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Prudovsky I. Cellular Mechanisms of FGF-Stimulated Tissue Repair. Cells 2021; 10:cells10071830. [PMID: 34360000 PMCID: PMC8304273 DOI: 10.3390/cells10071830] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 07/15/2021] [Accepted: 07/16/2021] [Indexed: 01/10/2023] Open
Abstract
Growth factors belonging to the FGF family play important roles in tissue and organ repair after trauma. In this review, I discuss the regulation by FGFs of the aspects of cellular behavior important for reparative processes. In particular, I focus on the FGF-dependent regulation of cell proliferation, cell stemness, de-differentiation, inflammation, angiogenesis, cell senescence, cell death, and the production of proteases. In addition, I review the available literature on the enhancement of FGF expression and secretion in damaged tissues resulting in the increased FGF supply required for tissue repair.
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Affiliation(s)
- Igor Prudovsky
- Maine Medical Center Research Institute, 81 Research Dr., Scarborough, ME 04074, USA
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2
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Sluzalska KD, Slawski J, Sochacka M, Lampart A, Otlewski J, Zakrzewska M. Intracellular partners of fibroblast growth factors 1 and 2 - implications for functions. Cytokine Growth Factor Rev 2020; 57:93-111. [PMID: 32475760 DOI: 10.1016/j.cytogfr.2020.05.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 05/04/2020] [Accepted: 05/07/2020] [Indexed: 01/01/2023]
Abstract
Fibroblast growth factors 1 and 2 (FGF1 and FGF2) are mainly considered as ligands of surface receptors through which they regulate a broad spectrum of biological processes. They are secreted in non-canonical way and, unlike other growth factors, they are able to translocate from the endosome to the cell interior. These unique features, as well as the role of the intracellular pool of FGF1 and FGF2, are far from being fully understood. An increasing number of reports address this problem, focusing on the intracellular interactions of FGF1 and 2. Here, we summarize the current state of knowledge of the FGF1 and FGF2 binding partners inside the cell and the possible role of these interactions. The partner proteins are grouped according to their function, including proteins involved in secretion, cell signaling, nucleocytoplasmic transport, binding and processing of nucleic acids, ATP binding, and cytoskeleton assembly. An in-depth analysis of the network of these binding partners could indicate novel, non-classical functions of FGF1 and FGF2 and uncover an additional level of a fine control of the well-known FGF-regulated cellular processes.
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Affiliation(s)
- Katarzyna Dominika Sluzalska
- Department of Protein Engineering, Faculty of Biotechnology, University of Wroclaw, ul. F. Joliot-Curie 14a, 50-383 Wroclaw, Poland
| | - Jakub Slawski
- Department of Biophysics, Faculty of Biotechnology, University of Wroclaw, ul. F. Joliot-Curie 14a, 50-383 Wroclaw, Poland
| | - Martyna Sochacka
- Department of Protein Engineering, Faculty of Biotechnology, University of Wroclaw, ul. F. Joliot-Curie 14a, 50-383 Wroclaw, Poland
| | - Agata Lampart
- Department of Protein Engineering, Faculty of Biotechnology, University of Wroclaw, ul. F. Joliot-Curie 14a, 50-383 Wroclaw, Poland
| | - Jacek Otlewski
- Department of Protein Engineering, Faculty of Biotechnology, University of Wroclaw, ul. F. Joliot-Curie 14a, 50-383 Wroclaw, Poland
| | - Malgorzata Zakrzewska
- Department of Protein Engineering, Faculty of Biotechnology, University of Wroclaw, ul. F. Joliot-Curie 14a, 50-383 Wroclaw, Poland.
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Kirov A, Kacer D, Conley BA, Vary CPH, Prudovsky I. AHNAK2 Participates in the Stress-Induced Nonclassical FGF1 Secretion Pathway. J Cell Biochem 2016; 116:1522-31. [PMID: 25560297 DOI: 10.1002/jcb.25047] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Accepted: 12/16/2014] [Indexed: 12/22/2022]
Abstract
FGF1 is a nonclassically released growth factor that regulates carcinogenesis, angiogenesis, and inflammation. In vitro and in vivo, FGF1 export is stimulated by cell stress. Upon stress, FGF1 is transported to the plasma membrane where it localizes prior to transmembrane translocation. To determine which proteins participate in the submembrane localization of FGF1 and its export, we used immunoprecipitation mass spectrometry to identify novel proteins that associate with FGF1 during heat shock. The heat shock-dependent association of FGF1 with the large protein AHNAK2 was observed. Heat shock induced the translocation of FGF1 and AHNAK2 to the cytoskeletal fraction. In heat-shocked cells, FGF1 and the C-terminal fragment of AHNAK2 colocalized with F-actin in the vicinity of the cell membrane. Depletion of AHNAK2 resulted in a drastic decrease of stress-induced FGF1 export but did not affect spontaneous FGF2 export and FGF1 release induced by the inhibition of Notch signaling. Thus, AHNAK2 is an important element of the FGF1 nonclassical export pathway.
