scholarly journals Plasticity of the lettuce infectious yellows virus minor coat protein (CPm) in mediating the foregut retention and transmission of a chimeric CPm mutant by whitefly vectors

2021 ◽  
Vol 102 (9) ◽  
Author(s):  
James C. K. Ng ◽  
James H. C. Peng ◽  
Angel Y. S. Chen ◽  
Tongyan Tian ◽  
Jaclyn S. Zhou ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Coat Protein ◽  
Retention Mechanism ◽  
Tem Analysis ◽  
Antibody Recognition ◽  
Transmission Electron ◽  
Lettuce Infectious Yellows Virus ◽  
A Minor ◽  
Minor Coat Protein

Transmission of the crinivirus, lettuce infectious yellows virus (LIYV), is determined by a minor coat protein (CPm)-mediated virion retention mechanism located in the foregut of its whitefly vector. To better understand the functions of LIYV CPm, chimeric CPm mutants engineered with different lengths of the LIYV CPm amino acid sequence and that of the crinivirus, lettuce chlorosis virus (LCV), were constructed based on bioinformatics and sequence alignment data. The 485 amino acid-long chimeric CPm of LIYV mutant, CPmP-1, contains 60 % (from position 3 to 294) of LCV CPm amino acids. The chimeric CPm of mutants CPmP-2, CPmP-3 and CPmP-4 contains 46 (position 3 to 208), 51 (position 3 to 238) and 41 % (position 261 to 442) of LCV CPm amino acids, respectively. All four mutants moved systemically, expressed the chimeric CPm and formed virus particles. However, following acquisition feeding of the virus preparations, only CPmP-1 was retained in the foreguts of a significant number of vectors and transmitted. In immuno-gold labelling transmission electron microscopy (IGL-TEM) analysis, CPmP-1 particles were distinctly labelled by antibodies directed against the LCV but not LIYV CPm. In contrast, CPmP-4 particles were not labelled by antibodies directed against the LCV or LIYV CPm, while CPmP-2 and -3 particles were weakly labelled by anti-LIYV CPm but not anti-LCV CPm antibodies. The unique antibody recognition and binding pattern of CPmP-1 was also displayed in the foreguts of whitefly vectors that fed on CPmP-1 virions. These results are consistent with the hypothesis that the chimeric CPm of CPmP-1 is incorporated into functional virions, with the LCV CPm region being potentially exposed on the surface and accessible to anti-LCV CPm antibodies.

scholarly journals The fate of absorbed and exogenous ammonia as influenced by forage or forage–concentrate diets in growing sheep

1996 ◽  
Vol 76 (2) ◽  
pp. 231-248 ◽  
Author(s):  
G. E. Lobley ◽  
P. J. M. Weijs ◽  
A. Connell ◽  
A. G. Calder ◽  
D. S. Brown ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Ammonium Salt ◽  
Free Amino ◽  
Essential Amino Acids ◽  
Whole Body ◽  
Minor Role ◽  
N Removal ◽  
A Minor ◽  
Branched Chains

