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Rozo-Lopez P, Brewer W, Käfer S, Martin MM, Parker BJ. Untangling an insect's virome from its endogenous viral elements. BMC Genomics 2023; 24:636. [PMID: 37875824 PMCID: PMC10594914 DOI: 10.1186/s12864-023-09737-z] [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] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Accepted: 10/12/2023] [Indexed: 10/26/2023] Open
Abstract
BACKGROUND Insects are an important reservoir of viral biodiversity, but the vast majority of viruses associated with insects have not been discovered. Recent studies have employed high-throughput RNA sequencing, which has led to rapid advances in our understanding of insect viral diversity. However, insect genomes frequently contain transcribed endogenous viral elements (EVEs) with significant homology to exogenous viruses, complicating the use of RNAseq for viral discovery. METHODS In this study, we used a multi-pronged sequencing approach to study the virome of an important agricultural pest and prolific vector of plant pathogens, the potato aphid Macrosiphum euphorbiae. We first used rRNA-depleted RNAseq to characterize the microbes found in individual insects. We then used PCR screening to measure the frequency of two heritable viruses in a local aphid population. Lastly, we generated a quality draft genome assembly for M. euphorbiae using Illumina-corrected Nanopore sequencing to identify transcriptionally active EVEs in the host genome. RESULTS We found reads from two insect-specific viruses (a Flavivirus and an Ambidensovirus) in our RNAseq data, as well as a parasitoid virus (Bracovirus), a plant pathogenic virus (Tombusvirus), and two phages (Acinetobacter and APSE). However, our genome assembly showed that part of the 'virome' of this insect can be attributed to EVEs in the host genome. CONCLUSION Our work shows that EVEs have led to the misidentification of aphid viruses from RNAseq data, and we argue that this is a widespread challenge for the study of viral diversity in insects.
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Affiliation(s)
- Paula Rozo-Lopez
- Department of Microbiology, University of Tennessee, Knoxville, TN, 37916, USA.
| | - William Brewer
- Department of Microbiology, University of Tennessee, Knoxville, TN, 37916, USA
| | - Simon Käfer
- Institut Für Biologie Und Umweltwissenschaften, Carl Von Ossietzky Universität Oldenburg, 26129, Oldenburg, Germany
| | - McKayla M Martin
- Department of Microbiology, University of Tennessee, Knoxville, TN, 37916, USA
| | - Benjamin J Parker
- Department of Microbiology, University of Tennessee, Knoxville, TN, 37916, USA.
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2
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Changenet P, Plaza P, Martin MM, Meyer YH, Rettig W. Dynamics of photoinduced charge-transfer in dimethylamino-substituted triphenylphosphines. ACTA ACUST UNITED AC 2017. [DOI: 10.1051/jcp/1996931697] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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3
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Barbehenn RV, Martin MM, Hagerman AE. Reassessment of the roles of the peritrophic envelope and hydrolysis in protecting polyphagous grasshoppers from ingested hydrolyzable tannins. J Chem Ecol 2013; 22:1901-19. [PMID: 24227115 DOI: 10.1007/bf02028511] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/1996] [Accepted: 05/27/1996] [Indexed: 11/26/2022]
Abstract
We examined several of the mechanisms that have been reported to enable polyphagous grasshoppers (Orthoptera: Acrididae) to tolerate ingested hydrolyzable tannins: hydrolysis, adsorption on the peritrophic envelope, and peritrophic envelope impermeability. None of these mechanisms explain the tolerance ofMelanoplus sanguinipes to ingested tannic acid. In this species, tannin hydrolysis was 12-47% complete, adsorption accounted for less than 1% of the tannic acid contained in the midgut, and the peritrophic envelope was permeated by several gallotannins. The foregut is the main site for the chemical transformation of tannic acid in this species. InPhoetaliotes nebrascensis, hydrolysis was more extensive (82% complete), but the peritrophic envelope was readily permeated by two gallotannins. Oxidizing redox conditions were found in the guts of both species, and ingested tannins were oxidized inM. sanguinipes. We hypothesize that the tolerance of some polyphagous grasshoppers to ingested hydrolyzable tannins may be the consequence of their ability to tolerate the reactive oxygen species generated by polyphenol oxidation, whereas others may rely on rapid and extensive hydrolysis.
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Affiliation(s)
- R V Barbehenn
- Department of Biology, University of Michigan, 48109-1048, Ann Arbor, Michigan
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4
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Abstract
The hydrocarbons of the common house cricketAcheta domesticus L. consist ofn-alkanes (4%), 2-methylalkanes (20%), x-methylalkanes (59%), an unidentified series of alkanes (trace), and olefins (16-185). The major n-alkane isn-nonacosane (3.5%). The major 2-methylalkanes are 2-methyloctacosane (8%) and 2-methyltriacontane (11%). The members of the homologous x-methylalkane series consist of mixtures of methylalkanes in which the methyl side-chain is located on the 13th, 15th, and 17th carbon atom in the chain. The major x-methylalkanes are the homologues containing 31 (3%), 33 (6.5%), 35 (12.5%), 37 (27%), and 39 (2.5%) carbon atoms. The olefins are a mixture of straight-chain and 2-methyl-alkenes and alkadienes. The major olefins contain 31 (3%) and 37 (7.5%) carbon atoms.
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Affiliation(s)
- R F Hutchins
- Department of Chemistry, University of Michigan, 48104, Ann Arbor, Michigan
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5
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Martin MM, Martin JS. Cellulose Digestion in the Midgut of the Fungus-Growing Termite Macrotermes natalensis: The Role of Acquired Digestive Enzymes. Science 2010; 199:1453-5. [PMID: 17796679 DOI: 10.1126/science.199.4336.1453] [Citation(s) in RCA: 120] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The midguts of adult workers of the higher termite species Macrotermes natalensis contain the entire set of digestive enzymes required for the digestion of native cellulose. The C(x)-cellulases and the beta-glucosidases are produced, at least in part, by the termite's own midgut epithelium and salivary glands. The C(1)-cellulases, on the other hand, are acquired by the termites when they feed on a fungus that grows in their nests. We propose that the involvement of acquired digestive enzymes could serve as the basis for a general strategy of resource utilization and further suggest that the acquisition of digestive enzymes may be a widespread phenomenon among mycophagous invertebrates.
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Berkowitz F, Lee PJ, Martin AL, Martin MM. Enlargement of the proximal pituitary stalk associated with spontaneous recovery from multiple pituitary hormone deficiencies. AJNR Am J Neuroradiol 2008; 29:1601-2. [PMID: 18499794 DOI: 10.3174/ajnr.a1117] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
We report the case of a child with multiple pituitary hormone deficiencies and a truncated pituitary stalk on MR imaging who had recovery of normal secretion of pituitary hormones in early adulthood. Follow-up MR imaging examination after recovery revealed marked enlargement of the proximal pituitary stalk. The case of our patient helps to explain the mechanism whereby some patients experience recovery of hormonal function.
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Affiliation(s)
- F Berkowitz
- Department of Radiology, Georgetown University Hospital, Washington, DC 20007, USA.
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7
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Abstract
KBG syndrome is a multiple congenital anomaly (MCA) syndrome comprising developmental delay, postnatal short stature, and delayed bone age. Many physical anomalies involving the face, hands, and costovertebral axis have been described in this syndrome. We present twin males with KBG syndrome and a review of 50 published case reports, with particular emphasis on the neurological aspects of KBG syndrome, including seizures, MRI findings, and behavior difficulties. It is argued that diagnostic criteria for KBG syndrome should include neurological involvement, that is, global developmental delay, seizures, and/or mental retardation (MR). The characteristic facial changes and representative hand and costovertebral anomalies are also defined. These diagnostic criteria were obtained from 50 publications and appeared to support the diagnosis in 43 cases. They will be helpful to pediatricians, geneticists, and neurologists in evaluating patients for this condition.
