The mobile nucleoporin Nup2p and chromatin-bound Prp20p function in endogenous NPC-mediated transcriptional control.
Nuclear pore complexes (NPCs) govern macromolecular transport between the nucleus and cytoplasm and serve as key positional markers within the nucleus. Several protein components of yeast NPCs have been implicated in the epigenetic control of gene expression. Among these, Nup2p is unique as it transiently associates with NPCs and, when artificially tethered to DNA, can prevent the spread of transcriptional activation or repression between flanking genes, a function termed boundary activity. To understand this function of Nup2p, we investigated the interactions of Nup2p with other proteins and with DNA using immunopurifications coupled with mass spectrometry and microarray analyses. These data combined with functional assays of boundary activity and epigenetic variegation suggest that Nup2p and the Ran guanylyl-nucleotide exchange factor, Prp20p, interact at specific chromatin regions and enable the NPC to play an active role in chromatin organization by facilitating the transition of chromatin between activity states.
Dilworth
David J
DJ
Institute for Systems Biology, Seattle, WA 98103, USA.
Tackett
Alan J
AJ
Rogers
Richard S
RS
Yi
Eugene C
EC
Christmas
Rowan H
RH
Smith
Jennifer J
JJ
Siegel
Andrew F
AF
Chait
Brian T
BT
Wozniak
Richard W
RW
Aitchison
John D
JD
D021581:Active Transport, Cell Nucleus / Q000502:physiology; D002843:Chromatin / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D020868:Gene Silencing / Q000502:physiology; D020662:Guanine Nucleotide Exchange Factors; D006657:Histones / Q000235:genetics / Q000378:metabolism; D046228:Microarray Analysis; D008954:Models, Biological; D022022:Nuclear Pore / Q000235:genetics / Q000378:metabolism*; D028861:Nuclear Pore Complex Proteins / Q000235:genetics / Q000378:metabolism*; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D009707:Nucleosomes / Q000378:metabolism; D016366:Open Reading Frames / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D016615:Telomere / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic / Q000502:physiology*
D002843:Chromatin; D004268:DNA-Binding Proteins; D020662:Guanine Nucleotide Exchange Factors; D006657:Histones; C493530:Htz1 protein, S cerevisiae; C400753:NUP2 protein, S cerevisiae; D028861:Nuclear Pore Complex Proteins; D009687:Nuclear Proteins; D009707:Nucleosomes; C495208:Nup60 protein, S cerevisiae; C067050:SRM1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins