1
|
An Y, Lim J, Glavatskikh M, Wang X, Norris-Drouin J, Hardy PB, Leisner TM, Pearce KH, Kireev D. In silico fragment-based discovery of CIB1-directed anti-tumor agents by FRASE-bot. Nat Commun 2024; 15:5564. [PMID: 38956119 PMCID: PMC11219766 DOI: 10.1038/s41467-024-49892-9] [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: 07/23/2023] [Accepted: 06/19/2024] [Indexed: 07/04/2024] Open
Abstract
Chemical probes are an indispensable tool for translating biological discoveries into new therapies, though are increasingly difficult to identify since novel therapeutic targets are often hard-to-drug proteins. We introduce FRASE-based hit-finding robot (FRASE-bot), to expedite drug discovery for unconventional therapeutic targets. FRASE-bot mines available 3D structures of ligand-protein complexes to create a database of FRAgments in Structural Environments (FRASE). The FRASE database can be screened to identify structural environments similar to those in the target protein and seed the target structure with relevant ligand fragments. A neural network model is used to retain fragments with the highest likelihood of being native binders. The seeded fragments then inform ultra-large-scale virtual screening of commercially available compounds. We apply FRASE-bot to identify ligands for Calcium and Integrin Binding protein 1 (CIB1), a promising drug target implicated in triple negative breast cancer. FRASE-based virtual screening identifies a small-molecule CIB1 ligand (with binding confirmed in a TR-FRET assay) showing specific cell-killing activity in CIB1-dependent cancer cells, but not in CIB1-depletion-insensitive cells.
Collapse
Affiliation(s)
- Yi An
- Center for Integrative Chemical Biology and Drug Discovery, UNC Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, 27513, USA
| | - Jiwoong Lim
- Center for Integrative Chemical Biology and Drug Discovery, UNC Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, 27513, USA
| | - Marta Glavatskikh
- Center for Integrative Chemical Biology and Drug Discovery, UNC Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, 27513, USA
| | - Xiaowen Wang
- Center for Integrative Chemical Biology and Drug Discovery, UNC Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, 27513, USA
- Chemistry department, University of Missouri, Columbia, Columbia, MO, 65211, USA
| | - Jacqueline Norris-Drouin
- Center for Integrative Chemical Biology and Drug Discovery, UNC Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, 27513, USA
| | - P Brian Hardy
- Center for Integrative Chemical Biology and Drug Discovery, UNC Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, 27513, USA
| | - Tina M Leisner
- Center for Integrative Chemical Biology and Drug Discovery, UNC Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, 27513, USA
| | - Kenneth H Pearce
- Center for Integrative Chemical Biology and Drug Discovery, UNC Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, 27513, USA.
| | - Dmitri Kireev
- Center for Integrative Chemical Biology and Drug Discovery, UNC Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, 27513, USA.
- Chemistry department, University of Missouri, Columbia, Columbia, MO, 65211, USA.
| |
Collapse
|
2
|
Haberman VA, Fleming SR, Leisner TM, Puhl AC, Feng E, Xie L, Chen X, Goto Y, Suga H, Parise LV, Kireev D, Pearce KH, Bowers AA. Discovery and Development of Cyclic Peptide Inhibitors of CIB1. ACS Med Chem Lett 2021; 12:1832-1839. [PMID: 34795874 DOI: 10.1021/acsmedchemlett.1c00438] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 10/22/2021] [Indexed: 12/16/2022] Open
Abstract
Calcium and integrin binding protein 1 (CIB1) is a small, intracellular protein recently implicated in survival and proliferation of triple-negative breast cancer (TNBC). Considering its interactions with PAK1 and downstream signaling, CIB1 has been suggested as a potential therapeutic target in TNBC. As such, CIB1 has been the focus of inhibitor discovery efforts. To overcome issues of potency and stability in previously reported CIB1 inhibitors, we deploy mRNA display to discover new cyclic peptide inhibitors with improved biophysical properties and cellular activity. We advance UNC10245131, a cyclic peptide with low nanomolar affinity and good selectivity for CIB1 over other EF-hand domain proteins and improved permeability and stability over previously identified linear peptide inhibitor UNC10245092. Unlike UNC10245092, UNC10245131 lacks cytotoxicity and does not affect downstream signaling. Despite this, UNC10245131 is a potent ligand that could aid in clarifying roles of CIB1 in TNBC survival and proliferation and other CIB1-associated biological phenotypes.
