1
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Noguchi GM, Castillo VC, Donaldson CJ, Flisher MR, Momen AT, Saghatelian A, Huising MO. Urocortin 3 contributes to paracrine inhibition of islet alpha cells in mice. J Endocrinol 2024; 261:e240018. [PMID: 38593829 PMCID: PMC11095665 DOI: 10.1530/joe-24-0018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Accepted: 04/08/2024] [Indexed: 04/11/2024]
Abstract
Pancreatic alpha cell activity and glucagon secretion lower as glucose levels increase. While part of the decrease is regulated by glucose itself, paracrine signaling by their neighboring beta and delta cells also plays an important role. Somatostatin from delta cells is an important local inhibitor of alpha cells at high glucose. Additionally, urocortin 3 (UCN3) is a hormone that is co-released from beta cells with insulin and acts locally to potentiate somatostatin secretion from delta cells. UCN3 thus inhibits insulin secretion via a negative feedback loop with delta cells, but its role with respect to alpha cells and glucagon secretion is not understood. We hypothesize that the somatostatin-driven glucagon inhibition at high glucose is regulated in part by UCN3 from beta cells. Here, we use a combination of live functional Ca2+ and cAMP imaging as well as direct glucagon secretion measurement, all from alpha cells in intact mouse islets, to determine the contributions of UCN3 to alpha cell behavior. Exogenous UCN3 treatment decreased alpha cell Ca2+ and cAMP levels and inhibited glucagon release. Blocking endogenous UCN3 signaling increased alpha cell Ca2+ by 26.8 ± 7.6%, but this did not result in increased glucagon release at high glucose. Furthermore, constitutive deletion of Ucn3 did not increase Ca2+ activity or glucagon secretion relative to controls. UCN3 is thus capable of inhibiting mouse alpha cells, but, given the subtle effects of endogenous UCN3 signaling on alpha cells, we propose that UCN3-driven somatostatin may serve to regulate local paracrine glucagon levels in the islet instead of inhibiting gross systemic glucagon release.
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Affiliation(s)
- Glyn M. Noguchi
- Department of Neurobiology, Physiology & Behavior, University of California Davis, Davis, CA, USA
| | - Vincent C. Castillo
- Department of Neurobiology, Physiology & Behavior, University of California Davis, Davis, CA, USA
| | | | - Marcus R. Flisher
- Department of Neurobiology, Physiology & Behavior, University of California Davis, Davis, CA, USA
| | - Ariana T. Momen
- Department of Neurobiology, Physiology & Behavior, University of California Davis, Davis, CA, USA
| | | | - Mark O. Huising
- Department of Neurobiology, Physiology & Behavior, University of California Davis, Davis, CA, USA
- Department of Physiology & Membrane Biology, University of California Davis, Davis, CA, USA
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2
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Xie L, Bowman ME, Louie GV, Zhang C, Ardejani MS, Huang X, Chu Q, Donaldson CJ, Vaughan JM, Shan H, Powers ET, Kelly JW, Lyumkis D, Noel JP, Saghatelian A. Biochemistry and Protein Interactions of the CYREN Microprotein. Biochemistry 2023; 62:3050-3060. [PMID: 37813856 DOI: 10.1021/acs.biochem.3c00397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/11/2023]
Abstract
Over the past decade, advances in genomics have identified thousands of additional protein-coding small open reading frames (smORFs) missed by traditional gene finding approaches. These smORFs encode peptides and small proteins, commonly termed micropeptides or microproteins. Several of these newly discovered microproteins have biological functions and operate through interactions with proteins and protein complexes within the cell. CYREN1 is a characterized microprotein that regulates double-strand break repair in mammalian cells through interaction with Ku70/80 heterodimer. Ku70/80 binds to and stabilizes double-strand breaks and recruits the machinery needed for nonhomologous end join repair. In this study, we examined the biochemical properties of CYREN1 to better understand and explain its cellular protein interactions. Our findings support that CYREN1 is an intrinsically disordered microprotein and this disordered structure allows it to enriches several proteins, including a newly discovered interaction with SF3B1 via a distinct short linear motif (SLiMs) on CYREN1. Since many microproteins are predicted to be disordered, CYREN1 is an exemplar of how microproteins interact with other proteins and reveals an unknown scaffolding function of this microprotein that may link NHEJ and splicing.
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Affiliation(s)
- Lina Xie
- Clayton Foundation Peptide Biology Laboratories, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Marianne E Bowman
- Jack H. Skirball Center for Chemical Biology and Proteomics, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Gordon V Louie
- Jack H. Skirball Center for Chemical Biology and Proteomics, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Cheng Zhang
- Laboratory of Genetics, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Maziar S Ardejani
- Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, California 92037, United States
| | - Xuemei Huang
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92037, United States
| | - Qian Chu
- Department of Pharmacy, China Pharmaceutical University, Nanjing 210009, Jiangsu, China
| | - Cynthia J Donaldson
- Clayton Foundation Peptide Biology Laboratories, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Joan M Vaughan
- Clayton Foundation Peptide Biology Laboratories, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Huanqi Shan
- Clayton Foundation Peptide Biology Laboratories, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Evan T Powers
- Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, California 92037, United States
| | - Jeffery W Kelly
- Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, California 92037, United States
| | - Dimitry Lyumkis
- Laboratory of Genetics, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Joseph P Noel
- Jack H. Skirball Center for Chemical Biology and Proteomics, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Alan Saghatelian
- Clayton Foundation Peptide Biology Laboratories, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, California 92037, United States
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3
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Tan D, Konduri S, Erikci Ertunc M, Zhang P, Wang J, Chang T, Pinto AFM, Rocha A, Donaldson CJ, Vaughan JM, Ludwig RG, Willey E, Iyer M, Gray PC, Maher P, Allen NJ, Zuchero JB, Dillin A, Mori MA, Kohama SG, Siegel D, Saghatelian A. A class of anti-inflammatory lipids decrease with aging in the central nervous system. Nat Chem Biol 2023; 19:187-197. [PMID: 36266352 PMCID: PMC9898107 DOI: 10.1038/s41589-022-01165-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 09/08/2022] [Indexed: 02/06/2023]
Abstract
Lipids contribute to the structure, development, and function of healthy brains. Dysregulated lipid metabolism is linked to aging and diseased brains. However, our understanding of lipid metabolism in aging brains remains limited. Here we examined the brain lipidome of mice across their lifespan using untargeted lipidomics. Co-expression network analysis highlighted a progressive decrease in 3-sulfogalactosyl diacylglycerols (SGDGs) and SGDG pathway members, including the potential degradation products lyso-SGDGs. SGDGs show an age-related decline specifically in the central nervous system and are associated with myelination. We also found that an SGDG dramatically suppresses LPS-induced gene expression and release of pro-inflammatory cytokines from macrophages and microglia by acting on the NF-κB pathway. The detection of SGDGs in human and macaque brains establishes their evolutionary conservation. This work enhances interest in SGDGs regarding their roles in aging and inflammatory diseases and highlights the complexity of the brain lipidome and potential biological functions in aging.
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Affiliation(s)
- Dan Tan
- Clayton Foundation Laboratories for Peptide Biology, Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Srihari Konduri
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA, USA
| | - Meric Erikci Ertunc
- Clayton Foundation Laboratories for Peptide Biology, Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Pan Zhang
- Department of Psychiatry, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Justin Wang
- Clayton Foundation Laboratories for Peptide Biology, Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Tina Chang
- Clayton Foundation Laboratories for Peptide Biology, Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Antonio F M Pinto
- Clayton Foundation Laboratories for Peptide Biology, Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Andrea Rocha
- Clayton Foundation Laboratories for Peptide Biology, Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Cynthia J Donaldson
- Clayton Foundation Laboratories for Peptide Biology, Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Joan M Vaughan
- Clayton Foundation Laboratories for Peptide Biology, Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Raissa G Ludwig
- Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas, Campinas, Brazil
| | - Elizabeth Willey
- Department of Molecular and Cellular Biology, Howard Hughes Medical Institute, The Glenn Center for Aging Research, University of California, Berkeley, Berkeley, CA, USA
| | - Manasi Iyer
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Peter C Gray
- Clayton Foundation Laboratories for Peptide Biology, Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Pamela Maher
- Cellular Neurobiology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Nicola J Allen
- Molecular Neurobiology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, USA
| | - J Bradley Zuchero
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Andrew Dillin
- Department of Molecular and Cellular Biology, Howard Hughes Medical Institute, The Glenn Center for Aging Research, University of California, Berkeley, Berkeley, CA, USA
| | - Marcelo A Mori
- Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas, Campinas, Brazil
| | - Steven G Kohama
- Oregon National Primate Research Center, Oregon Health and Science University, Portland, OR, USA
| | - Dionicio Siegel
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA, USA.
| | - Alan Saghatelian
- Clayton Foundation Laboratories for Peptide Biology, Salk Institute for Biological Studies, La Jolla, CA, USA.
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4
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Noguchi GM, Ou R, Castillo V, Donaldson CJ, Mawla AM, Huising MO. Functional Heterogeneity Among Pancreatic Alpha Cells. J Endocr Soc 2021. [PMCID: PMC8090148 DOI: 10.1210/jendso/bvab048.654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Historically, endocrine cells in the pancreatic islets have been assumed to function as relatively homogenous populations largely because we lacked the ability to measure individual cell activity with sufficient throughput to reliably detect heterogeneity within each population. The glucagon-secreting alpha cells play a vital role in regulating glycemia, but the mechanisms that control alpha cell activity and whether the alpha cells behave as a single unit or heterogeneously remain incompletely understood. To overcome the limitations in throughput that have to date prevented the study of alpha cells at the population level, we used genetically-encoded fluorescent indicators selectively expressed in alpha cells. Imaging intact mouse islets with these indicators in 3D responding to treatments in real time yields hundreds of individual alpha cell recordings per experiment. Calcium imaging showed reproducible heterogeneous responses to a panel of known physiological potentiators of glucagon secretion such as arginine vasopressin, epinephrine, and amino acids. Separate dose response experiments revealed that the proportion of alpha cells responding to each signal plateaus at different proportions of alpha cells. The calcium data correlate both with direct glucagon secretion levels as well as cAMP measurement. Our findings highlight previously unappreciated levels of functional heterogeneity among alpha cells and demonstrate that alpha cells are not a single uniform unit. Our observations suggest that dose-dependent increases in glucagon secretion in response to different physiological cues may be the result of mobilizing progressively larger proportions of the total alpha cell mass. We hypothesize that this functional heterogeneity is a built-in mechanism through which different physiological cues elicit graded glucagon responses from the alpha cells.
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Affiliation(s)
| | - Rosie Ou
- University of California - Davis, Davis, CA, USA
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5
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Ertunc ME, Kok BP, Parsons WH, Wang JG, Tan D, Donaldson CJ, Pinto AM, Vaughan JM, Ngo N, Lum KM, Henry CL, Coppola AR, Niphakis MJ, Cravatt BF, Saez E, Saghatelian A. Role of AIG1 and ADTRP in Endogenous FAHFA Regulation. FASEB J 2020. [DOI: 10.1096/fasebj.2020.34.s1.04337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | | | | | - Dan Tan
- Salk Institute for Biological Studies
| | | | | | | | - Nhi Ngo
- Lundbeck La Jolla Research Center
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6
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Chu Q, Martinez TF, Novak SW, Donaldson CJ, Tan D, Vaughan JM, Chang T, Diedrich JK, Andrade L, Kim A, Zhang T, Manor U, Saghatelian A. Regulation of the ER stress response by a mitochondrial microprotein. FASEB J 2020. [DOI: 10.1096/fasebj.2020.34.s1.04094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Qian Chu
- Salk Institute for Biological Studies
| | | | | | | | - Dan Tan
- Salk Institute for Biological Studies
| | | | | | | | | | | | | | - Uri Manor
- Salk Institute for Biological Studies
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7
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Erikci Ertunc M, Kok BP, Parsons WH, Wang JG, Tan D, Donaldson CJ, Pinto AFM, Vaughan JM, Ngo N, Lum KM, Henry CL, Coppola AR, Niphakis MJ, Cravatt BF, Saez E, Saghatelian A. AIG1 and ADTRP are endogenous hydrolases of fatty acid esters of hydroxy fatty acids (FAHFAs) in mice. J Biol Chem 2020; 295:5891-5905. [PMID: 32152231 DOI: 10.1074/jbc.ra119.012145] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 02/27/2020] [Indexed: 12/14/2022] Open
Abstract
Fatty acid esters of hydroxy fatty acids (FAHFAs) are a newly discovered class of signaling lipids with anti-inflammatory and anti-diabetic properties. However, the endogenous regulation of FAHFAs remains a pressing but unanswered question. Here, using MS-based FAHFA hydrolysis assays, LC-MS-based lipidomics analyses, and activity-based protein profiling, we found that androgen-induced gene 1 (AIG1) and androgen-dependent TFPI-regulating protein (ADTRP), two threonine hydrolases, control FAHFA levels in vivo in both genetic and pharmacologic mouse models. Tissues from mice lacking ADTRP (Adtrp-KO), or both AIG1 and ADTRP (DKO) had higher concentrations of FAHFAs particularly isomers with the ester bond at the 9th carbon due to decreased FAHFA hydrolysis activity. The levels of other lipid classes were unaltered indicating that AIG1 and ADTRP specifically hydrolyze FAHFAs. Complementing these genetic studies, we also identified a dual AIG1/ADTRP inhibitor, ABD-110207, which is active in vivo Acute treatment of WT mice with ABD-110207 resulted in elevated FAHFA levels, further supporting the notion that AIG1 and ADTRP activity control endogenous FAHFA levels. However, loss of AIG1/ADTRP did not mimic the changes associated with pharmacologically administered FAHFAs on extent of upregulation of FAHFA levels, glucose tolerance, or insulin sensitivity in mice, indicating that therapeutic strategies should weigh more on FAHFA administration. Together, these findings identify AIG1 and ADTRP as the first endogenous FAHFA hydrolases identified and provide critical genetic and chemical tools for further characterization of these enzymes and endogenous FAHFAs to unravel their physiological functions and roles in health and disease.
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Affiliation(s)
- Meric Erikci Ertunc
- Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, La Jolla, California 92037
| | - Bernard P Kok
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California 92037
| | - William H Parsons
- Department of Chemistry and Biochemistry, Oberlin College, Oberlin, Ohio 44074
| | - Justin G Wang
- Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, La Jolla, California 92037
| | - Dan Tan
- Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, La Jolla, California 92037
| | - Cynthia J Donaldson
- Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, La Jolla, California 92037
| | - Antonio F M Pinto
- Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, La Jolla, California 92037
| | - Joan M Vaughan
- Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, La Jolla, California 92037
| | - Nhi Ngo
- Lundbeck La Jolla Research Center, Inc., San Diego, California 92121
| | - Kenneth M Lum
- Lundbeck La Jolla Research Center, Inc., San Diego, California 92121
| | - Cassandra L Henry
- Lundbeck La Jolla Research Center, Inc., San Diego, California 92121
| | - Aundrea R Coppola
- Lundbeck La Jolla Research Center, Inc., San Diego, California 92121
| | - Micah J Niphakis
- Lundbeck La Jolla Research Center, Inc., San Diego, California 92121
| | - Benjamin F Cravatt
- Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, California 92037
| | - Enrique Saez
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California 92037
| | - Alan Saghatelian
- Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, La Jolla, California 92037.
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8
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Chu Q, Martinez TF, Novak SW, Donaldson CJ, Tan D, Vaughan JM, Chang T, Diedrich JK, Andrade L, Kim A, Zhang T, Manor U, Saghatelian A. Regulation of the ER stress response by a mitochondrial microprotein. Nat Commun 2019; 10:4883. [PMID: 31653868 PMCID: PMC6814811 DOI: 10.1038/s41467-019-12816-z] [Citation(s) in RCA: 99] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 09/13/2019] [Indexed: 12/14/2022] Open
Abstract
Cellular homeostasis relies on having dedicated and coordinated responses to a variety of stresses. The accumulation of unfolded proteins in the endoplasmic reticulum (ER) is a common stress that triggers a conserved pathway called the unfolded protein response (UPR) that mitigates damage, and dysregulation of UPR underlies several debilitating diseases. Here, we discover that a previously uncharacterized 54-amino acid microprotein PIGBOS regulates UPR. PIGBOS localizes to the mitochondrial outer membrane where it interacts with the ER protein CLCC1 at ER–mitochondria contact sites. Functional studies reveal that the loss of PIGBOS leads to heightened UPR and increased cell death. The characterization of PIGBOS reveals an undiscovered role for a mitochondrial protein, in this case a microprotein, in the regulation of UPR originating in the ER. This study demonstrates microproteins to be an unappreciated class of genes that are critical for inter-organelle communication, homeostasis, and cell survival. Cells trigger an unfolded protein response (UPR) in the endoplasmic reticulum, but its regulation by mitochondria is unclear. Here, the authors report a 54-residue microprotein PIGBOS that participates in inter-organelle contact between the endoplasmic reticulum and the mitochondria and may regulate UPR.
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Affiliation(s)
- Qian Chu
- The Salk Institute for Biological Studies, Clayton Foundation Laboratories for Peptide Biology, 10010N. Torrey Pines Rd, La Jolla, CA, 92037, USA
| | - Thomas F Martinez
- The Salk Institute for Biological Studies, Clayton Foundation Laboratories for Peptide Biology, 10010N. Torrey Pines Rd, La Jolla, CA, 92037, USA
| | - Sammy Weiser Novak
- The Salk Institute for Biological Studies, Waitt Advanced Biophotonics Center, 10010N. Torrey Pines Rd, La Jolla, CA, 92037, USA
| | - Cynthia J Donaldson
- The Salk Institute for Biological Studies, Clayton Foundation Laboratories for Peptide Biology, 10010N. Torrey Pines Rd, La Jolla, CA, 92037, USA
| | - Dan Tan
- The Salk Institute for Biological Studies, Clayton Foundation Laboratories for Peptide Biology, 10010N. Torrey Pines Rd, La Jolla, CA, 92037, USA
| | - Joan M Vaughan
- The Salk Institute for Biological Studies, Clayton Foundation Laboratories for Peptide Biology, 10010N. Torrey Pines Rd, La Jolla, CA, 92037, USA
| | - Tina Chang
- The Salk Institute for Biological Studies, Clayton Foundation Laboratories for Peptide Biology, 10010N. Torrey Pines Rd, La Jolla, CA, 92037, USA
| | - Jolene K Diedrich
- The Salk Institute for Biological Studies, Clayton Foundation Laboratories for Peptide Biology, 10010N. Torrey Pines Rd, La Jolla, CA, 92037, USA
| | - Leo Andrade
- The Salk Institute for Biological Studies, Waitt Advanced Biophotonics Center, 10010N. Torrey Pines Rd, La Jolla, CA, 92037, USA
| | - Andrew Kim
- The Salk Institute for Biological Studies, Clayton Foundation Laboratories for Peptide Biology, 10010N. Torrey Pines Rd, La Jolla, CA, 92037, USA
| | - Tong Zhang
- The Salk Institute for Biological Studies, Waitt Advanced Biophotonics Center, 10010N. Torrey Pines Rd, La Jolla, CA, 92037, USA
| | - Uri Manor
- The Salk Institute for Biological Studies, Waitt Advanced Biophotonics Center, 10010N. Torrey Pines Rd, La Jolla, CA, 92037, USA.
| | - Alan Saghatelian
- The Salk Institute for Biological Studies, Clayton Foundation Laboratories for Peptide Biology, 10010N. Torrey Pines Rd, La Jolla, CA, 92037, USA.
