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Otto NM, Potter LR. Vicinal glutamates are better phosphomimetics: Phosphorylation is required for allosteric activation of guanylyl cyclase-A. Front Mol Neurosci 2022; 15:1012784. [DOI: 10.3389/fnmol.2022.1012784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 09/22/2022] [Indexed: 11/06/2022] Open
Abstract
Multisite phosphorylation of guanylyl cyclase (GC)-A, also known as NPR-A or NPR1, is required for receptor activation by natriuretic peptides (NPs) because alanine substitutions for the first four GC-A phosphorylation sites produce an enzyme that cannot be stimulated by NPs. In contrast, single Glu substitutions for the first six chemically identified GC-A phosphorylation sites to mimic the negative charge of phosphate produced an enzyme that is activated by NPs but had an elevated Michaelis constant (Km), resulting in low activity. Here, we show that vicinal (double adjacent) Glu substitutions for the same sites to mimic the two negative charges of phosphate produced a near wild type (WT) enzyme with a low Km. Unlike the enzyme with single glutamate substitutions, the vicinally substituted enzyme did not require the functionally identified Ser-473-Glu substitution to achieve WT-like activity. Importantly, the negative charge associated with either phosphorylation or glutamate substitutions was required for allosteric activation of GC-A by ATP. We conclude that vicinal Glu substitutions are better phosphomimetics than single Glu substitutions and that phosphorylation is required for allosteric activation of GC-A in the absence and presence of NP. Finally, we suggest that the putative functionally identified phosphorylation sites, Ser-473 in GC-A and Ser-489 in GC-B, are not phosphorylation sites at all.
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Egbert JR, Uliasz TF, Lowther KM, Kaback D, Wagner BM, Healy CL, O’Connell TD, Potter LR, Jaffe LA, Yee SP. Epitope-tagged and phosphomimetic mouse models for investigating natriuretic peptide-stimulated receptor guanylyl cyclases. Front Mol Neurosci 2022; 15:1007026. [PMID: 36340689 PMCID: PMC9627482 DOI: 10.3389/fnmol.2022.1007026] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 09/28/2022] [Indexed: 01/25/2023] Open
Abstract
The natriuretic peptide receptors NPR1 and NPR2, also known as guanylyl cyclase A and guanylyl cyclase B, have critical functions in many signaling pathways, but much remains unknown about their localization and function in vivo. To facilitate studies of these proteins, we developed genetically modified mouse lines in which endogenous NPR1 and NPR2 were tagged with the HA epitope. To investigate the role of phosphorylation in regulating NPR1 and NPR2 guanylyl cyclase activity, we developed mouse lines in which regulatory serines and threonines were substituted with glutamates, to mimic the negative charge of the phosphorylated forms (NPR1-8E and NPR2-7E). Here we describe the generation and applications of these mice. We show that the HA-NPR1 and HA-NPR2 mice can be used to characterize the relative expression levels of these proteins in different tissues. We describe studies using the NPR2-7E mice that indicate that dephosphorylation of NPR2 transduces signaling pathways in ovary and bone, and studies using the NPR1-8E mice that indicate that the phosphorylation state of NPR1 is a regulator of heart, testis, and adrenal function.
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Affiliation(s)
- Jeremy R. Egbert
- Department of Cell Biology, University of Connecticut Health Center, Farmington, CT, United States,*Correspondence: Jeremy R. Egbert,
| | - Tracy F. Uliasz
- Department of Cell Biology, University of Connecticut Health Center, Farmington, CT, United States
| | - Katie M. Lowther
- Department of Cell Biology, University of Connecticut Health Center, Farmington, CT, United States,Center for Mouse Genome Modification, University of Connecticut Health Center, Farmington, CT, United States
| | - Deborah Kaback
- Department of Cell Biology, University of Connecticut Health Center, Farmington, CT, United States,Center for Mouse Genome Modification, University of Connecticut Health Center, Farmington, CT, United States
| | - Brandon M. Wagner
- Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, MN, United States
| | - Chastity L. Healy
- Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, MN, United States
| | - Timothy D. O’Connell
- Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, MN, United States
| | - Lincoln R. Potter
- Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, MN, United States,Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, United States,Lincoln R. Potter,
