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Sahasrabudhe DM, Liesveld JL, Minhajuddin M, Singh NA, Nath S, Kumar VM, Balys M, Evans AG, Azadniv M, Hansen JN, Becker MW, Sharon A, Thomas VK, Moore RG, Khera MK, Jordan CT, Singh RK. In silico predicted compound targeting the IQGAP1-GRD domain selectively inhibits growth of human acute myeloid leukemia. Sci Rep 2024; 14:12868. [PMID: 38834690 PMCID: PMC11150481 DOI: 10.1038/s41598-024-63392-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2023] [Accepted: 05/28/2024] [Indexed: 06/06/2024] Open
Abstract
Acute myeloid leukemia (AML) is fatal in the majority of adults. Identification of new therapeutic targets and their pharmacologic modulators are needed to improve outcomes. Previous studies had shown that immunization of rabbits with normal peripheral WBCs that had been incubated with fluorodinitrobenzene elicited high titer antibodies that bound to a spectrum of human leukemias. We report that proteomic analyses of immunoaffinity-purified lysates of primary AML cells showed enrichment of scaffolding protein IQGAP1. Immunohistochemistry and gene-expression analyses confirmed IQGAP1 mRNA overexpression in various cytogenetic subtypes of primary human AML compared to normal hematopoietic cells. shRNA knockdown of IQGAP1 blocked proliferation and clonogenicity of human leukemia cell-lines. To develop small molecules targeting IQGAP1 we performed in-silico screening of 212,966 compounds, selected 4 hits targeting the IQGAP1-GRD domain, and conducted SAR of the 'fittest hit' to identify UR778Br, a prototypical agent targeting IQGAP1. UR778Br inhibited proliferation, induced apoptosis, resulted in G2/M arrest, and inhibited colony formation by leukemia cell-lines and primary-AML while sparing normal marrow cells. UR778Br exhibited favorable ADME/T profiles and drug-likeness to treat AML. In summary, AML shows response to IQGAP1 inhibition, and UR778Br, identified through in-silico studies, selectively targeted AML cells while sparing normal marrow.
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Affiliation(s)
- Deepak M Sahasrabudhe
- Wilmot Cancer Institute, University of Rochester Medical Center, 601 Elmwood Avenue, Box 704, Rochester, NY, 14618, USA.
- Department of Medicine, Hematology/Oncology, University of Rochester Medical Center, Rochester, NY, USA.
| | - Jane L Liesveld
- Wilmot Cancer Institute, University of Rochester Medical Center, 601 Elmwood Avenue, Box 704, Rochester, NY, 14618, USA
- Department of Medicine, Hematology/Oncology, University of Rochester Medical Center, Rochester, NY, USA
| | - Mohammad Minhajuddin
- Division of Hematology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, US
| | - Niloy A Singh
- Department of Medicine, Hematology/Oncology, University of Rochester Medical Center, Rochester, NY, USA
| | - Subhangi Nath
- Department of Chemistry, Birla Institute of Technology, Ranchi, Jharkhand, India
| | - Vishuwes Muthu Kumar
- Department of Chemistry, Birla Institute of Technology, Ranchi, Jharkhand, India
| | - Marlene Balys
- Genomics Research Center, University of Rochester Medical Center, Rochester, NY, USA
| | - Andrew G Evans
- Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, Rochester, NY, USA
| | - Mitra Azadniv
- Department of Medicine, Hematology/Oncology, University of Rochester Medical Center, Rochester, NY, USA
| | - Jeanne N Hansen
- Department of Psychological and Brain Sciences, Colgate University, Hamilton, NY, USA
| | | | - Ashoke Sharon
- Department of Chemistry, Birla Institute of Technology, Ranchi, Jharkhand, India
| | - V Kaye Thomas
- Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, NY, 14642, USA
| | - Richard G Moore
- Division of Obstetrics and Gynecology, University of Rochester Medical Center, Rochester, NY, USA
| | - Manoj K Khera
- Presude Lifesciences Pvt Ltd., Uttam Nagar, New Delhi, 110059, India
| | - Craig T Jordan
- Division of Hematology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, US
| | - Rakesh K Singh
- Division of Obstetrics and Gynecology, University of Rochester Medical Center, Rochester, NY, USA.
- Wilmot Cancer Institute, University of Rochester Medical Center, 601 Elmwood Avenue, Rochester, NY, 14642, USA.
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2
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Thapa N, Chen M, Cryns VL, Anderson R. A p85 isoform switch enhances PI3K activation on endosomes by a MAP4- and PI3P-dependent mechanism. Cell Rep 2024; 43:114119. [PMID: 38630589 DOI: 10.1016/j.celrep.2024.114119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 02/21/2024] [Accepted: 03/29/2024] [Indexed: 04/19/2024] Open
Abstract
Phosphatidylinositol 3-kinase α (PI3Kα) is a heterodimer of p110α catalytic and p85 adaptor subunits that is activated by agonist-stimulated receptor tyrosine kinases. Although p85α recruits p110α to activated receptors on membranes, p85α loss, which occurs commonly in cancer, paradoxically promotes agonist-stimulated PI3K/Akt signaling. p110α localizes to microtubules via microtubule-associated protein 4 (MAP4), facilitating its interaction with activated receptor kinases on endosomes to initiate PI3K/Akt signaling. Here, we demonstrate that in response to agonist stimulation and p85α knockdown, the residual p110α, coupled predominantly to p85β, exhibits enhanced recruitment with receptor tyrosine kinases to endosomes. Moreover, the p110α C2 domain binds PI3-phosphate, and this interaction is also required to recruit p110α to endosomes and for PI3K/Akt signaling. Stable knockdown of p85α, which mimics the reduced p85α levels observed in cancer, enhances cell growth and tumorsphere formation, and these effects are abrogated by MAP4 or p85β knockdown, underscoring their role in the tumor-promoting activity of p85α loss.
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Affiliation(s)
- Narendra Thapa
- School of Medicine and Public Health, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, WI 53705, USA
| | - Mo Chen
- School of Medicine and Public Health, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, WI 53705, USA
| | - Vincent L Cryns
- Department of Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, WI 53705, USA
| | - Richard Anderson
- School of Medicine and Public Health, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, WI 53705, USA.