Collapse
Affiliation(s)
- Victoria A. Haberman
- Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina 27599, United States
- Center for Integrative Chemical Biology and Drug Discovery, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina 27599, United States
| | - Steven R. Fleming
- Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina 27599, United States
- Center for Integrative Chemical Biology and Drug Discovery, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina 27599, United States
| | - Tina M. Leisner
- Center for Integrative Chemical Biology and Drug Discovery, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina 27599, United States
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, North Carolina 27599, United States
| | - Ana C. Puhl
- Center for Integrative Chemical Biology and Drug Discovery, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina 27599, United States
| | - Emerald Feng
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, North Carolina 27599, United States
| | - Ling Xie
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, North Carolina 27599, United States
| | - Xian Chen
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, North Carolina 27599, United States
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina 27599, United States
| | - Yuki Goto
- Department of Chemistry, Graduate School of Science, The University of Tokyo, Tokyo 113-0033, Japan
- JST, PRESTO, Tokyo 113-0033, Japan
| | - Hiroaki Suga
- Department of Chemistry, Graduate School of Science, The University of Tokyo, Tokyo 113-0033, Japan
- JST, CREST, Tokyo 113-0033, Japan
| | - Leslie V. Parise
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, North Carolina 27599, United States
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina 27599, United States
| | - Dmitri Kireev
- Center for Integrative Chemical Biology and Drug Discovery, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina 27599, United States
| | - Kenneth H. Pearce
- Center for Integrative Chemical Biology and Drug Discovery, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina 27599, United States
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina 27599, United States
| | - Albert A. Bowers
- Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina 27599, United States
- Center for Integrative Chemical Biology and Drug Discovery, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina 27599, United States
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina 27599, United States
| |
Collapse
|
3
|
Ghandili S, Oqueka T, Schmitz M, Janning M, Körbelin J, Westphalen CB, P Haen S, Loges S, Bokemeyer C, Klose H, K Hennigs J. Integrative public data-mining pipeline for the validation of novel independent prognostic biomarkers for lung adenocarcinoma. Biomark Med 2020; 14:1651-1662. [PMID: 33336597 DOI: 10.2217/bmm-2020-0405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Aim: We aimed to develop a candidate-based integrative public data mining strategy for validation of novel prognostic markers in lung adenocarcinoma. Materials & methods: An in silico approach integrating meta-analyses of publicly available clinical information linked RNA expression, gene copy number and mutation datasets combined with independent immunohistochemistry and survival datasets. Results: After validation of pipeline integrity utilizing data from the well-characterized prognostic factor Ki-67, prognostic impact of the calcium- and integrin-binding protein, CIB1, was analyzed. CIB1 was overexpressed in lung adenocarcinoma which correlated with pathological tumor and pathological lymph node status and impaired overall/progression-free survival. In multivariate analyses, CIB1 emerged as UICC stage-independent risk factor for impaired survival. Conclusion: Our pipeline holds promise to facilitate further identification and validation of novel lung cancer-associated prognostic markers.
Collapse
Affiliation(s)
- Susanne Ghandili
- Division of Pneumology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Department of Medicine II - Oncology, Hematology, Bone Marrow Transplantation, Center of Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Tim Oqueka
- Division of Pneumology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Melanie Schmitz
- Division of Pneumology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Department of Medicine II - Oncology, Hematology, Bone Marrow Transplantation, Center of Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Melanie Janning
- Department of Medicine II - Oncology, Hematology, Bone Marrow Transplantation, Center of Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Institute of Tumor Biology, Center for Experimental Medicine, Hubertus Wald Tumorzentrum - University Cancer Center Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Jakob Körbelin
- Division of Pneumology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Department of Medicine II - Oncology, Hematology, Bone Marrow Transplantation, Center of Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - C Benedikt Westphalen
- Department of Medicine III & Comprehensive Cancer Center, Ludwig-Maximilians-University, Munich, Germany
| | - Sebastian P Haen
- Department of Medicine II - Oncology, Hematology, Bone Marrow Transplantation, Center of Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Sonja Loges
- Department of Medicine II - Oncology, Hematology, Bone Marrow Transplantation, Center of Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Institute of Tumor Biology, Center for Experimental Medicine, Hubertus Wald Tumorzentrum - University Cancer Center Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Carsten Bokemeyer
- Department of Medicine II - Oncology, Hematology, Bone Marrow Transplantation, Center of Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Hans Klose
- Division of Pneumology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Jan K Hennigs
- Division of Pneumology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Department of Medicine II - Oncology, Hematology, Bone Marrow Transplantation, Center of Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| |
Collapse
|
4
|
Abstract
Sound-induced mechanical stimuli are detected by elaborate mechanosensory transduction (MT) machinery in highly specialized hair cells of the inner ear. Genetic studies of inherited deafness in the past decades have uncovered several molecular constituents of the MT complex, and intense debate has surrounded the molecular identity of the pore-forming subunits. How the MT components function in concert in response to physical stimulation is not fully understood. In this review, we summarize and discuss multiple lines of evidence supporting the hypothesis that transmembrane channel-like 1 is a long-sought MT channel subunit. We also review specific roles of other components of the MT complex, including protocadherin 15, cadherin 23, lipoma HMGIC fusion partner-like 5, transmembrane inner ear, calcium and integrin-binding family member 2, and ankyrins. Based on these recent advances, we propose a unifying theory of hair cell MT that may reconcile most of the functional discoveries obtained to date. Finally, we discuss key questions that need to be addressed for a comprehensive understanding of hair cell MT at molecular and atomic levels.