| | - Laurinda A. Jaffe
- Department of Cell Biology, University of Connecticut Health Center, Farmington, CT, United States,Laurinda A. Jaffe,
| | - Siu-Pok Yee
- Department of Cell Biology, University of Connecticut Health Center, Farmington, CT, United States,Center for Mouse Genome Modification, University of Connecticut Health Center, Farmington, CT, United States,Siu-Pok Yee,
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Novel NPR2 Gene Mutations Affect Chondrocytes Function via ER Stress in Short Stature. Cells 2022; 11:cells11081265. [PMID: 35455946 PMCID: PMC9024524 DOI: 10.3390/cells11081265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 03/25/2022] [Accepted: 04/06/2022] [Indexed: 12/10/2022] Open
Abstract
Natriuretic peptide receptor 2 (NPR2) plays a key role in cartilage and bone morphogenesis. The NPR2 gene mutations result in acromesomelic dysplasia, Maroteaux type (AMDM), short stature with nonspecific skeletal abnormalities (SNSK), and epiphyseal chondrodysplasia, Miura type (ECDM). However, the pathogenic mechanism remains unclear. In our study, we identified one de novo (R557C) and six novel variants (G602W, V970F, R767*, R363*, F857S, and Y306S) in five independent Chinese families with familial short stature. Three patients with heterozygous mutations (G602W, V970F, and R767*) were diagnosed with SNSK (height SD score ranged from −2.25 to −5.60), while another two with compound heterozygous mutations (R363* and F857S, R557C and Y306S) were diagnosed with AMDM (height SD score ranged from −3.10 to −5.35). Among three patients with heterozygous status, two patients before puberty initiation with rhGH treatment significantly improved their growth (height velocity 7.2 cm/year, 6.0 cm/year), and one patient in puberty had a poor response to the rhGH treatment (height velocity 2.5 cm/year). Seven NPR2 gene variants were constructed and overexpressed in HEK293T and ATDC5 cells, and we found that ATDC5 cells with mutant NPR2 gene showed decreased differentiation, as evidenced by lower expression of ColII, ColX, and BMP4 and higher expression of Sox9. Moreover, the apoptosis rate was elevated in ATDC5 cells expressing the mutant NPR2 gene. N-glycosylation modification, plasma membrane localization, and ER stress resulted from the accumulation of mutant protein in ER, as shown by the higher expression of GRP78 and p-IRE1α. Overall, our results provide a novel insight into NPR2 loss of function, which could promote chondrocyte apoptosis and repress cell differentiation through ER stress and the unfolded protein response.
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Hanley PC, Kanwar HS, Martineau C, Levine MA. Short Stature is Progressive in Patients with Heterozygous NPR2 Mutations. J Clin Endocrinol Metab 2020; 105:5877389. [PMID: 32720985 PMCID: PMC7442278 DOI: 10.1210/clinem/dgaa491] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Accepted: 07/22/2020] [Indexed: 11/19/2022]
Abstract
BACKGROUND NPR2 encodes atrial natriuretic peptide receptor B (ANPRB), a regulator of skeletal growth. Biallelic loss-of-function mutations in NPR2 result in acromesomelic dysplasia Maroteaux type (AMDM; OMIM 602875), while heterozygous mutations may account for 2% to 6% of idiopathic short stature (ISS). OBJECTIVE Describe the physical proportions and growth characteristics of an extended family with novel NPR2 mutations including members with AMDM, ISS, or normal stature. DESIGN AND PARTICIPANTS We performed whole exome sequencing in 2 healthy parents and 2 children with AMDM. Detailed genotyping and phenotyping were performed on members of a multigenerational family in an academic medical center. We expressed mutant proteins in mammalian cells and characterized expression and function. RESULTS The sisters with AMDM were compound heterozygotes for missense mutations in the NPR2 gene, a novel p.P93S (maternal) and the previously reported p.R989L (paternal). Both mutant ANPRB proteins were normally expressed in HEK293T cells and exhibited dominant negative effects on wild-type ANPRB catalytic activity. Heterozygous relatives had proportionate short stature (height z-scores -2.06 ± 0.97, median ± SD) compared with their wild-type siblings (-1.37 ± 0.59). Height z-scores progressively and significantly decreased as NPR2-heterozygous children matured, while remaining constant in their wild-type siblings. CONCLUSIONS Biallelic NPR2 mutations cause severe skeletal dysplasia (AMDM), whereas heterozygous mutations lead to a subtler phenotype characterized by progressive short stature with by increasing loss of height potential with age.