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3
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Ragupathi A, Kim C, Jacinto E. The mTORC2 signaling network: targets and cross-talks. Biochem J 2024; 481:45-91. [PMID: 38270460 PMCID: PMC10903481 DOI: 10.1042/bcj20220325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 11/29/2023] [Accepted: 12/18/2023] [Indexed: 01/26/2024]
Abstract
The mechanistic target of rapamycin, mTOR, controls cell metabolism in response to growth signals and stress stimuli. The cellular functions of mTOR are mediated by two distinct protein complexes, mTOR complex 1 (mTORC1) and mTORC2. Rapamycin and its analogs are currently used in the clinic to treat a variety of diseases and have been instrumental in delineating the functions of its direct target, mTORC1. Despite the lack of a specific mTORC2 inhibitor, genetic studies that disrupt mTORC2 expression unravel the functions of this more elusive mTOR complex. Like mTORC1 which responds to growth signals, mTORC2 is also activated by anabolic signals but is additionally triggered by stress. mTORC2 mediates signals from growth factor receptors and G-protein coupled receptors. How stress conditions such as nutrient limitation modulate mTORC2 activation to allow metabolic reprogramming and ensure cell survival remains poorly understood. A variety of downstream effectors of mTORC2 have been identified but the most well-characterized mTORC2 substrates include Akt, PKC, and SGK, which are members of the AGC protein kinase family. Here, we review how mTORC2 is regulated by cellular stimuli including how compartmentalization and modulation of complex components affect mTORC2 signaling. We elaborate on how phosphorylation of its substrates, particularly the AGC kinases, mediates its diverse functions in growth, proliferation, survival, and differentiation. We discuss other signaling and metabolic components that cross-talk with mTORC2 and the cellular output of these signals. Lastly, we consider how to more effectively target the mTORC2 pathway to treat diseases that have deregulated mTOR signaling.
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Affiliation(s)
- Aparna Ragupathi
- Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers University, New Brunswick, NJ, U.S.A
| | - Christian Kim
- Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers University, New Brunswick, NJ, U.S.A
| | - Estela Jacinto
- Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers University, New Brunswick, NJ, U.S.A
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4
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Lin TY, Ramsamooj S, Perrier T, Liberatore K, Lantier L, Vasan N, Karukurichi K, Hwang SK, Kesicki EA, Kastenhuber ER, Wiederhold T, Yaron TM, Huntsman EM, Zhu M, Ma Y, Paddock MN, Zhang G, Hopkins BD, McGuinness O, Schwartz RE, Ersoy BA, Cantley LC, Johnson JL, Goncalves MD. Epinephrine inhibits PI3Kα via the Hippo kinases. Cell Rep 2023; 42:113535. [PMID: 38060450 PMCID: PMC10809223 DOI: 10.1016/j.celrep.2023.113535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 10/23/2023] [Accepted: 11/16/2023] [Indexed: 12/30/2023] Open
Abstract
The phosphoinositide 3-kinase p110α is an essential mediator of insulin signaling and glucose homeostasis. We interrogated the human serine, threonine, and tyrosine kinome to search for novel regulators of p110α and found that the Hippo kinases phosphorylate p110α at T1061, which inhibits its activity. This inhibitory state corresponds to a conformational change of a membrane-binding domain on p110α, which impairs its ability to engage membranes. In human primary hepatocytes, cancer cell lines, and rodent tissues, activation of the Hippo kinases MST1/2 using forskolin or epinephrine is associated with phosphorylation of T1061 and inhibition of p110α, impairment of downstream insulin signaling, and suppression of glycolysis and glycogen synthesis. These changes are abrogated when MST1/2 are genetically deleted or inhibited with small molecules or if the T1061 is mutated to alanine. Our study defines an inhibitory pathway of PI3K signaling and a link between epinephrine and insulin signaling.
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Affiliation(s)
- Ting-Yu Lin
- Meyer Cancer Center, Weill Cornell Medicine, New York, NY 10021, USA; Weill Cornell Graduate School of Medical Sciences, New York, NY 10021, USA
| | - Shakti Ramsamooj
- Meyer Cancer Center, Weill Cornell Medicine, New York, NY 10021, USA; Division of Endocrinology, Weill Cornell Medicine, New York, NY 10021, USA
| | - Tiffany Perrier
- Meyer Cancer Center, Weill Cornell Medicine, New York, NY 10021, USA; Division of Endocrinology, Weill Cornell Medicine, New York, NY 10021, USA
| | | | - Louise Lantier
- Molecular Physiology & Biophysics, Vanderbilt University, Nashville, TN 37232, USA
| | - Neil Vasan
- Meyer Cancer Center, Weill Cornell Medicine, New York, NY 10021, USA
| | | | - Seo-Kyoung Hwang
- Meyer Cancer Center, Weill Cornell Medicine, New York, NY 10021, USA; Division of Endocrinology, Weill Cornell Medicine, New York, NY 10021, USA
| | | | | | | | - Tomer M Yaron
- Meyer Cancer Center, Weill Cornell Medicine, New York, NY 10021, USA; Englander Institute for Precision Medicine, Institute for Computational Biomedicine, Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY 10065, USA
| | - Emily M Huntsman
- Meyer Cancer Center, Weill Cornell Medicine, New York, NY 10021, USA; Englander Institute for Precision Medicine, Institute for Computational Biomedicine, Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY 10065, USA
| | - Mengmeng Zhu
- Proteomics and Metabolomics Core Facility, Weill Cornell Medicine, New York, NY 10021, USA
| | - Yilun Ma
- Meyer Cancer Center, Weill Cornell Medicine, New York, NY 10021, USA
| | - Marcia N Paddock
- Meyer Cancer Center, Weill Cornell Medicine, New York, NY 10021, USA
| | - Guoan Zhang
- Proteomics and Metabolomics Core Facility, Weill Cornell Medicine, New York, NY 10021, USA
| | | | - Owen McGuinness
- Molecular Physiology & Biophysics, Vanderbilt University, Nashville, TN 37232, USA
| | - Robert E Schwartz
- Division of Gastroenterology & Hepatology, Weill Cornell Medicine, New York, NY 10021, USA
| | - Baran A Ersoy
- Division of Gastroenterology & Hepatology, Weill Cornell Medicine, New York, NY 10021, USA
| | - Lewis C Cantley
- Meyer Cancer Center, Weill Cornell Medicine, New York, NY 10021, USA
| | - Jared L Johnson
- Meyer Cancer Center, Weill Cornell Medicine, New York, NY 10021, USA.
| | - Marcus D Goncalves
- Meyer Cancer Center, Weill Cornell Medicine, New York, NY 10021, USA; Division of Endocrinology, Weill Cornell Medicine, New York, NY 10021, USA.