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Affiliation(s)
- Aleksandr Kirov
- Center for Molecular Medicine, Maine Medical Center Research Institute, Maine Medical Center, Scarborough, 04074, Maine
| | - Doreen Kacer
- Center for Molecular Medicine, Maine Medical Center Research Institute, Maine Medical Center, Scarborough, 04074, Maine
| | - Barbara A Conley
- Center for Molecular Medicine, Maine Medical Center Research Institute, Maine Medical Center, Scarborough, 04074, Maine
| | - Calvin P H Vary
- Center for Molecular Medicine, Maine Medical Center Research Institute, Maine Medical Center, Scarborough, 04074, Maine
| | - Igor Prudovsky
- Center for Molecular Medicine, Maine Medical Center Research Institute, Maine Medical Center, Scarborough, 04074, Maine
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4
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Prudovsky I, Kacer D, Davis J, Shah V, Jayanthi S, Huber I, Dakshinamurthy R, Ganter O, Soldi R, Neivandt D, Guvench O, Suresh Kumar TK. Folding of Fibroblast Growth Factor 1 Is Critical for Its Nonclassical Release. Biochemistry 2016; 55:1159-67. [PMID: 26836284 DOI: 10.1021/acs.biochem.5b01341] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Fibroblast growth factor 1 (FGF1), a ubiquitously expressed pro-angiogenic protein that is involved in tissue repair, carcinogenesis, and maintenance of vasculature stability, is released from the cells via a stress-dependent nonclassical secretory pathway. FGF1 secretion is a result of transmembrane translocation of this protein. It correlates with the ability of FGF1 to permeabilize membranes composed of acidic phospholipids. Like several other nonclassically exported proteins, FGF1 exhibits β-barrel folding. To assess the role of folding of FGF1 in its secretion, we applied targeted mutagenesis in combination with a complex of biophysical methods and molecular dynamics studies, followed by artificial membrane permeabilization and stress-induced release experiments. It has been demonstrated that a mutation of proline 135 located in the C-terminus of FGF1 results in (i) partial unfolding of FGF1, (ii) a decrease in FGF1's ability to permeabilize bilayers composed of phosphatidylserine, and (iii) drastic inhibition of stress-induced FGF1 export. Thus, folding of FGF1 is critical for its nonclassical secretion.
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Affiliation(s)
- Igor Prudovsky
- Maine Medical Center Research Institute , 81 Research Drive, Scarborough, Maine 04074, United States.,Graduate School of Biomedical Science and Engineering, University of Maine , Jenness Hall, Orono, Maine 04469, United States
| | - Doreen Kacer
- Maine Medical Center Research Institute , 81 Research Drive, Scarborough, Maine 04074, United States
| | - Julie Davis
- Department of Chemistry and Biochemistry, University of Arkansas , Chemistry Building, Fayetteville, Arkansas 72701, United States
| | - Varun Shah
- Department of Chemistry and Biochemistry, University of Arkansas , Chemistry Building, Fayetteville, Arkansas 72701, United States
| | - Srinivas Jayanthi
- Department of Chemistry and Biochemistry, University of Arkansas , Chemistry Building, Fayetteville, Arkansas 72701, United States
| | - Isabelle Huber
- Department of Chemistry and Biochemistry, University of Arkansas , Chemistry Building, Fayetteville, Arkansas 72701, United States
| | - Rajalingam Dakshinamurthy
- Department of Chemistry and Biochemistry, University of Arkansas , Chemistry Building, Fayetteville, Arkansas 72701, United States
| | - Owen Ganter
- College of Pharmacy, University of New England , Pharmacy Building, 716 Stevens Avenue, Portland, Maine 04103, United States
| | - Raffaella Soldi
- Maine Medical Center Research Institute , 81 Research Drive, Scarborough, Maine 04074, United States
| | - David Neivandt
- Graduate School of Biomedical Science and Engineering, University of Maine , Jenness Hall, Orono, Maine 04469, United States
| | - Olgun Guvench
- Graduate School of Biomedical Science and Engineering, University of Maine , Jenness Hall, Orono, Maine 04469, United States.,College of Pharmacy, University of New England , Pharmacy Building, 716 Stevens Avenue, Portland, Maine 04103, United States
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5
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Sancho-Knapik S, Guillén N, Osada J. Cloning and expression of hepatic synaptotagmin 1 in mouse. Gene 2015; 562:236-43. [PMID: 25735570 DOI: 10.1016/j.gene.2015.02.074] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Revised: 02/17/2015] [Accepted: 02/27/2015] [Indexed: 11/29/2022]