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Affiliation(s)
- K L Skjei
- Department of Pediatrics, Division of Genetics, University of California, San Francisco, California 94143-0748, USA
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8
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Martin M, Colmenero C, Lorente L, Molina I, Trujillo A, Chopitea A. Crit Care 2003; 7:P133. [DOI: 10.1186/cc2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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9
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Carroll JF, Kyser CK, Martin MM. beta-Adrenoceptor density and adenylyl cyclase activity in obese rabbit hearts. Int J Obes (Lond) 2002; 26:627-32. [PMID: 12032745 DOI: 10.1038/sj.ijo.0801957] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [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: 07/02/2001] [Revised: 10/25/2001] [Accepted: 11/21/2001] [Indexed: 11/09/2022]
Abstract
OBJECTIVE To determine whether decreased cardiac responsiveness to isoproterenol in obesity is associated with alterations in beta-receptors and/or adenylyl cyclase activity. ANIMALS AND DESIGN: After 12 weeks of control or ad libitum high-fat diets, left ventricular tissue from lean and obese female New Zealand white rabbits was assayed for beta-receptor binding density (11 lean, 11 obese) and isoproterenol-stimulated adenylyl cyclase activity (eight lean, 10 obese). MEASUREMENTS Nonlinear least squares regression analysis was used to determine maximum density of beta-receptors and receptor affinity for (125)I-iodocyanopindolol. Four-parameter logistic regression was used to determine minimum, maximum, slope and EC(50) for isoproterenol-stimulated adenylyl cyclase activity. RESULTS Obese rabbits had elevated resting blood pressure and heart rate, and higher ventricular weights. However, beta-adrenoceptor density and affinity were not significantly different in lean and obese rabbits. Basal and maximum isoproterenol-stimulated adenylyl cyclase activity did not differ between lean and obese rabbits. In addition, maximal stimulation in response to sodium flouride did not differ between lean and obese. EC(50) for isoproterenol-stimulated adenylyl cyclase activity did not differ between lean and obese rabbits. CONCLUSION Obesity-related decreases in responsiveness of the isolated heart to isoproterenol are not associated with alterations in beta-receptor density and affinity. In addition, adenylyl cyclase activity appeared unchanged in ventricular preparations from obese rabbits. Decreased responsiveness to isoproterenol in obesity may be due to defects downstream of adenylyl cyclase activation of cyclic AMP.
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Affiliation(s)
- J F Carroll
- Department of Integrative Physiology, University of North Texas Health Science Center, Fort Worth, TX 76107, USA.
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10
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Zhao X, Martin MM, Elton TS. The transcription factors Sp1 and Sp3 are required for human angiotensin II type 1 receptor gene expression in H295-R cells. Biochim Biophys Acta 2001; 1522:195-206. [PMID: 11779634 DOI: 10.1016/s0167-4781(01)00341-4] [Citation(s) in RCA: 16] [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] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The peptide hormone angiotensin II regulates a variety of physiological responses which are mediated by its interaction with high affinity G protein-coupled receptors localized on the surface of target cells. Our previous studies have demonstrated that a 145 bp sequence within the promoter region was required for basal level expression of the human angiotensin II type 1 receptor (hAT(1)R) gene. In the present study, deletional analysis of the hAT(1)R promoter localized the major regulatory sequence to two overlapping GC boxes harbored within the -105 to -85 bp region relative to the transcription start site in H295-R cells. Electrophoretic mobility shift assays (EMSAs) using a double-stranded (ds) oligonucleotide corresponding to this region and H295-R cell nuclear extract resulted in five specific DNA-protein complexes. EMSAs performed with competitive ds-oligonucleotides which harbored the consensus binding site for Sp1 prevented the formation of the DNA-protein complexes. Supershift EMSAs also demonstrated that Sp1 and Sp3 could bind to the GC boxes present within the -105 to -85 bp region of the hAT(1)R promoter. Transactivation experiments utilizing Drosophila SL2 cells, which lack endogenous Sp family transcription factors, demonstrated that Sp1 and Sp3 activated the hAT(1)R promoter and that maximal activation was only achieved when both GC boxes were present. Taken together, these findings suggest that Sp1 and Sp3 are necessary for the expression of the hAT(1)R gene in H295-R cells.
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Affiliation(s)
- X Zhao
- Department of Chemistry and Biochemistry, Brigham Young University, C206 Benson Building, P.O. Box 25700, Provo, UT 84602-5700, USA
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11
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Martin MM, Victor X, Zhao X, McDougall JK, Elton TS. Identification and characterization of functional angiotensin II type 1 receptors on immortalized human fetal aortic vascular smooth muscle cells. Mol Cell Endocrinol 2001; 183:81-91. [PMID: 11604228 DOI: 10.1016/s0303-7207(01)00595-0] [Citation(s) in RCA: 10] [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: 11/16/2022]
Abstract
Studies investigating the mechanisms that govern the expression of the human angiotensin II type 1 receptor (hAT(1)R) gene have progressed slowly due to the lack of human cell lines that express the AT(1)R. Recently, however, an immortalized human fetal aortic vascular smooth muscle cell line (FLTR) was generated using an amphotropic recombinant retroviral construct containing the E6/E7 open reading frames of the human papillomavirus type 16. Radioligand binding studies were undertaken to determine whether angiotensin II (Ang II) receptors were expressed on these cells. FLTR cell membranes were shown to express high-affinity Ang II receptors having a B(max) value of 324+/-43 fmol/mg protein and a K(d) of 0.36+/-0.1 nM. In both membranes and intact cells, Ang II, Ang III and the selective AT(1)R antagonist, Losartan, all had a high affinity for the receptor, suggesting that FLTR cells express the AT(1)R subtype. The expression of the hAT(1)R was validated by Northern and Western blot and RT-PCR experiments. In intact FLTR cells, Ang II (100 nM) evoked an increase in intracellular calcium ([Ca(2+)](i)) and induced hyperplasia. Additionally, our results demonstrated that FLTR cells were readily transfected, and hAT(1)R promoter luciferase constructs exhibited robust promoter activity (i.e. approximately 22-fold increase over pGL3-Basic only). Finally, our results demonstrated that the hAT(1)R gene is differentially regulated in FLTR cells vs. H295-R cells, a human adrenocarcinoma cell line that also abundantly expresses the AT(1)R. Taken together, our results suggest that FLTR cells express functional AT(1)Rs and will provide an excellent model system in which to investigate hAT(1)R gene regulation.
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MESH Headings
- Angiotensins/pharmacology
- Animals
- Antihypertensive Agents/pharmacology
- Aorta/embryology
- Aorta/metabolism
- Calcium/metabolism
- Cell Line
- Cell Membrane/chemistry
- Cell Membrane/metabolism
- Culture Media, Serum-Free
- Fetus
- Genes, Reporter
- Humans
- Imidazoles/pharmacology
- Losartan/pharmacology
- Luciferases/genetics
- Luciferases/metabolism
- Muscle, Smooth, Vascular/embryology
- Muscle, Smooth, Vascular/metabolism
- Promoter Regions, Genetic
- Pyridines/pharmacology
- Receptor, Angiotensin, Type 1
- Receptors, Angiotensin/genetics
- Receptors, Angiotensin/metabolism
- Signal Transduction
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Affiliation(s)
- M M Martin
- Department of Chemistry and Biochemistry, Brigham Young University, C206 Benson Science Building, PO Box 25700, Provo, UT 84602-5400, USA
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12
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Abstract
37 participants receiving verbally aggressive messages during a mediated interaction viewed their interactants as less socially attractive.
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Affiliation(s)
- M M Martin
- Communication Studies Department, West Virginia University, Morgantown, WV 26506, USA.