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9
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Rathore A, Chu Q, Tan D, Martinez TF, Donaldson CJ, Diedrich JK, Yates JR, Saghatelian A. MIEF1 Microprotein Regulates Mitochondrial Translation. Biochemistry 2018; 57:5564-5575. [PMID: 30215512 DOI: 10.1021/acs.biochem.8b00726] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Recent technological advances led to the discovery of hundreds to thousands of peptides and small proteins (microproteins) encoded by small open reading frames (smORFs). Characterization of new microproteins demonstrates their role in fundamental biological processes and highlights the value in discovering and characterizing more microproteins. The elucidation of microprotein-protein interactions (MPIs) is useful for determining the biochemical and cellular roles of microproteins. In this study, we characterize the protein interaction partners of mitochondrial elongation factor 1 microprotein (MIEF1-MP) using a proximity labeling strategy that relies on APEX2. MIEF1-MP localizes to the mitochondrial matrix where it interacts with the mitochondrial ribosome (mitoribosome). Functional studies demonstrate that MIEF1-MP regulates mitochondrial translation via its binding to the mitoribosome. Loss of MIEF1-MP decreases the mitochondrial translation rate, while an elevated level of MIEF1-MP increases the translation rate. The identification of MIEF1-MP reveals a new gene involved in this process.
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Affiliation(s)
- Annie Rathore
- Clayton Foundation Laboratories for Peptide Biology , The Salk Institute for Biological Studies , 10010 North Torrey Pines Road , La Jolla , California 92037 , United States.,Division of Biological Sciences , University of California, San Diego , 9500 Gilman Drive , La Jolla , California 92093 , United States
| | - Qian Chu
- Clayton Foundation Laboratories for Peptide Biology , The Salk Institute for Biological Studies , 10010 North Torrey Pines Road , La Jolla , California 92037 , United States
| | - Dan Tan
- Clayton Foundation Laboratories for Peptide Biology , The Salk Institute for Biological Studies , 10010 North Torrey Pines Road , La Jolla , California 92037 , United States
| | - Thomas F Martinez
- Clayton Foundation Laboratories for Peptide Biology , The Salk Institute for Biological Studies , 10010 North Torrey Pines Road , La Jolla , California 92037 , United States
| | - Cynthia J Donaldson
- Clayton Foundation Laboratories for Peptide Biology , The Salk Institute for Biological Studies , 10010 North Torrey Pines Road , La Jolla , California 92037 , United States
| | - Jolene K Diedrich
- Mass Spectrometry Core for Proteomics and Metabolomics , The Salk Institute for Biological Studies , 10010 North Torrey Pines Road , La Jolla , California 92037 , United States.,Department of Molecular Medicine , The Scripps Research Institute , 10550 North Torrey Pines Road , La Jolla , California 92037 , United States
| | - John R Yates
- Department of Molecular Medicine , The Scripps Research Institute , 10550 North Torrey Pines Road , La Jolla , California 92037 , United States
| | - Alan Saghatelian
- Clayton Foundation Laboratories for Peptide Biology , The Salk Institute for Biological Studies , 10010 North Torrey Pines Road , La Jolla , California 92037 , United States
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10
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Chu Q, Rathore A, Diedrich JK, Donaldson CJ, Yates JR, Saghatelian A. Identification of Microprotein‐Protein Interactions via APEX Tagging. FASEB J 2018. [DOI: 10.1096/fasebj.2018.32.1_supplement.530.9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Qian Chu
- The Salk Institute for Biological StudiesLa JollaCA
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11
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Syed I, Lee J, Moraes-Vieira PM, Donaldson CJ, Sontheimer A, Aryal P, Wellenstein K, Kolar MJ, Nelson AT, Siegel D, Mokrosinski J, Farooqi IS, Zhao JJ, Yore MM, Peroni OD, Saghatelian A, Kahn BB. Palmitic Acid Hydroxystearic Acids Activate GPR40, Which Is Involved in Their Beneficial Effects on Glucose Homeostasis. Cell Metab 2018; 27:419-427.e4. [PMID: 29414687 PMCID: PMC5807007 DOI: 10.1016/j.cmet.2018.01.001] [Citation(s) in RCA: 113] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Revised: 08/24/2017] [Accepted: 01/03/2018] [Indexed: 12/28/2022]
Abstract
Palmitic acid hydroxystearic acids (PAHSAs) are endogenous lipids with anti-diabetic and anti-inflammatory effects. PAHSA levels are reduced in serum and adipose tissue of insulin-resistant people and high-fat diet (HFD)-fed mice. Here, we investigated whether chronic PAHSA treatment enhances insulin sensitivity and which receptors mediate PAHSA effects. Chronic PAHSA administration in chow- and HFD-fed mice raises serum and tissue PAHSA levels ∼1.4- to 3-fold. This improves insulin sensitivity and glucose tolerance without altering body weight. PAHSA administration in chow-fed, but not HFD-fed, mice augments insulin and glucagon-like peptide (GLP-1) secretion. PAHSAs are selective agonists for GPR40, increasing Ca+2 flux, but not intracellular cyclic AMP. Blocking GPR40 reverses improvements in glucose tolerance and insulin sensitivity in PAHSA-treated chow- and HFD-fed mice and directly inhibits PAHSA augmentation of glucose-stimulated insulin secretion in human islets. In contrast, GLP-1 receptor blockade in PAHSA-treated chow-fed mice reduces PAHSA effects on glucose tolerance, but not on insulin sensitivity. Thus, PAHSAs activate GPR40, which is involved in their beneficial metabolic effects.
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Affiliation(s)
- Ismail Syed
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Center for Life Sciences, Room 747, 330 Brookline Avenue, Boston, MA 02215, USA
| | - Jennifer Lee
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Center for Life Sciences, Room 747, 330 Brookline Avenue, Boston, MA 02215, USA
| | - Pedro M Moraes-Vieira
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Center for Life Sciences, Room 747, 330 Brookline Avenue, Boston, MA 02215, USA
| | - Cynthia J Donaldson
- Clayton Foundation Laboratories for Peptide Biology, Helmsley Center for Genomic Medicine, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Alexandra Sontheimer
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Center for Life Sciences, Room 747, 330 Brookline Avenue, Boston, MA 02215, USA
| | - Pratik Aryal
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Center for Life Sciences, Room 747, 330 Brookline Avenue, Boston, MA 02215, USA
| | - Kerry Wellenstein
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Center for Life Sciences, Room 747, 330 Brookline Avenue, Boston, MA 02215, USA
| | - Matthew J Kolar
- Clayton Foundation Laboratories for Peptide Biology, Helmsley Center for Genomic Medicine, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Andrew T Nelson
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Dionicio Siegel
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Jacek Mokrosinski
- University of Cambridge Metabolic Research Laboratories and NIHR Cambridge Biomedical Research Centre, Wellcome Trust-MRC Institute of Metabolic Science, Cambridge CB2 0QQ, UK
| | - I Sadaf Farooqi
- University of Cambridge Metabolic Research Laboratories and NIHR Cambridge Biomedical Research Centre, Wellcome Trust-MRC Institute of Metabolic Science, Cambridge CB2 0QQ, UK
| | - Juan Juan Zhao
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Center for Life Sciences, Room 747, 330 Brookline Avenue, Boston, MA 02215, USA
| | - Mark M Yore
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Center for Life Sciences, Room 747, 330 Brookline Avenue, Boston, MA 02215, USA
| | - Odile D Peroni
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Center for Life Sciences, Room 747, 330 Brookline Avenue, Boston, MA 02215, USA
| | - Alan Saghatelian
- Clayton Foundation Laboratories for Peptide Biology, Helmsley Center for Genomic Medicine, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Barbara B Kahn
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Center for Life Sciences, Room 747, 330 Brookline Avenue, Boston, MA 02215, USA.
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12
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van der Meulen T, Lee S, Noordeloos E, Donaldson CJ, Adams MW, Noguchi GM, Mawla AM, Huising MO. Artemether Does Not Turn α Cells into β Cells. Cell Metab 2018; 27:218-225.e4. [PMID: 29103923 PMCID: PMC5762275 DOI: 10.1016/j.cmet.2017.10.002] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Revised: 08/05/2017] [Accepted: 10/05/2017] [Indexed: 12/27/2022]
Abstract
Pancreatic α cells retain considerable plasticity and can, under the right circumstances, transdifferentiate into functionally mature β cells. In search of a targetable mechanistic basis, a recent paper suggested that the widely used anti-malaria drug artemether suppresses the α cell transcription factor Arx to promote transdifferentiation into β cells. However, key initial experiments in this paper were carried out in islet cell lines, and most subsequent validation experiments implied transdifferentiation without direct demonstration of α to β cell conversion. Indeed, we find no evidence that artemether promotes transdifferentiation of primary α cells into β cells. Moreover, artemether reduces Ins2 expression in primary β cells >100-fold, suppresses glucose uptake, and abrogates β cell calcium responses and insulin secretion in response to glucose. Our observations suggest that artemether induces general islet endocrine cell dedifferentiation and call into question the utility of artemisinins to promote α to β cell transdifferentiation in treating diabetes.
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Affiliation(s)
- Talitha van der Meulen
- Department of Neurobiology, Physiology & Behavior, College of Biological Sciences, University of California, Davis, CA 95616, USA
| | - Sharon Lee
- Department of Neurobiology, Physiology & Behavior, College of Biological Sciences, University of California, Davis, CA 95616, USA
| | - Els Noordeloos
- Department of Neurobiology, Physiology & Behavior, College of Biological Sciences, University of California, Davis, CA 95616, USA
| | - Cynthia J Donaldson
- Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Michael W Adams
- Department of Neurobiology, Physiology & Behavior, College of Biological Sciences, University of California, Davis, CA 95616, USA
| | - Glyn M Noguchi
- Department of Neurobiology, Physiology & Behavior, College of Biological Sciences, University of California, Davis, CA 95616, USA
| | - Alex M Mawla
- Department of Neurobiology, Physiology & Behavior, College of Biological Sciences, University of California, Davis, CA 95616, USA
| | - Mark O Huising
- Department of Neurobiology, Physiology & Behavior, College of Biological Sciences, University of California, Davis, CA 95616, USA; Department of Physiology and Membrane Biology, School of Medicine, University of California, Davis, CA 95616, USA.