Abstract
Mouse hepatic synaptotagmin 1 (SYT1) cDNA was cloned, characterized and compared to the brain one. The hepatic transcript was 1807 bp in length, smaller than the brain, and only encoded by 9 of 11 gene exons. In this regard, 5'-and 3'-untranslated regions were 66 and 476 bp, respectively; the open reading frame of 1266 bp codified for a protein of 421 amino acids, identical to the brain, with a predicted molecular mass of 47.4 kDa and highly conserved across different species. Immunoblotting of protein showed two isoforms of higher molecular masses than the theoretical prediction based on amino acid sequence suggesting posttranslational modifications. Subcellular distribution of protein isoforms corresponded to plasma membrane, lysosomes and microsomes and was identical between the brain and liver. Nonetheless, the highest molecular weight isoform was smaller in the liver, irrespective of subcellular location. Quantitative mRNA tissue distribution showed that it was widely expressed and that the highest values corresponded to the brain, followed by the liver, spleen, abdominal fat, intestine and skeletal muscle. These findings indicate tissue-specific splicing of the gene and posttranslational modification and the variation in expression in the different tissues might suggest a different requirement of SYT1 for the specific function in each organ.
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Affiliation(s)
- Sara Sancho-Knapik
- Departamento Bioquímica y Biología Molecular y Celular, Facultad de Veterinaria, Instituto de Investigación Sanitaria de Aragón (IIS), Universidad de Zaragoza, Spain
| | - Natalia Guillén
- Departamento de Toxicología, Facultad de Veterinaria, Universidad de Zaragoza, Spain
| | - Jesús Osada
- Departamento Bioquímica y Biología Molecular y Celular, Facultad de Veterinaria, Instituto de Investigación Sanitaria de Aragón (IIS), Universidad de Zaragoza, Spain; CIBER de Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Spain.
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6
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Jayanthi S, Kathir KM, Rajalingam D, Furr M, Daily A, Thurman R, Rutherford L, Chandrashekar R, Adams P, Prudovsky I, Kumar TKS. Copper binding affinity of the C2B domain of synaptotagmin-1 and its potential role in the nonclassical secretion of acidic fibroblast growth factor. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2014; 1844:2155-63. [PMID: 25224745 DOI: 10.1016/j.bbapap.2014.09.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2014] [Revised: 08/20/2014] [Accepted: 09/07/2014] [Indexed: 01/27/2023]
Abstract
Fibroblast growth factor 1 (FGF1) is a heparin-binding proangiogenic protein. FGF1 lacks the conventional N-terminal signal peptide required for secretion through the endoplasmic reticulum (ER)-Golgi secretory pathway. FGF1 is released through a Cu(2+)-mediated nonclassical secretion pathway. The secretion of FGF1 involves the formation of a Cu(2+)-mediated multiprotein release complex (MRC) including FGF1, S100A13 (a calcium-binding protein) and p40 synaptotagmin (Syt1). It is believed that the binding of Cu(2+) to the C2B domain is important for the release of FGF1 into the extracellular medium. In this study, using a variety of biophysical studies, Cu(2+) and lipid interactions of the C2B domain of Syt1 were characterized. Isothermal titration calorimetry (ITC) experiments reveal that the C2B domain binds to Cu(2+) in a biphasic manner involving an initial endothermic and a subsequent exothermic phase. Fluorescence energy transfer experiments using Tb(3+) show that there are two Cu(2+)-binding pockets on the C2B domain, and one of these is also a Ca(2+)-binding site. Lipid-binding studies using ITC demonstrate that the C2B domain preferentially binds to small unilamellar vesicles of phosphatidyl serine (PS). Results of the differential scanning calorimetry and limited trypsin digestion experiments suggest that the C2B domain is marginally destabilized upon binding to PS vesicles. These results, for the first time, suggest that the main role of the C2B domain of Syt1 is to serve as an anchor for the FGF1 MRC on the membrane bilayer. In addition, the binding of the C2B domain to the lipid bilayer is shown to significantly decrease the binding affinity of the protein to Cu(2+). The study provides valuable insights on the sequence of structural events that occur in the nonclassical secretion of FGF1.
