NoRC--a novel member of mammalian ISWI-containing chromatin remodeling machines.
Transcription by RNA polymerase I on nucleosomal templates requires binding of the transcription termination factor TTF-I to a cognate site 160 bp upstream of the transcription start site. Binding of TTF-I is accompanied by changes in the chromatin architecture which suggests that TTF-I recruits a remodeling activity to the rDNA promoter. We have cloned a cDNA that encodes TIP5 (TTF-I-interacting protein 5), a 205 kDa protein that shares a number of important protein domains with WSTF (Williams syndrome transcription factor) and hAcf1/WCRF180, the largest subunits of human chromatin remodeling complexes hCHRAC and WCRF. TIP5 co-localizes with the basal RNA polymerase I transcription factor UBF in the nucleolus and is associated with SNF2h. The cellular TIP5-SNF2h complex, termed NoRC (nucleolar remodeling complex), induces nucleosome sliding in an ATP- and histone H4 tail-dependent fashion. The results suggest that NoRC is a novel nucleolar chromatin remodeling machine that may serve a role in the regulation of the rDNA locus.
Strohner
R
R
Division of Molecular Biology of the Cell II, Deutsches Krebsforschungszentrum, D-69120 Heidelberg and Adolf-Butenandt-Institut, Schillerstrasse 44, D-80336 München, Germany.
Nemeth
A
A
Jansa
P
P
Hofmann-Rohrer
U
U
Santoro
R
R
Längst
G
G
Grummt
I
I
D016475:3T3 Cells; D000251:Adenosine Triphosphatases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D002843:Chromatin / Q000235:genetics* / Q000378:metabolism; D002868:Chromosomal Proteins, Non-Histone / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000378:metabolism; D006801:Humans; D008322:Mammals; D051379:Mice; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D011401:Promoter Regions, Genetic; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D014162:Transfection; D000092468:Bromodomain Containing Proteins
D000251:Adenosine Triphosphatases; D002843:Chromatin; D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; D014157:Transcription Factors; C436708:BAZ2A protein, human; D000092468:Bromodomain Containing Proteins; C499051:Baz2a protein, mouse; C086468:ISWI protein; C504003:TTF1 protein, human; C504004:Ttf1 protein, mouse; C409462:SMARCA5 protein, human; C498725:Smarca5 protein, mouse