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Affiliation(s)
- Patrick C Hanley
- Division of Endocrinology, Nemours Alfred I. duPont Hospital for Children, Wilmington, Delaware
- Correspondence and Reprint Requests: Patrick C. Hanley, MD, Division of Endocrinology, Nemours Alfred I. DuPont Hospital for Children, 1600 Rockland Rd, Wilmington, DE 19803. E-mail:
| | - Harsh S Kanwar
- Division of Endocrinology and Diabetes and Center for Bone Health, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Corine Martineau
- Division of Endocrinology and Diabetes and Center for Bone Health, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Michael A Levine
- Division of Endocrinology and Diabetes and Center for Bone Health, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania
- University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania
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Baena V, Owen CM, Uliasz TF, Lowther KM, Yee SP, Terasaki M, Egbert JR, Jaffe LA. Cellular Heterogeneity of the Luteinizing Hormone Receptor and Its Significance for Cyclic GMP Signaling in Mouse Preovulatory Follicles. Endocrinology 2020; 161:5834711. [PMID: 32384146 PMCID: PMC7574965 DOI: 10.1210/endocr/bqaa074] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Accepted: 05/02/2020] [Indexed: 12/14/2022]
Abstract
Meiotic arrest and resumption in mammalian oocytes are regulated by 2 opposing signaling proteins in the cells of the surrounding follicle: the guanylyl cyclase natriuretic peptide receptor 2 (NPR2), and the luteinizing hormone receptor (LHR). NPR2 maintains a meiosis-inhibitory level of cyclic guanosine 5'-monophosphate (cGMP) until LHR signaling causes dephosphorylation of NPR2, reducing NPR2 activity, lowering cGMP to a level that releases meiotic arrest. However, the signaling pathway between LHR activation and NPR2 dephosphorylation remains incompletely understood, due in part to imprecise information about the cellular localization of these 2 proteins. To investigate their localization, we generated mouse lines in which hemagglutinin epitope tags were added to the endogenous LHR and NPR2 proteins, and used immunofluorescence and immunogold microscopy to localize these proteins with high resolution. The results showed that the LHR protein is absent from the cumulus cells and inner mural granulosa cells, and is present in only 13% to 48% of the outer mural granulosa cells. In contrast, NPR2 is present throughout the follicle, and is more concentrated in the cumulus cells. Less than 20% of the NPR2 is in the same cells that express the LHR. These results suggest that to account for the LH-induced inactivation of NPR2, LHR-expressing cells send a signal that inactivates NPR2 in neighboring cells that do not express the LHR. An inhibitor of gap junction permeability attenuates the LH-induced cGMP decrease in the outer mural granulosa cells, consistent with this mechanism contributing to how NPR2 is inactivated in cells that do not express the LHR.
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Affiliation(s)
- Valentina Baena
- Department of Cell Biology, University of Connecticut Health Center, Farmington, Connecticut
| | - Corie M Owen
- Department of Cell Biology, University of Connecticut Health Center, Farmington, Connecticut
| | - Tracy F Uliasz
- Department of Cell Biology, University of Connecticut Health Center, Farmington, Connecticut
| | - Katie M Lowther
- Department of Cell Biology, University of Connecticut Health Center, Farmington, Connecticut
| | - Siu-Pok Yee
- Department of Cell Biology, University of Connecticut Health Center, Farmington, Connecticut
| | - Mark Terasaki
- Department of Cell Biology, University of Connecticut Health Center, Farmington, Connecticut
| | - Jeremy R Egbert
- Department of Cell Biology, University of Connecticut Health Center, Farmington, Connecticut
| | - Laurinda A Jaffe
- Department of Cell Biology, University of Connecticut Health Center, Farmington, Connecticut
- Correspondence: Laurinda A. Jaffe, Department of Cell Biology, University of Connecticut Health Center, Farmington, CT 06030 USA. E-mail:
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Plachy L, Dusatkova P, Maratova K, Petruzelkova L, Zemkova D, Elblova L, Kucerova P, Toni L, Kolouskova S, Snajderova M, Sumnik Z, Lebl J, Pruhova S. NPR2 Variants Are Frequent among Children with Familiar Short Stature and Respond Well to Growth Hormone Therapy. J Clin Endocrinol Metab 2020; 105:5716766. [PMID: 31990356 DOI: 10.1210/clinem/dgaa037] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 01/27/2020] [Indexed: 02/06/2023]
Abstract
CONTEXT The C-type natriuretic peptide receptor encoded by the NPR2 gene is a paracrine regulator of the growth plate; heterozygous NPR2 variants cause short stature with possible presence of different signs of bone dysplasia. To date, the effect of growth hormone (GH) treatment has been described in a few individuals with NPR2 gene variants with inconsistent results. OBJECTIVES To identify NPR2 gene variants among children with familial short stature (FSS) and to describe their phenotype, including GH treatment response. DESIGN, SETTINGS AND PATIENTS Out of 747 patients with short stature treated with GH in a single center, 87 with FSS met the inclusion criteria (pretreatment height ≤ -2 standard deviation in both the patient and the shorter parent, unknown genetic etiology). Next-generation sequencing methods were performed to search for NPR2 gene variants. The results were evaluated using the American College of Medical Genetics and Genomics guidelines. The GH treatment response (growth velocity improvement and height standard deviation score development over the first 5 years of treatment) was evaluated. RESULTS In 5/87 children (5.7%), a (likely) pathogenic variant in the NPR2 gene was identified (p.Ile558Thr [in 2], p.Arg205*, p.Arg557His, p.Ser603Thr). Two children had disproportionate short-limbed short stature, 1 a dysplastic 5th finger phalanx. The growth velocity in the first year of GH treatment accelerated by 3.6 to 4.2 cm/year; the height improved by 1.2 to 1.8 SD over 5 years of treatment. CONCLUSIONS NPR2 gene variants cause FSS in a significant proportion of children. Their GH treatment response is promising. Studies including final height data are necessary to assess the long-term efficacy of this therapy.