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Affiliation(s)
- Srinivas Jayanthi
- Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR 72701, USA.
| | | | | | - Mercede Furr
- Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR 72701, USA.
| | - Anna Daily
- Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR 72701, USA.
| | - Ryan Thurman
- Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR 72701, USA.
| | - Lindsay Rutherford
- Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR 72701, USA.
| | - Reena Chandrashekar
- Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR 72701, USA.
| | - Paul Adams
- Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR 72701, USA.
| | - Igor Prudovsky
- Maine Medical Center Research Institute, Scarborough, ME 04074, USA.
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Prudovsky I, Kumar TKS, Sterling S, Neivandt D. Protein-phospholipid interactions in nonclassical protein secretion: problem and methods of study. Int J Mol Sci 2013; 14:3734-72. [PMID: 23396106 PMCID: PMC3588068 DOI: 10.3390/ijms14023734] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Revised: 01/24/2013] [Accepted: 01/25/2013] [Indexed: 12/30/2022] Open
Abstract
Extracellular proteins devoid of signal peptides use nonclassical secretion mechanisms for their export. These mechanisms are independent of the endoplasmic reticulum and Golgi. Some nonclassically released proteins, particularly fibroblast growth factors (FGF) 1 and 2, are exported as a result of their direct translocation through the cell membrane. This process requires specific interactions of released proteins with membrane phospholipids. In this review written by a cell biologist, a structural biologist and two membrane engineers, we discuss the following subjects: (i) Phenomenon of nonclassical protein release and its biological significance; (ii) Composition of the FGF1 multiprotein release complex (MRC); (iii) The relationship between FGF1 export and acidic phospholipid externalization; (iv) Interactions of FGF1 MRC components with acidic phospholipids; (v) Methods to study the transmembrane translocation of proteins; (vi) Membrane models to study nonclassical protein release.
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Affiliation(s)
- Igor Prudovsky
- Maine Medical Center Research Institute, 81 Research Drive, Scarborough, ME 04074, USA
| | | | - Sarah Sterling
- Department of Chemical and Biological Engineering, University of Maine, Orono, ME 04469, USA; E-Mails: (S.S.); (D.N.)
| | - David Neivandt
- Department of Chemical and Biological Engineering, University of Maine, Orono, ME 04469, USA; E-Mails: (S.S.); (D.N.)
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8
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Abstract
Many secreted polypeptide regulators of angiogenesis are devoid of signal peptides. These proteins are released through nonclassical pathways independent of endoplasmic reticulum and Golgi. In most cases, the nonclassical protein export is induced by stress. It usually serves to stimulate repair or inflammation in damaged tissues. We review the secreted signal peptide-less regulators of angiogenesis and discuss the mechanisms and biological significance of their unconventional export.
