The 7472insC mitochondrial DNA mutation impairs the synthesis and extent of aminoacylation of tRNASer(UCN) but not its structure or rate of turnover

Marina Toompuu, Takehiro Yasukawa, Tsutomu Suzuki, Terhi Hakkinen, Johannes N. Spelbrink, Kimitsuna Watanabe, Howard T. Jacobs

Research output: Contribution to journalArticle

41 Citations (Scopus)

Abstract

The 7472insC mitochondrial DNA mutation in the tRNASer(UCN) gene is associated with sensorineural deafness combined, in some patients, with a wider neurological syndrome. In cultured cybrid cells it causes a 70% decrease in tRNASer(UCN) abundance and mild respiratory impairment, previously suggested to be due to decreased tRNA stability. When mitochondrial transcription was blocked by ethidium bromide treatment, the half-life of the mutant tRNA was not significantly different from that of wild-type tRNASer(UCN). Over-expression of mitochondrial translational elongation factor EF-Tu also had no effect on the mutant phenotype. However, during recovery from prolonged ethidium bromide treatment, the synthesis of the mutant tRNASer(UCN) was specifically impaired, without polarity effects on downstream tRNAs of the light strand transcription unit. We infer that the mutation acts posttranscriptionally to decrease tRNASer(UCN) abundance by affecting its synthesis rather than its stability. The extent of aminoacylation of the mutant tRNA was also decreased by ∼25%. In contrast, the mutation had no detectable effect on tRNASer(UCN) base modification or structure other than the insertion of an extra guanosine templated by the mutation, which was structurally protected from nuclease digestion like the surrounding nucleotides. These findings indicate a common molecular process underlying sensorineural deafness caused by mitochondrial tRNASer(UCN) mutations.

Original languageEnglish
Pages (from-to)22240-22250
Number of pages11
JournalJournal of Biological Chemistry
Volume277
Issue number25
DOIs
Publication statusPublished - Jun 21 2002
Externally publishedYes

Fingerprint

RNA, Transfer, Ser
Aminoacylation
Mitochondrial DNA
Mutation
Transfer RNA
Peptide Elongation Factor Tu
Ethidium
Deafness
Transcription
Transfer RNA Aminoacylation
Peptide Elongation Factors
Guanosine
Half-Life
Digestion
Cultured Cells
Nucleotides
Genes
Phenotype
Recovery

All Science Journal Classification (ASJC) codes

  • Biochemistry

Cite this

The 7472insC mitochondrial DNA mutation impairs the synthesis and extent of aminoacylation of tRNASer(UCN) but not its structure or rate of turnover. / Toompuu, Marina; Yasukawa, Takehiro; Suzuki, Tsutomu; Hakkinen, Terhi; Spelbrink, Johannes N.; Watanabe, Kimitsuna; Jacobs, Howard T.

In: Journal of Biological Chemistry, Vol. 277, No. 25, 21.06.2002, p. 22240-22250.

Research output: Contribution to journalArticle

Toompuu, Marina ; Yasukawa, Takehiro ; Suzuki, Tsutomu ; Hakkinen, Terhi ; Spelbrink, Johannes N. ; Watanabe, Kimitsuna ; Jacobs, Howard T. / The 7472insC mitochondrial DNA mutation impairs the synthesis and extent of aminoacylation of tRNASer(UCN) but not its structure or rate of turnover. In: Journal of Biological Chemistry. 2002 ; Vol. 277, No. 25. pp. 22240-22250.
@article{69bf3968c92a4a3caa286db4357bf088,
title = "The 7472insC mitochondrial DNA mutation impairs the synthesis and extent of aminoacylation of tRNASer(UCN) but not its structure or rate of turnover",
abstract = "The 7472insC mitochondrial DNA mutation in the tRNASer(UCN) gene is associated with sensorineural deafness combined, in some patients, with a wider neurological syndrome. In cultured cybrid cells it causes a 70{\%} decrease in tRNASer(UCN) abundance and mild respiratory impairment, previously suggested to be due to decreased tRNA stability. When mitochondrial transcription was blocked by ethidium bromide treatment, the half-life of the mutant tRNA was not significantly different from that of wild-type tRNASer(UCN). Over-expression of mitochondrial translational elongation factor EF-Tu also had no effect on the mutant phenotype. However, during recovery from prolonged ethidium bromide treatment, the synthesis of the mutant tRNASer(UCN) was specifically impaired, without polarity effects on downstream tRNAs of the light strand transcription unit. We infer that the mutation acts posttranscriptionally to decrease tRNASer(UCN) abundance by affecting its synthesis rather than its stability. The extent of aminoacylation of the mutant tRNA was also decreased by ∼25{\%}. In contrast, the mutation had no detectable effect on tRNASer(UCN) base modification or structure other than the insertion of an extra guanosine templated by the mutation, which was structurally protected from nuclease digestion like the surrounding nucleotides. These findings indicate a common molecular process underlying sensorineural deafness caused by mitochondrial tRNASer(UCN) mutations.",
author = "Marina Toompuu and Takehiro Yasukawa and Tsutomu Suzuki and Terhi Hakkinen and Spelbrink, {Johannes N.} and Kimitsuna Watanabe and Jacobs, {Howard T.}",
year = "2002",
month = "6",
day = "21",
doi = "10.1074/jbc.M200338200",
language = "English",
volume = "277",
pages = "22240--22250",
journal = "Journal of Biological Chemistry",
issn = "0021-9258",
publisher = "American Society for Biochemistry and Molecular Biology Inc.",
number = "25",

