1
|
Salmonella Genomic Island 1 requires a self-encoded small RNA for mobilization. Mol Microbiol 2021; 116:1533-1551. [PMID: 34784078 PMCID: PMC9299015 DOI: 10.1111/mmi.14846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 10/08/2021] [Accepted: 11/13/2021] [Indexed: 11/29/2022]
Abstract
The SGI1-family elements that are specifically mobilized by the IncA- and IncC-family plasmids are important vehicles of antibiotic resistance among enteric bacteria. Although SGI1 exploits many plasmid-derived conjugation and regulatory functions, the basic mobilization module of the island is unrelated to that of IncC plasmids. This module contains the oriT and encodes the mobilization proteins MpsA and MpsB, which belong to the tyrosine recombinases and not to relaxases. Here we report an additional, essential transfer factor of SGI1. This is a small RNA deriving from the 3'-end of a primary RNA that can also serve as mRNA of ORF S022. The functional domain of this sRNA named sgm-sRNA is encoded between the mpsA gene and the oriT of SGI1. Terminator-like sequence near the promoter of the primary transcript possibly has a regulatory function in controlling the amount of full-length primary RNA, which is converted to the active sgm-sRNA through consecutive maturation steps influenced by the 5'-end of the primary RNA. The mobilization module of SGI1 seems unique due to its atypical relaxase and the newly identified sgm-sRNA, which is required for the horizontal transfer of the island but appears to act differently from classical regulatory sRNAs.
Collapse
|
2
|
Superimposing hip extension on knee flexion evokes higher activation in biceps femoris than knee flexion alone. J Electromyogr Kinesiol 2021; 58:102541. [PMID: 33706051 DOI: 10.1016/j.jelekin.2021.102541] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 01/24/2021] [Accepted: 03/01/2021] [Indexed: 01/12/2023] Open
Abstract
Hamstring muscle function during knee flexion has been linked to hamstring injury and performance. However, it is unclear whether knee flexion alone (KF) requires similar hamstring electromyography (EMG) activity pattern to simultaneous hip extension and knee flexion (HE-KF), a combination that occurs in the late swing phase of sprinting. This study examined whether HE-KF maximal voluntary isometric contraction (MVIC) evokes higher (EMG) activity in biceps femoris long head (BFlh) and semitendinosus (ST) than KF alone. Effects of shank rotation angles were also tested. Twenty-one males performed the above-mentioned MVICs while EMG activity was measured along ST and BFlh. Conditions were compared using a one-way mixed functional ANOVA model under a fully Bayesian framework. Higher EMG activity was found in HE-KF in all shank rotation positions than in KF in the middle region of BFlh (highest in the 9th channel, by 0.022 mV [95%CrI 0.014 to 0.030] in neutral shank position). For ST, this was only observed in the neutral shank position and in the most proximal channel (by 0.013 mV [95%CrI 0.001 to 0.025]). We observed muscle- and region-specific responses to HE-KF. Future studies should examine whether hamstring activation in this task is related to injury risk and sprint performance.
Collapse
|
3
|
Local Aphid Species Infestation on Invasive Weeds Affects Virus Infection of Nearest Crops Under Different Management Systems - A Preliminary Study. FRONTIERS IN PLANT SCIENCE 2020; 11:684. [PMID: 32670307 PMCID: PMC7330602 DOI: 10.3389/fpls.2020.00684] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Accepted: 04/30/2020] [Indexed: 06/11/2023]
Abstract
In the present study, we conducted field surveys to detect the population density of the most important invasive weed species and their associated virus vectoring aphids in crops grown under high input field (HIF) vs. low-input field (LIF) conditions, with and without fertilizers and pesticides. The most frequent invasive weed species were annual fleabane, Erigeron annua (L.), Canadian horseweed, Erigeron canadensis (L.) and Canadian goldenrod, Solidago canadensis (L.). These species were predominantly hosts of the aphids Brachycaudus helichrysi and Aulacorthum solani under both management systems. The 13% higher coverage of E. annua under LIF conditions resulted in a 30% higher B. helichrysi abundance and ∼85% higher A. solani abundance compared with HIF conditions. To reveal the incidence of virus infection in crop plants and invasive weeds, high-throughput sequencing of small RNAs was performed. Bioinformatics analysis combined with independent validation methods revealed the presence of six viruses, but with strikingly different patterns under LIF and HIF conditions. Their presence without symptoms in invasive weeds and crop plants supports the necessity of employing new approaches to those currently employed in invasive weed management. These findings also suggest that invasive weeds could serve as hosts for local aphid species and reservoirs for plant pathogenic viruses, both under low and high input management systems. In this light, as here demonstrated, viruses transmitted by local aphid species were found to differ between the management systems; hence, the importance of B. helichrysi and A. solani as virus vectors in particular clearly needs to be re-evaluated. Altogether, we accept that the present study is a pilot one and individual virus vectoring of aphids still needs to be directly tested. Even so, it represents one of the first contributions to this particular area, and thereby paves the way for further similar applied research in the future.