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Affiliation(s)
- Igor Prudovsky
- Maine Medical Center Research Institute, 81 Research Drive, Scarborough, ME 04074, USA
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Craxton M. A manual collection of Syt, Esyt, Rph3a, Rph3al, Doc2, and Dblc2 genes from 46 metazoan genomes--an open access resource for neuroscience and evolutionary biology. BMC Genomics 2010; 11:37. [PMID: 20078875 PMCID: PMC2823689 DOI: 10.1186/1471-2164-11-37] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2009] [Accepted: 01/15/2010] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Synaptotagmin proteins were first identified in nervous tissue, residing in synaptic vesicles. Synaptotagmins were subsequently found to form a large family, some members of which play important roles in calcium triggered exocytic events. These members have been investigated intensively, but other family members are not well understood, making it difficult to grasp the meaning of family membership in functional terms. Further difficulty arises as families are defined quite legitimately in different ways: by common descent or by common possession of distinguishing features. One definition does not necessarily imply the other. The evolutionary range of genome sequences now available, can shed more light on synaptotagmin gene phylogeny and clarify family relationships. The aim of compiling this open access collection of synaptotagmin and synaptotagmin-like sequences, is that its use may lead to greater understanding of the biological function of these proteins in an evolutionary context. RESULTS 46 metazoan genomes were examined and their complement of Syt, Esyt, Rph3a, Rph3al, Doc2 and Dblc2 genes identified. All of the sequences were compared, named, then examined in detail. Esyt genes were formerly named Fam62. The species in this collection are Trichoplax, Nematostella, Capitella, Helobdella, Lottia, Ciona, Strongylocentrotus, Branchiostoma, Ixodes, Daphnia, Acyrthosiphon, Tribolium, Nasonia, Apis, Anopheles, Drosophila, Caenorhabditis, Takifugu, Tetraodon, Gasterosteus, Oryzias, Danio, Xenopus, Anolis, Gallus, Taeniopygia,Ornithorhynchus, Monodelphis, Mus and Homo. All of the data described in this paper is available as additional files. CONCLUSIONS Only a subset of synaptotagmin proteins appear able to function as calcium triggers. Syt1, Syt7 and Syt9 are ancient conserved synaptotagmins of this type. Some animals carry extensive repertoires of synaptotagmin genes. Other animals of no less complexity, carry only a small repertoire. Current understanding does not explain why this is so. The biological roles of many synaptotagmins remain to be understood. This collection of genes offers prospects for fruitful speculation about the functional roles of the synaptotagmin repertoires of different animals and includes a great range of biological complexity. With reference to this gene collection, functional relationships among Syt, Esyt, Rph3a, Rph3al, Doc2 and Dblc2 genes, which encode similar proteins, can better be assessed in future.
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Affiliation(s)
- Molly Craxton
- Medical Research Council Laboratory of Molecular Biology, Hills Road, Cambridge CB20QH, UK.
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10
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NMR characterization of copper and lipid interactions of the C2B domain of synaptotagmin I-relevance to the non-classical secretion of the human acidic fibroblast growth factor (hFGF-1). BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2009; 1798:297-302. [PMID: 19835837 DOI: 10.1016/j.bbamem.2009.09.024] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2009] [Revised: 09/18/2009] [Accepted: 09/30/2009] [Indexed: 11/21/2022]
Abstract
Human fibroblast growth factor (hFGF-1) is a approximately 17 kDa heparin binding cytokine. It lacks the conventional hydrophobic N-terminal signal sequence and is secreted through non-classical secretion routes. Under stress, hFGF-1 is released as a multiprotein complex consisting of hFGF-1, S100A13 (a calcium binding protein), and p40 synaptotagmin (Syt1). Copper (Cu(2+)) is shown to be required for the formation of the multiprotein hFGF-1 release complex (Landriscina et al. ,2001; Di Serio et al., 2008). Syt1, containing the lipid binding C2B domain, is believed to play an important role in the eventual export of the hFGF-1 across the lipid bilayer. In this study, we characterize Cu(2+) and lipid interactions of the C2B domain of Syt1 using multidimensional NMR spectroscopy. The results highlight how Cu(2+) appears to stabilize the protein bound to pS vesicles. Cu(2+) and lipid binding interface mapped using 2D (1)H-(15)N heteronuclear single quantum coherence experiments reveal that residues in beta-strand I contributes to the unique Cu(2+) binding site in the C2B domain. In the absence of metal ions, residues located in Loop II and beta-strand IV contribute to binding to unilamelar pS vesicles. In the presence of Cu(2+), additional residues located in Loops I and III appear to stabilize the protein-lipid interactions. The results of this study provide valuable information towards understanding the molecular mechanism of the Cu(2+)-induced non-classical secretion of hFGF-1.
