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Schytte GN, Christensen B, Bregenov I, Kjøge K, Scavenius C, Petersen SV, Enghild JJ, Sørensen ES. FAM20C phosphorylation of the RGDSVVYGLR motif in osteopontin inhibits interaction with the αvβ3 integrin. J Cell Biochem 2020; 121:4809-4818. [PMID: 32115754 DOI: 10.1002/jcb.29708] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Accepted: 02/10/2020] [Indexed: 01/13/2023]
Abstract
Osteopontin (OPN) is a ubiquitously expressed, multifunctional, and highly phosphorylated protein. OPN contains two neighboring integrin-binding motifs, RGD and SVVYGLR, which mediate interaction with cells. Phosphorylation and proteolytic processing affect the integrin-binding activities of OPN. Here we report that the kinase, FAM20C, phosphorylates Ser146 in the 143 RGDSVVYGLR152 motif of OPN and that Ser146 is phosphorylated in vivo in human and bovine milk. Ser146 is located right next to the RGD motif and close by the regulatory thrombin and plasmin cleavage sites in the OPN sequence. Phosphorylation of Ser146 could potentially affect the proteolytic processing and the integrin-binding activities of OPN. We show that phosphorylation of Ser146 does not affect the susceptibility of OPN for thrombin or plasmin cleavage. However, phosphorylation of Ser146 significantly reduces the RGD-mediated interaction with the αv β3 integrin in MDA-MB-435 and Moαv cells. This suggests a new mechanism by which specific phosphorylation of OPN can regulate interaction with the αv β3 integrin and thereby affect OPN-cell interaction.
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Affiliation(s)
- Gitte N Schytte
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Brian Christensen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Ida Bregenov
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Katarzyna Kjøge
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Carsten Scavenius
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
- Interdisciplinary Nanoscience Center, Aarhus University, Aarhus, Denmark
| | | | - Jan J Enghild
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
- Interdisciplinary Nanoscience Center, Aarhus University, Aarhus, Denmark
| | - Esben S Sørensen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
- Interdisciplinary Nanoscience Center, Aarhus University, Aarhus, Denmark
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2
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Schytte GN, Christensen B, Bregenov I, Sørensen ES. Ras-transformation reduce FAM20C expression and osteopontin phosphorylation. Biosci Rep 2020; 40:BSR20194378. [PMID: 32830861 PMCID: PMC7494989 DOI: 10.1042/bsr20194378] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 07/07/2020] [Accepted: 08/19/2020] [Indexed: 12/30/2022] Open
Abstract
Family with sequence similarity 20, member C (FAM20C) is the main kinase of secreted phosphoproteins, including the multifunctional protein and cytokine, osteopontin (OPN). The phosphorylation of OPN varies greatly among cell types, tissues and species, and the different phospho-isoforms contribute to the multifunctionality of the protein. Expression of OPN is increased in human malignancies, and less phosphorylated isoforms of the protein have been associated with this phenotype. Here, we compared OPN from ras-transformed fibroblasts with that from their non-transformed parental cells, and found that OPN was less phosphorylated after ras-transformation. Furthermore, we demonstrated that expression of FAM20C mRNA was reduced five-fold in ras-transformed fibroblasts compared with non-transformed fibroblasts. Transfection with FAM20C of the ras-transformed fibroblasts restored the FAM20C mRNA expression but the phosphorylation of OPN was not increased proportionally. Likewise, the mRNA level of FAM20C was reduced in the malignant ras-transformed mammary cell line MCF10ACA1a compared with its non-transformed parental cell line MCF10A. These results suggest that expression of the FAM20C kinase is reduced after oncogenic ras-transformation, which potentially affects the phosphorylation of secreted phosphoproteins.