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Affiliation(s)
- Lukas Plachy
- Department of Pediatrics, 2nd Faculty of Medicine, Charles University in Prague and University Hospital Motol, Prague, 150 06, Czech Republic
| | - Petra Dusatkova
- Department of Pediatrics, 2nd Faculty of Medicine, Charles University in Prague and University Hospital Motol, Prague, 150 06, Czech Republic
| | - Klara Maratova
- Department of Pediatrics, 2nd Faculty of Medicine, Charles University in Prague and University Hospital Motol, Prague, 150 06, Czech Republic
| | - Lenka Petruzelkova
- Department of Pediatrics, 2nd Faculty of Medicine, Charles University in Prague and University Hospital Motol, Prague, 150 06, Czech Republic
| | - Dana Zemkova
- Department of Pediatrics, 2nd Faculty of Medicine, Charles University in Prague and University Hospital Motol, Prague, 150 06, Czech Republic
| | - Lenka Elblova
- Department of Pediatrics, 2nd Faculty of Medicine, Charles University in Prague and University Hospital Motol, Prague, 150 06, Czech Republic
| | - Petra Kucerova
- Department of Pediatrics, 2nd Faculty of Medicine, Charles University in Prague and University Hospital Motol, Prague, 150 06, Czech Republic
| | - Ledjona Toni
- Department of Pediatrics, 2nd Faculty of Medicine, Charles University in Prague and University Hospital Motol, Prague, 150 06, Czech Republic
| | - Stanislava Kolouskova
- Department of Pediatrics, 2nd Faculty of Medicine, Charles University in Prague and University Hospital Motol, Prague, 150 06, Czech Republic
| | - Marta Snajderova
- Department of Pediatrics, 2nd Faculty of Medicine, Charles University in Prague and University Hospital Motol, Prague, 150 06, Czech Republic
| | - Zdenek Sumnik
- Department of Pediatrics, 2nd Faculty of Medicine, Charles University in Prague and University Hospital Motol, Prague, 150 06, Czech Republic
| | - Jan Lebl
- Department of Pediatrics, 2nd Faculty of Medicine, Charles University in Prague and University Hospital Motol, Prague, 150 06, Czech Republic
| | - Stepanka Pruhova
- Department of Pediatrics, 2nd Faculty of Medicine, Charles University in Prague and University Hospital Motol, Prague, 150 06, Czech Republic
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Zhang DD, Wu YF, Chen WX, Xu Y, Liu SY, Luo HH, Jiang GM, Wu Y, Hu P. C-type natriuretic peptide attenuates renal osteodystrophy through inhibition of FGF-23/MAPK signaling. Exp Mol Med 2019; 51:1-18. [PMID: 31263178 PMCID: PMC6802631 DOI: 10.1038/s12276-019-0265-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Revised: 01/27/2019] [Accepted: 02/26/2019] [Indexed: 01/19/2023] Open
Abstract
Renal osteodystrophy (ROD) occurs as early as chronic kidney disease (CKD) stage 2 and seems ubiquitous in almost all pediatric patients with CKD stage 5. Fibroblast growth factor (FGF)-23, a bone-derived endocrine regulator of phosphate homeostasis, is overexpressed in CKD and disturbs osteoblast differentiation and matrix mineralization. In contrast, C-type natriuretic peptide (CNP) acts as a potent positive regulator of bone growth. In the present study, we infused CNP into uremic rats and observed whether CNP could attenuate ROD through the inhibition of FGF-23 cascades. In uremic rats, CNP administration significantly alleviated renal dysfunction, calcium phosphate metabolic disorders, hypovitaminosis D, secondary hyperparathyroidism, the decrease in bone turnover markers and retarded bone pathological progression. More importantly, within FGF-23/mitogen-activated protein kinase (MAPK) signaling, the fibroblast growth factor receptor-1, Klotho and alternative (STAT-1/phospho-STAT-1) elements were upregulated by CNP, whereas FGF-23, RAF-1/phospho-RAF-1, and downstream (ERK/phospho-ERK and P38/phospho-P38) elements were paradoxically underexpressed in bone tissue. Therefore, CNP exerts a therapeutic effect on ROD through inhibition of FGF-23/MAPK signaling at the RAF-1 level.