Collapse
Affiliation(s)
- Wang Zheng
- Departments of Otolaryngology and Neurology, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA;
| | - Jeffrey R Holt
- Departments of Otolaryngology and Neurology, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA;
| |
Collapse
|
5
|
Puhl AC, Bogart JW, Haberman VA, Larson JE, Godoy AS, Norris-Drouin JL, Cholensky SH, Leisner TM, Frye SV, Parise LV, Bowers AA, Pearce KH. Discovery and Characterization of Peptide Inhibitors for Calcium and Integrin Binding Protein 1. ACS Chem Biol 2020; 15:1505-1516. [PMID: 32383857 DOI: 10.1021/acschembio.0c00144] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Calcium and integrin binding protein 1 (CIB1) is an EF-hand-containing, small intracellular protein that has recently been implicated in cancer cell survival and proliferation. In particular, CIB1 depletion significantly impairs tumor growth in triple-negative breast cancer (TNBC). Thus, CIB1 is a potentially attractive target for cancer chemotherapy that has yet to be validated by a chemical probe. To produce a probe molecule to the CIB1 helix 10 (H10) pocket and demonstrate that it is a viable target for molecular intervention, we employed random peptide phage display to screen and select CIB1-binding peptides. The top peptide sequence selected, UNC10245092, was produced synthetically, and binding to CIB1 was confirmed by isothermal titration calorimetry (ITC) and a time-resolved fluorescence resonance energy transfer (TR-FRET) assay. Both assays showed that the peptide bound to CIB1 with low nanomolar affinity. CIB1 was cocrystallized with UNC10245092, and the 2.1 Å resolution structure revealed that the peptide binds as an α-helix in the H10 pocket, displacing the CIB1 C-terminal H10 helix and causing conformational changes in H7 and H8. UNC10245092 was further derivatized with a C-terminal Tat-derived cell penetrating peptide (CPP) to demonstrate its effects on TNBC cells in culture, which are consistent with results of CIB1 depletion. These studies provide a first-in-class chemical tool for CIB1 inhibition in cell culture and validate the CIB1 H10 pocket for future probe and drug discovery efforts.
Collapse
Affiliation(s)
- Ana C. Puhl
- Center for Integrative Chemical Biology and Drug Discovery, Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina 27599, United States
| | - Jonathan W. Bogart
- Center for Integrative Chemical Biology and Drug Discovery, Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina 27599, United States
| | - Victoria A. Haberman
- Center for Integrative Chemical Biology and Drug Discovery, Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina 27599, United States
| | - Jacob E. Larson
- Center for Integrative Chemical Biology and Drug Discovery, Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina 27599, United States
| | - Andre S. Godoy
- Institute of Physics of São Carlos, University of São Paulo, Av. Joao Dagnone, 1100 − Jardim Santa Angelina, São Carlos 13563-120, Brazil
| | - Jacqueline L. Norris-Drouin
- Center for Integrative Chemical Biology and Drug Discovery, Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina 27599, United States
| | - Stephanie H. Cholensky
- Center for Integrative Chemical Biology and Drug Discovery, Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina 27599, United States
| | - Tina M. Leisner
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, North Carolina 27599, United States
| | - Stephen V. Frye
- Center for Integrative Chemical Biology and Drug Discovery, Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina 27599, United States
- UNC Lineberger Comprehensive Cancer Center, Chapel Hill, North Carolina 27599, United States
| | - Leslie V. Parise
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, North Carolina 27599, United States
- UNC Lineberger Comprehensive Cancer Center, Chapel Hill, North Carolina 27599, United States
| | - Albert A. Bowers
- Center for Integrative Chemical Biology and Drug Discovery, Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina 27599, United States
- UNC Lineberger Comprehensive Cancer Center, Chapel Hill, North Carolina 27599, United States
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599, United States
| | - Kenneth H. Pearce
- Center for Integrative Chemical Biology and Drug Discovery, Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina 27599, United States
- UNC Lineberger Comprehensive Cancer Center, Chapel Hill, North Carolina 27599, United States
| |
Collapse
|
6
|
Jeanclos E, Knobloch G, Hoffmann A, Fedorchenko O, Odersky A, Lamprecht AK, Schindelin H, Gohla A. Ca 2+ functions as a molecular switch that controls the mutually exclusive complex formation of pyridoxal phosphatase with CIB1 or calmodulin. FEBS Lett 2020; 594:2099-2115. [PMID: 32324254 DOI: 10.1002/1873-3468.13795] [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: 03/18/2020] [Revised: 04/14/2020] [Accepted: 04/15/2020] [Indexed: 11/09/2022]