}

TY - JOUR

T1 - The 7472insC mitochondrial DNA mutation impairs the synthesis and extent of aminoacylation of tRNASer(UCN) but not its structure or rate of turnover

AU - Toompuu, Marina

AU - Yasukawa, Takehiro

AU - Suzuki, Tsutomu

AU - Hakkinen, Terhi

AU - Spelbrink, Johannes N.

AU - Watanabe, Kimitsuna

AU - Jacobs, Howard T.

PY - 2002/6/21

Y1 - 2002/6/21

N2 - The 7472insC mitochondrial DNA mutation in the tRNASer(UCN) gene is associated with sensorineural deafness combined, in some patients, with a wider neurological syndrome. In cultured cybrid cells it causes a 70% decrease in tRNASer(UCN) abundance and mild respiratory impairment, previously suggested to be due to decreased tRNA stability. When mitochondrial transcription was blocked by ethidium bromide treatment, the half-life of the mutant tRNA was not significantly different from that of wild-type tRNASer(UCN). Over-expression of mitochondrial translational elongation factor EF-Tu also had no effect on the mutant phenotype. However, during recovery from prolonged ethidium bromide treatment, the synthesis of the mutant tRNASer(UCN) was specifically impaired, without polarity effects on downstream tRNAs of the light strand transcription unit. We infer that the mutation acts posttranscriptionally to decrease tRNASer(UCN) abundance by affecting its synthesis rather than its stability. The extent of aminoacylation of the mutant tRNA was also decreased by ∼25%. In contrast, the mutation had no detectable effect on tRNASer(UCN) base modification or structure other than the insertion of an extra guanosine templated by the mutation, which was structurally protected from nuclease digestion like the surrounding nucleotides. These findings indicate a common molecular process underlying sensorineural deafness caused by mitochondrial tRNASer(UCN) mutations.

AB - The 7472insC mitochondrial DNA mutation in the tRNASer(UCN) gene is associated with sensorineural deafness combined, in some patients, with a wider neurological syndrome. In cultured cybrid cells it causes a 70% decrease in tRNASer(UCN) abundance and mild respiratory impairment, previously suggested to be due to decreased tRNA stability. When mitochondrial transcription was blocked by ethidium bromide treatment, the half-life of the mutant tRNA was not significantly different from that of wild-type tRNASer(UCN). Over-expression of mitochondrial translational elongation factor EF-Tu also had no effect on the mutant phenotype. However, during recovery from prolonged ethidium bromide treatment, the synthesis of the mutant tRNASer(UCN) was specifically impaired, without polarity effects on downstream tRNAs of the light strand transcription unit. We infer that the mutation acts posttranscriptionally to decrease tRNASer(UCN) abundance by affecting its synthesis rather than its stability. The extent of aminoacylation of the mutant tRNA was also decreased by ∼25%. In contrast, the mutation had no detectable effect on tRNASer(UCN) base modification or structure other than the insertion of an extra guanosine templated by the mutation, which was structurally protected from nuclease digestion like the surrounding nucleotides. These findings indicate a common molecular process underlying sensorineural deafness caused by mitochondrial tRNASer(UCN) mutations.

UR - http://www.scopus.com/inward/record.url?scp=0037151016&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0037151016&partnerID=8YFLogxK

U2 - 10.1074/jbc.M200338200

DO - 10.1074/jbc.M200338200

M3 - Article

VL - 277

SP - 22240

EP - 22250

JO - Journal of Biological Chemistry

JF - Journal of Biological Chemistry

SN - 0021-9258

IS - 25

ER -