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13
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Chu Q, Rathore A, Diedrich JK, Donaldson CJ, Yates JR, Saghatelian A. Identification of Microprotein-Protein Interactions via APEX Tagging. Biochemistry 2017; 56:3299-3306. [PMID: 28589727 PMCID: PMC5499098 DOI: 10.1021/acs.biochem.7b00265] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 05/17/2017] [Indexed: 02/08/2023]
Abstract
Microproteins are peptides and small proteins encoded by small open reading frames (smORFs). Newer technologies have led to the recent discovery of hundreds to thousands of new microproteins. The biological functions of a few microproteins have been elucidated, and these microproteins have fundamental roles in biology ranging from limb development to muscle function, highlighting the value of characterizing these molecules. The identification of microprotein-protein interactions (MPIs) has proven to be a successful approach to the functional characterization of these genes; however, traditional immunoprecipitation methods result in the enrichment of nonspecific interactions for microproteins. Here, we test and apply an in situ proximity tagging method that relies on an engineered ascorbate peroxidase 2 (APEX) to elucidate MPIs. The results demonstrate that APEX tagging is superior to traditional immunoprecipitation methods for microproteins. Furthermore, the application of APEX tagging to an uncharacterized microprotein called C11orf98 revealed that this microprotein interacts with nucleolar proteins nucleophosmin and nucleolin, demonstrating the ability of this approach to identify novel hypothesis-generating MPIs.
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Affiliation(s)
- Qian Chu
- Clayton
Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Annie Rathore
- Clayton
Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, California 92037, United States
- Division
of Biological Sciences, University of California,
San Diego, 9500 Gilman
Drive, La Jolla, California 92093, United States
| | - Jolene K. Diedrich
- Clayton
Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, California 92037, United States
- Department
of Chemical Physiology, The Scripps Research
Institute, 10550 North
Torrey Pines Road, La Jolla, California 92037, United States
| | - Cynthia J. Donaldson
- Clayton
Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, California 92037, United States
| | - John R. Yates
- Department
of Chemical Physiology, The Scripps Research
Institute, 10550 North
Torrey Pines Road, La Jolla, California 92037, United States
| | - Alan Saghatelian
- Clayton
Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, California 92037, United States
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14
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Abstract
The impact of warfarin therapy on the functions of extrahepatic vitamin K-dependent proteins (VKDP) is less clearly understood and less widely recognised in clinical practice than that on the hepatic counterparts (clotting factors II, VII, IX and X). Warfarin inhibits osteocalcin, an abundant extrahepatic VKDP involved in the mineralisation and maturation of bone and thus, primarily by this mechanism, may have an adverse effect on bone health. Whilst some studies do link warfarin use to an increase in osteoporosis and fracture risk others have not. Warfarin also inhibits the extrahepatic VKDP matrix gla protein (MGP) which acts to prevent ectopic calcification of the vasculature. Studies have consistently found a correlation between warfarin use and vascular calcification with inhibition of MGP believed to be the main cause. Inhibition of MGP also appears to explain warfarin's well established teratogenic effect. Further adverse effects may also arise from warfarin's inhibition of other known extrahepatic VKDPs. The available evidence is intriguing, and suggests that the impact of warfarin on the extrahepatic functions of vitamin K-dependent proteins warrants further careful consideration.
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Affiliation(s)
- C J Donaldson
- a Faculty of Life Sciences and Medicine , King's College London , London , UK
| | - D J Harrington
- b The Nutristasis Unit, Viapath, St. Thomas' Hospital , London , UK.,c Division of Women's Health , School of Medicine, King's College London , London , UK
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15
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van der Meulen T, Mawla AM, DiGruccio MR, Adams MW, Nies V, Dólleman S, Liu S, Ackermann AM, Cáceres E, Hunter AE, Kaestner KH, Donaldson CJ, Huising MO. Virgin Beta Cells Persist throughout Life at a Neogenic Niche within Pancreatic Islets. Cell Metab 2017; 25:911-926.e6. [PMID: 28380380 PMCID: PMC8586897 DOI: 10.1016/j.cmet.2017.03.017] [Citation(s) in RCA: 147] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Revised: 02/14/2017] [Accepted: 03/21/2017] [Indexed: 12/21/2022]
Abstract
Postnatal maintenance or regeneration of pancreatic beta cells is considered to occur exclusively via the replication of existing beta cells, but clinically meaningful restoration of human beta cell mass by proliferation has never been achieved. We discovered a population of immature beta cells that is present throughout life and forms from non-beta precursors at a specialized micro-environment or "neogenic niche" at the islet periphery. These cells express insulin, but lack other key beta cell markers, and are transcriptionally immature, incapable of sensing glucose, and unable to support calcium influx. They constitute an intermediate stage in the transdifferentiation of alpha cells to cells that are functionally indistinguishable from conventional beta cells. We thus identified a lifelong source of new beta cells at a specialized site within healthy islets. By comparing co-existing immature and mature beta cells within healthy islets, we stand to learn how to mature insulin-expressing cells into functional beta cells.
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Affiliation(s)
- Talitha van der Meulen
- Department of Neurobiology, Physiology, and Behavior, College of Biological Sciences, University of California, Davis, Davis, CA 95616, USA
| | - Alex M Mawla
- Department of Neurobiology, Physiology, and Behavior, College of Biological Sciences, University of California, Davis, Davis, CA 95616, USA
| | - Michael R DiGruccio
- Department of Neurobiology, Physiology, and Behavior, College of Biological Sciences, University of California, Davis, Davis, CA 95616, USA
| | - Michael W Adams
- Waitt Advanced Biophotonics Center, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Vera Nies
- Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Sophie Dólleman
- Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Siming Liu
- Department of Neurobiology, Physiology, and Behavior, College of Biological Sciences, University of California, Davis, Davis, CA 95616, USA
| | - Amanda M Ackermann
- Division of Endocrinology and Diabetes, The Children's Hospital of Philadelphia, 3400 Civic Center Boulevard, Philadelphia, PA 19104, USA
| | - Elena Cáceres
- Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Anna E Hunter
- Department of Neurobiology, Physiology, and Behavior, College of Biological Sciences, University of California, Davis, Davis, CA 95616, USA
| | - Klaus H Kaestner
- Department of Genetics and Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Cynthia J Donaldson
- Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Mark O Huising
- Department of Neurobiology, Physiology, and Behavior, College of Biological Sciences, University of California, Davis, Davis, CA 95616, USA; Department of Physiology and Membrane Biology, School of Medicine, University of California, Davis, Davis, CA 95616, USA.
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16
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Lee J, Moraes-Vieira PM, Castoldi A, Aryal P, Yee EU, Vickers C, Parnas O, Donaldson CJ, Saghatelian A, Kahn BB. Branched Fatty Acid Esters of Hydroxy Fatty Acids (FAHFAs) Protect against Colitis by Regulating Gut Innate and Adaptive Immune Responses. J Biol Chem 2016; 291:22207-22217. [PMID: 27573241 DOI: 10.1074/jbc.m115.703835] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Indexed: 12/25/2022] Open
Abstract
We recently discovered a structurally novel class of endogenous lipids, branched palmitic acid esters of hydroxy stearic acids (PAHSAs), with beneficial metabolic and anti-inflammatory effects. We tested whether PAHSAs protect against colitis, which is a chronic inflammatory disease driven predominantly by defects in the innate mucosal barrier and adaptive immune system. There is an unmet clinical need for safe and well tolerated oral therapeutics with direct anti-inflammatory effects. Wild-type mice were pretreated orally with vehicle or 5-PAHSA (10 mg/kg) and 9-PAHSA (5 mg/kg) once daily for 3 days, followed by 10 days of either 0% or 2% dextran sulfate sodium water with continued vehicle or PAHSA treatment. The colon was collected for histopathology, gene expression, and flow cytometry. Intestinal crypt fractions were prepared for ex vivo bactericidal assays. Bone marrow-derived dendritic cells pretreated with vehicle or PAHSA and splenic CD4+ T cells from syngeneic mice were co-cultured to assess antigen presentation and T cell activation in response to LPS. PAHSA treatment prevented weight loss, improved colitis scores (stool consistency, hematochezia, and mouse appearance), and augmented intestinal crypt Paneth cell bactericidal potency via a mechanism that may involve GPR120. In vitro, PAHSAs attenuated dendritic cell activation and subsequent T cell proliferation and Th1 polarization. The anti-inflammatory effects of PAHSAs in vivo resulted in reduced colonic T cell activation and pro-inflammatory cytokine and chemokine expression. These anti-inflammatory effects appear to be partially GPR120-dependent. We conclude that PAHSA treatment regulates innate and adaptive immune responses to prevent mucosal damage and protect against colitis. Thus, PAHSAs may be a novel treatment for colitis and related inflammation-driven diseases.
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Affiliation(s)
- Jennifer Lee
- From the Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, and
| | - Pedro M Moraes-Vieira
- From the Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, and
| | - Angela Castoldi
- From the Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, and
| | - Pratik Aryal
- From the Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, and
| | - Eric U Yee
- Department of Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts 02215
| | - Christopher Vickers
- the Clayton Foundation Laboratories for Peptide Biology, Helmsley Center for Genomic Medicine, Salk Institute for Biological Studies, La Jolla, California 92037, and
| | - Oren Parnas
- the Broad Institute of the Massachusetts Institute of Technology and Harvard, Cambridge, Massachusetts 02142
| | - Cynthia J Donaldson
- the Clayton Foundation Laboratories for Peptide Biology, Helmsley Center for Genomic Medicine, Salk Institute for Biological Studies, La Jolla, California 92037, and
| | - Alan Saghatelian
- the Clayton Foundation Laboratories for Peptide Biology, Helmsley Center for Genomic Medicine, Salk Institute for Biological Studies, La Jolla, California 92037, and
| | - Barbara B Kahn
- From the Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, and
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17
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Abstract
Apolipoprotein E (ApoE) belongs to a large class of proteins that solubilize lipids for physiological transport. Humans have three different APOE alleles, APOE ε2, APOE ε3, and APOE ε4, and genetic studies identified ApoE4 as the strongest genetic risk factor for Alzheimer's disease (AD). People who are homozygous for ApoE4 (i.e., ApoE4/E4) are an order of magnitude more likely to develop late-onset AD (LOAD) than ApoE3/E3 carriers. Several differences between ApoE3 and ApoE4 may contribute to AD including the observation that ApoE4 is degraded to a greater extent than ApoE3 in the human brain. Experiments with high-temperature requirement serine peptidase A1 (HtrA1), which is found in the nervous system, demonstrate that HtrA1 is an allele-selective ApoE-degrading enzyme that degrades ApoE4 more quickly than ApoE3. This activity is specific to HtrA1, as similar assays with HtrA2 showed minimal ApoE4 proteolysis and trypsin had no preference between ApoE4 and ApoE3. HtrA1 has also been reported to cleave the tau protein (Tau) and the amyloid protein precursor (APP) to hinder the formation of toxic amyloid deposits associated with AD. Competition assays with ApoE4, ApoE3, and Tau revealed that ApoE4 inhibits Tau degradation. Thus, the identification of ApoE4 as an in vitro HtrA1 substrate suggests a potential biochemical mechanism that links ApoE4 regulation of AD proteins such as Tau.