Collapse
|
4
|
Identification and Characterization of oriT and Two Mobilization Genes Required for Conjugative Transfer of Salmonella Genomic Island 1. Front Microbiol 2019; 10:457. [PMID: 30894848 PMCID: PMC6414798 DOI: 10.3389/fmicb.2019.00457] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 02/20/2019] [Indexed: 11/13/2022] Open
Abstract
The integrative mobilizable elements of SGI1-family considerably contribute to the spread of resistance to critically important antibiotics among enteric bacteria. Even though many aspects of SGI1 mobilization by IncA and IncC plasmids have been explored, the basic transfer elements such as oriT and self-encoded mobilization proteins remain undiscovered. Here we describe the mobilization region of SGI1 that is well conserved throughout the family and carries the oriT SGI1 and two genes, mpsA and mpsB (originally annotated as S020 and S019, respectively) that are essential for the conjugative transfer of SGI1. OriT SGI1, which is located in the vicinity of the two mobilization genes proved to be a 125-bp GC-rich sequence with several important inverted repeat motifs. The mobilization proteins MpsA and MpsB are expressed from a bicistronic mRNA, although MpsB can be produced from its own mRNA as well. The protein structure predictions imply that MpsA belongs to the lambda tyrosine recombinase family, while MpsB resembles the N-terminal core DNA binding domains of these enzymes. The results suggest that MpsA may act as an atypical relaxase, which needs MpsB for SGI1 transfer. Although the helper plasmid-encoded relaxase proved not to be essential for SGI1 transfer, it appeared to be important to achieve the high transfer rate of the island observed with the IncA/IncC-SGI1 system.
Collapse
|
5
|
Region-dependent hamstrings activity in Nordic hamstring exercise and stiff-leg deadlift defined with high-density electromyography. Scand J Med Sci Sports 2017; 28:992-1000. [PMID: 29143379 DOI: 10.1111/sms.13016] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/06/2017] [Indexed: 01/03/2023]
Abstract
Recent studies suggest region-specific metabolic activity in hamstring muscles during injury prevention exercises, but the neural representation of this phenomenon is unknown. The aim of this study was to examine whether regional differences are evident in the activity of biceps femoris long head (BFlh) and semitendinosus (ST) muscles during two common injury prevention exercises. Twelve male participants without a history of hamstring injury performed the Nordic hamstring exercise (NHE) and stiff-leg deadlift (SDL) while BFlh and ST activities were recorded with high-density electromyography (HD-EMG). Normalized activity was calculated from the distal, middle, and proximal regions in the eccentric phase of each exercise. In NHE, ST overall activity was substantially higher than in BFlh (d = 1.06 ± 0.45), compared to trivial differences between muscles in SDL (d = 0.19 ± 0.34). Regional differences were found in NHE for both muscles, with different proximal-distal patterns: The distal region showed the lowest activity level in ST (regional differences, d range = 0.55-1.41) but the highest activity level in BFlh (regional differences, d range = 0.38-1.25). In SDL, regional differences were smaller in both muscles (d range = 0.29-0.67 and 0.16-0.63 in ST and BFlh, respectively) than in NHE. The use of HD-EMG in hamstrings revealed heterogeneous hamstrings activity during typical injury prevention exercises. High-density EMG might be useful in future studies to provide a comprehensive overview of hamstring muscle activity in other exercises and high-injury risk tasks.
