Overexpressed mitochondrial leucyl-tRNA synthetase suppresses the A3243G mutation in the mitochondrial tRNA(Leu(UUR)) gene.
The A3243G mutation in the human mitochondrial tRNA(Leu(UUR)) gene causes a number of human diseases. This mutation reduces the level and fraction of aminoacylated tRNA(Leu(UUR)) and eliminates nucleotide modification at the wobble position of the anticodon. These deficiencies are associated with mitochondrial translation defects that result in decreased levels of mitochondrial translation products and respiratory chain enzyme activities. We have suppressed the respiratory chain defects in A3243G mutant cells by overexpressing human mitochondrial leucyl-tRNA synthetase. The rates of oxygen consumption in suppressed cells were directly proportional to the levels of leucyl-tRNA synthetase. Fifteenfold higher levels of leucyl-tRNA synthetase resulted in wild-type respiratory chain function. The suppressed cells had increased steady-state levels of tRNA(Leu(UUR)) and up to threefold higher steady-state levels of mitochondrial translation products, but did not have rates of protein synthesis above those in parental mutant cells. These data suggest that suppression of the A3243G mutation occurred by increasing protein stability. This suppression of a tRNA gene mutation by increasing the steady-state levels of its cognate aminoacyl-tRNA synthetase is a model for potential therapies for human pathogenic tRNA mutations.
Park
Hyejeong
H
Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA.
Davidson
Edgar
E
King
Michael P
MP
D002460:Cell Line; D004272:DNA, Mitochondrial / Q000235:genetics / Q000378:metabolism; D004579:Electron Transport / Q000235:genetics; D006801:Humans; D007935:Leucine-tRNA Ligase / Q000096:biosynthesis* / Q000235:genetics; D008928:Mitochondria / Q000201:enzymology; D028361:Mitochondrial Diseases / Q000235:genetics*; D009154:Mutation; D014176:Protein Biosynthesis / Q000235:genetics; D012346:RNA, Transfer, Amino Acyl / Q000235:genetics* / Q000378:metabolism; D013489:Suppression, Genetic
D004272:DNA, Mitochondrial; D012346:RNA, Transfer, Amino Acyl; D007935:Leucine-tRNA Ligase
Hum Mol Genet. 2000 Mar 1;9(4):467-75
10699170
Proc Natl Acad Sci U S A. 2004 Oct 19;101(42):15070-5
15477592
Nucleic Acids Res. 1993 Feb 11;21(3):657-62
7680123
Chem Biol. 2006 Oct;13(10):1091-100
17052613
EMBO J. 2002 Dec 2;21(23):6581-9
12456664
EMBO J. 2001 Sep 3;20(17):4794-802
11532943
Mitochondrion. 2007 May;7(3):230-3
17300999
Ann Neurol. 2008 Jan;63(1):35-9
17886296
Ann Neurol. 2007 Sep;62(3):278-87
17823937
Mol Cell Biol. 1992 Feb;12(2):480-90
1732728
Science. 1989 Oct 27;246(4929):500-3
2814477
Proc Natl Acad Sci U S A. 1992 May 15;89(10):4221-5
1584755
Nature. 2006 Sep 7;443(7107):50-5
16906134
Curr Top Cell Regul. 1985;27:387-96
4092493
J Biol Chem. 1993 May 15;268(14):10228-37
7683672
Nat Genet. 1998 Apr;18(4):350-3
9537417
Nucleic Acids Res. 2008 May;36(9):3065-74
18400783
Nature. 1990 Dec 13;348(6302):651-3
2102678
Proc Natl Acad Sci U S A. 1978 Mar;75(3):1091-5
349556
Gene. 2003 Jan 16;303:63-8
12559567
Nucleic Acids Res. 1999 Feb 1;27(3):756-63
9889270
Acta Neurol Scand. 2007 Jul;116(1):1-14
17587249
J Biol Chem. 2000 Feb 11;275(6):4251-7
10660592
Hum Mol Genet. 1996 Jan;5(1):123-29
8789449
Biochemistry. 2003 Feb 4;42(4):958-64
12549915
Curr Genet. 1998 Feb;33(2):110-6
9506898
Biochemistry. 2005 Mar 1;44(8):3010-6
15723544
Curr Genet. 1997 Jun;31(6):494-6
9211792
Methods Enzymol. 1996;264:183-96
8965692
Hum Mol Genet. 2007 Oct 15;16(20):2472-81
17656376
RNA. 2007 Jan;13(1):87-96
17095544
J Biol Chem. 1999 Oct 15;274(42):29744-8
10514449
EMBO Rep. 2003 Jan;4(1):53-8
12524521
J Mol Biol. 2004 May 21;339(1):17-29
15123417
Ann Neurol. 1996 Aug;40(2):172-80
8773598
J Biol Chem. 2000 Jun 23;275(25):19198-209
10858457
J Biol Chem. 2000 May 5;275(18):13994-4003
10788526
Ann Neurol. 2000 Aug;48(2):188-93
10939569
J Biol Chem. 1982 Apr 10;257(7):3575-80
6460769
Proc Natl Acad Sci U S A. 1979 Sep;76(9):4350-4
388439
Gene. 2006 Aug 1;377:169-76
16777356
Anal Biochem. 1987 Nov 1;166(2):368-79
2449095
FEBS Lett. 2005 May 23;579(13):2948-52
15893315
Am J Hum Genet. 1998 Aug;63(2):447-54
9683591
Hum Mol Genet. 2003 Oct 15;12 Spec No 2:R293-301
12928485
J Biol Chem. 1997 Oct 24;272(43):27189-96
9341162