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Affiliation(s)
- Gitte N Schytte
- Department of Molecular Biology and Genetics, Science Park, Aarhus University, Aarhus, Denmark
| | - Brian Christensen
- Department of Molecular Biology and Genetics, Science Park, Aarhus University, Aarhus, Denmark
| | - Ida Bregenov
- Department of Molecular Biology and Genetics, Science Park, Aarhus University, Aarhus, Denmark
| | - Esben S Sørensen
- Department of Molecular Biology and Genetics, Science Park, Aarhus University, Aarhus, Denmark
- Interdisciplinary Nanoscience Center, Aarhus University, Aarhus, Denmark
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Adetula AA, Gu L, Nwafor CC, Du X, Zhao S, Li S. Transcriptome sequencing reveals key potential long non-coding RNAs related to duration of fertility trait in the uterovaginal junction of egg-laying hens. Sci Rep 2018; 8:13185. [PMID: 30181614 PMCID: PMC6123486 DOI: 10.1038/s41598-018-31301-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 08/13/2018] [Indexed: 12/19/2022] Open
Abstract
Duration of fertility, (DF) is an important functional trait in poultry production and lncRNAs have emerged as important regulators of various process including fertility. In this study we applied a genome-guided strategy to reconstruct the uterovaginal junction (UVJ) transcriptome of 14 egg-laying birds with long- and short-DF (n = 7); and sought to uncover key lncRNAs related to duration of fertility traits by RNA-sequencing technology. Examination of RNA-seq data revealed a total of 9977 lncRNAs including 2576 novel lncRNAs. Differential expression (DE) analysis of lncRNA identified 223 lncRNAs differentially expressed between the two groups. DE-lncRNA target genes prediction uncovered over 200 lncRNA target genes and functional enrichment tests predict a potential function of DE-lncRNAs. Gene ontology classification and pathway analysis revealed 8 DE-lncRNAs, with the majority of their target genes enriched in biological functions such as reproductive structure development, developmental process involved in reproduction, response to cytokine, carbohydrate binding, chromatin organization, and immune pathways. Differential expression of lncRNAs and target genes were confirmed by qPCR. Together, these results significantly expand the utility of the UVJ transcriptome and our analysis identification of key lncRNAs and their target genes regulating DF will form the baseline for understanding the molecular functions of lncRNAs regulating DF.
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Affiliation(s)
- Adeyinka Abiola Adetula
- Key Laboratory of Agricultural Animal Genetics, Breeding, and Reproduction, Ministry of Education, Huazhong Agricultural University, Wuhan, Hubei Province, 430070, China
| | - Lantao Gu
- Key Laboratory of Agricultural Animal Genetics, Breeding, and Reproduction, Ministry of Education, Huazhong Agricultural University, Wuhan, Hubei Province, 430070, China
| | | | - Xiaoyong Du
- College of Informatics, Huazhong Agricultural University, Wuhan, 430070, China
| | - Shuhong Zhao
- Key Laboratory of Agricultural Animal Genetics, Breeding, and Reproduction, Ministry of Education, Huazhong Agricultural University, Wuhan, Hubei Province, 430070, China
| | - Shijun Li
- Key Laboratory of Agricultural Animal Genetics, Breeding, and Reproduction, Ministry of Education, Huazhong Agricultural University, Wuhan, Hubei Province, 430070, China.
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Abstract
We review the evolution and structure of members of the transforming growth factor β (TGF-β) family, antagonistic or agonistic modulators, and receptors that regulate TGF-β signaling in extracellular environments. The growth factor (GF) domain common to all family members and many of their antagonists evolved from a common cystine knot growth factor (CKGF) domain. The CKGF superfamily comprises six distinct families in primitive metazoans, including the TGF-β and Dan families. Compared with Wnt/Frizzled and Notch/Delta families that also specify body axes, cell fate, tissues, and other families that contain CKGF domains that evolved in parallel, the TGF-β family was the most fruitful in evolution. Complexes between the prodomains and GFs of the TGF-β family suggest a new paradigm for regulating GF release by conversion from closed- to open-arm procomplex conformations. Ternary complexes of the final step in extracellular signaling show how TGF-β GF dimers bind type I and type II receptors on the cell surface, and enable understanding of much of the specificity and promiscuity in extracellular signaling. However, structures suggest that when GFs bind repulsive guidance molecule (RGM) family coreceptors, type I receptors do not bind until reaching an intracellular, membrane-enveloped compartment, blurring the line between extra- and intracellular signaling. Modulator protein structures show how structurally diverse antagonists including follistatins, noggin, and members of the chordin family bind GFs to regulate signaling; complexes with the Dan family remain elusive. Much work is needed to understand how these molecular components assemble to form signaling hubs in extracellular environments in vivo.