Collapse
|
6
|
Identification of oriT and a recombination hot spot in the IncA/C plasmid backbone. Sci Rep 2017; 7:10595. [PMID: 28878309 PMCID: PMC5587640 DOI: 10.1038/s41598-017-11097-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 08/17/2017] [Indexed: 11/08/2022] Open
Abstract
Dissemination of multiresistance has been accelerating among pathogenic bacteria in recent decades. The broad host-range conjugative plasmids of the IncA/C family are effective vehicles of resistance determinants in Gram-negative bacteria. Although more than 150 family members have been sequenced to date, their conjugation system and other functions encoded by the conserved plasmid backbone have been poorly characterized. The key cis-acting locus, the origin of transfer (oriT), has not yet been unambiguously identified. We present evidence that IncA/C plasmids have a single oriT locus immediately upstream of the mobI gene encoding an indispensable transfer factor. The fully active oriT spans ca. 150-bp AT-rich region overlapping the promoters of mobI and contains multiple inverted and direct repeats. Within this region, the core domain of oriT with reduced but detectable transfer activity was confined to a 70-bp segment containing two inverted repeats and one copy of a 14-bp direct repeat. In addition to oriT, a second locus consisting of a 14-bp imperfect inverted repeat was also identified, which mimicked the function of oriT but which was found to be a recombination site. Recombination between two identical copies of these sites is RecA-independent, requires a plasmid-encoded recombinase and resembles the functioning of dimer-resolution systems.
Collapse
|
7
|
Measuring temporal liking simultaneously to Temporal Dominance of Sensations in several intakes. An application to Gouda cheeses in 6 Europeans countries. Food Res Int 2017; 99:426-434. [DOI: 10.1016/j.foodres.2017.05.035] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Revised: 04/25/2017] [Accepted: 05/29/2017] [Indexed: 10/19/2022]
|
8
|
In vivo fascicle behavior of the flexor hallucis longus muscle at different walking speeds. Scand J Med Sci Sports 2017; 27:1716-1723. [PMID: 28156022 DOI: 10.1111/sms.12810] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/31/2016] [Indexed: 12/27/2022]
Abstract
Ankle plantar flexor muscles support and propel the body in the stance phase of locomotion. Besides the triceps surae, flexor hallucis longus muscle (FHL) may also contribute to this role, but very few in vivo studies have examined FHL function during walking. Here, we investigated FHL fascicle behavior at different walking speeds. Ten healthy males walked overground at three different speeds while FHL fascicle length changes were recorded with ultrasound and muscle activity was recorded with surface electromyography (EMG). Fascicle length at heel strike at toe off and at peak EMG activity did not change with speed. Range of FHL fascicle length change (3.5-4.5 and 1.9-2.9 mm on average in stance and push-off phase, respectively), as well as minimum (53.5-54.9 and 53.8-55.7 mm) and maximum (58-58.4 and 56.8-57.7 mm) fascicle length did not change with speed in the stance or push-off phase. Mean fascicle velocity did not change in the stance phase, but increased significantly in the push-off phase between slow and fast walking speeds (P=.021). EMG activity increased significantly in both phases from slow to preferred and preferred to fast speed (P<.02 in all cases). FHL muscle fascicles worked near-isometrically during the whole stance phase (at least during slow walking) and operated at approximately the same length at different walking speeds. FHL and medial gastrocnemius (MG) have similar fiber length to muscle belly length ratios and, according to our results, also exhibit similar fascicle behavior at different walking speeds.
