Inactivation of NMD increases viability of sup45 nonsense mutants in Saccharomyces cerevisiae.
BACKGROUND
The nonsense-mediated mRNA decay (NMD) pathway promotes the rapid degradation of mRNAs containing premature termination codons (PTCs). In yeast Saccharomyces cerevisiae, the activity of the NMD pathway depends on the recognition of the PTC by the translational machinery. Translation termination factors eRF1 (Sup45) and eRF3 (Sup35) participate not only in the last step of protein synthesis but also in mRNA degradation and translation initiation via interaction with such proteins as Pab1, Upf1, Upf2 and Upf3.


RESULTS
In this work we have used previously isolated sup45 mutants of S. cerevisiae to characterize degradation of aberrant mRNA in conditions when translation termination is impaired. We have sequenced his7-1, lys9-A21 and trp1-289 alleles which are frequently used for analysis of nonsense suppression. We have established that sup45 nonsense and missense mutations lead to accumulation of his7-1 mRNA and CYH2 pre-mRNA. Remarkably, deletion of the UPF1 gene suppresses some sup45 phenotypes. In particular, sup45-n upf1Delta double mutants were less temperature sensitive, and more resistant to paromomycin than sup45 single mutants. In addition, deletion of either UPF2 or UPF3 restored viability of sup45-n double mutants.


CONCLUSIONS
This is the first demonstration that sup45 mutations do not only change translation fidelity but also acts by causing a change in mRNA stability.
Chabelskaya
Svetlana
S
Department of Genetics and Breeding, St Petersburg State University, Universitetskaya emb, 7/9, 199034, St Petersburg, Russia. shabels@mail.ru
Gryzina
Valentina
V
Moskalenko
Svetlana
S
Le Goff
Catherine
C
Zhouravleva
Galina
G
D048868:Adaptor Proteins, Signal Transducing; D001483:Base Sequence; D018389:Codon, Nonsense / Q000235:genetics*; D015536:Down-Regulation; D017353:Gene Deletion; D015966:Gene Expression Regulation, Fungal; D008969:Molecular Sequence Data; D010454:Peptide Termination Factors / Q000235:genetics / Q000378:metabolism*; D010641:Phenotype; D020365:RNA Helicases / Q000235:genetics / Q000378:metabolism; D020871:RNA Stability / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics* / Q000254:growth & development* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism
D048868:Adaptor Proteins, Signal Transducing; D018389:Codon, Nonsense; C092470:NMD2 protein, S cerevisiae; D010454:Peptide Termination Factors; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; C080775:SUP45 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D015534:Trans-Activators; C096360:UPF3 protein, S cerevisiae; C074151:NAM7 protein, S cerevisiae; D020365:RNA Helicases
Proc Natl Acad Sci U S A. 1993 Aug 1;90(15):7034-8
8346213
Mol Cell Biol. 1992 May;12(5):2165-77
1569946
Genes Dev. 1993 Oct;7(10):1885-97
8104846
Genes Dev. 1995 Feb 15;9(4):423-36
7883167
Genes Dev. 1995 Feb 15;9(4):437-54
7883168
Yeast. 1995 Apr 15;11(4):355-60
7785336
Proc Natl Acad Sci U S A. 1995 Oct 24;92(22):10354-8
7479783
Mol Microbiol. 1996 Jun;20(6):1135-43
8809766
Mol Cell Biol. 1996 Oct;16(10):5477-90
8816461
Mol Cell Biol. 1996 Oct;16(10):5491-506
8816462
J Biol Chem. 1997 Aug 29;272(35):22163-72
9268361
Genes Dev. 1998 Jun 1;12(11):1665-77
9620853
Yeast. 1998 Jul;14(10):953-61
9717241
Mol Cell Biol. 1998 Oct;18(10):6121-30
9742129
Trends Genet. 1999 Feb;15(2):74-80
10098411
J Biol Chem. 1999 Jun 11;274(24):16677-80
10358005
Mol Cell Biol. 1999 Oct;19(10):6710-9
10490610
Nature. 2004 Nov 4;432(7013):112-8
15525991
Trends Genet. 2005 Mar;21(3):143-8
15734573
Proc Natl Acad Sci U S A. 2005 Jul 19;102(29):10244-9
16002465
RNA. 2005 Sep;11(9):1333-9
16043493
Biochem Soc Trans. 2006 Feb;34(Pt 1):39-42
16246174
Genes Dev. 2006 Feb 1;20(3):355-67
16452507
Mol Cell Biol. 2006 May;26(9):3390-400
16611983
Mol Cell Biol. 2000 Jul;20(13):4591-603
10848586
EMBO J. 2001 Feb 15;20(4):880-90
11179232
Gene. 2001 Aug 22;274(1-2):15-25
11674994
Mol Cell Biol. 2002 May;22(10):3301-15
11971964
EMBO J. 2003 Jan 15;22(2):175-82
12514123
Yeast. 2003 May;20(7):625-32
12734800
BMC Mol Biol. 2003 Feb 10;4:2
12589713
Biol Cell. 2003 May-Jun;95(3-4):195-209
12867083
EMBO J. 2003 Aug 1;22(15):3960-70
12881430
J Biol Chem. 2003 Oct 3;278(40):38287-91
12923185
Mol Cell. 2003 Dec;12(6):1439-52
14690598
Mol Microbiol. 2004 Feb;51(4):1129-42
14763985
RNA. 2004 Apr;10(4):691-703
15037778
Curr Opin Cell Biol. 2004 Jun;16(3):293-9
15145354
Genetika. 2004 May;40(5):599-606
15272556
J Biol Chem. 2004 Oct 29;279(44):45693-700
15337765
Mol Genet Genomics. 2004 Oct;272(3):297-307
15349771
Proc Natl Acad Sci U S A. 1979 Oct;76(10):5134-7
388431
J Cell Sci. 1989 Jul;93 ( Pt 3):491-500
2606940
Genes Dev. 1991 Dec;5(12A):2303-14
1748286
J Mol Biol. 1992 Apr 5;224(3):575-87
1314899
Genes Dev. 1993 Sep;7(9):1737-54
8370523