Abstract
Pyridoxal 5'-phosphate (PLP) is an essential cofactor for neurotransmitter metabolism. Pyridoxal phosphatase (PDXP) deficiency in mice increases PLP and γ-aminobutyric acid levels in the brain, yet how PDXP is regulated is unclear. Here, we identify the Ca2+ - and integrin-binding protein 1 (CIB1) as a PDXP interactor by yeast two-hybrid screening and find a calmodulin (CaM)-binding motif that overlaps with the PDXP-CIB1 interaction site. Pulldown and crosslinking assays with purified proteins demonstrate that PDXP directly binds to CIB1 or CaM. CIB1 or CaM does not alter PDXP phosphatase activity. However, elevated Ca2+ concentrations promote CaM binding and, thereby, diminish CIB1 binding to PDXP, as both interactors bind in a mutually exclusive way. Hence, the PDXP-CIB1 complex may functionally differ from the PDXP-Ca2+ -CaM complex.
Collapse
Affiliation(s)
- Elisabeth Jeanclos
- Institute of Pharmacology and Toxicology, University of Würzburg, Germany
- Rudolf Virchow Center for Experimental Biomedicine, University of Würzburg, Germany
- Leibniz Institute for Analytical Sciences ISAS, Dortmund, Germany
| | - Gunnar Knobloch
- Institute of Pharmacology and Toxicology, University of Würzburg, Germany
- Rudolf Virchow Center for Experimental Biomedicine, University of Würzburg, Germany
| | - Axel Hoffmann
- Institute of Pharmacology and Toxicology, University of Würzburg, Germany
- Rudolf Virchow Center for Experimental Biomedicine, University of Würzburg, Germany
- Institute of Biochemistry and Molecular Biology II, Heinrich Heine University Düsseldorf, Germany
| | - Oleg Fedorchenko
- Institute of Biochemistry and Molecular Biology II, Heinrich Heine University Düsseldorf, Germany
| | - Andrea Odersky
- Institute of Biochemistry and Molecular Biology II, Heinrich Heine University Düsseldorf, Germany
| | - Anna-Karina Lamprecht
- Institute of Pharmacology and Toxicology, University of Würzburg, Germany
- Rudolf Virchow Center for Experimental Biomedicine, University of Würzburg, Germany
| | - Hermann Schindelin
- Rudolf Virchow Center for Experimental Biomedicine, University of Würzburg, Germany
| | - Antje Gohla
- Institute of Pharmacology and Toxicology, University of Würzburg, Germany
- Rudolf Virchow Center for Experimental Biomedicine, University of Würzburg, Germany
- Institute of Biochemistry and Molecular Biology II, Heinrich Heine University Düsseldorf, Germany
| |
Collapse
|
7
|
Vallone R, Dal Cortivo G, D'Onofrio M, Dell'Orco D. Preferential Binding of Mg 2+ Over Ca 2+ to CIB2 Triggers an Allosteric Switch Impaired in Usher Syndrome Type 1J. Front Mol Neurosci 2018; 11:274. [PMID: 30174586 PMCID: PMC6107761 DOI: 10.3389/fnmol.2018.00274] [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: 04/26/2018] [Accepted: 07/20/2018] [Indexed: 12/20/2022] Open
Abstract
Calcium and integrin binding protein 2 (CIB2) shares with the other members of the CIB family the ability to bind Ca2+ and Mg2+ via two functional EF-hand motifs, namely EF3 and EF4. As a cation sensor, CIB2 is able to switch to a conformation likely associated with specific biological functions yet to be clarified. Recent findings demonstrate the involvement of CIB2 in hearing physiology and a single, conservative point mutation (p.E64D) has been related to Usher Syndrome type 1J (USH1J) and non-syndromic hearing loss. We present an exhaustive biochemical and biophysical characterization of human wild type (WT) and E64D CIB2. We found that CIB2 does not possibly work as a calcium sensor under physiological conditions, its affinity for Ca2+ (Kdapp = 0.5 mM) being too low for detecting normal intracellular levels. Instead, CIB2 displays a significantly high affinity for Mg2+ (Kdapp = 290 μM), and it is probably Mg2+ -bound under physiological conditions. At odds with the homologous protein CIB1, CIB2 forms a non-covalent dimer under conditions that mimic the physiological ones, and as such it interacts with its physiological target α7B integrin. NMR spectroscopy revealed a long-range allosteric communication between the residue E64, located at the N-terminal domain, and the metal cation binding site EF3, located at the C-terminal domain. The conservative E64D mutation breaks up such inter-domain communication resulting in the impaired ability of CIB2 to switch to its Mg2+-bound form. The ability to bind the target integrin peptide was substantially conserved for E64D CIB2, thus suggesting that the molecular defect associated with USH1J resides in its inability to sense Mg2+ and adopt the required conformation.