Collapse
|
9
|
FUNCTIONAL AND RTD H/Q RATIO IN 11-16-YEAR OLD MALE FOOTBALL PLAYERS. Br J Sports Med 2014. [DOI: 10.1136/bjsports-2014-093494.265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
10
|
T cell receptor (TCR) signal strength controls arthritis severity in proteoglycan-specific TCR transgenic mice. Clin Exp Immunol 2012; 167:346-55. [PMID: 22236012 DOI: 10.1111/j.1365-2249.2011.04506.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
T cell receptor transgenic (TCR-Tg) mice specific for the arthritogenic 5/4E8 epitope in the G1 domain of cartilage proteoglycan were generated and back-crossed into arthritis-prone BALB/c background. Although more than 90% of CD4(+) T cells of all TCR-Tg lines were 5/4E8-specific, one (TCR-TgA) was highly sensitive to G1-induced or spontaneous arthritis, while another (TCR-TgB) was less susceptible. Here we studied whether fine differences in TCR signalling controlled the onset and severity of arthritis. Mice from the two TCR-Tg lines were immunized side by side with purified recombinant human G1 (rhG1) domain for G1 domain of cartilage proteoglycan (PG)-induced arthritis (GIA). TCR-TgA mice developed severe and early-onset arthritis, whereas TCR-TgB mice developed weaker arthritis with delayed onset, although TCR-TgB CD4(+) T cells expressed approximately twice more TCR-Vβ4 chain protein. The more severe arthritis in TCR-TgA mice was associated with higher amounts of anti-G1 domain-specific antibodies, larger numbers of B cells and activated T helper cells. Importantly, TCR-TgB CD4(+) T cells were more sensitive to in vitro activation-induced apoptosis, correlating with their higher TCR and CD3 expression and with the increased TCR signal strength. These findings indicate that TCR signal strength determines the clinical outcome of arthritis induction: 'optimal' TCR signal strength leads to strong T cell activation and severe arthritis in TCR-TgA mice, whereas 'supra-optimal' TCR signal leads to enhanced elimination of self-reactive T cells, resulting in attenuated disease.
Collapse
|
11
|
Abstract
The transportation of rainbow trout in the presence of the anesthetic clove oil was investigated. Before the transportation tests, an acute experiment was conducted to verify that removal of the fish from the water for one minute does not significantly increase the glucose or cortisol concentration of the blood plasma. In the main experiment two different transportation conditions were compared: transport in water only and in water with anesthetic. During transportation without addition of clove oil, blood plasma glucose and cortisol concentrations changed significantly. The concentration of glucose increased from 4.92 mmol/L prior to transportation to 6.16 mmol/L and values similar to the initial ones (4.95 mmol/L) were observed 5 hours after transportation. Concentration of the stress hormone cortisol increased from the initial 37.2 ng/mL to 89.2 ng/mL and returned to a value of 36.1 ng/mL 3 hours post transportation. Respective values of glucose concentration have not changed significantly during transportation in the presence of clove oil (4.3; 4.4; 4.4 mmol/L), whereas those of cortisol showed a slight decrease with the passing of time (28.1; 26.7; 20.18 ng/mL). Results show that transportation stress can significantly be reduced by the use of anesthetics.
Collapse
|
12
|
Investigation of long-term stress induced by several stressors by determination of the concentration of different blood plasma components in a model of Prussian carp (Carassius auratus gibelio BLOCH, 1783) and Common carp (Cyprinus carpio L., 1758). ACTA BIOLOGICA HUNGARICA 2006; 57:301-13. [PMID: 17048694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Several compounds (carbohydrates, proteins, hormones, etc.) were used in fish to quantify the level of stress. Our investigations focused on two parameters of the blood plasma: plasma glucose and serum/plasma fructosamine (SeFa) that has not been tested on fish as yet. Experiments were conducted on two fish species. The concentrations of these components were investigated on Common carp (Cyprinus carpio L., 1758) and on Prussian carp (Carassius auratus gibelio BLOCH, 1783) from the Gödöllö-Isaszeg pond system by creating conditions different from ideal. Stress effects caused a fluctuating tendency in blood plasma glucose levels each week for both Common carp and Prussian carp, thus, there was no steady growth. However, SeFa concentrations exactly followed stress effects, moreover, it tolerated short-term negative effects (handling of fish, blood sampling) and did not cause alterations at individuals blood samplings. This experimental method can offer assistance to farmers in the daily routine (e.g. in fish transport) and in the technology of propagation.
