1
|
Quigley EB, DeVore SB, Khan SA, Geisterfer ZM, Rothfuss HM, Sequoia AO, Thompson PR, Gatlin JC, Cherrington BD, Navratil AM. GnRH Induces Citrullination of the Cytoskeleton in Murine Gonadotrope Cells. Int J Mol Sci 2024; 25:3181. [PMID: 38542155 PMCID: PMC10970285 DOI: 10.3390/ijms25063181] [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] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 03/06/2024] [Accepted: 03/07/2024] [Indexed: 04/06/2024] Open
Abstract
Peptidylarginine deiminases (PADs or PADIs) catalyze the conversion of positively charged arginine to neutral citrulline, which alters target protein structure and function. Our previous work established that gonadotropin-releasing hormone agonist (GnRHa) stimulates PAD2-catalyzed histone citrullination to epigenetically regulate gonadotropin gene expression in the gonadotrope-derived LβT2 cell line. However, PADs are also found in the cytoplasm. Given this, we used mass spectrometry (MS) to identify additional non-histone proteins that are citrullinated following GnRHa stimulation and characterized the temporal dynamics of this modification. Our results show that actin and tubulin are citrullinated, which led us to hypothesize that GnRHa might induce their citrullination to modulate cytoskeletal dynamics and architecture. The data show that 10 nM GnRHa induces the citrullination of β-actin, with elevated levels occurring at 10 min. The level of β-actin citrullination is reduced in the presence of the pan-PAD inhibitor biphenyl-benzimidazole-Cl-amidine (BB-ClA), which also prevents GnRHa-induced actin reorganization in dispersed murine gonadotrope cells. GnRHa induces the citrullination of β-tubulin, with elevated levels occurring at 30 min, and this response is attenuated in the presence of PAD inhibition. To examine the functional consequence of β-tubulin citrullination, we utilized fluorescently tagged end binding protein 1 (EB1-GFP) to track the growing plus end of microtubules (MT) in real time in transfected LβT2 cells. Time-lapse confocal microscopy of EB1-GFP reveals that the MT average lifetime increases following 30 min of GnRHa treatment, but this increase is attenuated by PAD inhibition. Taken together, our data suggest that GnRHa-induced citrullination alters actin reorganization and MT lifetime in gonadotrope cells.
Collapse
Affiliation(s)
- Elizabeth B. Quigley
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY 82071, USA; (E.B.Q.); (A.O.S.); (A.M.N.)
| | - Stanley B. DeVore
- Department of Pediatrics, University of Cincinnati College of Medicine, Division of Asthma Research, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229, USA;
| | | | - Zachary M. Geisterfer
- Department of Cell Biology, Duke University School of Medicine, Durham, NC 27710, USA;
| | - Heather M. Rothfuss
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY 82071, USA; (E.B.Q.); (A.O.S.); (A.M.N.)
| | - Ari O. Sequoia
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY 82071, USA; (E.B.Q.); (A.O.S.); (A.M.N.)
| | - Paul R. Thompson
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605, USA;
| | - Jesse C. Gatlin
- Department of Molecular Biology, University of Wyoming, Laramie, WY 82071, USA;
| | - Brian D. Cherrington
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY 82071, USA; (E.B.Q.); (A.O.S.); (A.M.N.)
| | - Amy M. Navratil
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY 82071, USA; (E.B.Q.); (A.O.S.); (A.M.N.)
| |
Collapse
|
2
|
Christensen AO, Li G, Young CH, Snow B, Khan SA, DeVore SB, Edwards S, Bouma GJ, Navratil AM, Cherrington BD, Rothfuss HM. Peptidylarginine deiminase enzymes and citrullinated proteins in female reproductive physiology and associated diseases†. Biol Reprod 2022; 107:1395-1410. [PMID: 36087287 PMCID: PMC10248218 DOI: 10.1093/biolre/ioac173] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 08/30/2022] [Accepted: 09/07/2022] [Indexed: 09/15/2023] Open
Abstract
Citrullination, the post-translational modification of arginine residues, is catalyzed by the four catalytically active peptidylarginine deiminase (PAD or PADI) isozymes and alters charge to affect target protein structure and function. PADs were initially characterized in rodent uteri and, since then, have been described in other female tissues including ovaries, breast, and the lactotrope and gonadotrope cells of the anterior pituitary gland. In these tissues and cells, estrogen robustly stimulates PAD expression resulting in changes in levels over the course of the female reproductive cycle. The best-characterized targets for PADs are arginine residues in histone tails, which, when citrullinated, alter chromatin structure and gene expression. Methodological advances have allowed for the identification of tissue-specific citrullinomes, which reveal that PADs citrullinate a wide range of enzymes and structural proteins to alter cell function. In contrast to their important physiological roles, PADs and citrullinated proteins are also involved in several female-specific diseases including autoimmune disorders and reproductive cancers. Herein, we review current knowledge regarding PAD expression and function and highlight the role of protein citrullination in both normal female reproductive tissues and associated diseases.