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13
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Palker TJ, Monteiro JM, Martin MM, Kakareka C, Smith JF, Cook JC, Joyce JG, Jansen KU. Antibody, cytokine and cytotoxic T lymphocyte responses in chimpanzees immunized with human papillomavirus virus-like particles. Vaccine 2001; 19:3733-43. [PMID: 11395208 DOI: 10.1016/s0264-410x(01)00093-7] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
We evaluated antibody, cytokine (IFN-gamma, IL-5, TNF-alpha), and cytotoxic T lymphocyte (CTL) responses in chimpanzees immunized with monovalent or quadrivalent (HPV-6, -11, -16, -18) L1 virus-like particle (VLP) vaccines administered i.m. on aluminum hydroxyphosphate (alum) at weeks 0, 8 and 24. Maximum serum antibody titers to type-specific, neutralizing, conformational epitopes on HPV-11 or -16 L1 VLPs were detected by radioimmunoassay (RIA) four weeks after the second and third immunizations. HPV-11 and -16 neutralizing antibodies were also detected at similar time points with an Human papillomaviruses (HPV) neutralization assay using pseudovirions. Depending on the VLP type used for immunization, HPV type-specific cytokine responses were most frequently seen four weeks after the second or third immunizations and between weeks 44-52. Transient HPV-16 L1-specific CTL activity was observed only between weeks 16-24 in 3 of 22 (13.6%) chimpanzees immunized with HPV-16 L1 VLPs. These findings provide evidence that immunization with multivalent L1 VLPs on alum can evoke both neutralizing antibodies and Th1 and Th2 cytokine responses to several HPV types; however, induction of CTLs is infrequent.
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Affiliation(s)
- T J Palker
- Department of Virus and Cell Biology, Merck Research Laboratories, Merck and Co., Inc., WP16-101, Sumneytown Pike, West Point, PA 19486, USA.
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14
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Barbehenn RV, Bumgarner SL, Roosen EF, Martin MM. Antioxidant defenses in caterpillars: role of the ascorbate-recycling system in the midgut lumen. J Insect Physiol 2001; 47:349-357. [PMID: 11166299 DOI: 10.1016/s0022-1910(00)00125-6] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
This study demonstrates that an ascorbate-recycling system in the midgut lumen can act as an effective antioxidant defense in caterpillars that feed on prooxidant-rich foods. In tannin-sensitive larvae of the forest tent caterpillar, Malacosoma disstria (Lasiocampidae), ingested tannic acid is oxidized in the midgut lumen, generating significant quantities of peroxides, including hydrogen peroxide, which readily diffuses across cell membranes and is a powerful cytotoxin. By contrast, in the tannin-tolerant larvae of the white-marked tussock moth, Orgyia leucostigma (Lymantriidae), tannic acid oxidation and the generation of peroxides are suppressed. The superior defense of O. leucostigma against oxidative stress imposed by the oxidation of ingested polyphenols can be explained by the presence of higher concentrations of ascorbate and glutathione in the midgut lumen. In O. leucostigma at least 50% of the ingested ascorbate present in the anterior midgut is still present in the posterior midgut, whereas in M. disstria, only 10% of the ascorbate is present in the posterior half of the midgut. We propose that the maintenance of higher levels of ascorbate in the midgut lumen of O. leucostigma than in M. disstria is explained by the secretion of glutathione into the midgut lumen by O. leucostigma, thereby forming a complete ascorbate-recycling system. The concentration of glutathione in the midgut lumen of O. leucostigma is 3.5-fold higher than in M. disstria and more than double the concentration in the diet. Our results emphasize the importance of a defensive strategy in herbivorous insects based on the maintenance of conditions in the gut lumen that reduce or eliminate the potential prooxidant behavior of ingested phenols.
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Affiliation(s)
- R V Barbehenn
- Department of Biology, University of Michigan, 48109-1048, Ann Arbor, MI, USA
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15
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Martin MM, Willardson BM, Burton GF, White CR, McLaughlin JN, Bray SM, Ogilvie JW, Elton TS. Human angiotensin II type 1 receptor isoforms encoded by messenger RNA splice variants are functionally distinct. Mol Endocrinol 2001; 15:281-93. [PMID: 11158334 DOI: 10.1210/mend.15.2.0598] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [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: 11/19/2022] Open
Abstract
Human tissues that express the angiotensin II (Ang II) type 1 receptor (hAT(1)R) can synthesize four distinct alternatively spliced hAT(1)R mRNA transcripts. In this study, we show that the relative abundance of these mRNA transcripts varies widely in human tissues, suggesting that each splice variant is functionally distinct. Here we demonstrate, for the first time, that the hAT(1)R-B mRNA splice variant encodes a novel long hAT(1)R isoform in vivo that has significantly diminished affinity for Ang II (i.e. >3-fold) when compared with the short hAT(1)R isoform (encoded by hAT(1)R-A mRNA splice variant). This reduced agonist affinity caused a significant shift to the right in the dose-response curve for Ang II-induced inositol trisphosphate production and Ca(2+) mobilization of the long hAT(1)R when compared with that of the short hAT(1)R. The functional differences between these isoforms allows Ang II responsiveness to be fine-tuned by regulating the relative abundance of the long and short hAT(1)R isoform expressed in a given human tissue.
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MESH Headings
- Adrenal Cortex Neoplasms/metabolism
- Alternative Splicing
- Amino Acid Sequence
- Angiotensin II/pharmacology
- Animals
- Base Sequence
- CHO Cells
- Cricetinae
- Exons
- Flow Cytometry
- Gene Expression
- Glycosylation
- Humans
- Inositol Phosphates/biosynthesis
- Kinetics
- Molecular Sequence Data
- RNA, Messenger/analysis
- RNA, Messenger/biosynthesis
- Receptor, Angiotensin, Type 1
- Receptor, Angiotensin, Type 2
- Receptors, Angiotensin/chemistry
- Receptors, Angiotensin/genetics
- Receptors, Angiotensin/physiology
- Reverse Transcriptase Polymerase Chain Reaction
- Structure-Activity Relationship
- Tissue Distribution
- Transfection
- Tumor Cells, Cultured
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Affiliation(s)
- M M Martin
- Department of Chemistry and Biochemistry, Brigham Young University, P.O. Box 25700, Provo, Utah 84602, USA
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16
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Yeager MD, Aste-Amezaga M, Brown DR, Martin MM, Shah MJ, Cook JC, Christensen ND, Ackerson C, Lowe RS, Smith JF, Keller P, Jansen KU. Neutralization of human papillomavirus (HPV) pseudovirions: a novel and efficient approach to detect and characterize HPV neutralizing antibodies. Virology 2000; 278:570-7. [PMID: 11118379 DOI: 10.1006/viro.2000.0674] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The development of vaccines against human papillomaviruses (HPVs) has long been hampered by the inability to grow HPVs in tissue culture and the lack of an efficient neutralization assay. To date, less than 10% of more than 100 different HPV types can be grown in athymic and "SCID" mouse xenograft systems or raft culture systems. Recently, the in vitro generation of HPV pseudovirions and their use in neutralization assays were demonstrated. The major shortcomings of the current approaches to HPV neutralization are the lack of HPV virions for most types for the xenograft methods and the time-consuming and inefficient generation of infective pseudovirions for the latter methods, which precludes their use in large-scale HPV clinical trials or epidemiological studies. We describe here a novel and efficient approach to generating pseudovirions in which HPV virus-like particles (VLPs) are coupled to the beta-lactamase gene as a reporter. We show that it is not necessary to encapsidate the reporter gene constructs into the pseudovirions. Using sera from human volunteers immunized with HPV-11 VLPs expressed in yeast, we demonstrate that our novel neutralization assay compares favorably with the athymic mouse neutralization assay. Furthermore, our assay was used to define neutralizing monoclonal antibodies to HPV-6, which were previously unknown.