Collapse
Affiliation(s)
- Rosario Vallone
- Section of Biological Chemistry, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Giuditta Dal Cortivo
- Section of Biological Chemistry, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | | | - Daniele Dell'Orco
- Section of Biological Chemistry, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| |
Collapse
|
8
|
Leisner TM, Freeman TC, Black JL, Parise LV. CIB1: a small protein with big ambitions. FASEB J 2016; 30:2640-50. [PMID: 27118676 DOI: 10.1096/fj.201500073r] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 04/05/2016] [Indexed: 12/11/2022]
Abstract
Calcium- and integrin-binding protein 1 (CIB1) is a small, ubiquitously expressed protein that was first identified as an intracellular binding partner of a platelet-specific α-integrin cytoplasmic tail. Although early studies revealed a role for CIB1 in regulating platelet integrin activity, recent studies have indicated a more diverse role for CIB1 in many different cell types and processes, including calcium signaling, migration, adhesion, proliferation, and survival. Increasing evidence also points to a novel role for CIB1 in cancer and cardiovascular disease. In addition, an array of CIB1 binding partners has been identified that provide important insight into how CIB1 may regulate these processes. Some of these binding partners include the serine/threonine kinases, p21-activated kinase 1 (PAK1), apoptosis signal-regulating kinase 1 (ASK1), and polo-like kinase 3 (PLK3). Structural and mutational studies indicate that CIB1 binds most or all of its partners via a well-defined hydrophobic cleft. Although CIB1 itself lacks known enzymatic activity, it supports the PI3K/AKT and MEK/ERK oncogenic signaling pathways, in part, by directly modulating enzymes in these pathways. In this review, we discuss our current understanding of CIB1 and key questions regarding structure and function and how this seemingly diminutive protein impacts important signaling pathways and cellular processes in human health and disease.-Leisner, T. M., Freeman, T. C., Black, J. L., Parise, L. V. CIB1: a small protein with big ambitions.
Collapse
Affiliation(s)
- Tina M Leisner
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Thomas C Freeman
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Justin L Black
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Leslie V Parise
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, North Carolina, USA; McAllister Heart Institute, University of North Carolina, Chapel Hill, North Carolina, USA; and Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina, USA
| |
Collapse
|
9
|
Sphingosine Kinases: Emerging Structure-Function Insights. Trends Biochem Sci 2016; 41:395-409. [PMID: 27021309 DOI: 10.1016/j.tibs.2016.02.007] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Revised: 02/08/2016] [Accepted: 02/17/2016] [Indexed: 12/15/2022]
Abstract
Sphingosine kinases (SK1 and SK2) catalyse the conversion of sphingosine into sphingosine 1-phosphate and control fundamental cellular processes, including cell survival, proliferation, differentiation, migration, and immune function. In this review, we highlight recent breakthroughs in the structural and functional characterisation of SK1 and these are contextualised by analysis of crystal structures for closely related prokaryotic lipid kinases. We identify a putative dimerisation interface and propose novel regulatory mechanisms governing structural plasticity induced by phosphorylation and interaction with phospholipids and proteins. Our analysis suggests that the catalytic function and regulation of the enzymes might be dependent on conformational mobility and it provides a roadmap for future interrogation of SK1 function and its role in physiology and disease.