Collapse
Affiliation(s)
- Amanda O Christensen
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY 82071, USA
| | - Guangyuan Li
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY 82071, USA
| | - Coleman H Young
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY 82071, USA
| | - Bryce Snow
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY 82071, USA
| | | | - Stanley B DeVore
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Sydney Edwards
- Animal Reproduction and Biotechnology Laboratory, Department of Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA
| | - Gerrit J Bouma
- Animal Reproduction and Biotechnology Laboratory, Department of Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA
| | - Amy M Navratil
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY 82071, USA
| | - Brian D Cherrington
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY 82071, USA
| | - Heather M Rothfuss
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY 82071, USA
| |
Collapse
|
3
|
Okamoto Y, Devoe S, Seto N, Minarchick V, Wilson T, Rothfuss HM, Mohning MP, Arbet J, Kroehl M, Visser A, August J, Thomas SM, Lenis Charry L, Fleischer C, Feser ML, Frazer-Abel AA, Norris JM, Cherrington BD, Janssen WJ, Kaplan MJ, Deane KD, Holers VM, Demoruelle MK. Sputum Neutrophil Extracellular Trap Subsets Associate with IgA Anti-Citrullinated Protein Antibodies in Subjects At-Risk for Rheumatoid Arthritis. Arthritis Rheumatol 2021; 74:38-48. [PMID: 34369110 PMCID: PMC8712364 DOI: 10.1002/art.41948] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 08/03/2021] [Indexed: 11/06/2022]
Abstract
Objective Mechanisms leading to anti–citrullinated protein antibody (ACPA) generation in rheumatoid arthritis (RA) are hypothesized to originate in the lung. We undertook this study to understand associations between neutrophil extracellular trap (NET) formation in the lung and local ACPA generation in subjects at risk of developing RA. Methods Induced sputum was collected from 49 subjects at risk of developing RA, 12 patients with RA, and 18 controls. Sputum neutrophils were tested for ex vivo NET formation, and sputum‐induced NET formation of control neutrophils was measured using immunofluorescence imaging. Sputum macrophages were tested for ex vivo endocytosis of apoptotic and opsonized cells. Levels of ACPA, NET remnants, and inflammatory proteins were quantified in sputum supernatant. Results Spontaneous citrullinated histone H3 (Cit‐H3)–expressing NET formation was higher in sputum neutrophils from at‐risk subjects and RA patients compared to controls (median 12%, 22%, and 0%, respectively; P < 0.01). In at‐risk subjects, sputum IgA ACPA correlated with the percentage of neutrophils that underwent Cit‐H3+ NET formation (r = 0.49, P = 0.002) and levels of Cit‐H3+ NET remnants (r = 0.70, P < 0.001). Reduced endocytic capacity of sputum macrophages was found in at‐risk subjects and RA patients compared to controls. Using a mediation model, we found that sputum inflammatory proteins were associated with sputum IgA ACPA through a pathway mediated by Cit‐H3+ NET remnants. Sputum‐induced Cit‐H3+ NET formation also correlated with sputum levels of interleukin‐1β (IL‐1β), IL‐6, and tumor necrosis factor in at‐risk subjects, suggesting a causal relationship. Conclusion These data support a potential mechanism for mucosal ACPA generation in subjects at risk of developing RA, whereby inflammation leads to increased citrullinated protein–expressing NETs that promote local ACPA generation.