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Affiliation(s)
- Qian Chu
- The Salk Institute for Biological Studies, Clayton Foundation Laboratories for Peptide Biology, 10010 N. Torrey Pines Rd, La Jolla, CA 92037, USA
| | - Jolene K. Diedrich
- The Salk Institute for Biological Studies, Clayton Foundation Laboratories for Peptide Biology, 10010 N. Torrey Pines Rd, La Jolla, CA 92037, USA
- Department of Chemical Physiology, The Scripps Research Institute, 10550 N. Torrey Pines Rd, La Jolla, CA 92037, USA
| | - Joan M. Vaughan
- The Salk Institute for Biological Studies, Clayton Foundation Laboratories for Peptide Biology, 10010 N. Torrey Pines Rd, La Jolla, CA 92037, USA
| | - Cynthia J. Donaldson
- The Salk Institute for Biological Studies, Clayton Foundation Laboratories for Peptide Biology, 10010 N. Torrey Pines Rd, La Jolla, CA 92037, USA
| | - Michael F. Nunn
- The Salk Institute for Biological Studies, Clayton Foundation Laboratories for Peptide Biology, 10010 N. Torrey Pines Rd, La Jolla, CA 92037, USA
| | - Kuo-Fen Lee
- The Salk Institute for Biological Studies, Clayton Foundation Laboratories for Peptide Biology, 10010 N. Torrey Pines Rd, La Jolla, CA 92037, USA
| | - Alan Saghatelian
- The Salk Institute for Biological Studies, Clayton Foundation Laboratories for Peptide Biology, 10010 N. Torrey Pines Rd, La Jolla, CA 92037, USA
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18
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Perrin MH, Tan LA, Vaughan JM, Lewis KA, Donaldson CJ, Miller C, Erchegyi J, Rivier JE, Sawchenko PE. Characterization of a Pachymedusa dacnicolor-Sauvagine analog as a new high-affinity radioligand for corticotropin-releasing factor receptor studies. J Pharmacol Exp Ther 2015; 353:307-17. [PMID: 25736419 DOI: 10.1124/jpet.114.222307] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
The corticotropin-releasing factor (CRF) peptide family comprises the mammalian peptides CRF and the urocortins as well as frog skin sauvagine and fish urophyseal urotensin. Advances in understanding the roles of the CRF ligand family and associated receptors have often relied on radioreceptor assays using labeled CRF ligands. These assays depend on stable, high-affinity CRF analogs that can be labeled, purified, and chemically characterized. Analogs of several of the native peptides have been used in this context, most prominently including sauvagine from the frog Phyllomedusa sauvageii (PS-Svg). Because each of these affords both advantages and disadvantages, new analogs with superior properties would be welcome. We find that a sauvagine-like peptide recently isolated from a different frog species, Pachymedusa dacnicolor (PD-Svg), is a high-affinity agonist whose radioiodinated analog, [(125)ITyr(0)-Glu(1), Nle(17)]-PD-Svg, exhibits improved biochemical properties over those of earlier iodinated agonists. Specifically, the PD-Svg radioligand binds both CRF receptors with comparably high affinity as its PS-Svg counterpart, but detects a greater number of sites on both type 1 and type 2 receptors. PD-Svg is also ∼10 times more potent at stimulating cAMP accumulation in cells expressing the native receptors. Autoradiographic localization using the PD-Svg radioligand shows robust specific binding to rodent brain and peripheral tissues that identifies consensus CRF receptor-expressing sites in a greater number and/or with greater sensitivity than its PS-Svg counterpart. We suggest that labeled analogs of PD-Svg may be useful tools for biochemical, structural, pharmacological, and anatomic studies of CRF receptors.
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Affiliation(s)
- Marilyn H Perrin
- Clayton Foundation Laboratories for Peptide Biology (M.H.P., J.M.V., K.A.L., C.J.D., C.M., J.E., J.E.R., P.E.S.) and Laboratory of Neuronal Structure and Function (L.A.T., P.E.S.), The Salk Institute for Biological Studies, La Jolla, California
| | - Laura A Tan
- Clayton Foundation Laboratories for Peptide Biology (M.H.P., J.M.V., K.A.L., C.J.D., C.M., J.E., J.E.R., P.E.S.) and Laboratory of Neuronal Structure and Function (L.A.T., P.E.S.), The Salk Institute for Biological Studies, La Jolla, California
| | - Joan M Vaughan
- Clayton Foundation Laboratories for Peptide Biology (M.H.P., J.M.V., K.A.L., C.J.D., C.M., J.E., J.E.R., P.E.S.) and Laboratory of Neuronal Structure and Function (L.A.T., P.E.S.), The Salk Institute for Biological Studies, La Jolla, California
| | - Kathy A Lewis
- Clayton Foundation Laboratories for Peptide Biology (M.H.P., J.M.V., K.A.L., C.J.D., C.M., J.E., J.E.R., P.E.S.) and Laboratory of Neuronal Structure and Function (L.A.T., P.E.S.), The Salk Institute for Biological Studies, La Jolla, California
| | - Cynthia J Donaldson
- Clayton Foundation Laboratories for Peptide Biology (M.H.P., J.M.V., K.A.L., C.J.D., C.M., J.E., J.E.R., P.E.S.) and Laboratory of Neuronal Structure and Function (L.A.T., P.E.S.), The Salk Institute for Biological Studies, La Jolla, California
| | - Charleen Miller
- Clayton Foundation Laboratories for Peptide Biology (M.H.P., J.M.V., K.A.L., C.J.D., C.M., J.E., J.E.R., P.E.S.) and Laboratory of Neuronal Structure and Function (L.A.T., P.E.S.), The Salk Institute for Biological Studies, La Jolla, California
| | - Judit Erchegyi
- Clayton Foundation Laboratories for Peptide Biology (M.H.P., J.M.V., K.A.L., C.J.D., C.M., J.E., J.E.R., P.E.S.) and Laboratory of Neuronal Structure and Function (L.A.T., P.E.S.), The Salk Institute for Biological Studies, La Jolla, California
| | - Jean E Rivier
- Clayton Foundation Laboratories for Peptide Biology (M.H.P., J.M.V., K.A.L., C.J.D., C.M., J.E., J.E.R., P.E.S.) and Laboratory of Neuronal Structure and Function (L.A.T., P.E.S.), The Salk Institute for Biological Studies, La Jolla, California
| | - Paul E Sawchenko
- Clayton Foundation Laboratories for Peptide Biology (M.H.P., J.M.V., K.A.L., C.J.D., C.M., J.E., J.E.R., P.E.S.) and Laboratory of Neuronal Structure and Function (L.A.T., P.E.S.), The Salk Institute for Biological Studies, La Jolla, California
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19
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Prothiwa M, Syed I, Huising MO, van der Meulen T, Donaldson CJ, Trauger SA, Kahn BB, Saghatelian A. Data-driven synthesis of proteolysis-resistant peptide hormones. J Am Chem Soc 2014; 136:17710-3. [PMID: 25496053 DOI: 10.1021/ja5065735] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Peptide hormones are key physiological regulators, and many would make terrific drugs; however, the therapeutic use of peptides is limited by poor metabolism including rapid proteolysis. To develop novel proteolysis-resistant peptide hormone analogs, we utilize a strategy that relies on data from simple mass spectrometry experiments to guide the chemical synthesis of proteolysis-resistant analogs (i.e., data-driven synthesis). Application of this strategy to oxyntomodulin (OXM), a peptide hormone that stimulates insulin secretion from islets and lowers blood glucose in vivo, defined the OXM cleavage site in serum, and this information was used to synthesize a proteolysis-resistant OXM analog (prOXM). prOXM and OXM have similar activity in binding and glucose stimulated-insulin secretion assays. Furthermore, prOXM is also active in vivo. prOXM reduces basal glucose levels and improves glucose tolerance in mice. The discovery of prOXM suggests that proteolysis-resistant variants of other important peptide hormones can also be found using this strategy to increase the number of candidate therapeutic peptides.
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Affiliation(s)
- Michaela Prothiwa
- Department of Chemistry and Chemical Biology, Harvard University , Cambridge, Massachusetts 02138, United States
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Benner C, van der Meulen T, Cacéres E, Tigyi K, Donaldson CJ, Huising MO. The transcriptional landscape of mouse beta cells compared to human beta cells reveals notable species differences in long non-coding RNA and protein-coding gene expression. BMC Genomics 2014; 15:620. [PMID: 25051960 PMCID: PMC4124169 DOI: 10.1186/1471-2164-15-620] [Citation(s) in RCA: 206] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Accepted: 07/10/2014] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Insulin producing beta cell and glucagon producing alpha cells are colocalized in pancreatic islets in an arrangement that facilitates the coordinated release of the two principal hormones that regulate glucose homeostasis and prevent both hypoglycemia and diabetes. However, this intricate organization has also complicated the determination of the cellular source(s) of the expression of genes that are detected in the islet. This reflects a significant gap in our understanding of mouse islet physiology, which reduces the effectiveness by which mice model human islet disease. RESULTS To overcome this challenge, we generated a bitransgenic reporter mouse that faithfully labels all beta and alpha cells in mouse islets to enable FACS-based purification and the generation of comprehensive transcriptomes of both populations. This facilitates systematic comparison across thousands of genes between the two major endocrine cell types of the islets of Langerhans whose principal hormones are of cardinal importance for glucose homeostasis. Our data leveraged against similar data for human beta cells reveal a core common beta cell transcriptome of 9900+ genes. Against the backdrop of overall similar beta cell transcriptomes, we describe marked differences in the repertoire of receptors and long non-coding RNAs between mouse and human beta cells. CONCLUSIONS The comprehensive mouse alpha and beta cell transcriptomes complemented by the comparison of the global (dis)similarities between mouse and human beta cells represent invaluable resources to boost the accuracy by which rodent models offer guidance in finding cures for human diabetes.