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5
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Wen T, Thapa N, Cryns VL, Anderson RA. Regulation of Phosphoinositide Signaling by Scaffolds at Cytoplasmic Membranes. Biomolecules 2023; 13:1297. [PMID: 37759697 PMCID: PMC10526805 DOI: 10.3390/biom13091297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 08/21/2023] [Accepted: 08/22/2023] [Indexed: 09/29/2023] Open
Abstract
Cytoplasmic phosphoinositides (PI) are critical regulators of the membrane-cytosol interface that control a myriad of cellular functions despite their low abundance among phospholipids. The metabolic cycle that generates different PI species is crucial to their regulatory role, controlling membrane dynamics, vesicular trafficking, signal transduction, and other key cellular events. The synthesis of phosphatidylinositol (3,4,5)-triphosphate (PI3,4,5P3) in the cytoplamic PI3K/Akt pathway is central to the life and death of a cell. This review will focus on the emerging evidence that scaffold proteins regulate the PI3K/Akt pathway in distinct membrane structures in response to diverse stimuli, challenging the belief that the plasma membrane is the predominant site for PI3k/Akt signaling. In addition, we will discuss how PIs regulate the recruitment of specific scaffolding complexes to membrane structures to coordinate vesicle formation, fusion, and reformation during autophagy as well as a novel lysosome repair pathway.
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Affiliation(s)
- Tianmu Wen
- School of Medicine and Public Health, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, WI 53705, USA; (T.W.); (N.T.)
| | - Narendra Thapa
- School of Medicine and Public Health, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, WI 53705, USA; (T.W.); (N.T.)
| | - Vincent L. Cryns
- Department of Medicine, University of Wisconsin Carbone Cancer Center, School of Medicine and Public Health, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, WI 53705, USA
| | - Richard A. Anderson
- School of Medicine and Public Health, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, WI 53705, USA; (T.W.); (N.T.)
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6
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Iyer VJ, Osman MA. Haldol Targets IQGAP1 Pathway and Promotes Novel Partner Interactions in Glioblastoma Cell Lines. MICROPUBLICATION BIOLOGY 2023; 2023:10.17912/micropub.biology.000822. [PMID: 37228393 PMCID: PMC10203884 DOI: 10.17912/micropub.biology.000822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Figures] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 04/14/2023] [Accepted: 04/19/2023] [Indexed: 05/27/2023]
Abstract
Glioblastoma multiform (GBM) is an incurable heterogenous brain cancer with few clinical target options. IQGAP1 is a scaffold oncoprotein involved in GBM with unclear mechanism. Here we report that the antipsychotic drug Haldol differentially alters IQGAP1 signaling and inhibits GBM cell proliferation, thus providing novel molecular signatures for GBM classification and potential targeted therapy in personalized medicine.
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Affiliation(s)
- Varun J. Iyer
- Department of Medicine, Division of Oncology, University of Toledo Medical Center, Toledo, Ohio, 43614 United States
| | - Mahasin A. Osman
- Department of Medicine, Division of Oncology, University of Toledo Medical Center, Toledo, Ohio, 43614 United States
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7
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Bardwell AJ, Paul M, Yoneda KC, Andrade-Ludeña MD, Nguyen OT, Fruman DA, Bardwell L. The WW domain of IQGAP1 binds directly to the p110α catalytic subunit of PI 3-kinase. Biochem J 2023; 480:BCJ20220493. [PMID: 37145016 PMCID: PMC10625650 DOI: 10.1042/bcj20220493] [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: 09/24/2022] [Revised: 04/24/2023] [Accepted: 05/05/2023] [Indexed: 05/06/2023]
Abstract
IQGAP1 is a multi-domain cancer-associated protein that serves as a scaffold protein for multiple signaling pathways. Numerous binding partners have been found for the calponin homology, IQ and GAP-related domains in IQGAP1. Identification of a binding partner for its WW domain has proven elusive, however, even though a cell-penetrating peptide derived from this domain has marked anti-tumor activity. Here, using in vitro binding assays with human proteins and co-precipitation from human cells, we show that the WW domain of human IQGAP1 binds directly to the p110α catalytic subunit of phosphoinositide 3-kinase (PI3K). In contrast, the WW domain does not bind to ERK1/2, MEK1/2, or the p85α regulatory subunit of PI3K when p85α is expressed alone. However, the WW domain is able to bind to the p110α/p85α heterodimer when both subunits are co-expressed, as well as to the mutationally activated p110α/p65α heterodimer. We present a model of the structure of the IQGAP1 WW domain, and experimentally identify key residues in the hydrophobic core and beta strands of the WW domain that are required for binding to p110α. These findings contribute to a more precise understanding of IQGAP1-mediated scaffolding, and of how IQGAP1-derived therapeutic peptides might inhibit tumorigenesis.
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Affiliation(s)
- A. Jane Bardwell
- Department of Developmental and Cell Biology, University of California, Irvine, CA, U.S.A
| | - Madhuri Paul
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA, U.S.A
| | - Kiku C. Yoneda
- Department of Developmental and Cell Biology, University of California, Irvine, CA, U.S.A
| | | | - Oanh T. Nguyen
- Department of Developmental and Cell Biology, University of California, Irvine, CA, U.S.A
| | - David A. Fruman
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA, U.S.A
| | - Lee Bardwell
- Department of Developmental and Cell Biology, University of California, Irvine, CA, U.S.A
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8
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Petrosyan A, Villani V, Aguiari P, Thornton ME, Wang Y, Rajewski A, Zhou S, Cravedi P, Grubbs BH, De Filippo RE, Sedrakyan S, Lemley KV, Csete M, Da Sacco S, Perin L. Identification and Characterization of the Wilms Tumor Cancer Stem Cell. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023:e2206787. [PMID: 37114795 PMCID: PMC10369255 DOI: 10.1002/advs.202206787] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 03/24/2023] [Indexed: 06/19/2023]
Abstract
A nephrogenic progenitor cell (NP) with cancer stem cell characteristics driving Wilms tumor (WT) using spatial transcriptomics, bulk and single cell RNA sequencing, and complementary in vitro and transplantation experiments is identified and characterized. NP from WT samples with NP from the developing human kidney is compared. Cells expressing SIX2 and CITED1 fulfill cancer stem cell criteria by reliably recapitulating WT in transplantation studies. It is shown that self-renewal versus differentiation in SIX2+CITED1+ cells is regulated by the interplay between integrins ITGβ1 and ITGβ4. The spatial transcriptomic analysis defines gene expression maps of SIX2+CITED1+ cells in WT samples and identifies the interactive gene networks involved in WT development. These studies define SIX2+CITED1+ cells as the nephrogenic-like cancer stem cells of WT and points to the renal developmental transcriptome changes as a possible driver in regulating WT formation and progression.