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Affiliation(s)
- M D Yeager
- Department of Virus and Cell Biology, Merck Research Laboratories, West Point, Pennsylvania 19486, USA
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17
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Abstract
Students (N = 259) reported on their motives for communicating with their instructors along with completing measures of affective and cognitive learning. The relational, functional, and participatory motives tended to be positively correlated with learning, but there were no significant associations for excuse-making and sycophantic motives with learning.
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Affiliation(s)
- M M Martin
- Communication Studies Department, West Virginia University, Morgantown, WV 26506, USA.
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18
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19
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Abstract
The peptide hormone angiotensin II regulates a variety of physiological responses which are mediated by its interaction with high affinity G protein-coupled receptors localized on the surface of target cells. To gain insights into the transcriptional regulation of the human angiotensin II type 1 receptor (hAT(1)R) gene, we have isolated 1 kb of the 5'-flanking sequence of this gene. Expression constructs containing various 5'-deletions of the hAT(1)R promoter region, fused upstream to the luciferase reporter gene, were transiently transfected into H295-R, HEC-1B and A549 cells. It was demonstrated that a 145 bp sequence within the promoter region was required for basal level expression of the hAT(1)R gene in all of the three cell lines investigated. Computer analysis indicated the existence of numerous putative transcription factor binding sites in this region. Further detailed deletion data suggested essential transcription factor binding sites between -98 and -79 bp. Electrophoretic mobility shift assays revealed that four protein-DNA complexes were formed within the -98 to -79 bp region of the hAT(1)R gene when incubated with H295-R cell nuclear extract. Site-directed mutagenesis experiments showed that a putative Sp1 binding site was critical for the basal level expression of the hAT(1)R gene.
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Affiliation(s)
- X Zhao
- Department of Chemistry and Biochemistry, Brigham Young University, C206 Benson Building, P.O. Box 25700, Provo, UT 84602, USA
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20
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Lazarov ME, Martin MM, Willardson BM, Elton TS. Molecular cloning and characterization of the human phosducin-like protein (hPhLP) promoter. Biochim Biophys Acta 2000; 1492:460-4. [PMID: 10899582 DOI: 10.1016/s0167-4781(00)00137-8] [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] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Phosducin-like protein (PhLP) is an inducible Gbetagamma binding protein which is hypothesized to be a ubiquitous G protein regulator. To elucidate the mechanisms regulating the expression of the human PhLP (hPhLP) gene, we have cloned and characterized its 5'-flanking region. Primer extension analysis identified a major transcription initiation site 172 bp upstream of the ATG start codon. Analysis of the 5'-flanking region revealed that, although it lacked a TATA box element, the hPhLP promoter did contain several consensus binding motifs including AP4, CCAAT, CREB, NF-kappaB, SP1 and E2F. Transient transfection analyses using a series of 5'-flanking deletion/luciferase reporter gene constructs identified a 25 bp sequence (-80 to -55 bp) that is necessary for basal level transcription of the hPhLP gene in all the cell lines investigated. Interestingly, dependent upon the cell line, distinct transcription factors bind to this region suggesting that basal level hPhLP gene transcription may be regulated in a tissue-specific manner.
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Affiliation(s)
- M E Lazarov
- Department of Chemistry and Biochemistry, Brigham Young University, C206 Benson Building, P.O. Box 25700, Provo, UT 84602-5700, USA
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Rothenberg SJ, Parker RM, York RG, Dearlove GE, Martin MM, Denny KH, Lief SD, Hoberman AM, Christian MS. Lack of effects of nose-only inhalation exposure on testicular toxicity in male rats. Toxicol Sci 2000; 53:127-34. [PMID: 10653530 DOI: 10.1093/toxsci/53.1.127] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Reductions in testicular mass, sperm motility, and mating frequency have been attributed to the stresses caused by confinement of Sprague-Dawley male rats in nose-only inhalation exposure tubes. Testicular changes, including an increase in testicular atrophy, have been detected at an increased incidence in male rats used in inhalation studies as compared with rats of the same age and strain used in oral toxicity studies. This study was designed to determine whether nose-only exposure of male rats caused testicular toxicity under conditions of cooling of the exposure room and appropriate acclimation to the exposure tubes. In order to acclimate the rats to the nose-only inhalation exposure apparatus, all male rats were placed in the exposure tubes for at least four successively increasing time intervals (15, 30, 45, and 60 min) on 4 separate days, with a rest period of approximately 48 h between the first and second acclimation. Twenty male rats were exposed nose-only to filtered air for approximately 2 h per day for 28 days before cohabitation and continuing throughout a 14-day cohabitation period. To reduce thermal stress, the exposure room temperature was maintained at 64 to 70 degrees F. Twenty control rats were housed in the same room as the exposed rats but were not placed in exposure tubes. End points monitored were body weight, testicular weight, sperm count, sperm motility, and histopathology of the testes, epididymides, prostate, and seminal vesicles. The control rats gained weight more rapidly than the exposed rats. All the rats in both groups mated successfully, and testicular weights, normalized to body weight, were similar for both groups. More importantly, there were no microscopic changes that could be considered an adverse effect on the reproductive tissues in the male rats placed in exposure tubes. Thus, nose-only exposure for up to 2 h per day for a total of 42 days did not cause adverse effects on the reproductive organs, fertility, or reproductive performance of male rats under the conditions of this study.
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Lazarov ME, Martin MM, Willardson BM, Elton TS. Human phosducin-like protein (hPhLP) messenger RNA stability is regulated by cis-acting instability elements present in the 3'-untranslated region. Biochim Biophys Acta 1999; 1446:253-64. [PMID: 10524200 DOI: 10.1016/s0167-4781(99)00098-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Phosducin (Pd) and phosducin-like protein (PhLP) have been shown to regulate G-protein signaling by binding G beta gamma subunits. To better define the function and regulation of PhLP, and to begin to investigate its potential role in human pathophysiological states, we have cloned the human PhLP (hPhLP) cDNA. The hPhLP shows 92% identity with the rat PhLP (rPhLP). However, unlike the rPhLP, no evidence of hPhLP isoforms were detected in the human tissues investigated. Additionally, unlike the rPhLP, alternative polyadenylation sites were detected in hPhLP cDNA clones which corresponded with two distinct mRNA transcripts, 1.2 kb and 3.1 kb, respectively. Interestingly, the predominantly expressed long transcript contains multiple AU-rich elements (AREs) in its 3'-untranslated region (3'-UTR) which have been shown to correlate with rapid mRNA turnover and translational control. This study shows that the hPhLP AREs are functional both in vitro and in vivo, with the long transcript exhibiting a much shorter mRNA half-life. We also demonstrate that subcloning of either the full-length 3'-UTR or the ARE-rich region of the long transcript immediately following the stop codon of luciferase reporter gene confers instability to the luciferase mRNA and results in a ninefold reduction of luciferase activity in the cell types investigated. Taken together, these findings suggest that the AREs present in the long hPhLP mRNA may play a critical role in the regulation of hPhLP gene expression.
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Affiliation(s)
- M E Lazarov
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT 84602, USA
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23
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Abstract
The relationship between self-disclosure and perceived understanding in the stepparent-stepchild relationship was investigated. Stepchildren (N = 165) completed a questionnaire about their communication with their stepparents. Participants reported on their self-disclosure (intentionality, amount, positiveness, depth, and honesty) and their feelings of being understood by their stepparents. The results showed that self-disclosure was positively related to perceived understanding. This was especially true for the relationship between honesty of self-disclosure and perceived understanding. Analyses involving gender of the individuals in the stepchild-stepparent dyad showed several differences. The relationship between self-disclosure and perceived understanding was more significant for stepdaughters than for stepsons.
