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Decsi K, Ahmed M, Rizk R, Abdul-Hamid D, Kovács GP, Tóth Z. Emerging Trends in Non-Protein Amino Acids as Potential Priming Agents: Implications for Stress Management Strategies and Unveiling Their Regulatory Functions. Int J Mol Sci 2024; 25:6203. [PMID: 38892391 PMCID: PMC11172521 DOI: 10.3390/ijms25116203] [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: 05/10/2024] [Revised: 05/29/2024] [Accepted: 06/03/2024] [Indexed: 06/21/2024] Open
Abstract
Plants endure the repercussions of environmental stress. As the advancement of global climate change continues, it is increasingly crucial to protect against abiotic and biotic stress effects. Some naturally occurring plant compounds can be used effectively to protect the plants. By externally applying priming compounds, plants can be prompted to trigger their defensive mechanisms, resulting in improved immune system effectiveness. This review article examines the possibilities of utilizing exogenous alpha-, beta-, and gamma-aminobutyric acid (AABA, BABA, and GABA), which are non-protein amino acids (NPAAs) that are produced naturally in plants during instances of stress. The article additionally presents a concise overview of the studies' discoveries on this topic, assesses the particular fields in which they might be implemented, and proposes new avenues for future investigation.
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Affiliation(s)
- Kincső Decsi
- Institute of Agronomy, Georgikon Campus, Hungarian University of Agriculture and Life Sciences, 8360 Keszthely, Hungary; (R.R.); (Z.T.)
| | - Mostafa Ahmed
- Festetics Doctoral School, Institute of Agronomy, Georgikon Campus, Hungarian University of Agriculture and Life Sciences, 8360 Keszthely, Hungary;
- Department of Agricultural Biochemistry, Faculty of Agriculture, Cairo University, Giza 12613, Egypt
| | - Roquia Rizk
- Institute of Agronomy, Georgikon Campus, Hungarian University of Agriculture and Life Sciences, 8360 Keszthely, Hungary; (R.R.); (Z.T.)
- Department of Agricultural Biochemistry, Faculty of Agriculture, Cairo University, Giza 12613, Egypt
| | - Donia Abdul-Hamid
- Heavy Metals Department, Central Laboratory for The Analysis of Pesticides and Heavy Metals in Food (QCAP), Dokki, Cairo 12311, Egypt;
| | - Gergő Péter Kovács
- Institute of Agronomy, Szent István Campus, Hungarian University of Agriculture and Life Sciences, 2100 Gödöllő, Hungary;
| | - Zoltán Tóth
- Institute of Agronomy, Georgikon Campus, Hungarian University of Agriculture and Life Sciences, 8360 Keszthely, Hungary; (R.R.); (Z.T.)
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2
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Lai P, Yang X, Li YH, Yin YL, Yao Q, Huang S, Fan YY, Song JK, Zhao GH. Characterization of CpCaM, a protein potentially involved in the growth of Cryptosporidium parvum. Parasitol Res 2023; 122:989-996. [PMID: 36879147 DOI: 10.1007/s00436-023-07803-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 02/24/2023] [Indexed: 03/08/2023]
Abstract
Cryptosporidium parvum is an important apicomplexan parasite causing severe diarrhea in both humans and animals. Calmodulin (CaM), a multifunctional and universal calcium-binding protein, contributes to the growth and development of apicomplexan parasites, but the role of CaM in C. parvum remains unknown. In this study, the CaM of C. parvum encoded by the cgd2_810 gene was expressed in Escherichia coli, and the biological functions of CpCaM were preliminarily investigated. The transcriptional level of the cgd2_810 gene peaked at 36 h post infection (pi), and the CpCaM protein was mainly located around the nucleus of the whole oocysts, in the middle of sporozoites and around the nucleus of merozoites. Anti-CpCaM antibody reduced the invasion of C. parvum sporozoites by 30.69%. The present study indicates that CpCaM is potentially involved in the growth of C. parvum. Results of the study expand our knowledge on the interaction between host and Cryptosporidium.