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Affiliation(s)
- Astgik Petrosyan
- GOFARR Laboratory, Children's Hospital Los Angeles, Division of Urology, Saban Research Institute, Los Angeles, CA, 90027, USA
- Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
| | - Valentina Villani
- GOFARR Laboratory, Children's Hospital Los Angeles, Division of Urology, Saban Research Institute, Los Angeles, CA, 90027, USA
| | - Paola Aguiari
- GOFARR Laboratory, Children's Hospital Los Angeles, Division of Urology, Saban Research Institute, Los Angeles, CA, 90027, USA
- David Geffen School of Medicine at UCLA - VA Healthcare System, Los Angeles, CA, 90095, USA
| | - Matthew E Thornton
- Department of Obstetrics and Gynecology, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
| | - Yizhou Wang
- Genomics Core, Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, 90048, USA
| | - Alex Rajewski
- Genomics Core, Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, 90048, USA
| | - Shengmei Zhou
- Department of Pathology and Laboratory Medicine, Children's Hospital Los Angeles, Los Angeles, CA, 90027, USA
| | - Paolo Cravedi
- Department of Medicine, Division of Nephrology and Translational Transplant Research Center, Recanati Miller Transplant Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Brendan H Grubbs
- Department of Obstetrics and Gynecology, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
| | - Roger E De Filippo
- GOFARR Laboratory, Children's Hospital Los Angeles, Division of Urology, Saban Research Institute, Los Angeles, CA, 90027, USA
- Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
| | - Sargis Sedrakyan
- GOFARR Laboratory, Children's Hospital Los Angeles, Division of Urology, Saban Research Institute, Los Angeles, CA, 90027, USA
- Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
| | - Kevin V Lemley
- Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
- Children's Hospital Los Angeles, Division of Nephrology, Department of Pediatrics, University of Southern California, Los Angeles, CA, 90027, USA
| | - Marie Csete
- Department of Anesthesiology, University of Southern California, Los Angeles, CA, 90033, USA
| | - Stefano Da Sacco
- GOFARR Laboratory, Children's Hospital Los Angeles, Division of Urology, Saban Research Institute, Los Angeles, CA, 90027, USA
- Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
| | - Laura Perin
- GOFARR Laboratory, Children's Hospital Los Angeles, Division of Urology, Saban Research Institute, Los Angeles, CA, 90027, USA
- Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
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9
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Mohapatra T, Dixit M. IQ Motif Containing GTPase Activating Proteins (IQGAPs), A-Kinase Anchoring Proteins (AKAPs) and Kinase Suppressor of Ras Proteins (KSRs) in Scaffolding Oncogenic Pathways and Their Therapeutic Potential. ACS OMEGA 2022; 7:45837-45848. [PMID: 36570181 PMCID: PMC9773950 DOI: 10.1021/acsomega.2c05505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Accepted: 11/18/2022] [Indexed: 06/17/2023]
Abstract
Scaffolding proteins colocalize interacting partners on their surface and facilitate complex formation. They have multiple domains and motifs, which provide binding sites for various molecules. This property of scaffolding proteins helps in the orderly transduction of signals. Abnormal signal transduction is frequently observed in cancers, which can also be attributed to the altered functionality of scaffolding proteins. IQ motif containing GTPase activating proteins (IQGAPs), kinase suppressor of Ras (KSR), and A-kinase anchoring proteins (AKAPs) tether oncogenic pathways RAS/RAF/MEK/ERK, PI3K/AKT, Hippo, Wnt, and CDC42/RAC to them. Scaffolding proteins are attractive drug targets as they are the controlling hub for multiple pathways and regulate crosstalk between them. The first part of this review describes the human scaffolding proteins known to play a role in oncogenesis, pathways altered by them, and the impact on oncogenic processes. The second part provides information on the therapeutic potential of scaffolding proteins and future possibilities. The information on the explored and unexplored areas of the therapeutic potential of scaffolding proteins will be equally helpful for biologists and chemists.
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Affiliation(s)
- Talina Mohapatra
- National
Institute of Science Education and Research, School of Biological Sciences, Bhubaneswar, Odisha 752050, India
- Homi
Bhabha National Institute, Training School
Complex, Anushaktinagar, Mumbai 400094, India
| | - Manjusha Dixit
- National
Institute of Science Education and Research, School of Biological Sciences, Bhubaneswar, Odisha 752050, India
- Homi
Bhabha National Institute, Training School
Complex, Anushaktinagar, Mumbai 400094, India
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10
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N-Linked Glycosylation in Chinese Hamster Ovary Cells Is Critical for Insulin-like Growth Factor 1 Signaling. Int J Mol Sci 2022; 23:ijms232314952. [PMID: 36499281 PMCID: PMC9735751 DOI: 10.3390/ijms232314952] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 10/22/2022] [Accepted: 10/23/2022] [Indexed: 12/03/2022] Open
Abstract
Cell surface proteins carrying N-glycans play important roles in inter- and intracellular processes including cell adhesion, development, and cellular recognition. Dysregulation of the glycosylation machinery has been implicated in various diseases, and investigation of global differential cell surface proteome effects due to the loss of N-glycosylation will provide comprehensive insights into their pathogenesis. Cell surface proteins isolated from Parent Pro-5 CHO cells (W5 cells), two CHO mutants with loss of N-glycosylation function derived from Pro-5 CHO (Lec1 and Lec4 cells), were subjected to proteome analysis via high-resolution LCMS. We identified 44 and 43 differentially expressed membrane proteins in Lec1 and Lec4 cells, respectively, as compared to W5 cells. The defective N-glycosylation mutants showed increased abundance of integrin subunits in Lec1 and Lec4 cells at the cell surface. We also found significantly reduced levels of IGF-1R (Insulin like growth factor-1 receptor); a receptor tyrosine kinase; and the GTPase activating protein IQGAP1 (IQ motif-containing GTPase activating protein), a highly conserved cytoplasmic scaffold protein) in Lec1 and Lec4 cells. In silico docking studies showed that the IQ domain of IQGAP1 interacts with the kinase domain of IGF-1R. The integrin signaling and insulin growth factor receptor signaling were also enriched according to GSEA analysis and pathway analysis of differentially expressed proteins. Significant reductions of phosphorylation of ERK1 and ERK2 in Lec1 and Lec4 cells were observed upon IGF-1R ligand (IGF-1 LR3) stimulation. IGF-1 LR3, known as Long arginine3-IGF-1, is a synthetic protein and lengthened analog of insulin-like growth factor 1. The work suggests a novel mechanism for the activation of IGF-1 dependent ERK signaling in CHO cells, wherein IQGAP1 plausibly functions as an IGF-1R-associated scaffold protein. Appropriate glycosylation by the enzymes MGAT1 and MGAT5 is thus essential for processing of cell surface receptor IGF-1R, a potential binding partner in IQGAP1 and ERK signaling, the integral components of the IGF pathway.