Changes in splanchnic energy and N metabolism were studied in sheep, prepared with vascular catheters across the portal-drained viscera (PDV) and the Liver, and maintained on supramaintenance intakes of either grass or grass + barley pellets. The animals were challenged, on both diets, with 4 d intra- mesenteric vein infusions of NH4CI (25 µmol/min) plus NH4HCO3(at either 0 or 125 µmol/min). On the final day of each treatment the natural abundance NH4Cl was replaced with15NH4Cl over a 10 h infusion while over the same period [l-13C]leucine was infused via a jugular vein. Measurements were made of blood flow plus mass transfers of NH3, urea, free amino acids and O2, across the PDV and liver. Enrichments of [14N15N]urea and [15N15N]urea plus [15N]glutamine, aspartate and glutamate were also monitored. Whole-body urea flux was determined by infusion of [14C]urea. At the end of the study the animals were infused for 3 h with15NH4CI, killed and liver samples assayed for intracellular free amino acid enrichments and concentrations. Blood flows across the splanchnic region were unaffected by either diet or level of ammonium salt infusion. At the lower ammonium salt infusion there was a trend for greater absorption of NH3across the PDV (P<0·10) with grass + barley than with the grass diet, while removal of urea was unaltered. At the higher ammonium salt infusions there was a significantly greater appearance of NH, across the PDV and this exceeded the extra infused. Urea-N removal, however, was also elevated and by more than that required to account for the additional NH3. The PDV contributed 19–28% to whole-body O2consumption and the liver 23–32%. Hepatic extraction of absorbed NH3was complete on all treatments and systemic pH remained constant. The fractions of urea-N apparently derived from NH3, were similar on the grass (0·59–0·64) and grass + barley (0·64–0·67) diets. Hepatic production of urea agreed well with urea flux measurements. Between the two levels of ammonium salt infusion and within diets the additional NH3removed across the PDV was accounted for by the increased urea-N production. The [14N15N]: [15N15N] ratio of the urea produced was 97:3, while the enrichment of hepatic intracellular free aspartate was lower than that of [14N15N]urea. Glutamine enrichments were 0·23–0·37 those of [14N15N]urea, indicating a minor role for those hepatocytes (probably perivenous) which contain glutamine synthetase (EC6.3.1.2). Leucine kinetics, either for the whole body or splanchnic tissues, were not different between diets or level of ammonium salt infusion, except for oxidation which was less on the grassfbarley ration. Amino acid concentrations were lower on the grass + barley diet but net PDV absorptions were similar. The pattern of essential amino acids absorbed into the PDV showed good agreement with the published composition of mixed rumen microbial protein. Fractional disappearances of absorbed free essential amino acids across the liver varied from 0·4 (branched chains) to near unity (histidine, phenylalanine)

Die primäre Proteinstruktur von Stämmen des Tabakmosaikvirus

1969 ◽  
Vol 24 (7) ◽  
pp. 870-877 ◽  
Author(s):  
J. Jauregui-Adell ◽  
I. Hindennach ◽  
H. G. Wittmann
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Coat Protein ◽  
Tobacco Mosaic Virus ◽  
Primary Structure ◽  
Amino Acid Sequences ◽  
The Other ◽  
Protein Subunit ◽  
Tryptic Peptides ◽  
Tmv Strains

The sequence of amino acids within the coat protein of the strain Holmes rib grass of tobacco mosaic virus (TMV) has been determined. In this communication the amino acid compositions of the coat protein and of all tryptic peptides are reported. Furthermore the experimental details are given for the elucidation of the amino acid sequences within the first three tryptic peptides, containing 61 amino acids.It has been found that the strain Holmes rib grass differs very extensively in the primary structure from the other TMV strains whose sequences are known. It differs from each of the other strains in more than 50% of the amino acid positions and it contains two amino acids less per protein subunit than the other TMV strains.

Die primäre Proteinstruktur von Stämmen des Tabakmosaikvirus

1969 ◽  
Vol 24 (7) ◽  
pp. 877-885 ◽  
Author(s):  
H. G. Wittmann ◽  
I. Hindennach ◽  
B. Wittmann-Liebold
Keyword(s):  
Experimental Data ◽  
Amino Acids ◽  
Amino Acid ◽  
Coat Protein ◽  
Amino Acid Sequence ◽  
Spatial Structure ◽  
Amino Acid Sequences ◽  
The Other ◽  
Tryptic Peptides ◽  
Tmv Strains

Experimental data for determining a) the amino acid sequences of eight tryptic peptides containing 95 amino acids and b) the order of the tryptic peptides are given. Combining the data of this and of a previous paper the complete amino acid sequence of the coat protein of the TMV strain Holmes rib grass (HRG) is established (Fig. 5). It is compared with three other TMV strains the sequences of which have been determined before (Fig. 6).Differences and similarities between the sequences of the four TMV strains are discussed. HRG has a deletion of two amino acids and it is the most distantly related of the four TMV strains. When the sequence of HRG is compared to that of any of the other strains it turns out that in each case more than 50% of the 156 positions contain different amino acids (Fig. 7).The number of positions with the same amino acid in all strains and mutants so far studied is 30 per cent. These positions are not randomly distributed but clustered mainly in two regions. This finding probably reflects the restriction of amino acid exchanges by the spatial structure of the viral rod.