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Affiliation(s)
- Peng Lai
- Key Laboratory of Ruminant Disease Prevention and Control (West), College of Veterinary Medicine, Northwest A&F University, Yangling, 712100, China
| | - Xin Yang
- Key Laboratory of Ruminant Disease Prevention and Control (West), College of Veterinary Medicine, Northwest A&F University, Yangling, 712100, China
| | - Yun-Hui Li
- Key Laboratory of Ruminant Disease Prevention and Control (West), College of Veterinary Medicine, Northwest A&F University, Yangling, 712100, China
| | - Yan-Ling Yin
- Key Laboratory of Ruminant Disease Prevention and Control (West), College of Veterinary Medicine, Northwest A&F University, Yangling, 712100, China
| | - Qian Yao
- Key Laboratory of Ruminant Disease Prevention and Control (West), College of Veterinary Medicine, Northwest A&F University, Yangling, 712100, China
| | - Shuang Huang
- Key Laboratory of Ruminant Disease Prevention and Control (West), College of Veterinary Medicine, Northwest A&F University, Yangling, 712100, China
| | - Ying-Ying Fan
- Key Laboratory of Ruminant Disease Prevention and Control (West), College of Veterinary Medicine, Northwest A&F University, Yangling, 712100, China
| | - Jun-Ke Song
- Key Laboratory of Ruminant Disease Prevention and Control (West), College of Veterinary Medicine, Northwest A&F University, Yangling, 712100, China.
| | - Guang-Hui Zhao
- Key Laboratory of Ruminant Disease Prevention and Control (West), College of Veterinary Medicine, Northwest A&F University, Yangling, 712100, China.
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3
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Munk M, Villalobo E, Villalobo A, Berchtold MW. Differential expression of the three independent CaM genes coding for an identical protein: Potential relevance of distinct mRNA stability by different codon usage. Cell Calcium 2022; 107:102656. [DOI: 10.1016/j.ceca.2022.102656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 09/01/2022] [Accepted: 09/25/2022] [Indexed: 11/24/2022]
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4
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Gu H, Kato T, Kumeta H, Kumaki Y, Tsukamoto T, Kikukawa T, Demura M, Ishida H, Vogel HJ, Aizawa T. Three-Dimensional Structure of the Antimicrobial Peptide Cecropin P1 in Dodecylphosphocholine Micelles and the Role of the C-Terminal Residues. ACS OMEGA 2022; 7:31924-31934. [PMID: 36120057 PMCID: PMC9475619 DOI: 10.1021/acsomega.2c02778] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 08/23/2022] [Indexed: 05/31/2023]
Abstract
Cecropin P1 (CP1) isolated from a large roundworm Ascaris suum, which is found in pig intestines, has been extensively studied as a model antimicrobial peptide (AMP). However, despite being a model AMP, its antibacterial mechanism is not well understood, particularly the function of its C-terminus. By using an Escherichia coli overexpression system with calmodulin as a fusion partner, we succeeded in the mass expression of recombinant peptides, avoiding toxicity to the host and degradation of CP1. The structure of the recombinant 15N- and 13C-labeled CP1 and its C-terminus truncated analogue in dodecylphosphocholine (DPC) micelles was determined by NMR. In this membrane-mimetic environment, CP1 formed an α-helix for almost its entire length, except for a short region at the C-terminus, and there was no evidence of a hinge, which is considered important for the expression of activity in other cecropins. Several NMR analyses showed that the entire length of CP1 was protected from water by micelles. Since the loss of the C-terminus of the analogue had little effect on the NMR structure or its interaction with the micelle, we investigated another role of the C-terminus of CP1 in its antimicrobial activity. The results showed that the C-terminal region affected the DNA-binding capacity of CP1, and this mechanism of action was also newly suggested that it contributed to the antimicrobial activity of CP1.