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11
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Muehlbauer LK, Wei T, Shishkova E, Coon JJ, Lambert PF. IQGAP1 and RNA Splicing in the Context of Head and Neck via Phosphoproteomics. J Proteome Res 2022; 21:2211-2223. [PMID: 35980772 PMCID: PMC9833422 DOI: 10.1021/acs.jproteome.2c00309] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
IQGAP1 (IQ motif-containing GTPase-activating protein 1) scaffolds several signaling pathways in mammalian cells that are implicated in carcinogenesis, including the RAS and PI3K pathways that involve multiple protein kinases. IQGAP1 has been shown to promote head and neck squamous cell carcinoma (HNSCC); however, the underlying mechanism(s) remains unclear. Here, we report a mass spectrometry-based analysis identifying differences in phosphorylation of cellular proteins in vivo and in vitro in the presence or absence of IQGAP1. By comparing the esophageal phosphoproteome profiles between Iqgap1+/+ and Iqgap1-/- mice, we identified RNA splicing as one of the most altered cellular processes. Serine/arginine-rich splicing factor 6 (SRSF6) was the protein with the most downregulated levels of phosphorylation in Iqgap1-/- tissue. We confirmed that the absence of IQGAP1 reduced SRSF6 phosphorylation both in vivo and in vitro. We then expanded our analysis to human normal oral keratinocytes. Again, we found factors involved in RNA splicing to be highly altered in the phosphoproteome profile upon genetic disruption of IQGAP1. Both the Clinical Proteomic Tumor Analysis Consortium (CPTAC) and the Cancer Genome Atlas (TCGA) data sets indicate that phosphorylation of splicing-related proteins is important in HNSCC prognosis. The Biological General Repository for Interaction Datasets (BioGRID) repository also suggested multiple interactions between IQGAP1 and splicing-related proteins. Based on these collective observations, we propose that IQGAP1 regulates the phosphorylation of splicing proteins, which potentially affects their splicing activities and, therefore, contributes to HNSCC. Raw data are available from the MassIVE database with identifier MSV000087770.
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Affiliation(s)
- Laura K. Muehlbauer
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Tao Wei
- McArdle Laboratory for Cancer Research, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, 53705, USA
| | - Evgenia Shishkova
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA
- National Center for Quantitative Biology of Complex Systems, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Joshua J. Coon
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA
- National Center for Quantitative Biology of Complex Systems, University of Wisconsin-Madison, Madison, WI 53706, USA
- Morgridge Institute for Research, Madison, WI 53706, USA
| | - Paul F. Lambert
- McArdle Laboratory for Cancer Research, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, 53705, USA
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12
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Chen M, Choi S, Wen T, Chen C, Thapa N, Lee JH, Cryns VL, Anderson RA. A p53-phosphoinositide signalosome regulates nuclear AKT activation. Nat Cell Biol 2022; 24:1099-1113. [PMID: 35798843 PMCID: PMC9833102 DOI: 10.1038/s41556-022-00949-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 05/26/2022] [Indexed: 01/13/2023]
Abstract
The tumour suppressor p53 and PI3K-AKT pathways have fundamental roles in the regulation of cell growth and apoptosis, and are frequently mutated in cancer. Here, we show that genotoxic stress induces nuclear AKT activation through a p53-dependent mechanism that is distinct from the canonical membrane-localized PI3K-AKT pathway. Following genotoxic stress, a nuclear PI3K binds p53 in the non-membranous nucleoplasm to generate a complex of p53 and phosphatidylinositol 3,4,5-trisphosphate (PtdIns(3,4,5)P3), which recruits AKT, PDK1 and mTORC2 to activate AKT and phosphorylate FOXO proteins, thereby inhibiting DNA damage-induced apoptosis. Wild-type p53 activates nuclear AKT in an on/off fashion following stress, whereas mutant p53 dose-dependently stimulates high basal AKT activity. The p53-PtdIns(3,4,5)P3 complex is dephosphorylated to p53-phosphatidylinositol 4,5-bisphosphate by PTEN to inhibit AKT activation. The nuclear p53-phosphoinositide signalosome is distinct from the canonical membrane-localized pathway and insensitive to PI3K inhibitors currently in the clinic, which underscores its therapeutic relevance.
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Affiliation(s)
- Mo Chen
- University of Wisconsin-Madison, School of Medicine and Public Health; 1300 University Avenue, Madison, WI 53706, USA
| | - Suyong Choi
- University of Wisconsin-Madison, School of Medicine and Public Health; 1300 University Avenue, Madison, WI 53706, USA
| | - Tianmu Wen
- University of Wisconsin-Madison, School of Medicine and Public Health; 1300 University Avenue, Madison, WI 53706, USA
| | - Changliang Chen
- University of Wisconsin-Madison, School of Medicine and Public Health; 1300 University Avenue, Madison, WI 53706, USA,Department of Medicine, University of Wisconsin Carbone Cancer Center, University of Wisconsin-Madison, School of Medicine and Public Health; 1111 Highland Avenue, Madison, WI 53705, USA
| | - Narendra Thapa
- University of Wisconsin-Madison, School of Medicine and Public Health; 1300 University Avenue, Madison, WI 53706, USA
| | - Jeong Hyo Lee
- University of Wisconsin-Madison, School of Medicine and Public Health; 1300 University Avenue, Madison, WI 53706, USA,Department of Medicine, University of Wisconsin Carbone Cancer Center, University of Wisconsin-Madison, School of Medicine and Public Health; 1111 Highland Avenue, Madison, WI 53705, USA
| | - Vincent L. Cryns
- Department of Medicine, University of Wisconsin Carbone Cancer Center, University of Wisconsin-Madison, School of Medicine and Public Health; 1111 Highland Avenue, Madison, WI 53705, USA,These authors contributed equally to this work,Correspondence: (R.A.A.); (V.L.C.)
| | - Richard A. Anderson
- University of Wisconsin-Madison, School of Medicine and Public Health; 1300 University Avenue, Madison, WI 53706, USA,These authors contributed equally to this work,Correspondence: (R.A.A.); (V.L.C.)
