A single amino acid insertion in LCYB2 deflects carotenoid biosynthesis in red carrot

Abstract Carotenoids are phytochemicals that are precursors of vitamin A and effective antioxidants, required for human health. The mechanisms and underlying genetic network responsible for regulating carotenoid production in plants, however, is poorly understood, despite the carotenoid biosynthesis pathway being known. We found that a single amino acid insertion in lycopene β-cyclase2 (LCYB2) caused catalytic failure, possibly due to a flux down of lycopene to the carotenoids which may be the molecular basis for the color of red carrot roots.

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Residues in the Apical Domain of the Feline and Canine Transferrin Receptors Control Host-Specific Binding and Cell Infection of Canine and Feline Parvoviruses

Journal of Virology ◽

10.1128/jvi.77.16.8915-8923.2003 ◽

2003 ◽

Vol 77 (16) ◽

pp. 8915-8923 ◽

Cited By ~ 54

Author(s):

Laura M. Palermo ◽

Karsten Hueffer ◽

Colin R. Parrish

Keyword(s):

Amino Acid ◽

Specific Binding ◽

Glycosylation Site ◽

Single Amino Acid ◽

Transferrin Receptors ◽

Cell Infection ◽

Feline Panleukopenia Virus ◽

Amino Acid Insertion ◽

Apical Domain ◽

Mutant Receptors

ABSTRACT Canine parvovirus (CPV) and feline panleukopenia virus (FPV) capsids bind to the transferrin receptors (TfRs) of their hosts and use these receptors to infect cells. The binding is partially host specific, as FPV binds only to the feline TfR, while CPV binds to both the canine and feline TfRs. The host-specific binding is controlled by a combination of residues within a raised region of the capsid. To define the TfR structures that interact with the virus, we altered the apical domain of the feline or canine TfR or prepared chimeras of these receptors and tested the altered receptors for binding to FPV or CPV capsids. Most changes in the apical domain of the feline TfR did not affect binding, but replacing Leu221 with Ser or Asp prevented receptor binding to either FPV or CPV capsids, while replacing Leu221 with Lys resulted in a receptor that bound only to CPV but not to FPV. Analysis of recombinants of the feline and canine TfRs showed that sequences controlling CPV-specific binding were within the apical domain and that more than one difference between these receptors determined the CPV-specific binding of the canine TfR. Single changes within the canine TfR which removed a single amino acid insertion or which eliminated a glycosylation site gave that receptor the expanded ability to bind to FPV and CPV. In some cases, binding of capsids to mutant receptors did not result in infection, suggesting a structural role for the receptor in cell infection by the viruses.

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3P293 Structure and fluorescent property of single amino acid insertion mutants of YFP(27. Bioimaging,Poster)

Seibutsu Butsuri ◽

10.2142/biophys.53.s260_4 ◽

2013 ◽

Vol 53 (supplement1-2) ◽

pp. S260

Author(s):

Rumika Tanaka ◽

Keiko Yoshizawa ◽

Tomonobu Watanabe ◽

Tatsuya Kawaguchi ◽

Katsumi Imada

Keyword(s):

Amino Acid ◽

Fluorescent Property ◽

Single Amino Acid ◽

Amino Acid Insertion ◽

Insertion Mutants

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1P066 Effects of single amino-acid insertion on amyloid β fibril formation(01C. Protein : Property,Poster,The 52nd Annual Meeting of the Biophysical Society of Japan(BSJ2014))

Seibutsu Butsuri ◽

10.2142/biophys.54.s151_6 ◽

2014 ◽

Vol 54 (supplement1-2) ◽

pp. S151

Author(s):

Kazuto Yamashita ◽

Motonari Tsubaki ◽

Eri Chatani

Keyword(s):

Amino Acid ◽

Annual Meeting ◽

Amyloid Β ◽

Fibril Formation ◽

Single Amino Acid ◽

Amino Acid Insertion ◽

Protein Property ◽

Biophysical Society

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Genetic Determinants of Altered Virulence of Type O Foot-and-Mouth Disease Virus

Journal of Virology ◽

10.1128/jvi.01657-19 ◽

2020 ◽

Vol 94 (7) ◽

Cited By ~ 1

Author(s):

Fan Yang ◽

Zixiang Zhu ◽

Weijun Cao ◽

Huanan Liu ◽

Ting Wei ◽

...