Collapse
Affiliation(s)
- Yuko Okamoto
- University of Colorado Denver, Division of Rheumatology, Aurora, CO, USA.,Tokyo Women's Medical University School of Medicine, Department of Rheumatology, Tokyo, Japan
| | - Stephanie Devoe
- University of Colorado Denver, Department of Immunology, Aurora, CO, USA
| | - Nickie Seto
- Systemic Autoimmunity Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda
| | - Valerie Minarchick
- University of Colorado Denver, Division of Rheumatology, Aurora, CO, USA
| | - Timothy Wilson
- University of Colorado Denver, Division of Rheumatology, Aurora, CO, USA
| | - Heather M Rothfuss
- University of Wyoming, Department of Zoology and Physiology, Laramie, WY, USA
| | - Michael P Mohning
- National Jewish Health, Division of Pulmonary, Critical Care and Sleep Medicine, Denver, CO, USA
| | - Jaron Arbet
- University of Colorado Denver, Department of Biostatistics and Informatics, Aurora, CO, USA
| | - Miranda Kroehl
- University of Colorado Denver, Department of Biostatistics and Informatics, Aurora, CO, USA
| | - Ashley Visser
- University of Colorado Denver, Division of Rheumatology, Aurora, CO, USA
| | - Justin August
- University of Colorado Denver, Division of Rheumatology, Aurora, CO, USA
| | - Stacey M Thomas
- National Jewish Health, Division of Pulmonary, Critical Care and Sleep Medicine, Denver, CO, USA
| | - Laura Lenis Charry
- University of Colorado Denver, Division of Rheumatology, Aurora, CO, USA
| | - Chelsie Fleischer
- University of Colorado Denver, Division of Rheumatology, Aurora, CO, USA
| | - Marie L Feser
- University of Colorado Denver, Division of Rheumatology, Aurora, CO, USA
| | | | - Jill M Norris
- Colorado School of Public Health, Department of Epidemiology, Aurora, CO, USA
| | - Brian D Cherrington
- University of Wyoming, Department of Zoology and Physiology, Laramie, WY, USA
| | - William J Janssen
- National Jewish Health, Division of Pulmonary, Critical Care and Sleep Medicine, Denver, CO, USA
| | - Mariana J Kaplan
- Systemic Autoimmunity Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda
| | - Kevin D Deane
- University of Colorado Denver, Division of Rheumatology, Aurora, CO, USA
| | - V Michael Holers
- University of Colorado Denver, Division of Rheumatology, Aurora, CO, USA
| | | |
Collapse
|
4
|
Li G, Young CH, Snow B, Christensen AO, Demoruelle MK, Nemmara VV, Thompson PR, Rothfuss HM, Cherrington BD. Identification and Characterization of the Lactating Mouse Mammary Gland Citrullinome. Int J Mol Sci 2020; 21:ijms21072634. [PMID: 32290104 PMCID: PMC7177251 DOI: 10.3390/ijms21072634] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [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: 03/12/2020] [Revised: 04/07/2020] [Accepted: 04/08/2020] [Indexed: 02/07/2023] Open
Abstract
Citrullination is a post-translational modification (PTM) in which positively charged peptidyl-arginine is converted into neutral peptidyl-citrulline by peptidylarginine deiminase (PAD or PADI) enzymes. The full protein citrullinome in many tissues is unknown. Herein, we used mass spectrometry and identified 107 citrullinated proteins in the lactation day 9 (L9) mouse mammary gland including histone H2A, α-tubulin, and β-casein. Given the importance of prolactin to lactation, we next tested if it stimulates PAD-catalyzed citrullination using mouse mammary epithelial CID-9 cells. Stimulation of CID-9 cells with 5 µg/mL prolactin for 10 min induced a 2-fold increase in histone H2A citrullination and a 4.5-fold increase in α-tubulin citrullination. We next investigated if prolactin-induced citrullination regulates the expression of lactation genes β-casein (Csn2) and butyrophilin (Btn1a1). Prolactin treatment for 12 h increased β-casein and butyrophilin mRNA expression; however, this increase was significantly inhibited by the pan-PAD inhibitor, BB-Cl-amidine (BB-ClA). We also examined the effect of tubulin citrullination on the overall polymerization rate of microtubules. Our results show that citrullinated tubulin had a higher maximum overall polymerization rate. Our work suggests that protein citrullination is an important PTM that regulates gene expression and microtubule dynamics in mammary epithelial cells.
Collapse
Affiliation(s)
- Guangyuan Li
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY 82071, USA; (G.L.); (C.H.Y.); (B.S.); (A.O.C.); (H.M.R.)
| | - Coleman H. Young
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY 82071, USA; (G.L.); (C.H.Y.); (B.S.); (A.O.C.); (H.M.R.)
| | - Bryce Snow
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY 82071, USA; (G.L.); (C.H.Y.); (B.S.); (A.O.C.); (H.M.R.)
| | - Amanda O. Christensen
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY 82071, USA; (G.L.); (C.H.Y.); (B.S.); (A.O.C.); (H.M.R.)
| | - M. Kristen Demoruelle
- Division of Rheumatology, University of Colorado School of Medicine, Aurora, CO 80045, USA;
| | - Venkatesh V. Nemmara
- Department of Chemistry and Biochemistry, Rowan University, Glassboro, NJ 08028, USA;
| | - Paul R. Thompson
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605, USA;
| | - Heather M. Rothfuss
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY 82071, USA; (G.L.); (C.H.Y.); (B.S.); (A.O.C.); (H.M.R.)
| | - Brian D. Cherrington
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY 82071, USA; (G.L.); (C.H.Y.); (B.S.); (A.O.C.); (H.M.R.)