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Affiliation(s)
- Andrew P Hinck
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15260
| | - Thomas D Mueller
- Department of Plant Physiology and Biophysics, Julius-von-Sachs Institute of the University Wuerzburg, D-97082 Wuerzburg, Germany
| | - Timothy A Springer
- Program in Cellular and Molecular Medicine and Division of Hematology, Department of Medicine, Boston Children's Hospital, Boston, Massachusetts 02115
- Department of Biological Chemistry and Pharmacology, Harvard Medical School, Boston, Massachusetts 02115
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Appeltant R, Somfai T, Maes D, VAN Soom A, Kikuchi K. Porcine oocyte maturation in vitro: role of cAMP and oocyte-secreted factors - A practical approach. J Reprod Dev 2016; 62:439-449. [PMID: 27349308 PMCID: PMC5081730 DOI: 10.1262/jrd.2016-016] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Polyspermy or the penetration of more than one sperm cell remains a problem during porcine in vitro fertilization (IVF). After in
vitro culture of porcine zygotes, only a low percentage of blastocysts develop and their quality is inferior to that of in vivo
derived blastocysts. It is unknown whether the cytoplasmic maturation of the oocyte is sufficiently sustained in current in vitro maturation
(IVM) procedures. The complex interplay between oocyte and cumulus cells during IVM is a key factor in this process. By focusing on this bidirectional
communication, it is possible to control the coordination of cumulus expansion, and nuclear and cytoplasmic maturation during IVM to some extent. Therefore,
this review focuses on the regulatory mechanisms between oocytes and cumulus cells to further the development of new in vitro embryo production
(IVP) procedures, resulting in less polyspermy and improved oocyte developmental potential. Specifically, we focused on the involvement of cAMP in maturation
regulation and function of oocyte-secreted factors (OSFs) in the bidirectional regulatory loop between oocyte and cumulus cells. Our studies suggest that
maintaining high cAMP levels in the oocyte during the first half of IVM sustained improved oocyte maturation, resulting in an enhanced response after IVF and
cumulus matrix disassembly. Recent research indicated that the addition of OSFs during IVM enhanced the developmental competence of small follicle-derived
oocytes, which was stimulated by epidermal growth factor (EGF) via developing EGF-receptor signaling.
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Affiliation(s)
- Ruth Appeltant
- Division of Animal Sciences, Institute of Agrobiological Sciences, National Agriculture and Food Research Organization, Ibaraki 305-8602, Japan
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Canonical and noncanonical intraflagellar transport regulates craniofacial skeletal development. Proc Natl Acad Sci U S A 2016; 113:E2589-97. [PMID: 27118846 DOI: 10.1073/pnas.1519458113] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The primary cilium is a cellular organelle that coordinates signaling pathways critical for cell proliferation, differentiation, survival, and homeostasis. Intraflagellar transport (IFT) plays a pivotal role in assembling primary cilia. Disruption and/or dysfunction of IFT components can cause multiple diseases, including skeletal dysplasia. However, the mechanism by which IFT regulates skeletogenesis remains elusive. Here, we show that a neural crest-specific deletion of intraflagellar transport 20 (Ift20) in mice compromises ciliogenesis and intracellular transport of collagen, which leads to osteopenia in the facial region. Whereas platelet-derived growth factor receptor alpha (PDGFRα) was present on the surface of primary cilia in wild-type osteoblasts, disruption of Ift20 down-regulated PDGFRα production, which caused suppression of PDGF-Akt signaling, resulting in decreased osteogenic proliferation and increased cell death. Although osteogenic differentiation in cranial neural crest (CNC)-derived cells occurred normally in Ift20-mutant cells, the process of mineralization was severely attenuated due to delayed secretion of type I collagen. In control osteoblasts, procollagen was easily transported from the endoplasmic reticulum (ER) to the Golgi apparatus. By contrast, despite having similar levels of collagen type 1 alpha 1 (Col1a1) expression, Ift20 mutants did not secrete procollagen because of dysfunctional ER-to-Golgi trafficking. These data suggest that in the multipotent stem cells of CNCs, IFT20 is indispensable for regulating not only ciliogenesis but also collagen intracellular trafficking. Our study introduces a unique perspective on the canonical and noncanonical functions of IFT20 in craniofacial skeletal development.