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Affiliation(s)
- Hao Gu
- Graduate
School of Life Science, Hokkaido University, N10, W8, Kita-ku, Sapporo 060-0810, Japan
| | - Takasumi Kato
- Graduate
School of Life Science, Hokkaido University, N10, W8, Kita-ku, Sapporo 060-0810, Japan
| | - Hiroyuki Kumeta
- Faculty
of Advanced Life Science, Hokkaido University, N10, W8, Kita-ku, Sapporo 060-0810, Japan
| | - Yasuhiro Kumaki
- Faculty
of Advanced Life Science, Hokkaido University, N10, W8, Kita-ku, Sapporo 060-0810, Japan
| | - Takashi Tsukamoto
- Faculty
of Advanced Life Science, Hokkaido University, N10, W8, Kita-ku, Sapporo 060-0810, Japan
| | - Takashi Kikukawa
- Faculty
of Advanced Life Science, Hokkaido University, N10, W8, Kita-ku, Sapporo 060-0810, Japan
| | - Makoto Demura
- Faculty
of Advanced Life Science, Hokkaido University, N10, W8, Kita-ku, Sapporo 060-0810, Japan
| | - Hiroaki Ishida
- Department
of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada
| | - Hans J. Vogel
- Department
of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada
| | - Tomoyasu Aizawa
- Faculty
of Advanced Life Science, Hokkaido University, N10, W8, Kita-ku, Sapporo 060-0810, Japan
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5
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Zhang Y, Daniel EA, Metcalf J, Dai Y, Reif GA, Wallace DP. CaMK4 overexpression in polycystic kidney disease promotes mTOR-mediated cell proliferation. J Mol Cell Biol 2022; 14:6674767. [PMID: 36002021 PMCID: PMC9802383 DOI: 10.1093/jmcb/mjac050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 06/01/2022] [Accepted: 08/18/2022] [Indexed: 01/14/2023] Open
Abstract
Autosomal dominant polycystic kidney disease (ADPKD) is characterized by progressive enlargement of fluid-filled cysts, causing nephron loss and a decline in renal function. Mammalian target of rapamycin (mTOR) is overactive in cyst-lining cells and contributes to abnormal cell proliferation and cyst enlargement; however, the mechanism for mTOR stimulation remains unclear. We discovered that calcium/calmodulin (CaM) dependent kinase IV (CaMK4), a multifunctional kinase, is overexpressed in the kidneys of ADPKD patients and PKD mouse models. In human ADPKD cells, CaMK4 knockdown reduced mTOR abundance and the phosphorylation of ribosomal protein S6 kinase (S6K), a downstream target of mTOR. Pharmacologic inhibition of CaMK4 with KN-93 reduced phosphorylated S6K and S6 levels and inhibited cell proliferation and in vitro cyst formation of ADPKD cells. Moreover, inhibition of calcium/CaM-dependent protein kinase kinase-β and CaM, two key upstream regulators of CaMK4, also decreased mTOR signaling. The effects of KN-93 were independent of the liver kinase B1-adenosine monophosphate-activated protein kinase (AMPK) pathway, and the combination of KN-93 and metformin, an AMPK activator, had additive inhibitory effects on mTOR signaling and in vitro cyst growth. Our data suggest that increased CaMK4 expression and activity contribute to mTOR signaling and the proliferation of cystic cells of ADPKD kidneys.
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Affiliation(s)
- Yan Zhang
- Department of Internal Medicine, University of Kansas Medical Center, Kansas City, KS 66160-3018, USA,Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, KS 66160-3018, USA
| | - Emily A Daniel
- Department of Internal Medicine, University of Kansas Medical Center, Kansas City, KS 66160-3018, USA,Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, KS 66160-3018, USA
| | - July Metcalf
- Department of Internal Medicine, University of Kansas Medical Center, Kansas City, KS 66160-3018, USA,Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, KS 66160-3018, USA
| | - Yuqiao Dai
- Department of Internal Medicine, University of Kansas Medical Center, Kansas City, KS 66160-3018, USA,Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, KS 66160-3018, USA
| | - Gail A Reif
- Department of Internal Medicine, University of Kansas Medical Center, Kansas City, KS 66160-3018, USA,Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, KS 66160-3018, USA
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6
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Mazzotta GM, Bellanda M, Minervini G, Damulewicz M, Cusumano P, Aufiero S, Stefani M, Zambelli B, Mammi S, Costa R, Tosatto SCE. Calmodulin Enhances Cryptochrome Binding to INAD in Drosophila Photoreceptors. Front Mol Neurosci 2018; 11:280. [PMID: 30177872 PMCID: PMC6109769 DOI: 10.3389/fnmol.2018.00280] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 07/24/2018] [Indexed: 12/13/2022] Open
Abstract
Light is the main environmental stimulus that synchronizes the endogenous timekeeping systems in most terrestrial organisms. Drosophila cryptochrome (dCRY) is a light-responsive flavoprotein that detects changes in light intensity and wavelength around dawn and dusk. We have previously shown that dCRY acts through Inactivation No Afterpotential D (INAD) in a light-dependent manner on the Signalplex, a multiprotein complex that includes visual-signaling molecules, suggesting a role for dCRY in fly vision. Here, we predict and demonstrate a novel Ca2+-dependent interaction between dCRY and calmodulin (CaM). Through yeast two hybrid, coimmunoprecipitation (Co-IP), nuclear magnetic resonance (NMR) and calorimetric analyses we were able to identify and characterize a CaM binding motif in the dCRY C-terminus. Similarly, we also detailed the CaM binding site of the scaffold protein INAD and demonstrated that CaM bridges dCRY and INAD to form a ternary complex in vivo. Our results suggest a process whereby a rapid dCRY light response stimulates an interaction with INAD, which can be further consolidated by a novel mechanism regulated by CaM.