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Affiliation(s)
- Christopher Benner
- />Razzavi Newman Integrated Genomics and Bioinformatics Core, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037 USA
| | - Talitha van der Meulen
- />Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037 USA
| | - Elena Cacéres
- />Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037 USA
| | - Kristof Tigyi
- />Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037 USA
| | - Cynthia J Donaldson
- />Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037 USA
| | - Mark O Huising
- />Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037 USA
- />Department of Neurobiology, Physiology & Behavior, University of California, One Shields Avenue, 180 Briggs Hall, Davis, CA 95616 USA
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Vaughan JM, Donaldson CJ, Fischer WH, Perrin MH, Rivier JE, Sawchenko PE, Vale WW. Posttranslational processing of human and mouse urocortin 2: characterization and bioactivity of gene products. Endocrinology 2013; 154:1553-64. [PMID: 23493376 PMCID: PMC3602626 DOI: 10.1210/en.2012-2011] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Mouse (m) and human (h) urocortin 2 (Ucn 2) were identified by molecular cloning strategies and the primary sequence of their mature forms postulated by analogy to closely related members of the corticotropin-releasing factor (CRF) neuropeptide family. Because of the paucity of Ucn 2 proteins in native tissues, skin, muscle, and pancreatic cell lines were transduced with lentiviral constructs and secretion media were used to isolate and characterize Ucn 2 products and study processing. Primary structures were assigned using a combination of Edman degradation sequencing and mass spectrometry. For mUcn 2, transduced cells secreted a 39 amino acid peptide and the glycosylated prohormone lacking signal peptide; both forms were C-terminally amidated and highly potent to activate the type 2 CRF receptor. Chromatographic profiles of murine tissue extracts were consistent with cleavage of mUcn 2 prohormone to a peptidic form. By contrast to mUcn 2, mammalian cell lines transduced with hUcn 2 constructs secreted significant amounts of an 88 amino acid glycosylated hUcn 2 prohormone but were unable to further process this molecule. Similarly, WM-266-4 melanoma cells that express endogenous hUcn 2 secreted only the glycosylated prohormone lacking the signal peptide and unmodified at the C terminus. Although not amidated, hUcn 2 prohormone purified from overexpressing lines activated CRF receptor 2. Hypoxia and glycosylation, paradigms that might influence secretion or processing of gene products, did not significantly impact hUcn 2 prohormone cleavage. Our findings identify probable Ucn 2 processing products and should expedite the characterization of these proteins in mammalian tissues.
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Huising MO, Vaughan JM, Shah SH, Grillot KL, Donaldson CJ, Rivier J, Flik G, Vale WW. Residues of corticotropin releasing factor-binding protein (CRF-BP) that selectively abrogate binding to CRF but not to urocortin 1. J Biol Chem 2008; 283:8902-12. [PMID: 18234674 DOI: 10.1074/jbc.m709904200] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Corticotropin releasing factor-binding protein (CRF-BP) binds CRF and urocortin 1 (Ucn 1) with high affinity, thus preventing CRF receptor (CRFR) activation. Despite recent progress on the molecular details that govern interactions between CRF family neuropeptides and their cognate receptors, little is known concerning the mechanisms that allow CRF-BP to bind CRF and Ucn 1 with picomolar affinity. We conducted a comprehensive alanine scan of 76 evolutionarily conserved residues of CRF-BP and identified several residues that differentially affected the affinity for CRF over Ucn 1. We determined that both neuropeptides derive their similarly high affinity from distinct binding surfaces on CRF-BP. Alanine substitutions of arginine 56 (R56A) and aspartic acid 62 (D62A) reduce the affinity for CRF by approximately 100-fold, while only marginally affecting the affinity for Ucn 1. The selective reduction in affinity for CRF depends on glutamic acid 25 in the CRF peptide, as substitution of Glu(25) reduces the affinity for CRF-BP by approximately 2 orders of magnitude, but only in the presence of both Arg(56) and Asp(62) in human CRF-BP. We show that CRF-BP(R56A) and CRF-BP(D62A) have lost the ability to inhibit CRFR1-mediated responses to CRF that activate luciferase induction in HEK293T cells and ACTH release from cultured rat anterior pituitary cells. In contrast, both CRF-BP mutants retain the ability to inhibit Ucn 1-induced CRFR1 activation. Collectively our findings demonstrate that CRF-BP has distinct and separable binding surfaces for CRF and Ucn 1, opening new avenues for the design of ligand-specific antagonists based on CRF-BP.
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Affiliation(s)
- Mark O Huising
- Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.
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23
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Smith SM, Vaughan JM, Donaldson CJ, Fernandez RE, Li C, Chen A, Vale WW. Cocaine- and amphetamine-regulated transcript is localized in pituitary lactotropes and is regulated during lactation. Endocrinology 2006; 147:1213-23. [PMID: 16339196 DOI: 10.1210/en.2005-1392] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Cocaine- and amphetamine-regulated transcript (CART) is a highly expressed peptide implicated in the regulation of feeding, reward and reinforcement, and stress-related behaviors. CART has been localized to discrete cell populations in the brain, gut, adrenal gland, and pancreas. In contrast, CART-producing cell types in the pituitary gland remain ill defined. In the present study, double-label immunohistochemistry, employing a high-affinity antiserum we generated against CART-(62-102), was used to identify CART-producing cells in the pituitary gland. In the anterior pituitary, the majority of CART immunoreactivity (-ir) was localized in lactotropes; minor populations of CART-ir cells were identified as somatotropes and corticotropes. In the posterior pituitary, CART-ir extensively colocalized with oxytocin-containing fibers; in contrast, only a few vasopressin fibers contained CART-ir. As expected, CART colocalized with oxytocin in magnocellular neurons of the supraoptic nucleus. The effects of bromocriptine, a potent dopamine receptor agonist, were examined to determine whether CART mRNA expression and protein release are regulated in a similar fashion as prolactin. Similar to prolactin, CART mRNA expression and protein release were significantly decreased after bromocriptine treatment of dispersed rat anterior pituitary cells in culture. To explore the putative physiological role of pituitary CART, we compared levels of CART mRNA expression in lactating and nonlactating female rats. CART mRNA levels were significantly increased in the anterior pituitary and supraoptic nucleus of lactating rats. Furthermore, levels of CART in the systemic circulation were significantly elevated at the onset of lactation, peaked on d 10 of lactation and returned to baseline values 10 d after pups were weaned. The current study describes the cellular localization and regulation of CART expression and protein release from the rat pituitary gland. These findings suggest a putative role for CART in lactation.
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Affiliation(s)
- Sean M Smith
- Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, California 92037, USA
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Smith SM, Vaughan JM, Donaldson CJ, Rivier J, Li C, Chen A, Vale WW. Cocaine- and amphetamine-regulated transcript activates the hypothalamic-pituitary-adrenal axis through a corticotropin-releasing factor receptor-dependent mechanism. Endocrinology 2004; 145:5202-9. [PMID: 15271883 DOI: 10.1210/en.2004-0708] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Cocaine- and amphetamine-regulated transcript (CART) is a highly expressed hypothalamic transcript that is concentrated in areas associated with the stress response. There is evidence for a role of CART in the regulation of the hypothalamic-pituitary-adrenal (HPA) axis. However, it is not clear whether CART regulates activity of the HPA axis by directly stimulating ACTH release from pituitary corticotropes or through interaction with hypothalamic factors. To address this issue, the effects of central and peripheral administration of CART on the HPA axis were compared. Central administration of CART(55-102) (1 microg) significantly increased circulating levels of ACTH (481 +/- 122 vs. 93 +/- 14 pg/ml; CART vs. vehicle) and corticosterone (460 +/- 29 vs. 179 +/- 62 ng/ml; CART vs. vehicle). In contrast, iv injection of CART(55-102) (0.09-9.0 nmol/kg) did not significantly affect circulating levels of ACTH or corticosterone. The corticotropin-releasing factor (CRF) receptor antagonist Astressin B was used to determine whether CART(55-102) elicits ACTH secretion via a CRF receptor-dependent mechanism. Injection of Astressin B (50 microg/kg, iv) inhibited CART(55-102)-induced ACTH and corticosterone responses. The effects of CART(55-102) on CRF and arginine vasopressin (AVP) expression were also examined in static hypothalamic explants. RT-PCR analysis revealed a significant up-regulation of CRF and AVP mRNA levels after CART(55-102) (10 nm and 1 microm) treatment. Last, the effects of CART(55-102) on CRF- and AVP-mediated ACTH release was investigated in dispersed rat anterior pituitary cells. Incubation of CART(55-102) (10-100 nm) did not significantly affect ACTH release from anterior pituitary cells. Findings from the present study suggest that CART regulates activity of the HPA axis through a CRF-dependent central mechanism and not by means of direct interaction with pituitary corticotropes.
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Affiliation(s)
- Sean M Smith
- Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, California 92037, USA
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25
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Leal AMO, Blount AL, Donaldson CJ, Bilezikjian LM, Vale WW. Regulation of follicle-stimulating hormone secretion by the interactions of activin-A, dexamethasone and testosterone in anterior pituitary cell cultures of male rats. Neuroendocrinology 2003; 77:298-304. [PMID: 12806175 DOI: 10.1159/000070896] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2002] [Accepted: 03/27/2003] [Indexed: 11/19/2022]
Abstract
This study was designed to evaluate the effects of glucocorticoids and gonadal steroids on the expression of inhibin/activin subunits and follistatin of the anterior pituitary and test the hypothesis that resulting changes in the local activin/inhibin/follistatin tone contribute to steroid effects on follicle stimulating hormone (FSH) production from gonadotropes. In primary cell cultures of male rat anterior pituitaries, dexamethasone (DEX) or testosterone (T) stimulated FSH secretion and FSHbeta mRNA and their effects were additive with activin-A. Follistatin (FS288) and inhibin-A antagonized the rise in FSH secretion both in the absence and presence of exogenous activin-A. Despite the similarity in their action on FSH production, DEX and T had opposite effects on follistatin mRNA levels. Follistatin mRNA levels of cultured rat anterior pituitary cells were elevated upon the addition of DEX but attenuated by T. On the other hand, both DEX and T suppressed inhibin/activin betaB mRNA levels while only DEX affected betaA mRNA. In these cells, activin-A stimulated follistatin and inhibin/activin betaB mRNA levels but had no effect on betaA. Together, DEX and activin-A caused a further increase in follistatin mRNA levels while T attenuated the effect of activin-A alone. Both steroids attenuated the effect of activin-A on betaB mRNA accumulation. These results support the possibility that DEX and T, possibly acting on different subsets of anterior pituitary cells, use distinct mechanisms to modify the local activin/inhibin/follistatin circuitry and thereby upregulate FSH production from the anterior pituitary gonadotropes.