Keyword(s):

Amino Acid ◽

Host Range ◽

Foot And Mouth Disease ◽

Single Amino Acid ◽

Nucleotide Deletion ◽

Serotype O ◽

Amino Acid Insertion ◽

Leader Protein ◽

Mouth Disease Virus ◽

Viral Genes

ABSTRACT Under different circumstances, the alteration of several viral genes may give an evolutionary advantage to the virus to maintain its prevalence in nature. In this study, a 70-nucleotide deletion in the small fragment (S fragment) of the viral 5′-untranslated region (5′-UTR) together with one amino acid insertion in the leader protein (Lpro) that naturally occurred in several serotype O foot-and-mouth disease virus (FMDV) strains in China was identified. The properties of two field serotype O FMDV strains, with or without the 70-nucleotide deletion in the S fragment and the amino acid insertion in Lpro, were compared in vitro and in vivo. Clinical manifestations of FMD were clearly observed in cattle and pigs infected by the virus without the mutations. However, the virus with the mentioned mutations caused FMD outcomes only in pigs, not in cattle. To determine the role of the 70-nucleotide deletion in the S fragment and the single amino acid insertion in Lpro in the pathogenicity and host range of FMDV, four recombinant viruses, with complete genomes and a 70-nucleotide deletion in the S fragment, a single amino acid insertion in Lpro, or both mutations, were constructed and rescued. It showed that deletion of 70 nucleotides in the S fragment or insertion of one amino acid (leucine) at position 10 of Lpro partly decreased the viral pathogenicity of Mya-98 lineage virus in cattle and pigs. However, the virus with dual mutations caused clinical disease only in pigs, not in cattle. This suggested that the S fragment and Lpro are significantly associated with the virulence and host specificity of FMDV. The naturally occurring dual mutation in the S fragment and Lpro is a novel determinant of viral pathogenicity and host range for serotype O FMDV. IMPORTANCE FMD is probably the most important livestock disease in the world due to the severe economic consequences caused. The alteration of several viral genes may give the virus selective advantage to maintain its prevalence in nature. Here, we identified that a 70-nucleotide deletion in the S fragment combined with a single leucine insertion in the leader protein (Lpro) is a novel determinant of restricted growth on bovine cells, which significantly contributes to the altered virulence of serotype O FMDV in cattle. A synergistic and additive effect of the 70-nucleotide deletion in the S fragment and the single leucine insertion in Lpro on the virulence and host specificity of the virus was determined. These results will benefit efforts to understand the vial pathogenicity mechanism and molecular characteristics of FMDV.

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Feline Leukemia Virus Envelope Sequences That Affect T-Cell Tropism and Syncytium Formation Are Not Part of Known Receptor-Binding Domains

Journal of Virology ◽

10.1128/jvi.74.13.5754-5761.2000 ◽

2000 ◽

Vol 74 (13) ◽

pp. 5754-5761 ◽

Cited By ~ 18

Author(s):

Samuel R. Gwynn ◽

F. Claire Hankenson ◽

Adam S. Lauring ◽

Jennifer L. Rohn ◽

Julie Overbaugh

Keyword(s):

Tissue Culture ◽

T Cells ◽

Amino Acid ◽

T Cell ◽

Envelope Protein ◽

Leukemia Virus ◽

Feline Leukemia Virus ◽

Single Amino Acid ◽

Binding Domains ◽

Amino Acid Insertion

ABSTRACT The envelope protein is a primary pathogenic determinant for T-cell-tropic feline leukemia virus (FeLV) variants, the best studied of which is the immunodeficiency-inducing virus, 61C. We have previously demonstrated that T-cell-tropic, cytopathic, and syncytium-inducing viruses evolve in cats infected with a relatively avirulent, transmissible form of FeLV, 61E. The envelope gene of an 81T variant, which encoded scattered single-amino-acid changes throughout the envelope as well as a 4-amino-acid insertion in the C-terminal half of the surface unit (SU) of envelope, was sufficient to confer the T-cell-tropic, cytopathic phenotype (J. L. Rohn, M. S. Moser, S. R. Gwynn, D. N. Baldwin, and J. Overbaugh, J. Virol. 72:2686–2696, 1998). In the present study, we examined the role of the 4-amino-acid insertion in determining viral replication and tropism of FeLV-81T. The 4-amino-acid insertion was found to be functionally equivalent to a 6-amino-acid insertion at an identical location in the 61C variant. However, viruses expressing a chimeric 61E/81T SU, containing the insertion together with the N terminus of 61E SU, were found to be replication defective and were impaired in the processing of the envelope precursor into the functional SU and transmembrane (TM) proteins. In approximately 10% of cultured feline T cells (3201) transfected with the 61E/81T envelope chimeras and maintained over time, replication-competent tissue culture-adapted variants were isolated. Compensatory mutations in the SU of the tissue culture-adapted viruses were identified at positions 7 and 375, and each was shown to restore envelope protein processing when combined with the C-terminal 81T insertion. Unexpectedly, these viruses displayed different phenotypes in feline T cells: the virus with a change from glutamine to proline at position 7 acquired a T-cell-tropic, cytopathic phenotype, whereas the virus with a change from valine to leucine at position 375 had slower replication kinetics and caused no cytopathic effects. Given the differences in the replication properties of these viruses, it is noteworthy that the insertion as well as the two single-amino-acid changes all occur outside of predicted FeLV receptor-binding domains.

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