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Affiliation(s)
- Dong Dong Zhang
- Department of Pediatrics, the First Affiliated Hospital of Anhui Medical University, No. 218 Ji-Xi Road, 230022, Hefei, China
| | - Yang Fang Wu
- Department of Pediatrics, the First Affiliated Hospital of Anhui Medical University, No. 218 Ji-Xi Road, 230022, Hefei, China
| | - Wei Xia Chen
- Department of Pediatrics, the First Affiliated Hospital of Anhui Medical University, No. 218 Ji-Xi Road, 230022, Hefei, China
| | - Yao Xu
- Department of Pediatrics, the First Affiliated Hospital of Anhui Medical University, No. 218 Ji-Xi Road, 230022, Hefei, China
| | - Si Yan Liu
- Department of Pediatrics, the First Affiliated Hospital of Anhui Medical University, No. 218 Ji-Xi Road, 230022, Hefei, China
| | - Huang Huang Luo
- Department of Pediatrics, the First Affiliated Hospital of Anhui Medical University, No. 218 Ji-Xi Road, 230022, Hefei, China
| | - Guang Mei Jiang
- Department of Pediatrics, the First Affiliated Hospital of Anhui Medical University, No. 218 Ji-Xi Road, 230022, Hefei, China
| | - Yue Wu
- Department of Pediatrics, the First Affiliated Hospital of Anhui Medical University, No. 218 Ji-Xi Road, 230022, Hefei, China
| | - Peng Hu
- Department of Pediatrics, the First Affiliated Hospital of Anhui Medical University, No. 218 Ji-Xi Road, 230022, Hefei, China.
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Edmund AB, Walseth TF, Levinson NM, Potter LR. The pseudokinase domains of guanylyl cyclase-A and -B allosterically increase the affinity of their catalytic domains for substrate. Sci Signal 2019; 12:12/566/eaau5378. [PMID: 30696704 DOI: 10.1126/scisignal.aau5378] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Natriuretic peptides regulate multiple physiologic systems by activating transmembrane receptors containing intracellular guanylyl cyclase domains, such as GC-A and GC-B, also known as Npr1 and Npr2, respectively. Both enzymes contain an intracellular, phosphorylated pseudokinase domain (PKD) critical for activation of the C-terminal cGMP-synthesizing guanylyl cyclase domain. Because ATP allosterically activates GC-A and GC-B, we investigated how ATP binding to the PKD influenced guanylyl cyclase activity. Molecular modeling indicated that all the residues of the ATP-binding site of the prototypical kinase PKA, except the catalytic aspartate, are conserved in the PKDs of GC-A and GC-B. Kinase-inactivating alanine substitutions for the invariant lysine in subdomain II or the aspartate in the DYG-loop of GC-A and GC-B failed to decrease enzyme phosphate content, consistent with the PKDs lacking kinase activity. In contrast, both mutations reduced enzyme activation by blocking the ability of ATP to decrease the Michaelis constant without affecting peptide-dependent activation. The analogous lysine-to-alanine substitution in a glutamate-substituted phosphomimetic mutant form of GC-B also reduced enzyme activity, consistent with ATP stimulating guanylyl cyclase activity through an allosteric, phosphorylation-independent mechanism. Mutations designed to rigidify the conserved regulatory or catalytic spines within the PKDs increased guanylyl cyclase activity, increased sensitivity to natriuretic peptide, or reduced the Michaelis constant in the absence of ATP, consistent with ATP binding stabilizing the PKD in a conformation analogous to that of catalytically active kinases. We conclude that allosteric mechanisms evolutionarily conserved in the PKDs promote the catalytic activation of transmembrane guanylyl cyclases.
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Affiliation(s)
- Aaron B Edmund
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, 6-155 Jackson Hall, 321 Church St. SE, Minneapolis, MN 55455, USA
| | - Timothy F Walseth
- Department of Pharmacology, University of Minnesota, 6-120 Jackson Hall, 321 Church St. SE, Minneapolis, MN 55455, USA
| | - Nicholas M Levinson
- Department of Pharmacology, University of Minnesota, 6-120 Jackson Hall, 321 Church St. SE, Minneapolis, MN 55455, USA
| | - Lincoln R Potter
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, 6-155 Jackson Hall, 321 Church St. SE, Minneapolis, MN 55455, USA. .,Department of Pharmacology, University of Minnesota, 6-120 Jackson Hall, 321 Church St. SE, Minneapolis, MN 55455, USA
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9
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The regulatory role of the kinase-homology domain in receptor guanylyl cyclases: nothing 'pseudo' about it! Biochem Soc Trans 2018; 46:1729-1742. [PMID: 30420416 DOI: 10.1042/bst20180472] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2018] [Revised: 10/08/2018] [Accepted: 10/11/2018] [Indexed: 01/05/2023]
Abstract
The availability of genome sequence information and a large number of protein structures has allowed the cataloging of genes into various families, based on their function and predicted biochemical activity. Intriguingly, a number of proteins harbor changes in the amino acid sequence at residues, that from structural elucidation, are critical for catalytic activity. Such proteins have been categorized as 'pseudoenzymes'. Here, we review the role of the pseudokinase (or kinase-homology) domain in receptor guanylyl cyclases. These are multidomain single-pass, transmembrane proteins harboring an extracellular ligand-binding domain, and an intracellular domain composed of a kinase-homology domain that regulates the activity of the associated guanylyl cyclase domain. Mutations that lie in the kinase-homology domain of these receptors are associated with human disease, and either abolish or enhance cGMP production by these receptors to alter downstream signaling events. This raises the interesting possibility that one could identify molecules that bind to the pseudokinase domain and regulate the activities of these receptors, in order to alleviate symptoms in patients harboring these mutations.