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13
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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.
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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.
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14
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Wei T, Lambert PF. Role of IQGAP1 in Carcinogenesis. Cancers (Basel) 2021; 13:3940. [PMID: 34439095 PMCID: PMC8391515 DOI: 10.3390/cancers13163940] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 07/28/2021] [Accepted: 08/02/2021] [Indexed: 12/31/2022] Open
Abstract
Scaffolding proteins can play important roles in cell signaling transduction. IQ motif-containing GTPase-activating protein 1 (IQGAP1) influences many cellular activities by scaffolding multiple key signaling pathways, including ones involved in carcinogenesis. Two decades of studies provide evidence that IQGAP1 plays an essential role in promoting cancer development. IQGAP1 is overexpressed in many types of cancer, and its overexpression in cancer is associated with lower survival of the cancer patient. Here, we provide a comprehensive review of the literature regarding the oncogenic roles of IQGAP1. We start by describing the major cancer-related signaling pathways scaffolded by IQGAP1 and their associated cellular activities. We then describe clinical and molecular evidence for the contribution of IQGAP1 in different types of cancers. In the end, we review recent evidence implicating IQGAP1 in tumor-related immune responses. Given the critical role of IQGAP1 in carcinoma development, anti-tumor therapies targeting IQGAP1 or its associated signaling pathways could be beneficial for patients with many types of cancer.
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Affiliation(s)
| | - Paul F. Lambert
- McArdle Laboratory for Cancer Research, Department of Oncology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA;
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15
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Bao F, Hao P, An S, Yang Y, Liu Y, Hao Q, Ejaz M, Guo XX, Xu TR. Akt scaffold proteins: the key to controlling specificity of Akt signaling. Am J Physiol Cell Physiol 2021; 321:C429-C442. [PMID: 34161152 DOI: 10.1152/ajpcell.00146.2020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The phosphatidylinositol 3-kinase-Akt signaling pathway plays an essential role in regulating cell proliferation and apoptosis. Akt kinase is at the center of this signaling pathway and interacts with a variety of proteins. Akt is overexpressed in almost 80% of tumors. However, inhibiting Akt has serious clinical side effects so is not a suitable treatment for cancer. During recent years, Akt scaffold proteins have received increasing attention for their ability to regulate Akt signaling and have emerged as potential targets for cancer therapy. In this paper, we categorize Akt kinase scaffold proteins into four groups based on their cellular location: membrane-bound activator and inhibitor, cytoplasm, and endosome. We describe how these scaffolds interact with Akt kinase, how they affect Akt activity, and how they regulate the specificity of Akt signaling. We also discuss the clinical application of Akt scaffold proteins as targets for cancer therapy.
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Affiliation(s)
- Fan Bao
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, Yunnan, China.,Center of Stomatology, The First People's Hospital of Yunnan Province, Kunming, China.,The Affiliated Hospital of Kunming University of Science and Technology, Kunming, China
| | - Peiqi Hao
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, Yunnan, China
| | - Su An
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, Yunnan, China
| | - Yang Yang
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, Yunnan, China
| | - Ying Liu
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, Yunnan, China
| | - Qian Hao
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, Yunnan, China
| | - Mubashir Ejaz
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, Yunnan, China
| | - Xiao-Xi Guo
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, Yunnan, China
| | - Tian-Rui Xu
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, Yunnan, China
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16
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Wei T, Choi S, Buehler D, Lee D, Ward-Shaw E, Anderson RA, Lambert PF. Role of IQGAP1 in Papillomavirus-Associated Head and Neck Tumorigenesis. Cancers (Basel) 2021; 13:2276. [PMID: 34068608 PMCID: PMC8126105 DOI: 10.3390/cancers13092276] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 04/28/2021] [Accepted: 05/06/2021] [Indexed: 12/14/2022] Open
Abstract
Approximately 25% of head and neck squamous cell carcinomas (HNSCC) are associated with human papillomavirus (HPV) infection. In these cancers as well as in HPV-associated anogenital cancers, PI3K signaling is highly activated. We previously showed that IQ motif-containing GTPase activating protein 1 (IQGAP1), a PI3K pathway scaffolding protein, is overexpressed in and contributes to HNSCC and that blocking IQGAP1-mediated PI3K signaling reduces HPV-positive HNSCC cell survival and migration. In this study, we tested whether IQGAP1 promotes papillomavirus (PV)-associated HNSCCs. IQGAP1 was necessary for optimal PI3K signaling induced by HPV16 oncoproteins in transgenic mice and MmuPV1 infection, a mouse papillomavirus that causes HNSCC in mice. Furthermore, we found that, at 6 months post-infection, MmuPV1-infected Iqgap1-/- mice developed significantly less severe tumor phenotypes than MmuPV1-infected Iqgap1+/+ mice, indicating a role of IQGAP1 in MmuPV1-associated HNSCC. The tumors resulting from MmuPV1 infection showed features consistent with HPV infection and HPV-associated cancer. However, such IQGAP1-dependent effects on disease severity were not observed in an HPV16 transgenic mouse model for HNC. This may reflect that IQGAP1 plays a role in earlier stages of viral pathogenesis, or other activities of HPV16 oncogenes are more dominant in driving carcinogenesis than their influence on PI3K signaling.
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Affiliation(s)
- Tao Wei
- McArdle Laboratory for Cancer Research, School of Medicine and Public Health, University of Wisconsin, Madison, WI 53705, USA; (T.W.); (D.L.); (E.W.-S.)
| | - Suyong Choi
- School of Medicine and Public Health, University of Wisconsin, Madison, WI 53705, USA; (S.C.); (R.A.A.)
| | - Darya Buehler
- Department of Pathology and Laboratory Medicine, School of Medicine and Public Health, University of Wisconsin, Madison, WI 53705, USA;
| | - Denis Lee
- McArdle Laboratory for Cancer Research, School of Medicine and Public Health, University of Wisconsin, Madison, WI 53705, USA; (T.W.); (D.L.); (E.W.-S.)
| | - Ella Ward-Shaw
- McArdle Laboratory for Cancer Research, School of Medicine and Public Health, University of Wisconsin, Madison, WI 53705, USA; (T.W.); (D.L.); (E.W.-S.)
| | - Richard A. Anderson
- School of Medicine and Public Health, University of Wisconsin, Madison, WI 53705, USA; (S.C.); (R.A.A.)
| | - Paul F. Lambert
- McArdle Laboratory for Cancer Research, School of Medicine and Public Health, University of Wisconsin, Madison, WI 53705, USA; (T.W.); (D.L.); (E.W.-S.)
