Mrd1p is required for release of base-paired U3 snoRNA within the preribosomal complex.
In eukaryotes, ribosomes are made from precursor rRNA (pre-rRNA) and ribosomal proteins in a maturation process that requires a large number of snoRNPs and processing factors. A fundamental problem is how the coordinated and productive folding of the pre-rRNA and assembly of successive pre-rRNA-protein complexes is achieved cotranscriptionally. The conserved protein Mrd1p, which contains five RNA binding domains (RBDs), is essential for processing events leading to small ribosomal subunit synthesis. We show that full function of Mrd1p requires all five RBDs and that the RBDs are functionally distinct and needed during different steps in processing. Mrd1p mutations trap U3 snoRNA in pre-rRNP complexes both in base-paired and non-base-paired interactions. A single essential RBD, RBD5, is involved in both types of interactions, but its conserved RNP1 motif is not needed for releasing the base-paired interactions. RBD5 is also required for the late pre-rRNP compaction preceding A(2) cleavage. Our results suggest that Mrd1p modulates successive conformational rearrangements within the pre-rRNP that influence snoRNA-pre-rRNA contacts and couple U3 snoRNA-pre-rRNA remodeling and late steps in pre-rRNP compaction that are essential for cleavage at A(0) to A(2). Mrd1p therefore coordinates key events in biosynthesis of small ribosome subunits.
Lundkvist
Pär
P
Department of Molecular Biology and Functional Genomics, Stockholm University, SE-106 91 Stockholm, Sweden.
Jupiter
Sara
S
Segerstolpe
Asa
A
Osheim
Yvonne N
YN
Beyer
Ann L
AL
Wieslander
Lars
L
D000483:Alleles; D000595:Amino Acid Sequence; D020029:Base Pairing / Q000235:genetics*; D005472:Fluorouracil / Q000494:pharmacology; D015966:Gene Expression Regulation, Fungal / Q000187:drug effects; D005799:Genes, Dominant; D005816:Genetic Complementation Test; D008969:Molecular Sequence Data; D050505:Mutant Proteins / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D009963:Orotic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D017434:Protein Structure, Tertiary; D012322:RNA Precursors / Q000378:metabolism; D012323:RNA Processing, Post-Transcriptional / Q000187:drug effects; D020537:RNA, Small Nucleolar / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism*; D012261:Ribonucleoproteins / Q000378:metabolism; D012270:Ribosomes / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000254:growth & development / Q000378:metabolism* / Q000648:ultrastructure; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000378:metabolism*
C530595:Mrd1 protein, S cerevisiae; D050505:Mutant Proteins; D012322:RNA Precursors; D020537:RNA, Small Nucleolar; C117378:RNA, U3 small nucleolar; D016601:RNA-Binding Proteins; D012261:Ribonucleoproteins; D029701:Saccharomyces cerevisiae Proteins; D009963:Orotic Acid; C001242:5-fluoroorotic acid; D005472:Fluorouracil
Eukaryot Cell. 2005 Dec;4(12):2106-14
16339728
Yeast. 1998 Jul;14(10):953-61
9717241
Nat Biotechnol. 2001 Aug;19(8):773-6
11479573
Cell. 2002 Apr 19;109(2):145-8
12007400
Microbiol Rev. 1994 Mar;58(1):10-26
8177168
Nucleic Acids Res. 2006;34(15):4168-80
16936318
Mol Cell. 2007 Aug 3;27(3):339-52
17679086
Mol Cell. 2005 Oct 28;20(2):263-75
16246728
J Biol Chem. 2001 Apr 27;276(17):14338-43
11278842
Nucleic Acids Res. 1994 Nov 25;22(23):5139-47
7800512
FEBS J. 2005 May;272(9):2118-31
15853797
J Mol Biol. 2000 Oct 20;303(2):227-41
11023788
RNA Biol. 2007 Nov;4(3):118-30
18347437
Mol Cell. 2004 Dec 22;16(6):943-54
15610737
Proc Natl Acad Sci U S A. 1978 Aug;75(8):3593-7
358189
Yeast. 2000 Apr;16(6):553-60
10790693
J Biol Chem. 2004 Sep 3;279(36):37385-97
15231838
Mol Cell. 2004 Jul 23;15(2):295-301
15260980
RNA. 1997 Apr;3(4):337-43
9085841
EMBO J. 1995 Sep 1;14(17):4350-6
7556076
Nucleic Acids Res. 2006 Jun 13;34(10):3189-99
16772403
J Mol Biol. 1996 Jun 21;259(4):645-54
8683571
Genes Dev. 2004 Jul 1;18(13):1513-26
15231733
Mol Cell. 2005 Oct 7;20(1):53-64
16209945
J Cell Biol. 2008 Jun 16;181(6):935-44
18559667
Genes Dev. 1993 Apr;7(4):660-70
7681419
Nucleic Acids Res. 1995 Mar 11;23(5):725-8
7535921
EMBO Rep. 2008 Dec;9(12):1230-6
18833290
Mol Cell Biol. 2004 Oct;24(19):8600-10
15367679
Nucleic Acids Res. 2004 Mar 31;32(6):1993-9
15056729
Mol Cell Biol. 1999 Aug;19(8):5441-52
10409734
Genes Dev. 1993 Aug;7(8):1609-19
8339936
Curr Opin Struct Biol. 2001 Feb;11(1):53-8
11179892
J Biol Chem. 1995 Sep 8;270(36):20871-4
7545662
Curr Opin Struct Biol. 2008 Jun;18(3):305-14
18555681
Gene. 2003 Aug 14;313:17-42
12957375
Nucleic Acids Res. 2008 Aug;36(13):4364-80
18586827
Mol Cell. 2007 Nov 9;28(3):446-57
17996708
Mol Cell Biol. 1999 Sep;19(9):6012-9
10454548
Mol Cell. 2004 Jan 30;13(2):225-39
14759368
Mol Cell Biol. 2007 Aug;27(15):5414-29
17515605
Mol Cell Biol. 2000 Oct;20(19):7238-46
10982841
Mol Cell. 2002 Jul;10(1):105-15
12150911
Annu Rev Genet. 1999;33:261-311
10690410
J Biol Chem. 2002 May 24;277(21):18431-9
11884397
Nature. 2006 Jun 1;441(7093):651-5
16738661
Genetics. 2008 May;179(1):323-30
18493057
Mol Cell Biol. 2006 Oct;26(20):7437-50
16908538
J Mol Biol. 1997 Oct 31;273(3):552-71
9356246
Mol Cell. 2002 Feb;9(2):329-39
11864606
Mol Cell Biol. 2004 Dec;24(24):10766-76
15572680
Mol Cell Biol. 2005 Jul;25(13):5523-34
15964808