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Affiliation(s)
| | - Massimo Bellanda
- Department of Chemical Sciences, University of Padova, Padova, Italy
| | | | - Milena Damulewicz
- Department of Cell Biology and Imaging, Institute of Zoology and Biomedical Research, Faculty of Biology and Earth Sciences, Jagiellonian University, Kraków, Poland
| | - Paola Cusumano
- Department of Biology, University of Padova, Padova, Italy
| | - Simona Aufiero
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Monica Stefani
- Department of Chemical Sciences, University of Padova, Padova, Italy
| | - Barbara Zambelli
- Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy
| | - Stefano Mammi
- Department of Chemical Sciences, University of Padova, Padova, Italy
| | - Rodolfo Costa
- Department of Biology, University of Padova, Padova, Italy
| | - Silvio C E Tosatto
- Department of Biomedical Sciences, University of Padova, Padova, Italy.,CNR Institute of Neuroscience, Padova, Italy
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7
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Hortua Triana MA, Márquez-Nogueras KM, Vella SA, Moreno SNJ. Calcium signaling and the lytic cycle of the Apicomplexan parasite Toxoplasma gondii. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2018; 1865:1846-1856. [PMID: 30992126 DOI: 10.1016/j.bbamcr.2018.08.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2018] [Revised: 08/06/2018] [Accepted: 08/07/2018] [Indexed: 01/24/2023]
Abstract
Toxoplasma gondii has a complex life cycle involving different hosts and is dependent on fast responses, as the parasite reacts to changing environmental conditions. T. gondii causes disease by lysing the host cells that it infects and it does this by reiterating its lytic cycle, which consists of host cell invasion, replication inside the host cell, and egress causing host cell lysis. Calcium ion (Ca2+) signaling triggers activation of molecules involved in the stimulation and enhancement of each step of the parasite lytic cycle. Ca2+ signaling is essential for the cellular and developmental changes that support T. gondii parasitism. The characterization of the molecular players and pathways directly activated by Ca2+ signaling in Toxoplasma is sketchy and incomplete. The evolutionary distance between Toxoplasma and other eukaryotic model systems makes the comparison sometimes not informative. The advent of new genomic information and new genetic tools applicable for studying Toxoplasma biology is rapidly changing this scenario. The Toxoplasma genome reveals the presence of many genes potentially involved in Ca2+ signaling, even though the role of most of them is not known. The use of Genetically Encoded Calcium Indicators (GECIs) has allowed studies on the role of novel calcium-related proteins on egress, an essential step for the virulence and dissemination of Toxoplasma. In addition, the discovery of new Ca2+ players is generating novel targets for drugs, vaccines, and diagnostic tools and a better understanding of the biology of these parasites.
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Affiliation(s)
| | | | - Stephen A Vella
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA 30602, USA
| | - Silvia N J Moreno
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA 30602, USA; Department of Cellular Biology, University of Georgia, Athens, GA 30602, USA.
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8
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Villalobo A, Ishida H, Vogel HJ, Berchtold MW. Calmodulin as a protein linker and a regulator of adaptor/scaffold proteins. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2017; 1865:507-521. [PMID: 29247668 DOI: 10.1016/j.bbamcr.2017.12.004] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 12/07/2017] [Accepted: 12/08/2017] [Indexed: 01/29/2023]
Abstract
Calmodulin (CaM) is a universal regulator for a huge number of proteins in all eukaryotic cells. Best known is its function as a calcium-dependent modulator of the activity of enzymes, such as protein kinases and phosphatases, as well as other signaling proteins including membrane receptors, channels and structural proteins. However, less well known is the fact that CaM can also function as a Ca2+-dependent adaptor protein, either by bridging between different domains of the same protein or by linking two identical or different target proteins together. These activities are possible due to the fact that CaM contains two independently-folded Ca2+ binding lobes that are able to interact differentially and to some degree separately with targets proteins. In addition, CaM can interact with and regulates several proteins that function exclusively as adaptors. This review provides an overview over our present knowledge concerning the structural and functional aspects of the role of CaM as an adaptor protein and as a regulator of known adaptor/scaffold proteins.