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17
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Chen M, Horn HT, Wen T, Cryns VL, Anderson RA. Assessing In Situ Phosphoinositide-Protein Interactions Through Fluorescence Proximity Ligation Assay in Cultured Cells. Methods Mol Biol 2021; 2251:133-142. [PMID: 33481236 PMCID: PMC9789737 DOI: 10.1007/978-1-0716-1142-5_9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Proximity ligation assay (PLA) is a well-established method for detecting in situ interactions between two epitopes with high resolution and specificity. Notably, PLA is not only a robust method for studying protein-protein interaction but also an efficient approach to characterize and validate protein posttranslational modifications (PTM) using one antibody against the core protein and one against the PTM residue. Therefore, it could be applied as a powerful approach to detect specific interactions of endogenous phosphoinositides and their binding proteins within cells. Importantly, we have specifically detected the PLA signal between PtdIns(4,5)P2 and its binding effector p53 in the nucleus. This cutting-edge method fully complements other conventional approaches for studying phosphoinositide-protein interactions and provides important localization signals and robust quantitation of the detected interactions. Here, we present the PLA fluorescence protocol for detecting in situ phosphoinositide-protein interactions in cultured cells and is semiquantitative for interactions that are regulated by cellular signaling.
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Affiliation(s)
- Mo Chen
- University of Wisconsin-Madison, School of Medicine and Public Health, 1300 University Avenue, Madison, WI 53706, USA
| | - Hudson T. Horn
- University of Wisconsin-Madison, School of Medicine and Public Health, 1300 University Avenue, Madison, WI 53706, USA
| | - Tianmu Wen
- University of Wisconsin-Madison, School of Medicine and Public Health, 1300 University Avenue, Madison, WI 53706, USA
| | - Vincent L. Cryns
- Department of Medicine, University of Wisconsin Carbone Cancer Center, University of Wisconsin-Madison, School of Medicine and Public Health, 1111 Highland Avenue, Madison, WI 53705, USA
| | - Richard A. Anderson
- University of Wisconsin-Madison, School of Medicine and Public Health, 1300 University Avenue, Madison, WI 53706, USA,Correspondence to: Richard A. Anderson, 3750 Medical Sciences Center, 1300 University Avenue, Madison, WI 53706. Phone: 608-262-3753; Fax: 608-262-1257;
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18
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Phosphatidylinositol-3-OH kinase signalling is spatially organized at endosomal compartments by microtubule-associated protein 4. Nat Cell Biol 2020; 22:1357-1370. [PMID: 33139939 DOI: 10.1038/s41556-020-00596-4] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 09/24/2020] [Indexed: 12/20/2022]
Abstract
The canonical model of agonist-stimulated phosphatidylinositol-3-OH kinase (PI3K)-Akt signalling proposes that PI3K is activated at the plasma membrane, where receptors are activated and phosphatidylinositol-4,5-bisphosphate is concentrated. Here we show that phosphatidylinositol-3,4,5-trisphosphate generation and activated Akt are instead largely confined to intracellular membranes upon receptor tyrosine kinase activation. Microtubule-associated protein 4 (MAP4) interacts with and controls localization of membrane vesicle-associated PI3Kα to microtubules. The microtubule-binding domain of MAP4 binds directly to the C2 domain of the p110α catalytic subunit. MAP4 controls the interaction of PI3Kα with activated receptors at endosomal compartments along microtubules. Loss of MAP4 results in the loss of PI3Kα targeting and loss of PI3K-Akt signalling downstream of multiple agonists. The MAP4-PI3Kα assembly defines a mechanism for spatial control of agonist-stimulated PI3K-Akt signalling at internal membrane compartments linked to the microtubule network.
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19
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Wei T, Lambert PF. A highway to carcinogenesis: the role of IQGAP1, a signaling scaffolding protein, in head and neck cancer development. Oncoscience 2020; 7:49-51. [PMID: 32923516 PMCID: PMC7458336 DOI: 10.18632/oncoscience.511] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 04/30/2020] [Indexed: 12/17/2022] Open
Abstract
Head and neck squamous cell carcinoma (HNSCC) is the sixth most frequent cancer worldwide. One of the most critical signaling pathways in HNSCC is the Epidermal Growth Factor Receptor/ Phosphatidylinositol 3-Kinase (EGFR/PI3K) pathway. IQ motif-containing GTPase- activating protein 1 (IQGAP1), a protein upregulated in multiple types of cancer, acts as a scaffold for this pathway and others implicated in cancer. IQGAP1 is overexpressed in HNSCCs, and its overexpression correlates with poorer prognosis in HNSCC patients, indicating that IQGAP1 might be important in HNSCC development. Here, we summarized our recent demonstrating a role of IQGAP1 in promoting HNSCC, at least in part, by scaffolding the EGFR/PI3K signaling pathway.
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Affiliation(s)
- Tao Wei
- McArdle Laboratory for Cancer Research, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Paul F. Lambert
- McArdle Laboratory for Cancer Research, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
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20
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Trenton NJ, McLaughlin RT, Bellamkonda SK, Tsao DS, Rodzinski A, Mace EM, Orange JS, Schweikhard V, Diehl MR. Membrane and Actin Tethering Transitions Help IQGAP1 Coordinate GTPase and Lipid Messenger Signaling. Biophys J 2020; 118:586-599. [PMID: 31952801 DOI: 10.1016/j.bpj.2019.12.023] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 11/22/2019] [Accepted: 12/09/2019] [Indexed: 12/30/2022] Open
Abstract
The coordination of lipid messenger signaling with cytoskeletal regulation is central to many organelle-specific regulatory processes. This coupling often depends on the function of multidomain scaffolds that orchestrate transient interactions among multiple signaling intermediates and regulatory proteins on organelles. The number of possible scaffold interaction partners and the ability for these interactions to occur at different timescales makes investigations of scaffold functions challenging. This work employs live cell imaging to probe how the multidomain scaffold IQ motif containing GTPase activating protein 1 (IQGAP1) coordinates the activities of proteins affecting local actin polymerization, membrane processing, and phosphoinositide signaling. Using endosomes that are confined by a local actin network as a model system, we demonstrate that IQGAP1 can transition between different actin and endosomal membrane tethered states. Fast scaffold binding/disassociation transitions are shown to be driven by interactions between C-terminal scaffold domains and Rho GTPases at the membrane. Fluctuations in these binding modes are linked to negative regulation of actin polymerization. Although this control governs core elements of IQGAP1 dynamics, actin binding by the N-terminal calponin homology domain of the scaffold is shown to help the scaffold track the temporal development of endosome membrane markers, implying actin associations bolster membrane and actin coordination. Importantly, these effects are not easily distilled purely through standard (static) co-localization analyses or traditional pathway perturbations methods and were resolved by performing dynamic correlation and multiple regression analyses of IQGAP1 scaffold mutants. Using these capabilities with pharmacological inhibition, we provide evidence that membrane tethering is dependent on the activities of the lipid kinase phosphoinositide 3-kinase in addition to the Rho GTPases Rac1 and Cdc42. Overall, these methods and results point to a scaffold tethering mechanism that allows IQGAP1 to help control the amplitude of phosphoinositide lipid messenger signaling by coordinating signaling intermediate activities with the development and disassembly of local actin cytoskeletal networks.