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11
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Mohan SK, Rani SG, Kumar SM, Yu C. S100A13-C2A binary complex structure-a key component in the acidic fibroblast growth factor for the non-classical pathway. Biochem Biophys Res Commun 2009; 380:514-9. [PMID: 19284995 DOI: 10.1016/j.bbrc.2009.01.143] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2009] [Accepted: 01/18/2009] [Indexed: 11/30/2022]
Abstract
Fibroblast growth factors (FGFs) are key regulators of cell proliferation, differentiation, tumor-induced angiogenesis and migration. FGFs are essential for early embryonic development, organ formation and angiogenesis. They play important roles in tumor formation, inflammation, wound healing and restenosis. The biological effects of FGFs are mediated through the activation of the four transmembrane phosphotyrosine kinase receptors (FGFRs) in the presence of heparin sulfate proteoglycans (HSPGs) and therefore require the release of FGFs into the extracellular space. However, FGF-1 lacks the signal peptide required for the releasing of these proteins through the classical endoplasmic reticulum (ER)-Golgi secretary pathway. Maciag et al. demonstrated that FGF-1 is exported through a non-classical release pathway involving the formation of a specific multiprotein complex [M. Landriscina, R. Soldi, C. Bagala, I. Micucci, S. Bellum, F. Tarantini, I. Prudovsky, T. Maciag, S100A13 participates in the release of fibroblast growth factor 1 in response to heat shock in vitro, J. Biol. Chem. 276 (2001) 22544-22552; C.M. Carreira, T.M. LaVallee, F. Tarantini, A. Jackson, J.T. Lathrop, B. Hampton, W.H. Burgess, T. Maciag, S100A13 is involved in the regulation of fibroblast growth factor-1 and p40 synaptotagmin-1 release in vitro, J. Biol. Chem. 273 (1998) 22224-22231; T.M. LaValle, F. Tarantini, S. Gamble, C.M. Carreira, A. Jackson, T. Maciag, Synaptotagmin-1 is required for fibroblast growth factor-1 release, J. Biol. Chem. 273 (1998) 22217-22223; C. Bagalá, V. Kolev, A. Mandinova, R. Soldi, C. Mouta, I. Graziani, I, Prudovsky, T. Maciag, The alternative translation of synaptotagmin 1 mediates the non-classical release of FGF1, Biochem. Biophys. Res. Commun. 310 (2003) 1041-1047]. The protein constituents of this complex include FGF-1, S100A13 (a Ca(2+)-binding protein), and the p40 form of synaptotagmin 1 (Syt1). To understand the molecular events in the FGF-1 releasing pathway, we have studied the interactions of S100A13 with C2A by (1)H-(15)N HSQC titration and 3D-filtered NOESY experiments. We characterized the binary complex structure of S100A13-C2A by using a variety of multi-dimensional NMR experiments. This complex acts as a template for FGF-1 dimerization and multiprotein complex formation.
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Affiliation(s)
- Sepuru K Mohan
- Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan
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12
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Sukumaran SS, Banerjee S, Bhasker S, Thekkuveettil A. The cytoplasmic C2A domain of synaptotagmin shows sequence specific interaction with its own mRNA. Biochem Biophys Res Commun 2008; 373:509-14. [PMID: 18585366 DOI: 10.1016/j.bbrc.2008.06.063] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2008] [Accepted: 06/13/2008] [Indexed: 11/17/2022]
Abstract
Synaptotagmin-1 (Syt1) is essential in Ca(2+)-dependent neurotransmitter release, but its expression regulation is unknown. Here we report that the cytoplasmic Syt1 fragment forms ribonucleoprotein complex by interacting with the 3' untranslated region (3(')UTR) of its own mRNA. Two protein-binding domains, GU(15) repeat and GUCAAUG, within the Syt 3'UTR and the C2 domains in Syt1, especially C2A, are essential in this ribonucleoprotein complex formation. Furthermore, in in vitro assay the translation efficiency of Syt1 mRNA was downregulated in presence of 3'UTR. These results demonstrate for the fist time that the soluble fraction of Syt1 can interact with its own mRNA in a highly sequence specific manner.
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Affiliation(s)
- Sunitha S Sukumaran
- Division of Molecular Medicine, Sree Chitra Tirunal Institute for Medical Sciences and Technology, BMT Wing, Poojapura, Trivandrum, Kerala 695012, India
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13
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Prudovsky I, Tarantini F, Landriscina M, Neivandt D, Soldi R, Kirov A, Small D, Kathir KM, Rajalingam D, Kumar TKS. Secretion without Golgi. J Cell Biochem 2008; 103:1327-43. [PMID: 17786931 PMCID: PMC2613191 DOI: 10.1002/jcb.21513] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
A growing number of proteins devoid of signal peptides have been demonstrated to be released through the non-classical pathways independent of endoplasmic reticulum and Golgi. Among them are two potent proangiogenic cytokines FGF1 and IL1alpha. Stress-induced transmembrane translocation of these proteins requires the assembly of copper-dependent multiprotein release complexes. It involves the interaction of exported proteins with the acidic phospholipids of the inner leaflet of the cell membrane and membrane destabilization. Not only stress, but also thrombin treatment and inhibition of Notch signaling stimulate the export of FGF1. Non-classical release of FGF1 and IL1alpha presents a promising target for treatment of cardiovascular, oncologic, and inflammatory disorders.