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Affiliation(s)
- M M Martin
- Communication Studies Department, West Virginia University, Morgantown 26506-6293, USA
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Rothenberg SJ, Martin MM, Sherer KI, Parker RM, Dearlove GE, Christian MS. Method to protect rabbit eyes and reduce potential stress from eye irritation or injury associated with exposure to vapors and particulates in inhalation studies. Drug Chem Toxicol 1998; 21:269-73. [PMID: 9706460 DOI: 10.3109/01480549809002204] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Many pharmaceuticals are administered to children and adults as sprays provided in nebulizers or metered-dose inhalers. Stress associated with possible eye irritation and injury attributable to exposure to vapors and particulates during the required safety testing procedures of such medicines is a potential confounding factor in these studies. Reducing stress and the potential changes associated with stress is particularly important in safety studies involving pregnant animals because maternal stress has been known to be associated with adverse outcomes for the offspring. Training and acclimating rabbits to wearing modified pediatric swim goggles during exposure to vapors and aerosol particles provides a simple, inexpensive method to reduce or eliminate potential stress from eye irritation.
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Affiliation(s)
- S J Rothenberg
- Argus Research Laboratories, Inc., Horsham, PA 19044, USA
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25
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Martin MM, Wu SM, Martin AL, Rennert OM, Chan WY. Testicular seminoma in a patient with a constitutively activating mutation of the luteinizing hormone/chorionic gonadotropin receptor. Eur J Endocrinol 1998; 139:101-106. [PMID: 9703386 DOI: 10.1530/eje.0.1390101] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.3] [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: 05/22/2023]
Abstract
A white man who had been diagnosed, 35 years previously at the age of 27 months, to have precocious puberty, was later determined to have familial male-limited precocious puberty (FMPP), on the basis of his family history, increased serum testosterone, prepubertal concentrations of follicle stimulating hormone and luteinizing hormone, and Leydig cell hyperplasia. Recently, this diagnosis was confirmed by molecular genetic analysis that demonstrated the presence of a heterozygous constitutive activating mutation of the luteinizing hormone/chorionic gonadotropin receptor. This dominant gain-of-function Asp578Gly mutation has been shown constitutively to activate the receptor in the absence of the agonist, leading to enhanced synthesis of cAMP and, in turn, to increased, sustained production of testosterone. In 1994, this patient was found to have a testicular seminoma. He represents the first case of a testicular germ cell tumor described in an FMPP patient, raising the possibility of a potentially harmful effect of prolonged increased concentrations of sex hormones, with onset early in life, upon the cellular components of the testes.
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Affiliation(s)
- M M Martin
- Department of Pediatrics, Georgetown University Medical Center, Washington, DC 20007, USA
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Wiederrecht GJ, Sabers CJ, Brunn GJ, Martin MM, Dumont FJ, Abraham RT. Mechanism of action of rapamycin: new insights into the regulation of G1-phase progression in eukaryotic cells. Prog Cell Cycle Res 1998; 1:53-71. [PMID: 9552353 DOI: 10.1007/978-1-4615-1809-9_5] [Citation(s) in RCA: 121] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The immunosuppressant drug, rapamycin (RAP), is a potent inhibitor of IL-2-dependent T-cell proliferation. The antiproliferative effect of RAP is mediated through the formation of an active complex with its cytosolic receptor protein, FKBP12. The molecular target of the FKBP12.RAP complex is a putative lipid kinase termed the mammalian Target Of Rapamycin (mTOR). This review will discuss recent findings suggesting that mTOR is a novel regulator of G1- to S-phase progression in eukaryotic cells.
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Affiliation(s)
- G J Wiederrecht
- Department of Immunology, Mayo Clinic, Rochester, Minnesota 55905, USA
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Peterson LB, Cryan JG, Rosa R, Martin MM, Wilusz MB, Sinclair PJ, Wong F, Parsons JN, O'Keefe SJ, Parsons WH, Wyvratt M, Sigal NH, Williamson AR, Wiederrecht GJ. A tacrolimus-related immunosuppressant with biochemical properties distinct from those of tacrolimus. Transplantation 1998; 65:10-8. [PMID: 9448137 DOI: 10.1097/00007890-199801150-00004] [Citation(s) in RCA: 23] [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] [Indexed: 02/05/2023]
Abstract
BACKGROUND Tacrolimus (FK506) is an immunosuppressive drug 50-100 times more potent than cyclosporine (CsA), the current mainstay of organ transplant rejection therapy. Despite being chemically unrelated, CsA and tacrolimus exert their immunosuppressive effects through the inhibition of calcineurin (CaN), a critical signaling molecule during T-lymphocyte activation. Although numerous clinical studies have proven the therapeutic efficacy of drugs within this class, tacrolimus and CsA also have a strikingly similar profile of unwanted side effects. METHOD Our objective has been to identify a less toxic immunosuppressant through the modification of ascomycin (FK520). Quantitative in vitro immunosuppression and toxicity assays have demonstrated (see the accompanying article, p. 18) that we achieved our goal with L-732,531 (indolyl-ascomycin; indolyl-ASC), a 32-O-(1-hydroxyethylindol-5-yl) ascomycin derivative with an improved therapeutic index relative to tacrolimus. RESULTS We report that the attributes of indolyl-ASC may result from its distinctive biochemical properties. In contrast to tacrolimus, indolyl-ASC binds poorly to FK506 binding protein 12 (FKBP12), the major cytosolic receptor for tacrolimus and related compounds. However, the stability of the interaction between the FKBP12-indolyl-ASC complex and CaN is much greater than that of the FKBP12-tacrolimus complex. These distinguishing properties of indolyl-ASC result in the potent inhibition of CaN within T lymphocytes but may lower the accumulation of the drug at sites of toxicity. CONCLUSIONS Indolyl-ASC may define those properties needed to increase the therapeutic efficacy of a macrolactam immunoregulant for treating both human autoimmune disease and organ transplant rejection.
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Affiliation(s)
- L B Peterson
- Department of Molecular Pharmacology, Merck Research Laboratories, Rahway, New Jersey 07065, USA
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Gellon G, Harding KW, McGinnis N, Martin MM, McGinnis W. A genetic screen for modifiers of Deformed homeotic function identifies novel genes required for head development. Development 1997; 124:3321-31. [PMID: 9310327 DOI: 10.1242/dev.124.17.3321] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.1] [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: 11/20/2022]
Abstract
Only a few genes have been identified that participate in the developmental pathways which modulate homeotic (HOX) protein specificity or mediate HOX morphogenetic function. To identify more HOX pathway genes, we screened for mutations on loci on the Drosophila second chromosome that interact with the homeotic gene Deformed (Dfd). Genetic and molecular tests on the eight genes isolated in the screen place them in three general categories. Two genes appear to encode trithorax group functions, i.e. they are general activators of Hox gene expression or function. Four genes encode abundant, widely expressed proteins that may be required to mediate Dfd morphogenetic functions in certain tissues, including two genes for collagen IV protein variants. Finally, two of the genes are required for the development of a subset of embryonic Dfd-dependent structures, while leaving many other segmental structures intact. We cloned and characterized one of these two, which we have named apontic (apt). apt is required for the elaboration of dorsal and ventral head structures. It encodes a 484-amino-acid protein with no significant similarity to known protein sequences. The apt transcript pattern is normal in Dfd and Scr mutants, and the Dfd and Scr transcript patterns are normal in apt mutants. We propose that apt acts in parallel to, or as a cofactor with, HOX proteins to regulate homeotic targets in the ventral gnathal region.