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Li JJ, Sugimura S, Mueller TD, White MA, Martin GA, Ritter LJ, Liang XY, Gilchrist RB, Mottershead DG. Modifications of human growth differentiation factor 9 to improve the generation of embryos from low competence oocytes. Mol Endocrinol 2016; 29:40-52. [PMID: 25394262 DOI: 10.1210/me.2014-1173] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Growth differentiation factor 9 (GDF9) is an oocyte-derived growth factor that plays a critical role in ovarian folliculogenesis and oocyte developmental competence and belongs to the TGF-β family of proteins. Recombinant human GDF9 (hGDF9) is secreted in a latent form, which in the case of the fully processed protein, has the proregion noncovalently associated with the mature region. In this study, we investigated a number of amino acid residues in the mature region of hGDF9 that are different from the corresponding residues in the mouse protein, which is not latent. We designed, expressed, and purified 4 forms of chimeric hGDF9 (M1-M4) that we found to be active in a granulosa cell bioassay. Using a porcine in vitro maturation model with inherent low developmental competence (yielding 10%-20% blastocysts), we tested the ability of the chimeric hGDF9 proteins to improve oocyte maturation and developmental competence. Interestingly, one of the chimeric proteins, M3, was able to significantly increase the level of embryo production using such low competence oocytes. Our molecular modeling studies suggest that in the case of hGDF9 the Gly(391)Arg mutation probably increases receptor binding affinity, thereby creating an active protein for granulosa cells in vitro. However, for an improvement in oocyte developmental competence, a second mutation (Ser(412)Pro), which potentially decreases the affinity of the mature region for the proregion, is also required.
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Affiliation(s)
- Jing-Jie Li
- Center of Reproductive Medicine (J.-J.L., X.-Y.L.), the Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou 520655, China; Institute of Agriculture (S.S.), Department of Biological Production, Tokyo University of Agriculture and Technology, Tokyo 183-0057, Japan; Robinson Research Institute (J.-J.L., S.S., M.A.W., G.A.M., L.J.R., R.B.G., D.G.M.), School of Paediatrics and Reproductive Health, The University of Adelaide, Adelaide 5005, Australia; Discipline of Obstetrics and Gynaecology, School of Women's and Children's Health (R.B.G.), Royal Hospital for Women, University of New South Wales, Sydney, New South Wales 2031 Australia; and Department of Plant Physiology and Biophysics (T.D.M.), Julius-von-Sachs Institute of the University Wuerzburg, 97082 Wuerzburg, Germany
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Abstract
INTRODUCTION The conventional term 'casein kinase' (CK) denotes three classes of kinases - CK1, CK2 and Golgi-CK (G-CK)/Fam20C (family with sequence similarity 20, member C) - sharing the ability to phoshorylate casein in vitro, but otherwise unrelated to each other. All CKs have been reported to be implicated in human diseases, and reviews individually dealing with the druggability of CK1 and CK2 are available. Our aim is to provide a comparative analysis of the three classes of CKs as therapeutic targets. AREAS COVERED CK2 is the CK for which implication in neoplasia is best documented, with the survival of cancer cells often relying on its overexpression. An ample variety of cell-permeable CK2 inhibitors have been developed, with a couple of these now in clinical trials. Isoform-specific CK1 inhibitors that are expected to play a beneficial role in oncology and neurodegeneration have been also developed. In contrast, the pathogenic potential of G-CK/Fam20C is caused by its loss of function. Activators of Fam20C, notably sphingolipids and their analogs, may prove beneficial in this respect. EXPERT OPINION Optimization of CK2 and CK1 inhibitors will prove useful to develop new therapeutic strategies for treating cancer and neurodegenerative disorders, while the design of potent activators of G-CK/Fam20C will provide a new tool in the fields of bio-mineralization and hypophosphatemic diseases.
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Affiliation(s)
- Giorgio Cozza
- a 1 University of Padova, Department of Biomedical Sciences , Via Ugo Bassi 58B, 35131 Padova, Italy
| | - Lorenzo A Pinna
- a 1 University of Padova, Department of Biomedical Sciences , Via Ugo Bassi 58B, 35131 Padova, Italy .,b 2 University of Padova, Department of Biomedical Sciences and CNR Institute of Neurosciences , Padova, Italy ;
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Yalak G, Olsen BR. Proteomic database mining opens up avenues utilizing extracellular protein phosphorylation for novel therapeutic applications. J Transl Med 2015; 13:125. [PMID: 25927841 PMCID: PMC4427915 DOI: 10.1186/s12967-015-0482-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Accepted: 04/07/2015] [Indexed: 02/07/2023] Open
Abstract
Recent advances in extracellular signaling suggest that extracellular protein phosphorylation is a regulatory mechanism outside the cell. The list of reported active extracellular protein kinases and phosphatases is growing, and phosphorylation of an increasing number of extracellular matrix molecules and extracellular domains of trans-membrane proteins is being documented. Here, we use public proteomic databases, collagens – the major components of the extracellular matrix, extracellular signaling molecules and proteolytic enzymes as examples to assess what the roles of extracellular protein phosphorylation may be in health and disease. We propose that novel tools be developed to help assess the role of extracellular protein phosphorylation and translate the findings for biomedical applications. Furthermore, we suggest that the phosphorylation state of extracellular matrix components as well as the presence of extracellular kinases be taken into account when designing translational medical applications.
