Nucleolar clustering of dispersed tRNA genes.
Early transfer RNA (tRNA) processing events in Saccharomyces cerevisiae are coordinated in the nucleolus, the site normally associated with ribosome biosynthesis. To test whether spatial organization of the tRNA pathway begins with nucleolar clustering of the genes, we have probed the subnuclear location of five different tRNA gene families. The results show that tRNA genes, though dispersed in the linear genome, colocalize with 5S ribosomal DNA and U14 small nucleolar RNA at the nucleolus. Nucleolar localization requires tRNA gene transcription-complex formation, because inactivation of the promoter at a single locus removes its nucleolar association. This organization of tRNA genes must profoundly affect the spatial packaging of the genome and raises the question of whether gene types might be coordinated in three dimensions to regulate transcription.
Thompson
Martin
M
Department of Biological Chemistry, University of Michigan, Ann Arbor, MI 48109-0606, USA.
Haeusler
Rebecca A
RA
Good
Paul D
PD
Engelke
David R
DR
D002466:Cell Nucleolus / Q000235:genetics*; D004257:DNA Polymerase II / Q000378:metabolism; D004258:DNA Polymerase III / Q000378:metabolism; D004275:DNA, Ribosomal / Q000032:analysis / Q000235:genetics; D005800:Genes, Fungal; D020459:Genes, rRNA; D016681:Genome, Fungal; D007438:Introns; D005810:Multigene Family; D011401:Promoter Regions, Genetic; D012331:RNA, Fungal / Q000235:genetics; D012335:RNA, Ribosomal / Q000096:biosynthesis; D012341:RNA, Ribosomal, 5S / Q000235:genetics; D020537:RNA, Small Nucleolar / Q000032:analysis; D012343:RNA, Transfer / Q000235:genetics*; D012351:RNA, Transfer, Gln / Q000235:genetics; D012352:RNA, Transfer, Glu / Q000235:genetics; D012353:RNA, Transfer, Gly / Q000235:genetics; D012356:RNA, Transfer, Leu / Q000235:genetics; D012357:RNA, Transfer, Lys / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D014158:Transcription, Genetic
D004275:DNA, Ribosomal; D012331:RNA, Fungal; D012335:RNA, Ribosomal; D012341:RNA, Ribosomal, 5S; D020537:RNA, Small Nucleolar; D012351:RNA, Transfer, Gln; D012352:RNA, Transfer, Glu; D012353:RNA, Transfer, Gly; D012356:RNA, Transfer, Leu; D012357:RNA, Transfer, Lys; D012343:RNA, Transfer; D004257:DNA Polymerase II; D004258:DNA Polymerase III