Collapse
|
10
|
Novel and recurrent CIB2 variants, associated with nonsyndromic deafness, do not affect calcium buffering and localization in hair cells. Eur J Hum Genet 2015; 24:542-9. [PMID: 26173970 DOI: 10.1038/ejhg.2015.157] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Revised: 05/20/2015] [Accepted: 06/07/2015] [Indexed: 12/18/2022] Open
Abstract
Variants in CIB2 can underlie either Usher syndrome type I (USH1J) or nonsyndromic hearing impairment (NSHI) (DFNB48). Here, a novel homozygous missense variant c.196C>T and compound heterozygous variants, c.[97C>T];[196C>T], were found, respectively, in two unrelated families of Dutch origin. Besides, the previously reported c.272 T>C functional missense variant in CIB2 was identified in two families of Pakistani origin. The missense variants are demonstrated not to affect subcellular localization of CIB2 in vestibular hair cells in ex vivo expression experiments. Furthermore, these variants do not affect the ATP-induced calcium responses in COS-7 cells. However, based on the residues affected, the variants are suggested to alter αIIβ integrin binding. HI was nonsyndromic in all four families. However, deafness segregating with the c.272T>C variant in one Pakistani family is remarkably less severe than that in all other families with this mutation. Our results contribute to the insight in genotype-phenotype correlations of CIB2 mutations.
Collapse
|
11
|
Jamshidiha M, Ishida H, Sutherland C, Gifford JL, Walsh MP, Vogel HJ. Structural analysis of a calmodulin variant from rice: the C-terminal extension of OsCaM61 regulates its calcium binding and enzyme activation properties. J Biol Chem 2013; 288:32036-49. [PMID: 24052265 PMCID: PMC3814798 DOI: 10.1074/jbc.m113.491076] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Revised: 09/02/2013] [Indexed: 02/04/2023] Open
Abstract
OsCaM61 is one of five calmodulins known to be present in Oryza sativa that relays the increase of cytosolic [Ca(2+)] to downstream targets. OsCaM61 bears a unique C-terminal extension with a prenylation site. Using nuclear magnetic resonance (NMR) spectroscopy we studied the behavior of the calmodulin (CaM) domain and the C-terminal extension of OsCaM61 in the absence and presence of Ca(2+). NMR dynamics data for OsCaM61 indicate that the two lobes of the CaM domain act together unlike the independent behavior of the lobes seen in mammalian CaM and soybean CaM4. Also, data demonstrate that the positively charged nuclear localization signal region in the tail in apo-OsCaM61 is helical, whereas it becomes flexible in the Ca(2+)-saturated protein. The extra helix in apo-OsCaM61 provides additional interactions in the C-lobe and increases the structural stability of the closed apo conformation. This leads to a decrease in the Ca(2+) binding affinity of EF-hands III and IV in OsCaM61. In Ca(2+)-OsCaM61, the basic nuclear localization signal cluster adopts an extended conformation, exposing the C-terminal extension for prenylation or enabling OsCaM61 to be transferred to the nucleus. Moreover, Ser(172) and Ala(173), residues in the tail, interact with different regions of the protein. These interactions affect the ability of OsCaM61 to activate different target proteins. Altogether, our data show that the tail is not simply a linker between the prenyl group and the protein but that it also provides a new regulatory mechanism that some plants have developed to fine-tune Ca(2+) signaling events.
Collapse
Affiliation(s)
- Mostafa Jamshidiha
- From the Department of Biological Sciences, University of Calgary, Calgary, Alberta T2N 1N4, Canada and
| | - Hiroaki Ishida
- From the Department of Biological Sciences, University of Calgary, Calgary, Alberta T2N 1N4, Canada and
| | - Cindy Sutherland
- Smooth Muscle Research Group, Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta T2N 4N1,Canada
| | - Jessica L. Gifford
- From the Department of Biological Sciences, University of Calgary, Calgary, Alberta T2N 1N4, Canada and
| | - Michael P. Walsh
- Smooth Muscle Research Group, Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta T2N 4N1,Canada
| | - Hans J. Vogel
- From the Department of Biological Sciences, University of Calgary, Calgary, Alberta T2N 1N4, Canada and
| |
Collapse
|
12
|
Freeman TC, Black JL, Bray HG, Dagliyan O, Wu YI, Tripathy A, Dokholyan NV, Leisner TM, Parise LV. Identification of novel integrin binding partners for calcium and integrin binding protein 1 (CIB1): structural and thermodynamic basis of CIB1 promiscuity. Biochemistry 2013; 52:7082-90. [PMID: 24011356 DOI: 10.1021/bi400678y] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The short cytoplasmic tails of the α- and β-chains of integrin adhesion receptors regulate integrin activation and cell signaling. Significantly less is known about proteins that bind to α-integrin cytoplasmic tails (CTs) as opposed to β-CTs to regulate integrins. Calcium and integrin binding protein 1 (CIB1) was previously identified as an αIIb binding partner that inhibits agonist-induced activation of the platelet-specific integrin, αIIbβ3. A sequence alignment of all α-integrin CTs revealed that key residues in the CIB1 binding site of αIIb are well-conserved, and was used to delineate a consensus binding site (I/L-x-x-x-L/M-W/Y-K-x-G-F-F). Because the CIB1 binding site of αIIb is conserved in all α-integrins and CIB1 expression is ubiquitous, we asked if CIB1 could interact with other α-integrin CTs. We predicted that multiple α-integrin CTs were capable of binding to the same hydrophobic binding pocket on CIB1 with docking models generated by all-atom replica exchange discrete molecular dynamics. After demonstrating novel in vivo interactions between CIB1 and other whole integrin complexes with co-immunoprecipitations, we validated the modeled predictions with solid-phase competitive binding assays, which showed that other α-integrin CTs compete with the αIIb CT for binding to CIB1 in vitro. Isothermal titration calorimetry measurements indicated that this binding is driven by hydrophobic interactions and depends on residues in the CIB1 consensus binding site. These new mechanistic details of CIB1-integrin binding imply that CIB1 could bind to all integrin complexes and act as a broad regulator of integrin function.