- Correspondence:
| |
Collapse
|
5
|
Demoruelle MK, Harrall KK, Ho L, Purmalek MM, Seto NL, Rothfuss HM, Weisman MH, Solomon JJ, Fischer A, Okamoto Y, Kelmenson LB, Parish MC, Feser M, Fleischer C, Anderson C, Mahler M, Norris JM, Kaplan MJ, Cherrington BD, Holers VM, Deane KD. Anti-Citrullinated Protein Antibodies Are Associated With Neutrophil Extracellular Traps in the Sputum in Relatives of Rheumatoid Arthritis Patients. Arthritis Rheumatol 2017; 69:1165-1175. [PMID: 28182854 DOI: 10.1002/art.40066] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Accepted: 02/02/2017] [Indexed: 01/07/2023]
Abstract
OBJECTIVE Studies suggest that rheumatoid arthritis (RA)-related autoimmunity is initiated at a mucosal site. However, the factors associated with the mucosal generation of this autoimmunity are unknown, especially in individuals who are at risk of future RA. Therefore, we tested anti-cyclic citrullinated peptide (anti-CCP) antibodies in the sputum of RA-free first-degree relatives (FDRs) of RA patients and patients with classifiable RA. METHODS We evaluated induced sputum and serum samples from 67 FDRs and 20 RA patients for IgA anti-CCP and IgG anti-CCP, with cutoff levels for positivity determined in a control population. Sputum was also evaluated for cell counts, neutrophil extracellular traps (NETs) using sandwich enzyme-linked immunosorbent assays for protein/nucleic acid complexes, and total citrulline. RESULTS Sputum was positive for IgA and/or IgG anti-CCP in 14 of 20 RA patients (70%) and 17 of 67 FDRs (25%), including a portion of FDRs who were serum anti-CCP negative. In the FDRs, elevations of sputum IgA and IgG anti-CCP were associated with elevated sputum cell counts and NET levels. IgA anti-CCP was associated with ever smoking and with elevated sputum citrulline levels. CONCLUSION Anti-CCP is elevated in the sputum of FDRs, including seronegative FDRs, suggesting that the lung may be a site of anti-CCP generation in this population. The association of anti-CCP with elevated cell counts and NET levels in FDRs supports a hypothesis that local airway inflammation and NET formation may drive anti-CCP production in the lung and may promote the early stages of RA development. Longitudinal studies are needed to follow the evolution of these processes relative to the development of systemic autoimmunity and articular RA.
Collapse
Affiliation(s)
| | | | - Linh Ho
- University of Colorado Denver at Aurora
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
6
|
Young CH, Rothfuss HM, Gard PF, Muth A, Thompson PR, Ashley RL, Cherrington BD. Citrullination regulates the expression of insulin-like growth factor-binding protein 1 (IGFBP1) in ovine uterine luminal epithelial cells. Reproduction 2016; 153:1-10. [PMID: 29565015 DOI: 10.1530/rep-16-0494] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Revised: 09/28/2016] [Accepted: 10/10/2016] [Indexed: 01/19/2023]
Abstract
There are five peptidylarginine deiminase (PAD) isozymes designated as PADs 1, 2, 3, 4 and 6, and many are expressed in female reproductive tissues. These enzymes post-translationally convert positively charged arginine amino acids into neutral citrulline residues. Targets for PAD-catalyzed citrullination include arginine residues on histone tails, which results in chromatin decondensation and changes in gene expression. Some of the first studies examining PADs found that they are localized to rodent uterine epithelial cells. Despite these findings, the function of PAD-catalyzed citrullination in uterine epithelial cells is still unknown. To address this, we first examined PAD expression in uterine cross-sections from pregnant ewes on gestation day 25 (d25). Immunohistochemistry revealed that the levels of PADs 2 and 4 are robust in luminal and glandular epithelia compared with those of PADs 1 and 3. As PADs 2 and 4 have well-characterized roles in histone citrullination, we next hypothesized that PADs citrullinate histones in these uterine cells. Examination of caruncle lysates from pregnant ewes on gestation d25 and an ovine luminal epithelial (OLE) cell line shows that histone H3 arginine residues 2, 8, 17 and 26 are citrullinated, but histone H4 arginine 3 is not. Using a pan-PAD inhibitor, we next attenuated histone citrullination in OLE cells, which resulted in a significant decrease in the expression of insulin-like growth factor-binding protein 1 (IGFBP1) mRNA. As IGFBP1 is important for the migration and attachment of the trophectoderm to uterine endometrium, our results suggest that PAD-catalyzed citrullination may be an important post-translational mechanism for the establishment of pregnancy in ewes.