Structure and expression of ubiquitin gene transcripts in pine

1995 ◽  
Vol 25 (1) ◽  
pp. 1-7 ◽  
Author(s):  
M. Carol Alosi Carter ◽  
Rima M. Kulikauskas ◽  
Roderic B. Park
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Northern Blot Analysis ◽  
Amino Acid Sequences ◽  
Base Pairs ◽  
Phloem Tissue ◽  
Computer Aided Analysis ◽  
Computer Aided ◽  
Gene Transcripts ◽  
A Minor

Clones encoding polyubiquitin proteins were isolated from a cDNA library derived from Pinussabiniana phloem tissue. Two different polyubiquitin clones were sequenced. The amino acid sequences of the clones were compared with angiosperm polyubiquitin sequences and with corresponding sequences reported for animal, fungal, and protist polyubiquitins. A computer-aided analysis showed (i) that pine and angiosperm polyubiquitin amino acid sequences correspond perfectly, (ii) that plant polyubiquitins differ from animal polyubiquitins by three amino acids, and (iii) that fungal and protist polyubiquitins are variable, differing by one to eight amino acids from higher organisms. The expression of ubiquitin was studied in bark, cone, needle, phloem, root, and xylem tissues of pine by Northern blot analysis. In all of these tissues, transcripts of about 1000 base pairs were observed. A minor species of 1200 base pairs was seen in longer exposures of autoradiograms. Ubiquitin transcripts were more abundant (in relationship to total RNA) in phloem, cones, and roots than in bark, needles, or xylem.

scholarly journals A Two-Amino Acid Difference in the Coat Protein of Satellite panicum mosaic virus Isolates Is Responsible for Differential Synergistic Interactions with Panicum mosaic virus

2019 ◽  
Vol 32 (4) ◽  
pp. 479-490 ◽  
Author(s):  
R. V. Chowda-Reddy ◽  
Nathan Palmer ◽  
Serge Edme ◽  
Gautam Sarath ◽  
Frank Kovacs ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Coat Protein ◽  
Mosaic Virus ◽  
Severe Disease ◽  
Amino Acid Difference ◽  
Amino Acid Residues ◽  
Genomic Rna ◽  
Proso Millet ◽  
Synergistic Interactions

Panicum mosaic virus (PMV) (genus Panicovirus, family Tombusviridae) and its molecular parasite, Satellite panicum mosaic virus (SPMV), synergistically interact in coinfected proso and pearl millet (Panicum miliaceum L.) plants resulting in a severe symptom phenotype. In this study, we examined synergistic interactions between the isolates of PMV and SPMV by using PMV-NE, PMV85, SPMV-KS, and SPMV-Type as interacting partner viruses in different combinations. Coinfection of proso millet plants by PMV-NE and SPMV-KS elicited severe mosaic, chlorosis, stunting, and eventual plant death compared with moderate mosaic, chlorotic streaks, and stunting by PMV85 and SPMV-Type. In reciprocal combinations, coinfection of proso millet by either isolate of PMV with SPMV-KS but not with SPMV-Type elicited severe disease synergism, suggesting that SPMV-KS was the main contributor for efficient synergistic interaction with PMV isolates. Coinfection of proso millet plants by either isolate of PMV and SPMV-KS or SPMV-Type caused increased accumulation of coat protein (CP) and genomic RNA copies of PMV, compared with infections by individual PMV isolates. Additionally, CP and genomic RNA copies of SPMV-KS accumulated at substantially higher levels, compared with SMPV-Type in coinfected proso millet plants with either isolate of PMV. Hybrid viruses between SPMV-KS and SPMV-Type revealed that SPMV isolates harboring a CP fragment with four differing amino acids at positions 18, 35, 59, and 98 were responsible for differential synergistic interactions with PMV in proso millet plants. Mutation of amino acid residues at these positions in different combinations in SPMV-KS, similar to those as in SPMV-Type or vice-versa, revealed that A35 and R98 in SPMV-KS CP play critical roles in enhanced synergistic interactions with PMV isolates. Taken together, these data suggest that the two distinct amino acids at positions 35 and 98 in the CP of SPMV-KS and SPMV-Type are involved in the differential synergistic interactions with the helper viruses.