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Affiliation(s)
- Antonio Villalobo
- Department of Cancer Biology, Instituto de Investigaciones Biomédicas, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, Arturo Duperier 4, E-28029 Madrid, Spain.
| | - Hiroaki Ishida
- Department of Biological Sciences, University of Calgary, 2500 University Dr. N.W., Calgary, Alberta T2N 1N4, Canada
| | - Hans J Vogel
- Department of Biological Sciences, University of Calgary, 2500 University Dr. N.W., Calgary, Alberta T2N 1N4, Canada.
| | - Martin W Berchtold
- Department of Biology, University of Copenhagen, 13 Universitetsparken, DK-2100 Copenhagen Ø, Denmark.
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9
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Collu G, Farci D, Esposito F, Pintus F, Kirkpatrick J, Piano D. New insights into the operative network of FaEO, an enone oxidoreductase from Fragaria x ananassa Duch. PLANT MOLECULAR BIOLOGY 2017; 94:125-136. [PMID: 28283921 DOI: 10.1007/s11103-017-0597-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Accepted: 02/21/2017] [Indexed: 06/06/2023]
Abstract
The 2-methylene-furan-3-one reductase or Fragaria x ananassa Enone Oxidoreductase (FaEO) catalyses the last reductive step in the biosynthesis of 4-hydroxy-2,5-dimethyl-3(2H)-furanone, a major component in the characteristic flavour of strawberries. In the present work, we describe the association between FaEO and the vacuolar membrane of strawberry fruits. Even if FaEO lacks epitopes for stable or transient membrane-interactions, it contains a calmodulin-binding region, suggesting that in vivo FaEO may be associated with the membrane via a peripheral protein complex with calmodulin. Moreover, we also found that FaEO occurs in dimeric form in vivo and, as frequently observed for calmodulin-regulated proteins, it may be expressed in different isoforms by alternative gene splicing. Further mass spectrometry analysis confirmed that the isolated FaEO consists in the already known isoform and that it is the most characteristic during ripening. Finally, a characterization by absorption spectroscopy showed that FaEO has specific flavoprotein features. The relevance of these findings and their possible physiological implications are discussed.
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Affiliation(s)
- Gabriella Collu
- Laboratory of Plant Physiology and Photobiology, Department of Life and Environmental Sciences, University of Cagliari, V.le S. Ignazio da Laconi 13, 09123, Cagliari, Italy
| | - Domenica Farci
- Laboratory of Plant Physiology and Photobiology, Department of Life and Environmental Sciences, University of Cagliari, V.le S. Ignazio da Laconi 13, 09123, Cagliari, Italy
- Department of Molecular Sensory Systems, Center of Advanced European Studies and Research (caesar), Ludwig-Erhard-Allee 2, 52175, Bonn, Germany
| | - Francesca Esposito
- Department of Life and Environmental Sciences, University of Cagliari, Cittadella Universitaria, 09042, Monserrato, Italy
| | - Francesca Pintus
- Department of Life and Environmental Sciences, University of Cagliari, Cittadella Universitaria, 09042, Monserrato, Italy
| | - Joanna Kirkpatrick
- Leibniz Institute on Aging - Fritz Lipmann Institute, Beutebergstraβe 11, 07745, Jena, Germany
| | - Dario Piano
- Laboratory of Plant Physiology and Photobiology, Department of Life and Environmental Sciences, University of Cagliari, V.le S. Ignazio da Laconi 13, 09123, Cagliari, Italy.