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Affiliation(s)
| | - R Tyler McLaughlin
- Department of Bioengineering, Rice University, Houston, Texas; Graduate Program in Systems, Synthetic and Physical Biology, Rice University, Houston, Texas
| | | | - David S Tsao
- Department of Bioengineering, Rice University, Houston, Texas
| | | | - Emily M Mace
- Department of Pediatrics, Columbia University Irving Medical Center, New York, New York
| | - Jordan S Orange
- Department of Pediatrics, Columbia University Irving Medical Center, New York, New York
| | | | - Michael R Diehl
- Department of Bioengineering, Rice University, Houston, Texas; Graduate Program in Systems, Synthetic and Physical Biology, Rice University, Houston, Texas; Department of Chemistry, Rice University, Houston, Texas.
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21
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Chen M, Wen T, Horn HT, Chandrahas VK, Thapa N, Choi S, Cryns VL, Anderson RA. The nuclear phosphoinositide response to stress. Cell Cycle 2020; 19:268-289. [PMID: 31902273 PMCID: PMC7028212 DOI: 10.1080/15384101.2019.1711316] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Accumulating evidence reveals that nuclear phosphoinositides (PIs) serve as central signaling hubs that control a multitude of nuclear processes by regulating the activity of nuclear proteins. In response to cellular stressors, PIs accumulate in the nucleus and multiple PI isomers are synthesized by the actions of PI-metabolizing enzymes, kinases, phosphatases and phospholipases. By directly interacting with effector proteins, phosphoinositide signals transduce changes in cellular functions. Here we describe nuclear phosphoinositide signaling in multiple sub-nuclear compartments and summarize the literature that demonstrates roles for specific kinases, phosphatases, and phospholipases in the orchestration of nuclear phosphoinositide signaling in response to cellular stress. Additionally, we discuss the specific PI-protein complexes through which these lipids execute their functions by regulating the configuration, stability, and transcription activity of their effector proteins. Overall, our review provides a detailed landscape of the current understanding of the nuclear PI-protein interactome and its role in shaping the coordinated response to cellular stress.
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Affiliation(s)
- Mo Chen
- School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, USA
| | - Tianmu Wen
- School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, USA
| | - Hudson T. Horn
- School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, USA
| | | | - Narendra Thapa
- School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, USA
| | - Suyong Choi
- School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, USA
| | - Vincent L. Cryns
- Department of Medicine, University of Wisconsin Carbone Cancer Center, University of Wisconsin-Madison, School of Medicine and Public Health, Madison, WI, USA
| | - Richard A. Anderson
- School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, USA
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22
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Wei T, Choi S, Buehler D, Anderson RA, Lambert PF. A PI3K/AKT Scaffolding Protein, IQ Motif-Containing GTPase Associating Protein 1 (IQGAP1), Promotes Head and Neck Carcinogenesis. Clin Cancer Res 2019; 26:301-311. [PMID: 31597661 DOI: 10.1158/1078-0432.ccr-19-1063] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 08/15/2019] [Accepted: 10/03/2019] [Indexed: 12/12/2022]
Abstract
PURPOSE Head and neck cancer (HNC) is the sixth most common cancer worldwide with a 5-year survival rate of less than 50%. The PI3K/AKT/mTOR signaling pathway is frequently implicated in HNC. Recently, IQ motif-containing GTPase-activating protein 1 (IQGAP1) was discovered to scaffold the PI3K/AKT signaling pathway. IQGAP1 gene expression is increased in HNC, raising the hypothesis that IQGAP1 contributes to HNC. EXPERIMENTAL DESIGN We performed a combination of in vitro studies using human cancer cell lines treated with a cell-permeable peptide that interferes with IQGAP1's ability to bind to PI3K, and in vivo studies utilizing mice genetically knocked out for the Iqgap1 (Iqgap1 -/-). In vivo EGF stimulation assays were used to evaluate PI3K signaling. To study the role of IQGAP1 in HNC, we used a well-validated mouse model that drives HNC via a synthetic oral carcinogen, 4-nitroquinoline 1-oxide (4NQO). RESULTS IQGAP1 is necessary for efficient PI3K signaling in vitro and in vivo. Disruption of IQGAP1-scaffolded PI3K/AKT signaling reduced HNC cell survival. Iqgap1 -/- mice had significantly lower cancer incidences, lesser disease severity, and fewer cancer foci. IQGAP1 protein levels were increased in HNC arising in Iqgap1+/+ mice. The level of PI3K signaling in 4NQO-induced HNC arising in Iqgap1 -/- mice was significantly reduced, consistent with the hypothesis that IQGAP1 contributes to HNC at least partly through PI3K signaling. High IQGAP1 expression correlated with reduced survival, and high pS6 levels correlated with high IQGAP1 levels in patients with HNC. CONCLUSIONS These data demonstrate that IQGAP1 contributes to head and neck carcinogenesis.
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Affiliation(s)
- Tao Wei
- McArdle Laboratory for Cancer Research, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
| | - Suyong Choi
- University of Wisconsin-Madison, School of Medicine and Public Health, Madison, Wisconsin
| | - Darya Buehler
- Department of Pathology and Laboratory Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
| | - Richard A Anderson
- University of Wisconsin-Madison, School of Medicine and Public Health, Madison, Wisconsin
| | - Paul F Lambert
- McArdle Laboratory for Cancer Research, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin. .,Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
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