Morphology Tailoring of Hydroxyapatite Nanoparticles by Hydrothermal Processing with Amino Acids

2007 ◽  
Vol 280-283 ◽  
pp. 1533-1536 ◽  
Author(s):  
Wei Min Gao ◽  
Qun Yan Li ◽  
Cheng Xiang Ruan ◽  
Yun Fa Chen
Keyword(s):  
Amino Acids ◽  
Fourier Transform ◽  
Amino Acid ◽  
Homogeneous Precipitation ◽  
Hydrothermal Processing ◽  
Hydroxyapatite Nanoparticles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Size And Morphology

Hydroxyapatite (HAp) was synthesized in the presence of a variety of amino acids in order to investigate the effect of amino acid on the morphology of HAp obtained by homogeneous precipitation and hydrothermal treating. In the results of X-ray diffraction analysis, HAp synthesized in the presence of some amino acids showed different crystallinity compared with HAp synthesized in the absence of amino acid. The results of Fourier transform infrared spectroscopy suggested the adsorption of these amino acids on HAp. Microphotographs of transmission electron microscope showed that the size and morphology of HAp adsorbed amino acids changed significantly. Collectively, this study suggests that the morphology and the crystallinity of synthesized HAp are different owing to the variation of amino acids in the synthesizing condition.

High- and low-affinity transport of l-leucine and l-DOPA by the hetero amino acid exchangers LAT1 and LAT2 in LLC-PK1 renal cells

2004 ◽  
Vol 287 (2) ◽  
pp. F252-F261 ◽  
Author(s):  
Patrício Soares-da-Silva ◽  
Maria Paula Serrão
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Carboxylic Acid ◽  
Minor Component ◽  
Isobutyric Acid ◽  
Renal Cells ◽  
Rt Pcr ◽  
High Affinity ◽  
A Minor ◽  
In Cells

The present study examined the functional characteristics of the inward and outward l-[14C]DOPA and l-[14C]leucine transporters in LLC-PK1 cells. Uptake was initiated by the addition of Hanks' medium with a given concentration of l-[14C]DOPA or l-[14C]leucine. Saturation experiments were performed in cells incubated for 6 min with 0.25 μM concentration of the substrates in the absence and the presence of increasing concentrations of the nonlabeled substrates. Fractional outflow of intracellular l-[14C]DOPA or l-[14C]leucine was evaluated in cells loaded with 2.5 μM l-[14C]DOPA or 1 μM l-[14C]leucine for 6 min and then the corresponding efflux was monitored over 24 min. The high-affinity ( Km = 5.1 μM) uptake of l-[14C]leucine and the low-affinity ( Km = 120.0 μM) uptake of l-[14C]DOPA were largely promoted through a Na+-independent transporter. The uptake of the substrates was insensitive to N-(methylamino)-isobutyric acid but competitively inhibited by 2-aminobicyclo( 2 , 2 , 1 )-heptane-2-carboxylic acid (BCH). l- And d-neutral amino acids, but not acidic and basic amino acids, markedly inhibited l-[14C]DOPA and l-[14C]leucine accumulation. The uptake of l-[14C]leucine was a pH-insensitive process, whereas that of l-[14C]DOPA was sensitive to pH. The efflux of l-[14C]DOPA and l-[14C]leucine was markedly increased ( P < 0.05) by l-cysteine, l-leucine, BCH, and l-DOPA but not by l-arginine. RT-PCR detected LAT1 and LAT2 transcripts in LLC-PK1 cells. It is concluded that LLC-PK1 cells express both LAT1 and LAT2 transcripts and transport l-[14C]leucine through the Na+-independent pH-insensitive and high-affinity LAT1 transporter, whereas l-[14C]DOPA is mainly transported through the Na+-independent pH-insensitive and low-affinity LAT2 transporter and a minor component through a Na+-dependent transporter.

scholarly journals A Mutation in the Lettuce Infectious Yellows Virus Minor Coat Protein Disrupts Whitefly Transmission but Not In Planta Systemic Movement