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Affiliation(s)
- G Gellon
- Department of Biology, Yale University, New Haven, CT 06520-8114, USA
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29
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Baughman G, Wiederrecht GJ, Chang F, Martin MM, Bourgeois S. Tissue distribution and abundance of human FKBP51, and FK506-binding protein that can mediate calcineurin inhibition. Biochem Biophys Res Commun 1997; 232:437-43. [PMID: 9125197 DOI: 10.1006/bbrc.1997.6307] [Citation(s) in RCA: 91] [Impact Index Per Article: 3.4] [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: 02/04/2023]
Abstract
We previously described the isolation of an FK506-binding protein, FKBP51, that is predominantly expressed in murine T cells and is capable of mediating drug-dependent calcineurin inhibition in vitro. In addition, the gene for FKBP51 is induced by glucocorticoids. Screening of a human thymus cDNA library resulted in the identification of the human homologue of FKBP51. Expression of the 3.7 kb mRNA corresponding to FKBP51 is induced by glucocorticoids in the human T cell line, C7TK.4. The 51.2 kDa protein encoded by this gene shares 87% identity to murine FKBP51 and demonstrates a similar IC50 value for the FK506-mediated inhibition of calcineurin phosphatase in vitro. The distribution and abundance of FKBP51 and FKBP12 in seventeen human tissues were compared by Western analysis. Unlike its murine counterpart, the human FKBP51 is abundantly expressed in numerous tissues and in many cases, is in molar excess over FKBP12.
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Affiliation(s)
- G Baughman
- Regulatory Biology Laboratory, Salk Institute for Biological Studies, San Diego, California 92186-5800, USA
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30
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Abstract
A rapid, sensitive, and specific filter-based assay for calcineurin phosphatase that utilizes a 96-well microtiter plate format throughout is described. In this assay, either purified calcineurin phosphatase or a crude cellular extract containing calcineurin phosphatase is incubated with a 33P-labeled phosphopeptide substrate in a 96-well microtiter plate. Subsequent to quenching the dephosphorylation reaction, the incubation mixture is transferred to a 96-well Immobilon-P microtiter filtration plate affixed to a vacuum manifold. The phosphorylated peptide remains bound to the hydrophobic filter. The filtrate, containing the released 33P-labeled phosphate, is collected in a 96-well microtiter plate and is measured by liquid scintillation counting.
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Affiliation(s)
- MM Martin
- Department of Immunology Research, Merck Research Laboratories, Building R80W-107, Rahway, New Jersey, 07065
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31
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Dumont FJ, Ok H, Lin S, Kastner CA, Cryan J, Martin MM, Wiederrecht G, Staruch MJ. Mixed agonist/antagonist activity of an FK-506-related immunosuppressant: biological and biochemical characterization. J Pharmacol Exp Ther 1996; 276:1078-88. [PMID: 8786538] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
FK-506 blocks T cell activation by preventing lymphokine gene transcription through formation of a complex with FKBP12 that inhibits calcineurin phosphatase activity. Immunosuppressive FK-506 analogs (agonists) have been generated whose potency correlates with calcineurin inhibition. Nonimmunosuppressive antagonist analogs have also been identified, including L-685,818, which binds to FKBP12 but does not inhibit calcineurin. We describe a novel property of FK-506 analog, characterized as a mixed agonist/antagonist immunosuppressive activity. It is displayed by L-688,617, the 32 O-methoxyethoxymethyl derivative of the agonist L-683,590 (C21-ethyl). Although it binds to FKBP12 similarly to L-683,590, L-688,617 incompletely suppressed T cell proliferation induced by optimal activation and enhanced that induced by supraoptimal activation. In the latter situation, L-688,617 suppressed IL-2 production only partially but blocked activation-driven cell death. Moreover, a 1000-fold molar excess of L-688,617 antagonized the immunosuppressive activity of L-683,590. L-688,617 inhibited calcineurin phosphatase activity in cells only partially. The unique agonist/antagonist activity of L-688,617 may therefore reflect its high affinity for FKBP12, combined with a reduced ability of the drug-FKBP12 complex to inhibit calcineurin function. However, in a cell-free system, L-688,617 completely blocked this function when a large excess of FKBP12 over calcineurin was present, suggesting that the intracellular concentration of FKBP12 may be a limiting factor that prevents full agonist activity of L-688,617 in cells.
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Affiliation(s)
- F J Dumont
- Department of Immunology, Merck Research Laboratories, Rahway, New Jersey, USA
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Affiliation(s)
- M M Martin
- Brigham Young University, Department of Chemistry and Biochemistry, Provo, Utah 84602, USA
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Affiliation(s)
- B Su
- Brigham Young University, Department of Chemistry and Biochemistry, Provo, Utah 84602, USA
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34
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Abstract
To evaluate and functionally compare the rat AT1A and AT1B receptor subtypes, stable Chinese hamster ovary (CHO) cell lines expressing either recombinant receptor in approximately equal numbers were generated. Radioligand binding data suggests that the recombinant AT1A receptor is pharmacologically similar to the recombinant AT1B receptor. Functional studies indicate that both receptor subtypes can independently activate the phospholipase C/IP3 and the dihydropyridine-sensitive voltage-dependent Ca2+ channel signal transduction pathways with equal efficiency, but are unable to modulate cAMP accumulation under our experimental conditions. Furthermore, both receptors can be directly involved in the cellular growth properties of AII. Slot-blot experiments clearly demonstrate that these receptors are expressed in a tissue-specific manner. A sequence comparison of the 5' flanking regions of these two genes shows that they have very little sequence homology (approximately 36%), suggesting that although the AT1A and AT1B receptors appear to be pharmacologically and functionally similar, the control of their expression seems to be governed by distinct transcription factors.
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Affiliation(s)
- M M Martin
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT 84602, USA
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35
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Lam E, Martin MM, Timerman AP, Sabers C, Fleischer S, Lukas T, Abraham RT, O'Keefe SJ, O'Neill EA, Wiederrecht GJ. A novel FK506 binding protein can mediate the immunosuppressive effects of FK506 and is associated with the cardiac ryanodine receptor. J Biol Chem 1995; 270:26511-22. [PMID: 7592869 DOI: 10.1074/jbc.270.44.26511] [Citation(s) in RCA: 148] [Impact Index Per Article: 5.1] [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: 01/26/2023] Open
Abstract
FK506, an immunosuppressant that prolongs allograft survival, is a co-drug with its intracellular receptor, FKBP12. The FKBP12.FK506 complex inhibits calcineurin, a critical signaling molecule during T-cell activation. FKBP12 was, until recently, the sole FKBP known to mediate calcineurin inhibition at clinically relevant FK506 concentrations. The best characterized cellular function of FKBP12 is the modulation of ryanodine receptor isoform-1, a component of the calcium release channel of skeletal muscle sarcoplasmic reticulum. Recently, a novel protein, FKBP12.6, was found to inhibit calcineurin at clinically relevant FK506 concentrations. We have cloned the cDNA encoding human FKBP12.6 and characterized the protein. In transfected Jurkat cells, FKBP12.6 is equivalent to FKBP12 at mediating the inhibitory effects of FK506. Upon binding rapamycin, FKBP12.6 complexes with the 288-kDa mammalian target of rapamycin. In contrast to FKBP12, FKBP12.6 is not associated with ryanodine receptor isoform-1 but with the distinct ryanodine receptor isoform-2 in cardiac muscle sarcoplasmic reticulum. Our results suggest that FKBP12.6 has both a unique physiological role in excitation-contraction coupling in cardiac muscle and the potential to contribute to the immunosuppressive and toxic effects of FK506 and rapamycin.
