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Basic Characteristics of Mutations
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Mutation Site
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A529T |
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Mutation Site Sentence
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Other mutants harboring mutations in domain B and C of HBV polymerase sequence were as followed: L528M/A529T, L528M/Y551N, L528M/M552E, L528M/D553V, L528M/ L527P, L528R/A529T, Q530-to-Stop, M552Q, and L527P. |
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Mutation Level
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Amino acid level |
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Mutation Type
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Nonsynonymous substitution |
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Gene/Protein/Region
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P |
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Standardized Encoding Gene
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P
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Genotype/Subtype
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- |
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Viral Reference
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-
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Functional Impact and Mechanisms
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Disease
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Hepatitis B Virus Infection
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Immune
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- |
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Target Gene
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-
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Clinical and Epidemiological Correlations
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Clinical Information
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- |
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Treatment
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Lamivudine(LAM) |
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Location
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- |
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Literature Information
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PMID
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10827158
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Title
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Clearance of the original hepatitis B virus YMDD-motif mutants with emergence of distinct lamivudine-resistant mutants during prolonged lamivudine therapy
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Author
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Yeh CT,Chien RN,Chu CM,Liaw YF
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Journal
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Hepatology (Baltimore, Md.)
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Journal Info
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2000 Jun;31(6):1318-26
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Abstract
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Tyrosine-methionine-aspartate-aspartate (YMDD)-motif mutants may emerge and elicit immune clearance during prolonged lamivudine treatment. The aim of this study was to investigate the virological events following development of the original mutants. Twenty-three patients who developed YMDD-motif mutants during the Asian lamivudine trial were included. Serial serum samples from these patients were subjected to sequence analysis to identify new mutants. Site-directed mutagenesis experiments were performed to investigate whether the new mutations were responsible for lamivudine resistance. Of the 23 patients included, 13 harbored either one or a mixture of the two common YMDD-motif mutants (methionine 552-to-isoleucine [M552I] and leucine 528-to-methionine/methionine 552-to-valine [L528M/M552V]) throughout the course, whereas in the remaining 10 patients, distinct mutants became dominant over the original mutants to cause continuing chronic hepatitis. Of them, 3 developed an alanine 529-to-threonine (A529T) mutant, 6 developed a leucine 528-to-methionine/methionine 552-to-isoleucine (L528M/M552I) mutant, and 1 developed these two mutants sequentially. Site-directed mutagenesis experiments confirmed that the aforementioned mutations were responsible for the resistance to lamivudine in vitro. The nucleotide substitution in the A529T mutant concomitantly generated a stop codon at the surface gene, leading to impaired secretion of HBsAg. Strikingly, the replication of this mutant was lamivudine dependent. These results suggested that distinct lamivudine-resistant mutants could emerge and replace the original YMDD-motif mutants as the cause of continuing chronic hepatitis during prolonged lamivudine therapy.
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Sequence Data
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-
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