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10
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Ishida H, Nguyen LT, Gopal R, Aizawa T, Vogel HJ. Overexpression of Antimicrobial, Anticancer, and Transmembrane Peptides in Escherichia coli through a Calmodulin-Peptide Fusion System. J Am Chem Soc 2016; 138:11318-26. [DOI: 10.1021/jacs.6b06781] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Hiroaki Ishida
- Biochemistry
Research Group,
Department of Biological Sciences, University of Calgary, Calgary, Alberta T2N 1N4, Canada
| | - Leonard T. Nguyen
- Biochemistry
Research Group,
Department of Biological Sciences, University of Calgary, Calgary, Alberta T2N 1N4, Canada
| | - Ramamourthy Gopal
- Biochemistry
Research Group,
Department of Biological Sciences, University of Calgary, Calgary, Alberta T2N 1N4, Canada
| | - Tomoyasu Aizawa
- Biochemistry
Research Group,
Department of Biological Sciences, University of Calgary, Calgary, Alberta T2N 1N4, Canada
| | - Hans J. Vogel
- Biochemistry
Research Group,
Department of Biological Sciences, University of Calgary, Calgary, Alberta T2N 1N4, Canada
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11
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Structural characterization of the interaction of human lactoferrin with calmodulin. PLoS One 2012; 7:e51026. [PMID: 23236421 PMCID: PMC3516504 DOI: 10.1371/journal.pone.0051026] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2012] [Accepted: 10/29/2012] [Indexed: 12/21/2022] Open
Abstract
Lactoferrin (Lf) is an 80 kDa, iron (Fe3+)-binding immunoregulatory glycoprotein secreted into most exocrine fluids, found in high concentrations in colostrum and milk, and released from neutrophil secondary granules at sites of infection and inflammation. In a number of cell types, Lf is internalized through receptor-mediated endocytosis and targeted to the nucleus where it has been demonstrated to act as a transcriptional trans-activator. Here we characterize human Lf’s interaction with calmodulin (CaM), a ubiquitous, 17 kDa regulatory calcium (Ca2+)-binding protein localized in the cytoplasm and nucleus of activated cells. Due to the size of this intermolecular complex (∼100 kDa), TROSY-based NMR techniques were employed to structurally characterize Ca2+-CaM when bound to intact apo-Lf. Both CaM’s backbone amides and the ε-methyl group of key methionine residues were used as probes in chemical shift perturbation and cross-saturation experiments to define the binding interface of apo-Lf on Ca2+-CaM. Unlike the collapsed conformation through which Ca2+-CaM binds the CaM-binding domains of its classical targets, Ca2+-CaM assumes an extended structure when bound to apo-Lf. Apo-Lf appears to interact predominantly with the C-terminal lobe of Ca2+-CaM, enabling the N-terminal lobe to potentially bind another target. Our use of intact apo-Lf has made possible the identification of a secondary interaction interface, removed from CaM’s primary binding domain. Secondary interfaces play a key role in the target’s response to CaM binding, highlighting the importance of studying intact complexes. This solution-based approach can be applied to study other regulatory calcium-binding EF-hand proteins in intact intermolecular complexes.
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12
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Liu Z, Vogel HJ. Structural basis for the regulation of L-type voltage-gated calcium channels: interactions between the N-terminal cytoplasmic domain and Ca(2+)-calmodulin. Front Mol Neurosci 2012; 5:38. [PMID: 22518098 PMCID: PMC3324987 DOI: 10.3389/fnmol.2012.00038] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Accepted: 03/13/2012] [Indexed: 01/07/2023] Open
Abstract
It is well-known that the opening of L-type voltage-gated calcium channels can be regulated by calmodulin (CaM). One of the main regulatory mechanisms is calcium-dependent inactivation (CDI), where binding of apo-CaM to the cytoplasmic C-terminal domain of the channel can effectively sense an increase in the local calcium ion concentration. Calcium-bound CaM can bind to the IQ-motif region of the C-terminal region and block the calcium channel, thereby providing a negative feedback mechanism that prevents the rise of cellular calcium concentrations over physiological limits. Recently, an additional Ca2+/CaM-binding motif (NSCaTE, N-terminal spatial Ca2+ transforming element) was identified in the amino terminal cytoplasmic region of Cav1.2 and Cav1.3. This motif exists only in Cav1.2 and Cav1.3 channels, and a pronounced N-lobe (Ca2+/CaM) CDI effect was found for Cav1.3. To understand the molecular basis of this interaction, the complexes of Ca2+/CaM with the biosynthetically produced N-terminal region (residues 1–68) and NSCaTE peptide (residues 48–68) were investigated. We discovered that the NSCaTE motif in the N-terminal cytoplasmic region adopts an α-helical conformation, most likely due to its high alanine content. Additionally, the complex exhibits an unusual 1:2 protein:peptide stoichiometry when bound to Ca2+-CaM, and the N-lobe of CaM has a much stronger affinity for the peptide than the C-lobe. The complex structures of the isolated N- and C-lobe of Ca2+/CaM and the NSCaTE peptide were determined by nuclear magnetic resonance spectroscopy and data-driven protein-docking methods. Moreover, we also demonstrated that calcium binding protein 1, which competes with CaM for binding to the C-terminal cytoplasmic domain, binds only weakly to the NSCaTE region. The structures provide insights into the possible roles of this motif in the calcium regulatory network. Our study provides structural evidence for the CaM-bridge model proposed in previous studies.