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Affiliation(s)
- E Lam
- Department of Immunology Research, Merck Research Laboratories, Rahway, New Jersey 07065, USA
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36
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Baughman G, Wiederrecht GJ, Campbell NF, Martin MM, Bourgeois S. FKBP51, a novel T-cell-specific immunophilin capable of calcineurin inhibition. Mol Cell Biol 1995; 15:4395-402. [PMID: 7542743 PMCID: PMC230679 DOI: 10.1128/mcb.15.8.4395] [Citation(s) in RCA: 124] [Impact Index Per Article: 4.3] [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: 01/25/2023] Open
Abstract
The immunosuppressive drugs FK506 and cyclosporin A block T-lymphocyte proliferation by inhibiting calcineurin, a critical signaling molecule for activation. Multiple intracellular receptors (immunophilins) for these drugs that specifically bind either FK506 and rapamycin (FK506-binding proteins [FKBPs]) or cyclosporin A (cyclophilins) have been identified. We report the cloning and characterization of a new 51-kDa member of the FKBP family from murine T cells. The novel immunophilin, FKBP51, is distinct from the previously isolated and sequenced 52-kDa murine FKBP, demonstrating 53% identity overall. Importantly, Western blot (immunoblot) analysis showed that unlike all other FKBPs characterized to date, FKBP51 expression was largely restricted to T cells. Drug binding to recombinant FKBP51 was demonstrated by inhibition of peptidyl prolyl isomerase activity. As judged from peptidyl prolyl isomerase activity, FKBP51 had a slightly higher affinity for rapamycin than for FK520, an FK506 analog. FKBP51, when complexed with FK520, was capable of inhibiting calcineurin phosphatase activity in an in vitro assay system. Inhibition of calcineurin phosphatase activity has been implicated both in the mechanism of immunosuppression and in the observed toxic side effects of FK506 in nonlymphoid cells. Identification of a new FKBP that can mediate calcineurin inhibition and is restricted in its expression to T cells suggests that new immunosuppressive drugs may be identified that, by virtue of their specific interaction with FKBP51, would be targeted in their site of action.
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Affiliation(s)
- G Baughman
- Regulatory Biology Laboratory, Salk Institute for Biological Studies, San Diego, California 92186-5800, USA
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37
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Abstract
A human genomic DNA library was screened utilizing a human angiotensin II type 2 receptor (hAT2R) cDNA as a probe. Several positive clones were isolated and characterized. A comparison of the hAT2R cDNA sequence with the hAT2R genomic clone sequence suggests that the hAT2R gene is composed of three exons and spans at least 5 kb. Exons 1 and 2 encode for 5' untranslated mRNA sequence and exon 3 harbors the entire uninterrupted open reading frame of the hAT2R. Sequence analysis of the 5'-flanking region of the hAT2R gene demonstrates that it contains the typical sequence motifs found in many eukaryotic promoters. Interestingly, however, this promoter region also includes an interferon consensus sequence binding protein site (ICSBP) and a putative embryonal, long terminal repeat binding protein (ELP) site. The presence of these novel putative transcription factor binding sites suggests that this gene may be regulated in a unique manner.
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Affiliation(s)
- M M Martin
- Vascular Biology and Hypertension Program, University of Alabama at Birmingham 35294, USA
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38
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Sabers CJ, Martin MM, Brunn GJ, Williams JM, Dumont FJ, Wiederrecht G, Abraham RT. Isolation of a protein target of the FKBP12-rapamycin complex in mammalian cells. J Biol Chem 1995; 270:815-22. [PMID: 7822316 DOI: 10.1074/jbc.270.2.815] [Citation(s) in RCA: 644] [Impact Index Per Article: 22.2] [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] Open
Abstract
The immunosuppressive drug, rapamycin, interferes with an undefined signaling pathway required for the progression of G1-phase T-cells into S phase. Genetic analyses in yeast indicate that binding of rapamycin to its intracellular receptor, FKBP12, generates a toxic complex that inhibits cell growth in G1 phase. These analyses implicated two related proteins, TOR1 and TOR2, as targets of the FKBP12-rapamycin complex in yeast. In this study, we have used a glutathione S-transferase (GST)-FKBP12-rapamycin affinity matrix to isolate putative mammalian targets of rapamycin (mTOR) from tissue extracts. In the presence of rapamycin, immobilized GST-FKBP12 specifically precipitates similar high molecular mass proteins from both rat brain and murine T-lymphoma cell extracts. Binding experiments performed with rapamycin-sensitive and -resistant mutant clones derived from the YAC-1 T-lymphoma cell line demonstrate that the GST-FKBP12-rapamycin complex recovers significantly lower amounts of the candidate mTOR from rapamycin-resistant cell lines. The latter results suggest that mTOR is a relevant target of rapamycin in these cells. Finally, we report the isolation of a full-length mTOR cDNA that encodes a direct ligand for the FKBP12-rapamycin complex. The deduced amino acid sequence of mTOR displays 42 and 45% identity to those of yeast TOR1 and TOR2, respectively. These results strongly suggest that the FKBP12-rapamycin complex interacts with homologous ligands in yeast and mammalian cells and that the loss of mTOR function is directly related to the inhibitory effect of rapamycin on G1- to S-phase progression in T-lymphocytes and other sensitive cell types.
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Affiliation(s)
- C J Sabers
- Department of Pharmacology, Mayo Clinic, Rochester, Minnesota 55905
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39
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Abstract
A human adult lung cDNA library was screened and one full-length human angiotensin II type 2 receptor (hAT2R) clone was isolated and characterized. The hAT2R cDNA clone contains a 1089-base-pair open reading frame which encodes a protein of 363 amino acid residues. The hAT2R is approximately 92% identical in sequence to the rat and mouse AT2R sequences. Specific binding of [125I]CGP42112A was demonstrated in membranes from COS-7 cells transiently transfected with the hAT2R cDNA. Scatchard analysis and ligand displacement profiles were typical of the AT2R. Northern analysis demonstrated that the hAT2R mRNA was abundantly expressed in human adult lung and in human fetal kidney. Additionally, the hAT2R mRNA was just detectable in human adult heart and aorta. In contrast, the rat AT2R mRNA was abundantly expressed in the rat brain and just detectable in the rat lung.
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Affiliation(s)
- M M Martin
- Vascular Biology and Hypertension Program, University of Alabama at Birmingham 35294
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Su B, Martin MM, Beason KB, Miller PJ, Elton TS. The genomic organization and functional analysis of the promoter for the human angiotensin II type 1 receptor. Biochem Biophys Res Commun 1994; 204:1039-46. [PMID: 7980575 DOI: 10.1006/bbrc.1994.2567] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [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: 01/28/2023]
Abstract
We have cloned and characterized several human angiotensin II type 1 receptor (hAT1R) cDNAs by utilizing the 5'-RACE procedure. Sequence analysis demonstrated that human AT1 receptors are encoded by at least four distinct mRNA transcripts sharing an identical open reading frame, but differing in their organization of 5'-untranslated sequences. Therefore, even though multiple alternatively spliced forms of hAT1R mRNA are transcribed, they are all translated into identical receptors since the entire open reading frame of this receptor is harbored on a single exon. None of these exons coding for 5'-untranslated sequence is expressed in a tissue specific manner. By comparing the 5'-RACE cDNA clones with our hAT1R genomic clones, the organization of the hAT1R gene was determined. The human AT1 gene is comprised of at least four exons and spans at least 60 kb. Several putative promoter regions were characterized by utilizing primer extension and luciferase reporter gene constructs transfected into human adrenal cells. These results indicate that we have cloned a functional promoter for the hAT1R gene. Furthermore, this promoter harbors an adrenal specific response element.