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10
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Regulation of the Natriuretic Peptide Receptor 2 (Npr2) by Phosphorylation of Juxtamembrane Serine and Threonine Residues Is Essential for Bifurcation of Sensory Axons. J Neurosci 2018; 38:9768-9780. [PMID: 30249793 DOI: 10.1523/jneurosci.0495-18.2018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 08/28/2018] [Accepted: 09/18/2018] [Indexed: 12/31/2022] Open
Abstract
cGMP signaling elicited by activation of the transmembrane receptor guanylyl cyclase Npr2 (also known as guanylyl cyclase B) by the ligand CNP controls sensory axon bifurcation of DRG and cranial sensory ganglion (CSG) neurons entering the spinal cord or hindbrain, respectively. Previous studies have shown that Npr2 is phosphorylated on serine and threonine residues in its kinase homology domain (KHD). However, it is unknown whether phosphorylation of Npr2 is essential for axon bifurcation. Here, we generated a knock-in mouse line in which the seven regulatory serine and threonine residues in the KHD of Npr2 were substituted by alanine (Npr2-7A), resulting in a nonphosphorylatable enzyme. Real-time imaging of cGMP in DRG neurons with a genetically encoded fluorescent cGMP sensor or biochemical analysis of guanylyl cyclase activity in brain or lung tissue revealed the absence of CNP-induced cGMP generation in the Npr27A/7A mutant. Consequently, bifurcation of axons, but not collateral formation, from DRG or CSG in this mouse mutant was perturbed at embryonic and mature stages. In contrast, axon branching was normal in a mouse mutant in which constitutive phosphorylation of Npr2 is mimicked by a replacement of all of the seven serine and threonine sites by glutamic acid (Npr2-7E). Furthermore, we demonstrate that the Npr27A/7A mutation causes dwarfism as described for global Npr2 mutants. In conclusion, our in vivo studies provide strong evidence that phosphorylation of the seven serine and threonine residues in the KHD of Npr2 is an important regulatory element of Npr2-mediated cGMP signaling which affects physiological processes, such as axon bifurcation and bone growth.SIGNIFICANCE STATEMENT The branching of axons is a morphological hallmark of virtually all neurons. It allows an individual neuron to innervate different targets and to communicate with neurons located in different regions of the nervous system. The natriuretic peptide receptor 2 (Npr2), a transmembrane guanylyl cyclase, is essential for the initiation of bifurcation of sensory axons when entering the spinal cord or the hindbrain. By using two genetically engineered mouse lines, we show that phosphorylation of specific serine and threonine residues in juxtamembrane regions of Npr2 are required for its enzymatic activity and for axon bifurcation. These investigations might help to understand the regulation of Npr2 and its integration in intracellular signaling systems.
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11
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Irfanullah, Zeb A, Shinwari N, Shah K, Gilani SZT, Khan S, Lee KW, Raza SI, Hussain S, Liaqat K, Ahmad W. Molecular and in silico analyses validates pathogenicity of homozygous mutations in the NPR2 gene underlying variable phenotypes of Acromesomelic dysplasia, type Maroteaux. Int J Biochem Cell Biol 2018; 102:76-86. [PMID: 30016695 DOI: 10.1016/j.biocel.2018.07.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 07/12/2018] [Accepted: 07/13/2018] [Indexed: 01/13/2023]
Abstract
Homozygous and/or heterozygous loss of function mutations in the natriuretic peptide receptor B (NPR2) have been reported in causing acromesomelic dysplasia, type Maroteaux with variable clinical features and idiopathic short stature with nonspecific skeletal deformities. On the other hand, gain of function mutations in the same gene result in overgrowth disorder suggesting that NPR2 and its ligand, natriuretic peptide precursor C (CNP), are the key players of endochondral bone growth. However, the precise mechanism behind phenotypic variability of the NPR2 mutations is not fully understood so far. In the present study, three consanguineous families of Pakistani origin (A, B, C) with variable phenotypes of acromesomelic dysplasia, type Maroteaux were evaluated at clinical and molecular levels. Linkage analysis followed by Sanger sequencing of the NPR2 gene revealed three homozygous mutations including p.(Leu314 Arg), p.(Arg371*), and p.(Arg1032*) in family A, B and C, respectively. In silico structural and functional analyses substantiated that a novel missense mutation [p.(Leu314 Arg)] in family A allosterically affects binding of NPR2 homodimer to its ligand (CNP) which ultimately results in defective guanylate cyclase activity. A nonsense mutation [p.(Arg371*)] in family B entirely removed the transmembrane domain, protein kinase domain and guanylate cyclase domains of the NPR2 resulting in abolishing its guanylate cyclase activity. Another novel mutation [p.(Arg1032*)], found in family C, deteriorated the guanylate cyclase domain of the protein and probably plundered its guanylate cyclase activity. These results suggest that guanylate cyclase activity is the most critical function of the NPR2 and phenotypic severity of the NPR2 mutations is proportional to the reduction in its guanylate cyclase activity.