Collapse
|
13
|
Activation of microglia cells is dispensable for the induction of rat retroviral spongiform encephalopathy. J Neurovirol 2001; 7:501-10. [PMID: 11704882 DOI: 10.1080/135502801753248088] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
In the course of retroviral CNS infections, microglia activation has been observed frequently, and it has been hypothesized that activated microglia produce and secrete neurotoxic products like proinflammatory cytokines, by this promoting brain damage. We challenged this hypothesis in a rat model for neurodegeneration. In a kinetic study, we found that microglia cells of rats neonatally inoculated with neurovirulent murine leukemia virus (MuLV) NT40 became infected in vivo to maximal levels within 9-13 days postinoculation (d.p.i.). Beginning from 13 d.p.i., degenerative alterations, i.e., vacuolization of neurons and neuropil were found in cerebellar and other brain-stem nuclei. Elevated numbers of activated microglia cells--as revealed by immunohistochemical staining with monoclonal antibody ED1--were first detected at 19 d.p.i. and were always locally associated with degenerated areas but not with nonaltered, yet infected, brain regions. Both neuropathological changes and activated microglia cells increased in intensity and numbers, respectively, with ongoing infection but did not spread to other than initially affected brain regions. By ribonuclease protection assays, we were unable to detect differences in the expression levels of tumor-necrosis-factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), and interleukin-6 (IL-6) in microglia cells nor in total brains from infected versus uninfected rats. Our results suggest that the activation of microglia in the course of MuLV neurodegeneration is rather a reaction to, and not the cause of, neuronal damage. Furthermore, overt expression of the proinflammatory cytokines TNF-alpha, IL-1beta, and IL-6 within the CNS is not required for the induction of retroviral associated neurodegeneration in rats.
Collapse
|
14
|
The human coronavirus 229E superfamily 1 helicase has RNA and DNA duplex-unwinding activities with 5'-to-3' polarity. RNA (NEW YORK, N.Y.) 2000; 6:1056-1068. [PMID: 10917600 PMCID: PMC1369980 DOI: 10.1017/s1355838200000728] [Citation(s) in RCA: 112] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The human coronavirus 229E replicase gene encodes a protein, p66HEL, that contains a putative zinc finger structure linked to a putative superfamily (SF) 1 helicase. A histidine-tagged form of this protein, HEL, was expressed using baculovirus vectors in insect cells. The purified recombinant protein had in vitro ATPase activity that was strongly stimulated by poly(U), poly(dT), poly(C), and poly(dA), but not by poly(G). The recombinant protein also had both RNA and DNA duplex-unwinding activities with 5'-to-3' polarity. The DNA helicase activity of the enzyme preferentially unwound 5'-oligopyrimidine-tailed, partial-duplex substrates and required a tail length of at least 10 nucleotides for effective unwinding. The combined data suggest that the coronaviral SF1 helicase functionally differs from the previously characterized RNA virus SF2 helicases.
Collapse
|
15
|
Molecular analysis of the coronavirus-receptor function of aminopeptidase N. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1998; 440:61-7. [PMID: 9782265 DOI: 10.1007/978-1-4615-5331-1_8] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Aminopeptidase N (APN) is a major cell surface for coronaviruses of the serogroup I. By using chimeric APN proteins assembled from human, porcine and feline APN we have identified determinants which are critically involved in the coronavirus-APN interaction. Our results indicate that human coronavirus 229E (HCV 229E) is distinct from the other serogroup I coronaviruses in that determinants located within the N-terminal parts of the human and feline APN proteins mediate the infection of HCV 229E, whereas determinants located within the C-terminal parts of porcine, feline and canine APN mediate the infection of transmissible gastro-enteritis virus (TGEV), feline infectious peritonitis virus (FIPV) and canine coronavirus (CCV), respectively. A further analysis of the mapped amino acid segments by site directed mutagenesis revealed that a short stretch of 8 amino acids in the hAPN protein plays a decisive role in mediating HCV 229E reception.