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Affiliation(s)
- Garif Yalak
- Department of Developmental Biology, Harvard Medical School/Harvard School of Dental Medicine, 188 Longwood Avenue, Boston, MA, 02115, USA.
| | - Bjorn R Olsen
- Department of Developmental Biology, Harvard Medical School/Harvard School of Dental Medicine, 188 Longwood Avenue, Boston, MA, 02115, USA.
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10
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Abstract
The term 'casein kinase' has been widely used for decades to denote protein kinases sharing the ability to readily phosphorylate casein in vitro. These fall into three main classes: two of them, later renamed as protein kinases CK1 (casein kinase 1, also known as CKI) and CK2 (also known as CKII), are pleiotropic members of the kinome functionally unrelated to casein, whereas G-CK, or genuine casein kinase, responsible for the phosphorylation of casein in the Golgi apparatus of the lactating mammary gland, has only been identified recently with Fam20C [family with sequence similarity 20C; also known as DMP-4 (dentin matrix protein-4)], a member of the four-jointed family of atypical protein kinases, being responsible for the phosphorylation of many secreted proteins. In hindsight, therefore, the term 'casein kinase' is misleading in every instance; in the case of CK1 and CK2, it is because casein is not a physiological substrate, and in the case of G-CK/Fam20C/DMP-4, it is because casein is just one out of a plethora of its targets, and a rather marginal one at that. Strikingly, casein kinases altogether, albeit representing a minimal proportion of the whole kinome, appear to be responsible for the generation of up to 40-50% of non-redundant phosphosites currently retrieved in human phosphopeptides database. In the present review, a short historical explanation will be provided accounting for the usage of the same misnomer to denote three unrelated classes of protein kinases, together with an update of our current knowledge of these pleiotropic enzymes, sharing the same misnomer while playing very distinct biological roles.
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11
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Tagliabracci VS, Engel JL, Wiley SE, Xiao J, Gonzalez DJ, Nidumanda Appaiah H, Koller A, Nizet V, White KE, Dixon JE. Dynamic regulation of FGF23 by Fam20C phosphorylation, GalNAc-T3 glycosylation, and furin proteolysis. Proc Natl Acad Sci U S A 2014; 111:5520-5. [PMID: 24706917 PMCID: PMC3992636 DOI: 10.1073/pnas.1402218111] [Citation(s) in RCA: 223] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The family with sequence similarity 20, member C (Fam20C) has recently been identified as the Golgi casein kinase. Fam20C phosphorylates secreted proteins on Ser-x-Glu/pSer motifs and loss-of-function mutations in the kinase cause Raine syndrome, an often-fatal osteosclerotic bone dysplasia. Fam20C is potentially an upstream regulator of the phosphate-regulating hormone fibroblast growth factor 23 (FGF23), because humans with FAM20C mutations and Fam20C KO mice develop hypophosphatemia due to an increase in full-length, biologically active FGF23. However, the mechanism by which Fam20C regulates FGF23 is unknown. Here we show that Fam20C directly phosphorylates FGF23 on Ser(180), within the FGF23 R(176)XXR(179)/S(180)AE subtilisin-like proprotein convertase motif. This phosphorylation event inhibits O-glycosylation of FGF23 by polypeptide N-acetylgalactosaminyltransferase 3 (GalNAc-T3), and promotes FGF23 cleavage and inactivation by the subtilisin-like proprotein convertase furin. Collectively, our results provide a molecular mechanism by which FGF23 is dynamically regulated by phosphorylation, glycosylation, and proteolysis. Furthermore, our findings suggest that cross-talk between phosphorylation and O-glycosylation of proteins in the secretory pathway may be an important mechanism by which secreted proteins are regulated.