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Affiliation(s)
- Irfanullah
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University Islamabad, Pakistan; Department of Chemistry, Shaheed Benazir Bhutto University, Sheringal, Upper Dir, Pakistan
| | - Amir Zeb
- Division of Life Sciences, Division of Applied Life Sciences (BK21 Plus), Plant Molecular Biology and Biotechnology Research Center (PMBBRC), Gyeongsang National University, Jinju, Republic of Korea
| | - Naila Shinwari
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University Islamabad, Pakistan
| | - Khadim Shah
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University Islamabad, Pakistan
| | - Syed Zohaib Tayyab Gilani
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University Islamabad, Pakistan
| | - Saadullah Khan
- Department of Biotechnology & Genetic Engineering, Kohat University of Science & Technology (KUST), Kohat, KPK, Pakistan
| | - Keun Woo Lee
- Division of Life Sciences, Division of Applied Life Sciences (BK21 Plus), Plant Molecular Biology and Biotechnology Research Center (PMBBRC), Gyeongsang National University, Jinju, Republic of Korea
| | - Syed Irfan Raza
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University Islamabad, Pakistan
| | - Shabir Hussain
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University Islamabad, Pakistan
| | - Khurram Liaqat
- Department of Biotechnology, Faculty of Biological Sciences, Quaid-i-Azam University Islamabad, Pakistan
| | - Wasim Ahmad
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University Islamabad, Pakistan.
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12
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Tröster P, Haseleu J, Petersen J, Drees O, Schmidtko A, Schwaller F, Lewin GR, Ter-Avetisyan G, Winter Y, Peters S, Feil S, Feil R, Rathjen FG, Schmidt H. The Absence of Sensory Axon Bifurcation Affects Nociception and Termination Fields of Afferents in the Spinal Cord. Front Mol Neurosci 2018; 11:19. [PMID: 29472841 PMCID: PMC5809486 DOI: 10.3389/fnmol.2018.00019] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Accepted: 01/15/2018] [Indexed: 12/16/2022] Open
Abstract
A cGMP signaling cascade composed of C-type natriuretic peptide, the guanylyl cyclase receptor Npr2 and cGMP-dependent protein kinase I (cGKI) controls the bifurcation of sensory axons upon entering the spinal cord during embryonic development. However, the impact of axon bifurcation on sensory processing in adulthood remains poorly understood. To investigate the functional consequences of impaired axon bifurcation during adult stages we generated conditional mouse mutants of Npr2 and cGKI (Npr2fl/fl;Wnt1Cre and cGKIKO/fl;Wnt1Cre) that lack sensory axon bifurcation in the absence of additional phenotypes observed in the global knockout mice. Cholera toxin labeling in digits of the hind paw demonstrated an altered shape of sensory neuron termination fields in the spinal cord of conditional Npr2 mouse mutants. Behavioral testing of both sexes indicated that noxious heat sensation and nociception induced by chemical irritants are impaired in the mutants, whereas responses to cold sensation, mechanical stimulation, and motor coordination are not affected. Recordings from C-fiber nociceptors in the hind limb skin showed that Npr2 function was not required to maintain normal heat sensitivity of peripheral nociceptors. Thus, the altered behavioral responses to noxious heat found in Npr2fl/fl;Wnt1Cre mice is not due to an impaired C-fiber function. Overall, these data point to a critical role of axonal bifurcation for the processing of pain induced by heat or chemical stimuli.