Collapse
Affiliation(s)
- Thomas C Freeman
- Department of Biochemistry and Biophysics, ‡Lineberger Comprehensive Cancer Center, and §McAllister Heart Institute, School of Medicine, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina 27599, United States
| | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Huang H, Vogel HJ. Purification and stable isotope labeling of the calcium- and integrin-binding protein 1 for structural and functional NMR studies. Methods Mol Biol 2013; 963:99-113. [PMID: 23296607 DOI: 10.1007/978-1-62703-230-8_7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
The Calcium- and Integrin-Binding protein 1 (CIB1) has been identified as an important regulatory Ca(2+)-binding protein that is involved in various cellular functions. Nuclear Magnetic Resonance (NMR) spectroscopy provides a powerful approach to study the structure, dynamics, and interactions of CIB1 and related proteins. Multidimensional NMR spectroscopy combined with various selective isotope labeling strategies has proven to be successful in the structure determination of CIB1. Moreover, the same approach allowed the detection of conformational changes when the protein binds different metal ions, and it facilitated the study of the interaction of CIB1 with the cytoplasmic domain of the human integrin αIIb subunit. In this protocol, we describe the purification and isotope labeling strategies for productive NMR studies of CIB1. The same isotope labeling strategies can be implemented to study numerous related regulatory calcium-binding proteins.
Collapse
Affiliation(s)
- Hao Huang
- Samuel Lunenfeld Research Institute, Mt. Sinai Hospital, Toronto, Canada
| | | |
Collapse
|
14
|
Alterations of the CIB2 calcium- and integrin-binding protein cause Usher syndrome type 1J and nonsyndromic deafness DFNB48. Nat Genet 2012; 44:1265-71. [PMID: 23023331 PMCID: PMC3501259 DOI: 10.1038/ng.2426] [Citation(s) in RCA: 180] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2012] [Accepted: 09/06/2012] [Indexed: 11/08/2022]
Abstract
Sensorineural hearing loss is genetically heterogeneous. Here we report that mutations in CIB2, encoding a Ca2+- and integrin-binding protein, are associated with nonsyndromic deafness (DFNB48) and Usher syndrome type 1J (USH1J). There is one mutation of CIB2 that is a prevalent cause of DFNB48 deafness in Pakistan; other CIB2 mutations contribute to deafness elsewhere in the world. In rodents, CIB2 is localized in the mechanosensory stereocilia of inner ear hair cells and in retinal photoreceptor and pigmented epithelium cells. Consistent with molecular modeling predictions of Ca2+ binding, CIB2 significantly decreased the ATP-induced Ca2+ responses in heterologous cells, while DFNB48 mutations altered CIB2 effects on Ca2+ responses. Furthermore, in zebrafish and Drosophila, CIB2 is essential for the function and proper development of hair cells and retinal photoreceptor cells. We show that CIB2 is a new member of the vertebrate Usher interactome.