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Affiliation(s)
| | | | | | | | | | - Hitesh Nidumanda Appaiah
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN 46202; and
| | - Antonius Koller
- Stony Brook University Proteomics Center, School of Medicine, Stony Brook University, Stony Brook, NY 11794
| | - Victor Nizet
- Pediatrics
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA 92093
| | - Kenneth E. White
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN 46202; and
| | - Jack E. Dixon
- Departments of Pharmacology
- Cellular and Molecular Medicine, and
- Chemistry and Biochemistry and
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12
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Juengel JL, Davis GH, McNatty KP. Using sheep lines with mutations in single genes to better understand ovarian function. Reproduction 2013; 146:R111-23. [DOI: 10.1530/rep-12-0509] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Livestock populations have been subjected to strong selection pressure to improve reproductive success, and this has led to the identification of lines of animals with increased fecundity. These animals provide a rich biological resource for discovery of genes and regulatory mechanisms that underpin improved reproductive success. To date, three genes, all related to the transforming growth factor β pathway, have been identified as having mutations that lead to alterations in ovulation in sheep. In addition, several other sheep lines have been identified with putative mutations in single genes with major effects on ovulation rate. This review is focused on the identification of the mutations affecting ovulation rate and how these discoveries have provided new insights into control of ovarian function.
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Tagliabracci VS, Pinna LA, Dixon JE. Secreted protein kinases. Trends Biochem Sci 2012; 38:121-30. [PMID: 23276407 DOI: 10.1016/j.tibs.2012.11.008] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Revised: 11/25/2012] [Accepted: 11/29/2012] [Indexed: 11/28/2022]
Abstract
Protein kinases constitute one of the largest gene families and control many aspects of cellular life. In retrospect, the first indication for their existence was reported 130 years ago when the secreted protein, casein, was shown to contain phosphate. Despite its identification as the first phosphoprotein, the responsible kinase has remained obscure. This conundrum was solved with the discovery of a novel family of atypical protein kinases that are secreted and appear to phosphorylate numerous extracellular proteins, including casein. Fam20C, the archetypical member, phosphorylates secreted proteins within Ser-x-Glu/pSer motifs. This discovery has solved a 130-year-old mystery and has shed light on several human disorders of biomineralization.
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14
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Tagliabracci VS, Engel JL, Wen J, Wiley SE, Worby CA, Kinch LN, Xiao J, Grishin NV, Dixon JE. Secreted kinase phosphorylates extracellular proteins that regulate biomineralization. Science 2012; 336:1150-3. [PMID: 22582013 PMCID: PMC3754843 DOI: 10.1126/science.1217817] [Citation(s) in RCA: 339] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Protein phosphorylation is a fundamental mechanism regulating nearly every aspect of cellular life. Several secreted proteins are phosphorylated, but the kinases responsible are unknown. We identified a family of atypical protein kinases that localize within the Golgi apparatus and are secreted. Fam20C appears to be the Golgi casein kinase that phosphorylates secretory pathway proteins within S-x-E motifs. Fam20C phosphorylates the caseins and several secreted proteins implicated in biomineralization, including the small integrin-binding ligand, N-linked glycoproteins (SIBLINGs). Consequently, mutations in Fam20C cause an osteosclerotic bone dysplasia in humans known as Raine syndrome. Fam20C is thus a protein kinase dedicated to the phosphorylation of extracellular proteins.