2010 ◽  
Vol 84 (23) ◽  
pp. 12165-12173 ◽  
Author(s):  
Lucy R. Stewart ◽  
Vicente Medina ◽  
Tongyan Tian ◽  
Massimo Turina ◽  
Bryce W. Falk ◽  
...  
Keyword(s):  
Coat Protein ◽  
Molecular Evidence ◽  
In Planta ◽  
Mutant Genotype ◽  
Reading Frame ◽  
Systemic Movement ◽  
Whitefly Transmission ◽  
Chenopodium Murale ◽  
Lettuce Infectious Yellows Virus ◽  
Minor Coat Protein

ABSTRACT The Lettuce infectious yellows virus (LIYV) RNA 2 mutant p1-5b was previously isolated from Bemisia tabaci-transmitted virus maintained in Chenopodium murale plants. p1-5b RNA 2 contains a single-nucleotide deletion in the minor coat protein (CPm) open reading frame (ORF) that is predicted to result in a frameshift and premature termination of the protein. Using the recently developed agroinoculation system for LIYV, we tested RNA 2 containing the p1-5b CPm mutant genotype (agro-pR6-5b) in Nicotiana benthamiana plants. We showed that plant infection triggered by agro-pR6-5b spread systemically and resulted in the formation of virions similar to those produced in p1-5b-inoculated protoplasts. However, virions derived from these mutant CPm genotypes were not transmitted by whiteflies, even though virion concentrations were above the typical transmission thresholds. In contrast, and as demonstrated for the first time, an engineered restoration mutant (agro-pR6-5bM1) was capable of both systemic movement in plants and whitefly transmission. These results provide strong molecular evidence that the full-length LIYV-encoded CPm is dispensable for systemic plant movement but is required for whitefly transmission.

scholarly journals A 38-Amino-Acid Sequence Encompassing the Arm Domain of the Cucumber Necrosis Virus Coat Protein Functions as a Chloroplast Transit Peptide in Infected Plants

2006 ◽  
Vol 80 (16) ◽  
pp. 7952-7964 ◽  
Author(s):  
Yu Xiang ◽  
Kishore Kakani ◽  
Ron Reade ◽  
Elizabeth Hui ◽  
D'Ann Rochon
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Coat Protein ◽  
Transit Peptide ◽  
Proteolytic Cleavage ◽  
Binding Motif ◽  
Necrosis Virus ◽  
Chloroplast Transit Peptide ◽  
Cucumber Necrosis Virus ◽  
Chloroplast Stroma

ABSTRACT Experiments to determine the subcellular location of the coat protein (CP) of the tombusvirus Cucumber necrosis virus (CNV) have been conducted. By confocal microscopy, it was found that an agroinfiltrated CNV CP-green fluorescent protein (GFP) fusion targets chloroplasts in Nicotiana benthamiana leaves and that a 38-amino-acid (aa) region that includes the complete CP arm region plus the first 4 amino acids of the shell domain are sufficient for targeting. Western blot analyses of purified and fractionated chloroplasts showed that the 38-aa region directs import to the chloroplast stroma, suggesting that the CNV arm can function as a chloroplast transit peptide (TP) in plants. Several features of the 38-aa region are similar to features typical of chloroplast TPs, including (i) the presence of an alanine-rich uncharged region near the N terminus, followed by a short region rich in basic amino acids; (ii) a conserved chloroplast TP phosphorylation motif; (iii) the requirement that the CNV 38-aa sequence be present at the amino terminus of the imported protein; and (iv) specific proteolytic cleavage upon import into the chloroplast stroma. In addition, a region just downstream of the 38-aa sequence contains a 14-3-3 binding motif, suggesting that chloroplast targeting requires 14-3-3 binding, as has been suggested for cellular proteins that are targeted to chloroplasts. Chloroplasts of CNV-infected plants were found to contain CNV CP, but only the shell and protruding domain regions were present, indicating that CNV CP enters chloroplasts during infection and that proteolytic cleavage occurs as predicted from agroinfiltration studies. We also found that particles of a CNV CP mutant deficient in externalization of the arm region have a reduced ability to establish infection. The potential biological significance of these findings is discussed.

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