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Affiliation(s)
- Angela M O Leal
- Clayton Foundation Laboratories for Peptide Biology, The Salk Institute, La Jolla, Calif., USA
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26
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Abstract
A polymorphic Alu element belonging to the young Ya5 subfamily of Alu repeats located in the progesterone receptor gene has been characterized. Using a polymerase chain reaction (PCR)-based assay, the genetic diversity associated with the PROGINS Alu repeat was determined in a diverse array of human populations. The level of insertion polymorphism associated with PROGINS suggests that it will be a useful marker for the study of human evolution. In addition, we determined the distribution of the PROGINS Alu insertion in two groups of women from greater New Orleans, LA with breast cancer. The PROGINS Alu insertion was not associated with breast cancer in the populations tested.
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Affiliation(s)
- C J Donaldson
- Department of Pathology, Louisiana State University Health Sciences Center, 1901 Perdido Street, New Orleans, LA 70112, USA
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27
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Leal AMO, Takabe K, Wang L, Donaldson CJ, MacConell LA, Bilezikjian LM, Verma IM, Vale W. Effect of adenovirus-mediated overexpression of follistatin and extracellular domain of activin receptor type II on gonadotropin secretion in vitro and in vivo. Endocrinology 2002; 143:964-9. [PMID: 11861519 DOI: 10.1210/endo.143.3.8667] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Activins are dimeric proteins that stimulate the synthesis and secretion of pituitary FSH by interacting with two classes of receptors, type I and type II, to initiate their intracellular signaling cascade. The extracellular domain of type II activin receptor (ActRII-ECD) contains all structural determinants sufficient for high affinity ligand binding. A soluble recombinant ActRII-ECD has been reported to attenuate FSH secretion from cultured rat anterior pituitary cells in response to exogenous activin A or endogenous activin B. Follistatin is a binding protein that acts as an extracellular factor to bind and inactivate activin. We constructed adenoviral vectors able to mediate expression of follistatin 288 (AdexCAFS288) and ActRII-ECD (AdexCAECD) and tested their biological activities both in vitro and in vivo. The data show that adenovirus-mediated overexpression of either ActRII-ECD or follistatin was able to attenuate FSH secretion by cultured rat anterior pituitary cells. However, AdexCAFS288 overexpression of follistatin was more effective than adenovirus-mediated overexpression of ActRII-ECD. In vivo, a single ip injection of AdexCAFS288 induced the expression of high levels of follistatin and resulted in the suppression of serum FSH levels in castrated male rats for up to 12 d postinjection. Infection with AdexCAFS288 had no effect on LH secretion in vitro or in vivo, demonstrating its selectivity. In conclusion, the results demonstrate the effectiveness of adenovirus-mediated overexpression of follistatin and ActRII-ECD to regulate FSH secretion and the potential of using this strategy as a tool to further define the critical role of activin/inhibin/follistatin circuitry in the modulation of the reproductive system.
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Affiliation(s)
- Angela M O Leal
- Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, La Jolla, California 92037, USA
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Gray PC, Greenwald J, Blount AL, Kunitake KS, Donaldson CJ, Choe S, Vale W. Identification of a binding site on the type II activin receptor for activin and inhibin. J Biol Chem 2000; 275:3206-12. [PMID: 10652306 DOI: 10.1074/jbc.275.5.3206] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Type II activin receptors (ActRII and ActRIIB) are single-transmembrane domain serine/threonine kinase receptors that bind activin to initiate the signaling and cellular responses triggered by this hormone. Inhibin also binds type II activin receptors and antagonizes many activin effects. Here we describe alanine scanning mutagenesis of the ActRII extracellular domain. We identify a cluster of three hydrophobic residues (Phe(42), Trp(60), and Phe(83)) that, when individually mutated to alanine in the context of the full-length receptor, cause the disruption of activin and inhibin binding to ActRII. Each of the alanine-substituted ActRII mutants retaining activin binding maintains the ability to form cross-linked complexes with activin and supports activin cross-linking to the type I activin receptor ALK4. Unlike wild-type ActRII, the three mutants unable to bind activin do not cause an increase in activin signaling when transiently expressed in a corticotroph cell line. Together, our results implicate these residues in forming a critical binding surface on ActRII required for functional interactions with both activin and inhibin. This first identification of a transforming growth factor-beta family member binding site may provide a general basis for characterizing binding sites for other members of the superfamily.
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Affiliation(s)
- P C Gray
- Clayton Foundation Laboratories for Peptide Biology, Salk Institute for Biological Studies, La Jolla, California 92037, USA
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Abstract
Activins and inhibins belong to the transforming growth factor-beta-like superfamily of growth and differentiation factors that exert pleiotropic effects in many target tissues. Heteromeric association of activin with two structurally related receptor serine/threonine kinases, activin receptor types I and II, initiates downstream signaling events. The extracellular domain of type II mouse activin receptor (ActRII ECD) was expressed in the baculovirus system, purified in three steps by lectin affinity, anion exchange, and reverse phase chromatography, and further characterized by mass spectrometry. The reduction in the apparent size of the purified ActRII ECD on SDS-PAGE after treatment with glycosidases provided evidence for N- and O-linked oligosaccharides. Specific receptor/ligand complexes of [125I] activin A to ActRII ECD or [125I]ActRII ECD to activin A were analyzed by cross-linking and immunoprecipitation. Two major radiolabeled bands were observed on SDS-PAGE with mobilities consistent with the expected size of ActRII ECD/betaA or ActRII ECD/betaAbetaA. When inhibin A was cross-linked to [125I]ActRII ECD, a slower migrating complex corresponding to ActRII ECD/betaAalpha was also observed. The apparent dissociation constant (Kd) for activin A binding to ActRII ECD was 2-7 nM. This Kd value is approximately an order of magnitude greater than that of the full-length membrane-associated type II receptor. Treatment of cultured rat anterior pituitary cells with ActRII ECD attenuated FSH secretion in response to exogenous activin A or endogenous activin B. These data indicate that the soluble ActRII ECD has structural determinants that are sufficient for high affinity ligand binding.
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Affiliation(s)
- C J Donaldson
- The Clayton Foundation Laboratories for Peptide Biology, The Salk Institute, La Jolla, California 92037, USA
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Abstract
The mouse and human urocortin genes (Ucn and UCN, respectively) have been isolated, characterized, and found to have very similar structures. Each has two exons, and the entire coding region is located in the second exon, as is the case for the gene of the related peptide, corticotropin-releasing factor. Several putative transcription factor-binding sites were identified in each of the urocortin promoters, including a TATA box, a cyclic AMP response element (CRE), GATA-binding sites, and a C/EBP-binding site as well as a Brn-2-binding site(s). Sequence analyses of the mouse and human genes also revealed the presence of a previously identified gene, Mpv17, in the 5' region upstream of the urocortin gene. Functional studies following transient transfection of urocortin reporter plasmids in PC12 cells revealed that the urocortin promoter is controlled by both positive and negative elements; the CRE is important for basal activity as well as responsiveness to forskolin stimulation.
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Affiliation(s)
- L Zhao
- The Clayton Foundation Laboratories for Peptide Biology, The Salk Institute, La Jolla, California 92037, USA
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Cervini LA, Donaldson CJ, Koerber SC, Vale WW, Rivier JE. Human growth hormone-releasing hormone hGHRH(1-29)-NH2: systematic structure-activity relationship studies. J Med Chem 1998; 41:717-27. [PMID: 9513600 DOI: 10.1021/jm970618s] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Two complete and two partial structure-activity relationship scans of the active fragment of human growth hormone-releasing hormone, [Nle27]-hGHRH(1-29)-NH2, have identified potent agonists in vitro. Single-point replacement of each amino acid by alanine led to the identification of [Ala8]-, [Ala9]-, [Ala15]- (Felix et al. Peptides 1986 1986, 481), [Ala22]-, and [Ala28, Nle27]-hGHRH(1-29)-NH2 as being 2-6 times more potent than hGHRH(1-40)-OH (standard) in vitro. Nearly complete loss of potency was seen for [Ala1], [Ala3], [Ala5], [Ala6], [Ala10], [Ala11], [Ala13], [Ala14], and [Ala23], whereas [Ala16], [Ala18], [Ala24], [Ala25], [Ala26], and [Ala29] yielded equipotent analogues and [Ala7], [Ala12], [Ala17], [Ala20], [Ala21], and [Ala27] gave weak agonists with potencies 15-40% that of the standard. The multiple-alanine-substituted peptides [MeTyr1,Ala15,22,Nle27]-hGHRH(1-29)-NH2 (29) and [MeTyr1,Ala8,9,15,22,28,Nle 27]-hGHRH(1-29)-NH2 (30) released growth hormone 26 and 11 times, respectively, more effectively than the standard in vitro. Individual substitution of the nine most potent peptides identified from the Ala series with the helix promoter alpha-aminoisobutyric acid (Aib) produced similar results, except for [Aib8] (doubling vs [Ala8]), [Aib9] (having vs [Ala9]), and [Aib15] (10-fold decrease vs [Ala15]). A series of cyclic analogues was synthesized having the general formula cyclo(25-29)[MeTyr1,-Ala15,Xaa25,Nle27,Yaa29+ ++]-GHRH(1-29)-NH2, where Xaa and Yaa represent the bridgehead residues of a side-chain cystine or [i-(i + 4)] lactam ring. The ring size, bridgehead amino acid chirality, and side-chain amide bond location were varied in this partial series in an attempt to maximize potency. Application of lactam constraints in the C-terminus of GHRH(1-29)-NH2 identified cyclo(25-29)[MeTyr1,Ala15,DAsp25,Nle27,Orn29+ ++]-hGHRH(1-29)-NH2 (46) as containing the optimum bridging element (19-membered ring) in this region of the molecule. This analogue (46) was 17 times more potent than the standard. Equally effective was an [i-(i + 3)] constraint yielding the 18-membered ring cyclo(25-28)[MeTyr1,Ala15,Glu25,Nle,27Lys28]- hGHRH-(1-29)-NH2 (51) which was 14 times more potent than the standard. A complete [i-(i + 3)] scan of cyclo(i,i + 3)[MeTyr1,Ala15,Glui,Lys(i + 3),Nle27]-hGHRH(1-29)-NH2 was then produced in order to test the effects of a Glu-to-Lys lactam bridge at all points in the peptide. Of the 26 analogues in the series, 11 had diminished potencies of less than 10% that of the agonist standard, 4 were weak agonists (15-40% relative potency), and 4 analogues were equipotent to the standard. The 7 most potent analogues ranged in potency from 3 to 14 times greater than that of the standard and contained the [i-(i + 3)] cycles between residues 4-7, 5-8, 9-12, 16-19, 21-24, 22-25, and 25-28. The combined results from these systematic studies allowed for an analysis of structural features in the native peptide that are important for receptor activation. Reinforcement of the characteristics of amphiphilicity, helicity, and peptide dipolar effects, using recognized medicinal chemistry approaches including introduction of conformational constraints, has resulted in several potent GHRH analogues.