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Affiliation(s)
- Vincent S. Tagliabracci
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093–0721, USA
| | - James L. Engel
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093–0721, USA
| | - Jianzhong Wen
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093–0721, USA
| | - Sandra E. Wiley
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093–0721, USA
| | - Carolyn A. Worby
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093–0721, USA
| | - Lisa N. Kinch
- University of Texas, Southwestern Medical Center, Dallas, TX 75390–9050, USA
| | - Junyu Xiao
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093–0721, USA
| | - Nick V. Grishin
- University of Texas, Southwestern Medical Center, Dallas, TX 75390–9050, USA
- Howard Hughes Medical Institute, Chevy Chase, MD 20815–6789, USA
| | - Jack E. Dixon
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093–0721, USA
- Howard Hughes Medical Institute, Chevy Chase, MD 20815–6789, USA
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15
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Pulkki MM, Myllymaa S, Pasternack A, Lun S, Ludlow H, Al-Qahtani A, Korchynskyi O, Groome N, Juengel JL, Kalkkinen N, Laitinen M, Ritvos O, Mottershead DG. The bioactivity of human bone morphogenetic protein-15 is sensitive to C-terminal modification: characterization of the purified untagged processed mature region. Mol Cell Endocrinol 2011; 332:106-15. [PMID: 20937357 DOI: 10.1016/j.mce.2010.10.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2010] [Revised: 09/06/2010] [Accepted: 10/04/2010] [Indexed: 11/18/2022]
Abstract
Oocyte-derived bone morphogenetic protein-15 (BMP15) is critical for the regulation of mammalian fertility. Previously we have found that a C-terminal His(6)-tag destroys the bioactivity of growth differentiation-9 (GDF9, a homolog of BMP15). In this study we found that recombinant human BMP15 is produced by HEK-293T cells in an active form, but the bioactivity is lost by C-terminal modification, specifically, fusion to a Flag tag. After purification the mature BMP15 wt is active in transcriptional reporter assays specific for Smad1/5/8 in human granulosa-luteal (hGL) and COV434 granulosa tumor cells, whereas BMP15 with a carboxy-terminal Flag tag remains inactive. Using these same cell models we found that treatment with purified mature BMP15 wt causes a rapid phosphorylation of Smad1. The purified BMP15 wt is a potent stimulator of rat granulosa cell DNA synthesis, which could be antagonized by the BMPRII ectodomain-Fc fusion molecule, whereas the BMP15C-Flag was completely inactive. Further, the BMP15 wt form is a potent stimulator of inhibin B production in hGL cells. We found that the purified BMP15 wt consists of P16 and -17, both of which are post-translationally modified forms. This is the first characterization of a purified untagged human BMP15 mature region, which is stable and highly bioactive in human and rodent granulosa cells and as such is of importance for studies on human fertility.
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Affiliation(s)
- Minna M Pulkki
- Department of Bacteriology and Immunology, Haartman Institute, 00014 University of Helsinki, Helsinki, Finland.
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Abstract
Inhibin A and B, dimeric glycoproteins comprising an α- and β((A/B))-subunit, negatively regulate follicle stimulating hormone (FSH) synthesis by the pituitary. The expression of α- and β-subunits within Sertoli cells of the testis and granulosa cells of the ovary is controlled by a range of transcription factors, including CREB, SP-1, Smads, and GATA factors. The inhibin α- and β-subunits are synthesized as precursor molecules consisting of an N-terminal propeptide and a C-terminal mature domain. Recently, we showed that hydrophobic residues within the propeptides of the α- and β-subunits interact noncovalently with their mature domains, maintaining the molecules in a conformation competent for dimerization. Dimeric precursors are cleaved by proprotein convertases and mature inhibins are secreted from the cell noncovalently associated with their propeptides. Propeptides may increase the half-life of inhibin A and B in circulation, but they are readily displaced in the presence of the high-affinity receptors, betaglycan, and ActRII.
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Salvi M, Cesaro L, Tibaldi E, Pinna LA. Motif Analysis of Phosphosites Discloses a Potential Prominent Role of the Golgi Casein Kinase (GCK) in the Generation of Human Plasma Phospho-Proteome. J Proteome Res 2010; 9:3335-8. [DOI: 10.1021/pr100058r] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Mauro Salvi
- Department of Biological Chemistry, University of Padova, V.le G. Colombo 3, 35131 Padova, Italy, and Venetian Institute for Molecular Medicine, via Orus 2, 35129 Padova, Italy
| | - Luca Cesaro
- Department of Biological Chemistry, University of Padova, V.le G. Colombo 3, 35131 Padova, Italy, and Venetian Institute for Molecular Medicine, via Orus 2, 35129 Padova, Italy
| | - Elena Tibaldi
- Department of Biological Chemistry, University of Padova, V.le G. Colombo 3, 35131 Padova, Italy, and Venetian Institute for Molecular Medicine, via Orus 2, 35129 Padova, Italy
| | - Lorenzo A. Pinna
- Department of Biological Chemistry, University of Padova, V.le G. Colombo 3, 35131 Padova, Italy, and Venetian Institute for Molecular Medicine, via Orus 2, 35129 Padova, Italy
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