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Affiliation(s)
- Igor Prudovsky
- Maine Medical Center Research Institute, Maine Medical Center, Scarborough, Maine 04074, USA.
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14
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Graziani I, Bagalá C, Duarte M, Soldi R, Kolev V, Tarantini F, Suresh Kumar TK, Doyle A, Neivandt D, Yu C, Maciag T, Prudovsky I. Release of FGF1 and p40 synaptotagmin 1 correlates with their membrane destabilizing ability. Biochem Biophys Res Commun 2006; 349:192-9. [PMID: 16930531 PMCID: PMC1779946 DOI: 10.1016/j.bbrc.2006.08.021] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2006] [Accepted: 08/04/2006] [Indexed: 10/24/2022]
Abstract
Fibroblast growth factor (FGF)1 is released from cells as a constituent of a complex that contains the small calcium binding protein S100A13, and the p40 kDa form of synaptotagmin (Syt)1, through an ER-Golgi-independent stress-induced pathway. FGF1 and the other components of its secretory complex are signal peptide-less proteins. We examined their capability to interact with lipid bilayers by studying protein-induced carboxyfluorescein release from liposomes of different phospholipid (pL) compositions. FGF1, p40 Syt1, and S100A13 induced destabilization of liposomes composed of acidic but not of zwitterionic pL. We produced mutants of FGF1 and p40 Syt1, in which specific basic amino acid residues in the regions that bind acidic pL were substituted. The ability of these mutants to induce liposomes destabilization was strongly attenuated, and they exhibited drastically diminished spontaneous and stress-induced release. Apparently, the non-classical release of FGF1 and p40 Syt1 involves destabilization of membranes containing acidic pL.
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Affiliation(s)
- Irene Graziani
- Maine Medical Center Research Institute, Scarborough, Maine 04074, USA
| | - Cinzia Bagalá
- Maine Medical Center Research Institute, Scarborough, Maine 04074, USA
| | - Maria Duarte
- Maine Medical Center Research Institute, Scarborough, Maine 04074, USA
| | - Raffaella Soldi
- Maine Medical Center Research Institute, Scarborough, Maine 04074, USA
| | - Vihren Kolev
- Maine Medical Center Research Institute, Scarborough, Maine 04074, USA
| | - Francesca Tarantini
- Department of Critical Care Medicine and Surgery, Gerontology and Geriatrics Unit, University of Florence, Florence 50139, Italy
| | | | - Andrew Doyle
- Department of Chemical and Biological Engineering, and Functional Genomics Program, University of Maine, Orono, ME 04469 USA
| | - David Neivandt
- Department of Chemical and Biological Engineering, and Functional Genomics Program, University of Maine, Orono, ME 04469 USA
| | - Chin Yu
- Department of Chemistry, National Tsing Hua University, Hsinchu 30043, Taiwan
| | - Thomas Maciag
- Maine Medical Center Research Institute, Scarborough, Maine 04074, USA
| | - Igor Prudovsky
- Maine Medical Center Research Institute, Scarborough, Maine 04074, USA
- * To whom correspondence should be addressed. Center for Molecular Medicine, Maine Medical Center Research Institute, 81 Research Drive, Scarborough ME 04074. Telephone: 207-885-8146; Fax 201-885-8179;
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15
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Sreenath AS, Kumar KR, Reddy GV, Sreedevi B, Praveen D, Monika S, Sudha S, Reddy MG, Reddanna P. Evidence for the association of synaptotagmin with glutathione S-transferases: implications for a novel function in human breast cancer. Clin Biochem 2005; 38:436-43. [PMID: 15820774 DOI: 10.1016/j.clinbiochem.2005.01.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2004] [Revised: 01/04/2005] [Accepted: 01/17/2005] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To analyze the pattern of changes in GSTs in cancerous and adjacent non-cancerous tissues obtained from breast cancer patients undergoing surgery. DESIGN AND METHODS Cytosolic GST purification, assay of GST, protein expression levels, and GST-synaptotagmin association were analyzed using standard biochemical techniques like GSH-affinity purification, spectrophotometry, SDS-PAGE, Western blots, and matrix-assisted laser desorption and ionization-time of flight (MALDI-TOF). RESULTS GST activity in cancerous tissues (0.26 U/mg protein) was significantly higher (P < 0.05) as compared to those from adjacent non-cancerous tissues (0.14 U/mg protein) of breast cancer patients. Further analysis of GST subunits on SDS-PAGE and Western blots using class-specific GST antibodies revealed significant elevation in GST-pi levels in cancer tissues with no appreciable changes in GST-alpha and GST-mu. Along with the elevation of GST-pi levels, high molecular weight proteins (approximately 70 kDa) cross reacting with GST antibodies were detected only in surgically resected tumor biopsies but not in the non-cancerous tissues adjacent to the tumor. Based on MALDI-TOF analysis, the high molecular weight band was identified as synaptotagmin V bound to GST-M1 with 47% sequence coverage after processing on an MS-FIT search engine. CONCLUSIONS Our results suggest a novel putative functional role for the GST-synaptotagmin complex in human breast cancers. As this association of GST M1-synaptotagmin was not seen in adjacent non-cancerous tissues, this can be used as a marker for breast cancers.