Collapse
|
15
|
Huang H, Bogstie JN, Vogel HJ. Biophysical and structural studies of the human calcium- and integrin-binding protein family: understanding their functional similarities and differences. Biochem Cell Biol 2012; 90:646-56. [PMID: 22779914 DOI: 10.1139/o2012-021] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The human calcium- and integrin-binding protein 1 (CIB1) plays important roles in various cellular functions. In this study, three other members of this protein family (CIB2-4: CIB2, CIB3, and CIB4) were purified and subsequently characterized using biophysical and structural approaches. As expected from sequence alignments, CIB2-4 were shown to bind calcium (Ca(2+)) and magnesium (Mg(2+)) ions. Binding of Ca(2+) or Mg(2+) ions changes the secondary structure of CIB2-4 and the exposure of hydrophobic surface area. Ca(2+) and Mg(2+) ions also stabilize the tertiary structures for CIB2 and CIB3. Through in vitro binding experiments, we show that CIB2 can interact with the integrin αIIb cytoplasmic domain and the integrin α7b membrane-proximal fragment. Fluorescence experiments using a 7-azatryptophan labeled peptide demonstrate that CIB2, CIB3, and CIB4 are binding partners for the integrin αIIb subunit, which suggests that they are potentially involved in regulating integrin αIIb subunit activation. The distinct responses of αIIb to the different CIB3 and CIB4 metal (Ca(2+) and Mg(2+)) binding states imply a potential connection between the calcium and integrin signaling pathways.
Collapse
Affiliation(s)
- Hao Huang
- Biochemistry Research Group, Department of Biological Sciences, University of Calgary, 2500 University Dr. NW, Calgary, AB T2N 1N4, Canada
| | | | | |
Collapse
|
16
|
Gifford JL, Ishida H, Vogel HJ. Structural insights into calmodulin-regulated L-selectin ectodomain shedding. J Biol Chem 2012; 287:26513-27. [PMID: 22711531 DOI: 10.1074/jbc.m112.373373] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The L-selectin glycoprotein receptor mediates the initial steps of leukocyte migration into secondary lymphoid organs and sites of inflammation. Following cell activation through the engagement of G-protein-coupled receptors or immunoreceptors, the extracellular domains of L-selectin are rapidly shed, a process negatively controlled via the binding of the ubiquitous eukaryotic calcium-binding protein calmodulin to the cytoplasmic tail of L-selectin. Here we present the solution structure of calcium-calmodulin bound to a peptide encompassing the cytoplasmic tail and part of the transmembrane domain of L-selectin. The structure and accompanying biophysical study highlight the importance of both calcium and the transmembrane segment of L-selectin in the interaction between these two proteins, suggesting that by binding this region, calmodulin regulates in an "inside-out" fashion the ectodomain shedding of the receptor. Our structure provides the first molecular insight into the emerging new role for calmodulin as a transmembrane signaling partner.
Collapse
Affiliation(s)
- Jessica L Gifford
- Biochemistry Research Group, Department of Biological Sciences, University of Calgary, Calgary, Alberta T2N 1N4, Canada
| | | | | |
Collapse
|
17
|
Huang H, Vogel HJ. Structural basis for the activation of platelet integrin αIIbβ3 by calcium- and integrin-binding protein 1. J Am Chem Soc 2012; 134:3864-72. [PMID: 22283712 PMCID: PMC3290099 DOI: 10.1021/ja2111306] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Calcium and integrin binding protein 1 (CIB1) is a specific binding partner for the cytoplasmic domain of the αIIb subunit of the highly abundant platelet integrin αIIbβ3. This protein has been suggested to be involved in the regulation of the activation of αIIbβ3, a process leading to platelet aggregation and blood coagulation. In this work, the solution structure of the deuterated Ca(2+)-CIB1 protein complexed with an αIIb peptide was first determined through modern RDC-based NMR methods. Next, we generated a complex structure for CIB1 and the αIIb domain (Ca(2+)-CIB1/αIIb) using the program Haddock, which is based on experimental restraints obtained for the protein-peptide interface from cross-saturation NMR experiments. In this data-driven complex structure, the N-terminal α-helix of the cytoplasmic domain of αIIb is buried in the hydrophobic pocket of the C-lobe of Ca(2+)-CIB1. The C-terminal acidic tail of αIIb remains unstructured and likely interacts with several positively charged residues in the N-lobe of Ca(2+)-CIB1. A potential molecular mechanism for the CIB1-mediated activation of the platelet integrin could be proposed on the basis of the model structure of this protein complex. Another feature of this work is that, in the NMR cross-saturation experiments, we applied the selective radio frequency irradiation to the smaller binding partner (the αIIb peptide), and successfully detected the binding interface on the larger binding partner Ca(2+)-CIB1 through its selectively protonated methyl groups. This 'reverse' methodology has a broad potential to be employed to many other complexes where synthetic peptides and a suitably isotope-labeled medium- to large-sized protein are used to study protein-protein interactions.
Collapse
Affiliation(s)
- Hao Huang
- Biochemistry Research Group, Department of Biological Sciences, University of Calgary, Calgary (AB), Canada, T2N 1N4
| | | |
Collapse
|