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Affiliation(s)
- Philip Tröster
- Developmental Neurobiology, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Julia Haseleu
- Molecular Physiology of Somatic Sensation, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Jonas Petersen
- Institute of Pharmacology, College of Pharmacy, Goethe University, Frankfurt am Main, Germany.,Institute of Pharmacology and Toxicology, Zentrum für Biomedizinische Ausbildung und Forschung (ZBAF), Witten/Herdecke University, Witten, Germany
| | - Oliver Drees
- Institute of Pharmacology and Toxicology, Zentrum für Biomedizinische Ausbildung und Forschung (ZBAF), Witten/Herdecke University, Witten, Germany
| | - Achim Schmidtko
- Institute of Pharmacology, College of Pharmacy, Goethe University, Frankfurt am Main, Germany.,Institute of Pharmacology and Toxicology, Zentrum für Biomedizinische Ausbildung und Forschung (ZBAF), Witten/Herdecke University, Witten, Germany
| | - Frederick Schwaller
- Molecular Physiology of Somatic Sensation, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Gary R Lewin
- Molecular Physiology of Somatic Sensation, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Gohar Ter-Avetisyan
- Developmental Neurobiology, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - York Winter
- Cognitive Neurobiology, Humboldt University of Berlin, Berlin, Germany
| | - Stefanie Peters
- Interfaculty Institute of Biochemistry, University of Tübingen, Tübingen, Germany
| | - Susanne Feil
- Interfaculty Institute of Biochemistry, University of Tübingen, Tübingen, Germany
| | - Robert Feil
- Interfaculty Institute of Biochemistry, University of Tübingen, Tübingen, Germany
| | - Fritz G Rathjen
- Developmental Neurobiology, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Hannes Schmidt
- Developmental Neurobiology, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
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13
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Dephosphorylation is the mechanism of fibroblast growth factor inhibition of guanylyl cyclase-B. Cell Signal 2017; 40:222-229. [PMID: 28964968 DOI: 10.1016/j.cellsig.2017.09.021] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 09/19/2017] [Accepted: 09/26/2017] [Indexed: 12/30/2022]
Abstract
Activating mutations in fibroblast growth factor receptor 3 (FGFR3) and inactivating mutations of guanylyl cyclase-B (GC-B, also called NPRB or NPR2) cause dwarfism. FGF exposure inhibits GC-B activity in a chondrocyte cell line, but the mechanism of the inactivation is not known. Here, we report that FGF exposure causes dephosphorylation of GC-B in rat chondrosarcoma cells, which correlates with a rapid, potent and reversible inhibition of C-type natriuretic peptide-dependent activation of GC-B. Cells expressing a phosphomimetic mutant of GC-B that cannot be inactivated by dephosphorylation because it contains glutamate substitutions for all known phosphorylation sites showed no decrease in GC-B activity in response to FGF. We conclude that FGF rapidly inactivates GC-B by a reversible dephosphorylation mechanism, which may contribute to the signaling network by which activated FGFR3 causes dwarfism.
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14
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Dickey DM, Otto NM, Potter LR. Skeletal overgrowth-causing mutations mimic an allosterically activated conformation of guanylyl cyclase-B that is inhibited by 2,4,6,-trinitrophenyl ATP. J Biol Chem 2017; 292:10220-10229. [PMID: 28450398 DOI: 10.1074/jbc.m117.780536] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Revised: 04/24/2017] [Indexed: 11/06/2022] Open
Abstract
Activating mutations in the receptor for C-type natriuretic peptide (CNP), guanylyl cyclase B (GC-B, also known as Npr2 or NPR-B), increase cellular cGMP and cause skeletal overgrowth, but how these mutations affect GTP catalysis is poorly understood. The A488P and R655C mutations were compared with the known mutation V883M. Neither mutation affected GC-B concentrations. The A488P mutation decreased the EC50 5-fold, increased Vmax 2.6-fold, and decreased the Km 13-fold, whereas the R655C mutation decreased the EC50 5-fold, increased the Vmax 2.1-fold, and decreased the Km 4.7-fold. Neither mutation affected maximum activity at saturating CNP concentrations. Activation by R655C did not require disulfide bond formation. Surprisingly, the A488P mutant only activated the receptor when it was phosphorylated. In contrast, the R655C mutation converted GC-B-7A from CNP-unresponsive to CNP-responsive. Interestingly, neither mutant was activated by ATP, and the Km and Hill coefficient of each mutant assayed in the absence of ATP were similar to those of wild-type GC-B assayed in the presence of ATP. Finally, 1 mm 2,4,6,-trinitrophenyl ATP inhibited all three mutants by as much as 80% but failed to inhibit WT-GC-B. We conclude that 1) the A488P and R655C missense mutations result in a GC-B conformation that mimics the allosterically activated conformation, 2) GC-B phosphorylation is required for CNP-dependent activation by the A488P mutation, 3) the R655C mutation abrogates the need for phosphorylation in receptor activation, and 4) an ATP analog selectively inhibits the GC-B mutants, indicating that a pharmacologic approach could reduce GC-B dependent human skeletal overgrowth.
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Affiliation(s)
- Deborah M Dickey
- From the Department of Biochemistry, Molecular Biology, and Biophysics and
| | - Neil M Otto
- From the Department of Biochemistry, Molecular Biology, and Biophysics and
| | - Lincoln R Potter
- From the Department of Biochemistry, Molecular Biology, and Biophysics and .,the Department of Pharmacology, University of Minnesota, Minneapolis, Minnesota 55455
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