAP1 and active β1 integrin, and that suppression of RacGAP1 expression triggered elevated Rac1 activity during spreading on fibronectin. Consistent with these findings, reduced expression of filamin-A, IQGAP1 or RacGAP1 triggered unconstrained membrane protrusion and disrupted directional cell migration on fibrillar extracellular matrices. These findings suggest a model whereby integrin engagement, followed by filamin-A, IQGAP1 and RacGAP1 recruitment, deactivates Rac1 to constrain its activity spatially and thereby coordinate directional cell migration.
Collapse
Affiliation(s)
- Guillaume Jacquemet
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, UK
| | | | | | | | | | | | | | | |
Collapse
|
48
|
Osman MA, Sarkar FH, Rodriguez-Boulan E. A molecular rheostat at the interface of cancer and diabetes. Biochim Biophys Acta Rev Cancer 2013; 1836:166-76. [PMID: 23639840 DOI: 10.1016/j.bbcan.2013.04.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Accepted: 04/23/2013] [Indexed: 12/17/2022]
Abstract
Epidemiology studies revealed the connection between several types of cancer and type 2 diabetes (T2D) and suggested that T2D is both a symptom and a risk factor of pancreatic cancer. High level of circulating insulin (hyperinsulinemia) in obesity has been implicated in promoting aggressive types of cancers. Insulin resistance, a symptom of T2D, pressures pancreatic β-cells to increase insulin secretion, leading to hyperinsulinemia, which in turn leads to a gradual loss of functional β-cell mass, thus indicating a fine balance and interplay between β-cell function and mass. While the mechanisms of these connections are unclear, the mTORC1-Akt signaling pathway has been implicated in controlling β-cell function and mass, and in mediating the link of cancer and T2D. However, incomplete understating of how the pathway is regulated and how it integrates body metabolism has hindered its efficacy as a clinical target. The IQ motif containing GTPase activating protein 1 (IQGAP1)-Exocyst axis is a growth factor- and nutrient-sensor that couples cell growth and division. Here we discuss how IQGAP1-Exocyst, through differential interactions with Rho-type of small guanosine triphosphatases (GTPases), acts as a rheostat that modulates the mTORC1-Akt and MAPK signals, and integrates β-cell function and mass with insulin signaling, thus providing a molecular mechanism for cancer initiation in diabetes. Delineating this regulatory pathway may have the potential of contributing to optimizing the efficacy and selectivity of future therapies for cancer and diabetes.
Collapse
Affiliation(s)
- Mahasin A Osman
- Warren Alpert Medical School, Division of Biology and Medicine, Molecular Pharmacology, Physiology and Biotechnology, Brown University, Providence, RI 02912, USA.
| | | | | |
Collapse
|