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Affiliation(s)
- L A Cervini
- Clayton Foundation Laboratories for Peptide Biology, Salk Institute, La Jolla, California 92037, USA
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Abstract
Urocortin, a new member of the CRF peptide family which also includes urotensin I and sauvagine, was recently cloned from the rat midbrain. The synthetic replicate of urocortin was found to bind with high affinity to type 1 and type 2 CRF receptors and, based upon its anatomic localization within the brain, was proposed to be a natural ligand for the type 2 CRF receptors. Using a genomic library, we have cloned the human counterpart of rat urocortin and localized it to human chromosome 2. Human and rat urocortin share 95% identity within the mature peptide region. Synthetic human urocortin binds with high affinity to CRF receptor types 1, 2 alpha, and 2 beta, stimulates cAMP accumulation from cells stably transfected with these receptors, and acts in vitro to release ACTH from dispersed rat anterior pituitary cells. In addition, the CRF-binding protein binds human urocortin with high affinity and can prevent urocortin-stimulated ACTH secretion in vitro. The inhibitory effect of the CRF-binding protein on human urocortin can be blocked by biologically inactive CRF fragments, such as CRF(9-33).
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Affiliation(s)
- C J Donaldson
- Clayton Foundation Laboratories for Peptide Biology, Salk Institute, La Jolla 92037, USA
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34
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Abstract
Corticotropin releasing factor (CRF), a key neuroregulator of the hypothalamic-pituitary-adrenal cortical axis, also displays a broad range of effects on the endocrine, central nervous and immune systems. Having recently characterized the human pituitary CRF receptor by expression cloning of cDNA from a human Cushing's corticotropic adenoma, we report here the structure of the cDNA for a rat brain CRF receptor (rCRF-R) which was cloned by hybridization from a rat brain cDNA library. The sequence of the rCRF-R encodes a 415 amino acid protein comprising seven membrane spanning domains. The rCRF-R is 97% identical at the amino acid level to the human pituitary tumor CRF receptor, differing by only 12 amino acids. When expressed in COSM6 cells, the rCRF-R binds CRF with high affinity (Kd = 1.7 (0.8-3.8)nM). The receptor transduces a CRF stimulated accumulation of intracellular cAMP which is inhibited by the CRF antagonist, alpha helCRF(9-41). These results suggest that the brain expresses a CRF receptor similar to that in the pituitary.
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Affiliation(s)
- M H Perrin
- Clayton Foundation Laboratories for Peptide Biology, Salk Institute, La Jolla, CA 92037
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35
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Abstract
Activin has been suggested to be an autocrine/paracrine regulator in the human placenta. In the present study, we examined the expression of the gene encoding activin type II receptor (ActRII) in this tissue. Using primers corresponding to the published sequence of human ActRII, a 456bp fragment was obtained from cDNAs prepared from the placenta, as well as the ovary and brain, by polymerase chain reaction (PCR). Southern blot hybridization of the PCR products and DNA cloning and sequencing confirmed that the product is the authentic ActRII. Trophoblast cells prepared from both first trimester and term placentae expressed the ActRII gene. When trophoblast cells from term placenta were separated into syncytiotrophoblast- and cytotrophoblast-enriched fractions and incubated for 1-6 days, ActRII gene expression was observed in both cell preparations, with the syncytiotrophoblast-enriched fraction having higher levels of expression at days 1, 3, and 4. These results provide the first direct evidence that the activin type II receptor mRNA is present in human trophoblast cells and strengthen the hypothesis that activin is an autocrine/paracrine regulator of placental function. To our knowledge, this is also the first report that the ActRII gene is expressed in the human brain and ovary.
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Affiliation(s)
- C Peng
- Department of Obstetrics and Gynaecology, University of British Columbia, Vancouver, Canada
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36
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Perrin MH, Bilezikjian LM, Hoeger C, Donaldson CJ, Rivier J, Haas Y, Vale WW. Molecular and functional characterization of GnRH receptors cloned from rat pituitary and a mouse pituitary tumor cell line. Biochem Biophys Res Commun 1993; 191:1139-44. [PMID: 7916600 DOI: 10.1006/bbrc.1993.1335] [Citation(s) in RCA: 76] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A cDNA for a GnRH receptor (mtGnRH-R) was obtained from a mouse gonadotropic pituitary cell line (alpha T3-1) by expression cloning. This full-length cDNA was subsequently used as a probe to clone a rat pituitary GnRH receptor (rGnRH-R). The two receptors differ by 13 amino acids and are 100% identical to those recently reported. The analysis of the cloned receptors by photoaffinity-labeling followed by SDS-PAGE reveals a major band of approximately 70 kDa. This is in contrast to the native rat pituitary and mouse alpha T3-1 receptors whose major labeled species migrate with an apparent size of approximately 45 kDa. Functional studies reveal that both receptors, when transiently expressed in COSM6 cells, can bind GnRH with high affinity and transduce the stimulation of IP3 accumulation in response to GnRH.
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Affiliation(s)
- M H Perrin
- Clayton Foundation Laboratories for Peptide Biology, Salk Institute for Biological Studies, La Jolla, CA 92037
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37
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Kornreich WD, Galyean R, Hernandez JF, Craig AG, Donaldson CJ, Yamamoto G, Rivier C, Vale W, Rivier J. Alanine series of ovine corticotropin releasing factor (oCRF): a structure-activity relationship study. J Med Chem 1992; 35:1870-6. [PMID: 1316969 DOI: 10.1021/jm00088a024] [Citation(s) in RCA: 82] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Previous structure-activity relationship studies of CRF have shown that residues 1-4 were not necessary for receptor binding or transduction, that residues 4-8 were important for activation, and that residues 12-41 were mostly responsible for binding. Finally it was proposed that CRF assumed an alpha-helical structure when interacting with its receptor. By systematic substitution of each residue (except residues 1-4) in ovine CRF (oCRF) by Ala, we have investigated the role played by individual side chains in receptor recognition and activation. Out of 33 analogues (synthesized using SPPS on an MBHA resin, purified by RPHPLC and characterized by amino acid and mass spectral analyses), a significant loss of biological potency (less than 1% potency of native) was observed for 6 analogues ([Ala6], [Ala8], [Ala10], [Ala12], [Ala14], and [Ala38]); 12 analogues had biological potencies ranging from 1% to 60% and ranked as follows: [Ala35] less than [Ala16] less than [Ala9] less than [Ala19] less than [Ala15] less than [Ala13] less than [Ala7] less than [Ala23] less than [Ala11] less than or equal to [Ala21] less than [Ala27] less than or equal to [Ala18]; 8 analogues were found to be equipotent (greater than 60% and less than 150%) ([Ala5], [Ala17], [Ala26], [Ala29], [Ala30], [Ala34], [Ala36], and [Ala37]; and 7 analogues were found to be approximately 2-5 times more potent than native oCRF ([Ala25] = [Ala40] less than or equal to [Ala39] less than or equal to [Ala33] less than [Ala20] less than [Ala22] less than [Ala32], in an in vitro pituitary cell culture assay. In summary, the Ala substitutions which showed the greatest loss of potency (less than 1% of native oCRF) were those replacing hydrophobic residues while those showing the greatest increase in potency were replacing hydrophilic residues. Of the 22 Ala-containing analogues in the C-terminal half of the molecule, 17 analogues have equal or greater potencies than native oCRF. Substitution of Ala in the N-terminal region (residues 5-19) on the other hand is generally detrimental to biological activity. These results suggest that the side chains of residues 5-19 are very important for receptor binding and activation while, in the C-terminal region, the amino acid side chains may be more responsible for structural conservation than for functional expression.
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Affiliation(s)
- W D Kornreich
- Clayton Foundation Laboratories for Peptide Biology, Salk Institute, La Jolla, California 92037
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38
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Abstract
A full-length cDNA for the type II human activin receptor was cloned by hybridization from a human testis cDNA library. The sequence encodes a 513 amino acid protein that is 99% identical, at the amino acid level, with the mouse type II activin receptor. The type II human activin receptor consists of an extracellular domain that specifically binds activin A with a Kd of 360 pM, a single-membrane spanning domain, and an intracellular kinase domain with predicted serine/threonine specificity.
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Affiliation(s)
- C J Donaldson
- Clayton Foundation Laboratories for Peptide Biology, Salk Institute, La Jolla, CA 92037
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