Collapse
|
16
|
Characterization of determinants involved in the feline infectious peritonitis virus receptor function of feline aminopeptidase N. J Gen Virol 1998; 79 ( Pt 6):1387-91. [PMID: 9634079 DOI: 10.1099/0022-1317-79-6-1387] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Feline aminopeptidase N (fAPN) is a major cell surface receptor for feline infectious peritonitis virus (FIPV), transmissible gastroenteritis virus (TGEV), human coronavirus 229E (HCV 229E) and canine coronavirus (CCV). By using chimeric molecules assembled from porcine, human and feline APN we have analysed the determinants involved in the coronavirus receptor function of fAPN. Our results show that amino acids 670-840 of fAPN are critically involved in its FIPV and TGEV receptor function whereas amino acids 135-297 are essential for the HCV 229E receptor function. We also demonstrate that a chimeric molecule assembled from human and porcine APN is able to act as a receptor for FIPV. This is surprising as neither human nor porcine APN by themselves mediate FIPV infection. These results suggest that different determinants in the APN protein are involved in mediating the coronavirus receptor function.
Collapse
|
17
|
Identification of residues critical for the human coronavirus 229E receptor function of human aminopeptidase N. J Gen Virol 1997; 78 ( Pt 11):2795-802. [PMID: 9367365 DOI: 10.1099/0022-1317-78-11-2795] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Aminopeptidase N (APN) is the major cell surface receptor for group 1 coronaviruses. In this study, we have isolated and characterized a feline APN cDNA and shown that the transfection of human embryonic kidney cells with this cDNA renders them susceptible to infection with the feline coronavirus feline infectious peritonitis virus, the human coronavirus (HCV) 229E and the porcine coronavirus porcine transmissible gastroenteritis virus. By using chimeric APN genes, assembled from porcine and feline sequences, we have shown that, analogously to the human APN protein, a region within the amino-terminal part of the feline APN protein (encompassing amino acids 132-295) is essential for its HCV 229E receptor function. Furthermore, by comparing the relevant feline, human and porcine APN sequences, we were able to identify a hypervariable stretch of eight amino acids that are more closely related in the feline and human APN proteins than in the porcine APN molecule. Using PCR-directed mutagenesis, we converted this stretch of amino acids within the porcine APN molecule to the corresponding residues of the human APN molecule. These changes were sufficient to convert porcine APN into a functional receptor for HCV 229E and thus define a small number of residues that are critically important for the HCV 229E receptor function of human APN.
Collapse
|
18
|
Histamine reactions in blood pressure and heart rate in trained and untrained albino rats [proceedings]. AGENTS AND ACTIONS 1978; 8:404-5. [PMID: 685772 DOI: 10.1007/bf01968651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
|
19
|
Alpha and beta adrenergic sensitivity in trained and untrained albino rats. EUROPEAN JOURNAL OF APPLIED PHYSIOLOGY AND OCCUPATIONAL PHYSIOLOGY 1976; 36:65-73. [PMID: 187426 DOI: 10.1007/bf00421635] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The effects on the blood pressure and heart rate responses of different adrenergic stimulants (norepinephrine, sympathomim, epinephrine and isoproterenol) and blocking agents (phenoxybenzamine and propranolol) were studied in control (N=55) and exercising (N=52) albino rats under anaesthesia. The test rats exercised by regular swimming for 10-14 weeks. Alpha stimulation and beta blocking produced smaller responses while alpha blocking and beta stimulation were followed by greater changes after training as compared with the control animals. The assumption of a modified adrenergic receptor sensitivity could not be substantiated by the results; the observations indicate rather a complex change in the autonomous regulation following regular physical exercise.
Collapse
|
20
|
[Experimental tendon substitute with knitted polyester transplant]. Zentralbl Chir 1965; 90:2275-80. [PMID: 5888301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
|