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Affiliation(s)
- Zhihong Liu
- Department of Biological Sciences, University of Calgary, Calgary AB, Canada
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13
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Chagot B, Chazin WJ. Solution NMR structure of Apo-calmodulin in complex with the IQ motif of human cardiac sodium channel NaV1.5. J Mol Biol 2010; 406:106-19. [PMID: 21167176 DOI: 10.1016/j.jmb.2010.11.046] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2010] [Revised: 11/22/2010] [Accepted: 11/23/2010] [Indexed: 12/19/2022]
Abstract
The function of the human voltage-gated sodium channel Na(V)1.5 is regulated in part by intracellular calcium signals. The ubiquitous calcium sensor protein calmodulin (CaM) is an important part of the complex calcium-sensing apparatus in Na(V)1.5. CaM interacts with an IQ (isoleucine-glutamine) motif in the large intracellular C-terminal domain of the channel. Using co-expression and co-purification, we have been able to isolate a CaM-IQ motif complex and to determine its high-resolution structure in absence of calcium using multi-dimensional solution NMR. Under these conditions, the Na(V)1.5 IQ motif interacts with the C-terminal domain (C-lobe) of CaM, with the N-terminal domain remaining free in solution. The structure reveals that the C-lobe adopts a semi-open conformation with the IQ motif bound in a narrow hydrophobic groove. Sequence similarities between voltage-gated sodium channels and voltage-gated calcium channels suggest that the structure of the CaM-Na(V)1.5 IQ motif complex can serve as a general model for the interaction between CaM and ion channel IQ motifs under low-calcium conditions. The structure also provides insight into the biochemical basis for disease-associated mutations that map to the IQ motif in Na(V)1.5.
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Affiliation(s)
- Benjamin Chagot
- Department of Biochemistry, Vanderbilt University, Nashville, TN 37232, USA
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Ishida H, Rainaldi M, Vogel HJ. Structural studies of soybean calmodulin isoform 4 bound to the calmodulin-binding domain of tobacco mitogen-activated protein kinase phosphatase-1 provide insights into a sequential target binding mode. J Biol Chem 2009; 284:28292-28305. [PMID: 19667066 PMCID: PMC2788880 DOI: 10.1074/jbc.m109.025080] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2009] [Revised: 07/10/2009] [Indexed: 01/22/2023] Open
Abstract
The calcium regulatory protein calmodulin (CaM) binds in a calcium-dependent manner to numerous target proteins. The calmodulin-binding domain (CaMBD) region of Nicotiana tabacum MAPK phosphatase has an amino acid sequence that does not resemble the CaMBD of any other known Ca(2+)-CaM-binding proteins. Using a unique fusion protein strategy, we have been able to obtain a high resolution solution structure of the complex of soybean Ca(2+)-CaM4 (SCaM4) and this CaMBD. Complete isotope labeling of both parts of the complex in the fusion protein greatly facilitated the structure determination by NMR. The 12-residue CaMBD region was found to bind exclusively to the C-lobe of SCaM4. A specific Trp and Leu side chain are utilized to facilitate strong binding through a novel "double anchor" motif. Moreover, the orientation of the helical peptide on the surface of Ca(2+)-SCaM4 is distinct from other known complexes. The N-lobe of Ca(2+)-SCaM4 in the complex remains free for additional interactions and could possibly act as a calcium-dependent adapter protein. Signaling through the MAPK pathway and increases in intracellular Ca(2+) are both hallmarks of the plant stress response, and our data support the notion that coordination of these responses may occur through the formation of a unique CaM-MAPK phosphatase multiprotein complex.
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Affiliation(s)
- Hiroaki Ishida
- Department of Biological Sciences, University of Calgary, Calgary, Alberta T2N 1N4, Canada
| | - Mario Rainaldi
- Department of Biological Sciences, University of Calgary, Calgary, Alberta T2N 1N4, Canada
| | - Hans J Vogel
- Department of Biological Sciences, University of Calgary, Calgary, Alberta T2N 1N4, Canada.
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