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Affiliation(s)
- B Su
- Vascular Biology and Hypertension Program, University of Alabama at Birmingham 35294
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Sewell TJ, Lam E, Martin MM, Leszyk J, Weidner J, Calaycay J, Griffin P, Williams H, Hung S, Cryan J. Inhibition of calcineurin by a novel FK-506-binding protein. J Biol Chem 1994; 269:21094-102. [PMID: 7520438] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
FK-506, a potent immunosuppressive drug, acts during the commitment phase of T-lymphocyte activation to block a subset of calcium-associated events necessary for transcription of certain early lymphokine genes. The drug binds to an abundant, cytosolic 11.8-kDa protein termed the FK-506-binding protein (FKBP12). The FKBP12.FK-506 complex inhibits calcineurin, a calcium-dependent phosphatase that is a component of the signal transduction pathway leading to early lymphokine gene transcription. FKBP12 is one member of a growing gene family. Prior to this report, all other FKBP family members had been irrelevant to the mechanism of action of FK-506 because no other FKBP.FK-506 complexes were able to bind and inhibit calcineurin. Here, we report the purification and characterization of a novel FK-506-binding protein, FKBP12.6. Having 85% amino acid sequence identity to FKBP12, FKBP12.6 is, among the FKBPs, most closely related to FKBP12. When complexed with FK-506, FKBP12.6 binds to and inhibits calcineurin, making it only the second FKBP discovered thus far to do so. The ability to inhibit calcineurin establishes the potential relevance of FKBP12.6 to the immunosuppressive or toxic side effects of FK-506.
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Affiliation(s)
- T J Sewell
- Department of Immunology Research, Merck Research Laboratories, Rahway, New Jersey 07065
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Abstract
Mammalian genomes contain clusters of homeobox genes (Hox-C, HOX-C) which are structurally similar to the homeotic genes of the Drosophila HOM complex. One method for assessing the functional similarity of particular Drosophila HOM and mammalian Hox genes is to test the ability of Hox genes to induce homeotic phenotypes when expressed in developing Drosophila. Here we describe such functional tests using mouse HoxB9 (formerly Hox-2.5), whose closest structural relative in Drosophila is Abdominal-B. When expressed from a heat shock promoter, HoxB9 induces transformations of head towards more posterior identities in Drosophila larvae and adults. These transformations share some similarities with the phenotypic effects produced by ectopically expressed Abdominal-B, but are also similar to the transformations induced by Antennapedia and mouse HoxB6 (Hox-2.2), suggesting that HoxB9 specifies a positional identity that is intermediate between Antennapedia and Abdominal-B.
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Affiliation(s)
- J Malicki
- Department of Genetics, Yale University, New Haven, CT 06511
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Abstract
Recently, the nearly complete peptide sequence of a 25 kDa rapamycin and FK-506 binding protein that had been isolated from calf thymus, brain, and spleen was reported (1). Based upon the amino acid sequence of this bovine protein, bFKBP25, we have isolated from a JURKAT cDNA library the cDNA encoding the human homolog, hFKBP25. Translation of the open reading frame contained within this cDNA clone yields a sequence that, in its C-terminal half, is 41% identical to the major human FK-506 binding protein, hFKBP12, and 43% identical to hFKBP13. The N-terminal half of hFKBP25 is unrelated to any known protein.
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Affiliation(s)
- G Wiederrecht
- Department of Immunology Research, Merck Research Labs, Rahway, New Jersey 07065
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Elton TS, Stephan CC, Taylor GR, Kimball MG, Martin MM, Durand JN, Oparil S. Isolation of two distinct type I angiotensin II receptor genes. Biochem Biophys Res Commun 1992; 184:1067-73. [PMID: 1575725 DOI: 10.1016/0006-291x(92)90700-u] [Citation(s) in RCA: 103] [Impact Index Per Article: 3.2] [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: 12/27/2022]
Abstract
A rat genomic Southern blot, probed with a type I angiotensin II receptor probe, demonstrated that two highly homologous type I angiotensin II receptors were present. A rat genomic library was subsequently screened and four clones were isolated. From restriction mapping, differential hybridization, polymerase chain reaction amplification and sequence analyses we have determined that there are two unique type I angiotensin II receptor genes. The first of these genes corresponds to the published rat vascular complementary DNA sequence; the second, corresponds to a novel receptor not previously described.
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Affiliation(s)
- T S Elton
- Department of Medicine, University of Alabama, Birmingham 35294
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Martin MM. What do you think? In regard to bladder management. SCI Nurs 1991; 8:55. [PMID: 2047838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Martin MM, Feldman NT. Promoting sleep for the MI patient. Crit Care Nurse 1990; 10:74. [PMID: 2357878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Martin MM, Feldman NT. Promoting sleep for the MI patient. Crit Care Nurse 1990. [DOI: 10.4037/ccn1990.10.1.74] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
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Martin MM, Snider AR, Bove EL, Serwer GA, Rosenthal A, Peters J, Pollock P. Two-dimensional and Doppler echocardiographic evaluation after arterial switch repair in infancy for complete transposition of the great arteries. Am J Cardiol 1989; 63:332-6. [PMID: 2913736 DOI: 10.1016/0002-9149(89)90341-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The most recent postoperative echocardiographic examinations of all children who underwent arterial switch repair of transposition of the great arteries from August 1985 to December 1987 were reviewed. The patients included 35 children whose age at operation was 12 +/- 16 days and whose weight was 3.6 +/- 0.4 kg. Thirty-three patients are alive and well; 1 died intraoperatively and 1 died immediately postoperatively. The time of the follow-up echocardiographic examination ranged from 1 day to 2.5 years (mean 9.2 months) with 11 patients examined greater than 1 year after surgery. Complete examination of the repair site was possible in all patients. Echocardiographic visualization of distortion of the great arteries at the suture lines was seen in all patients; however, Doppler evidence of hemodynamically significant obstruction at the repair site was uncommon. On Doppler examination in the surviving 33 patients, 16 had no supravalvular pulmonary stenosis and 14 had mild to moderate supravalvular pulmonary stenosis with peak systolic pressure gradients ranging from 16 to 56 mm Hg (mean 31). Three patients had severe supravalvular pulmonary stenosis and peak systolic pressure gradients of 66, 74 and 77 mm Hg (2 have had reoperation, 1 is awaiting surgery). On Doppler examination, 4 patients had mild supravalvular aortic stenosis with peak systolic gradients ranging from 10 to 29 mm Hg. Doppler gradients were confirmed in 10 patients who had catheterization 12 +/- 3 months after surgery. Three patients had mild pulmonary regurgitation by Doppler examination, 5 had mild aortic regurgitation, 4 had mild tricuspid regurgitation and 2 had mild mitral regurgitation.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- M M Martin
- Department of Pediatrics, C.S. Mott Children's Hospital, University of Michigan Medical Center, Ann Arbor 48109
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Affiliation(s)
- M M Martin
- Department of Pediatrics, C.S. Mott Children's Hospital, University of Michigan, Ann Arbor
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Martin MM, Lemmer JH, Shaffer E, Dick M, Bove EL. Obstruction to left coronary artery blood flow secondary to obliteration of the coronary ostium in supravalvular aortic stenosis. Ann Thorac Surg 1988; 45:16-20. [PMID: 3337571 DOI: 10.1016/s0003-4975(10)62386-7] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Supravalvular aortic stenosis is characterized by obstruction of the left ventricular outflow tract distal to the aortic valve, and may result in diminished coronary artery blood flow. This report describes the cases of 2 patients in whom obstruction to left coronary artery flow was caused by obliteration of the coronary ostium itself. This mechanism differs from the more commonly recognized cause--valve leaflet adhesion to the obstructing ridge of aortic tissue. The coronary artery obstruction found in these 2 patients required direct enlargement of the left coronary ostium in both. This mechanism of impaired coronary artery flow deserves emphasis, as traditional methods of extended patch aortoplasty may fail to relieve the coronary ostial narrowing.
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Affiliation(s)
- M M Martin
- Department of Surgery, C. S. Mott Children's Hospital, University of Michigan, Ann Arbor
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