Collapse
Affiliation(s)
- Coleman H Young
- Department of Zoology and PhysiologyUniversity of Wyoming, Laramie, Wyoming, USA
| | - Heather M Rothfuss
- Department of Zoology and PhysiologyUniversity of Wyoming, Laramie, Wyoming, USA
| | - Philip F Gard
- Department of Zoology and PhysiologyUniversity of Wyoming, Laramie, Wyoming, USA
| | - Aaron Muth
- Department of Biochemistry and Molecular PharmacologyUniversity of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Paul R Thompson
- Department of Biochemistry and Molecular PharmacologyUniversity of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Ryan L Ashley
- Department of Animal and Range SciencesNew Mexico State University, Las Cruces, New Mexico, USA
| | - Brian D Cherrington
- Department of Zoology and PhysiologyUniversity of Wyoming, Laramie, Wyoming, USA
| |
Collapse
|
7
|
Holland AD, Rothfuss HM, Lidstrom ME. Development of a defined medium supporting rapid growth for Deinococcus radiodurans and analysis of metabolic capacities. Appl Microbiol Biotechnol 2006; 72:1074-82. [PMID: 16575566 DOI: 10.1007/s00253-006-0399-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2006] [Revised: 02/26/2006] [Accepted: 03/02/2006] [Indexed: 10/24/2022]
Abstract
A morpholinepropanesulfonic acid (MOPS)-buffered rich defined medium (RDM) was optimized to support a reproducible 2.6-h doubling time at 35 degrees C for Deinococcus radiodurans R1 and used to gain insight into vitamin and carbon metabolism. D. radiodurans was shown to require biotin and niacin for growth in this medium. A glutamine-serine simple defined medium (SDM) was developed that supported a 4-h doubling time, and this medium was used to probe sulfur and methionine metabolism. Vitamin B(12) was shown to alleviate methionine auxotrophy, and under these conditions, sulfate was used as the sole sulfur source. Phenotypic characterization of a methionine synthase deletion mutant demonstrated that the B(12) alleviation of methionine auxotrophy was due to the necessity of the B(12)-dependent methionine synthase in methionine biosynthesis. Growth on ammonium as the sole nitrogen source in the presence of vitamin B(12) was demonstrated, but it was not possible to achieve reproducibly good growth in the absence of at least one amino acid as a nitrogen source. Growth on sulfate, cysteine, and methionine as sulfur sources demonstrated the function of a complete sulfur recycling pathway in this strain. These studies have demonstrated that rapid growth of D. radiodurans R1 can be achieved in a MOPS-based medium solely containing a carbon source, salts, four vitamins, and two amino acids.
Collapse
Affiliation(s)
- Alexandra D Holland
- Department of Chemical Engineering, University of Washington, Seattle, WA 98195-2180, USA
| | | | | |
Collapse
|
8
|
Abstract
Deinococcus radiodurans is a highly radiation-resistant bacterium that is classed in a major subbranch of the bacterial domain. Since very little is known about gene expression in this bacterium, an initial study of promoters was undertaken. In order to isolate promoters and study promoter function, a series of integrative vectors for stable chromosomal insertion in D. radiodurans were developed. These vectors are based on Escherichia coli replicons that are unable to replicate autonomously in D. radiodurans and carry homologous sequences for replacement recombination in the D. radiodurans chromosome. The resulting integration vectors were used to study expression of reporter genes fused to a number of putative promoters that were amplified from the D. radiodurans R1 genome. Further analysis of these and other putative promoters was performed by Northern hybridization and primer extension experiments. In contrast to previous reports, the -10 and -35 regions of these promoters resembled the sigma(70) consensus sequence of E. coli.
Collapse
Affiliation(s)
- R Meima
- Department of Chemical Engineering, University of Washington, Seattle, WA 98195, USA
| | | | | | | |
Collapse
|