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Affiliation(s)
- A S Sreenath
- Department of Animal Sciences, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India
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16
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Abstract
Background Synaptotagmins exist as a large gene family in mammals. There is much interest in the function of certain family members which act crucially in the regulated synaptic vesicle exocytosis required for efficient neurotransmission. Knowledge of the functions of other family members is relatively poor and the presence of Synaptotagmin genes in plants indicates a role for the family as a whole which is wider than neurotransmission. Identification of the Synaptotagmin genes within completely sequenced genomes can provide the entire Synaptotagmin gene complement of each sequenced organism. Defining the detailed structures of all the Synaptotagmin genes and their encoded products can provide a useful resource for functional studies and a deeper understanding of the evolution of the gene family. The current rapid increase in the number of sequenced genomes from different branches of the tree of life, together with the public deposition of evolutionarily diverse transcript sequences make such studies worthwhile. Results I have compiled a detailed list of the Synaptotagmin genes of Caenorhabditis, Anopheles, Drosophila, Ciona, Danio, Fugu, Mus, Homo, Arabidopsis and Oryza by examining genomic and transcript sequences from public sequence databases together with some transcript sequences obtained by cDNA library screening and RT-PCR. I have compared all of the genes and investigated the relationship between plant Synaptotagmins and their non-Synaptotagmin counterparts. Conclusions I have identified and compared 98 Synaptotagmin genes from 10 sequenced genomes. Detailed comparison of transcript sequences reveals abundant and complex variation in Synaptotagmin gene expression and indicates the presence of Synaptotagmin genes in all animals and land plants. Amino acid sequence comparisons indicate patterns of conservation and diversity in function. Phylogenetic analysis shows the origin of Synaptotagmins in multicellular eukaryotes and their great diversification in animals. Synaptotagmins occur in land plants and animals in combinations of 4–16 in different species. The detailed delineation of the Synaptotagmin genes presented here, will allow easier identification of Synaptotagmins in future. Since the functional roles of many of these genes are unknown, this gene collection provides a useful resource for future studies.
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Tucker WC, Weber T, Chapman ER. Reconstitution of Ca2+-Regulated Membrane Fusion by Synaptotagmin and SNAREs. Science 2004; 304:435-8. [PMID: 15044754 DOI: 10.1126/science.1097196] [Citation(s) in RCA: 289] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
We investigated the effect of synaptotagmin I on membrane fusion mediated by neuronal SNARE proteins, SNAP-25, syntaxin, and synaptobrevin, which were reconstituted into vesicles. In the presence of Ca2+, the cytoplasmic domain of synaptotagmin I (syt) strongly stimulated membrane fusion when synaptobrevin densities were similar to those found in native synaptic vesicles. The Ca2+ dependence of syt-stimulated fusion was modulated by changes in lipid composition of the vesicles and by a truncation that mimics cleavage of SNAP-25 by botulinum neurotoxin A. Stimulation of fusion was abolished by disrupting the Ca2+-binding activity, or by severing the tandem C2 domains, of syt. Thus, syt and SNAREs are likely to represent the minimal protein complement for Ca2+-triggered exocytosis.
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Affiliation(s)
- Ward C Tucker
- Department of Physiology, University of Wisconsin, Madison, WI 53706, USA
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