Cotranscriptional Recruitment to the mRNA Export Receptor Mex67p Contributes to Nuclear Pore Anchoring of Activated Genes

Guennaelle Dieppois; Nahid Iglesias; Françoise Stutz

doi:10.1128/mcb.00870-06

Cotranscriptional Recruitment to the mRNA Export Receptor Mex67p Contributes to Nuclear Pore Anchoring of Activated Genes

Molecular and Cellular Biology ◽

10.1128/mcb.00870-06 ◽

2006 ◽

Vol 26 (21) ◽

pp. 7858-7870 ◽

Cited By ~ 132

Author(s):

Guennaelle Dieppois ◽

Nahid Iglesias ◽

Françoise Stutz

Keyword(s):

Transcriptional Activation ◽

Mrna Export ◽

Nuclear Periphery ◽

Nuclear Pore ◽

Coding Region ◽

Messenger Ribonucleoprotein ◽

Gene Positioning ◽

Independent Process ◽

Stable Association ◽

Early Recruitment

ABSTRACT Transcription activation of some Saccharomyces cerevisiae genes is paralleled by their repositioning to the nuclear periphery, but the mechanism underlying gene anchoring is poorly defined. We show that the nuclear pore complex-associated Mlp1p and the shuttling mRNA export receptor Mex67p contribute to the stable association of the activated GAL10 and HSP104 genes with the nuclear periphery. However, we find no obligatory link between gene positioning and gene expression. Furthermore, gene anchoring correlates with the cotranscriptional recruitment of Mex67p to transcribing genes. Notably, the association of Mex67p with chromatin is not mediated by RNA. Interestingly, a mutant GAL2 gene lacking the coding region is still able to recruit Mex67p upon transcriptional activation and to relocate to the nuclear periphery. Together these data suggest that, at least for GAL2, nascent messenger ribonucleoprotein does not play a major role in gene anchoring and that the early recruitment of Mex67p contributes to gene repositioning by virtue of an RNA-independent process.

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A negative feedback loop at the nuclear periphery regulates GAL gene expression

Molecular Biology of the Cell ◽

10.1091/mbc.e11-06-0547 ◽

2012 ◽

Vol 23 (7) ◽

pp. 1367-1375 ◽

Cited By ~ 44

Author(s):

Erin M. Green ◽

Ying Jiang ◽

Ryan Joyner ◽

Karsten Weis

Keyword(s):

Gene Expression ◽

Negative Feedback ◽

Transcriptional Activation ◽

Feedback Loop ◽

Nuclear Periphery ◽

Gene Interaction ◽

Nuclear Pore ◽

Negative Feedback Loop ◽

Gating Model ◽

Gene Positioning

The genome is nonrandomly organized within the nucleus, but it remains unclear how gene position affects gene expression. Silenced genes have frequently been found associated with the nuclear periphery, and the environment at the periphery is believed to be refractory to transcriptional activation. However, in budding yeast, several highly regulated classes of genes, including the GAL7-10-1 gene cluster, are known to translocate to the nuclear periphery concurrent with their activation. To investigate the role of gene positioning on GAL gene expression, we monitored the effects of mutations that disrupt the interaction between the GAL locus and the periphery or synthetically tethered the locus to the periphery. Localization to the nuclear periphery was found to dampen initial GAL gene induction and was required for rapid repression after gene inactivation, revealing a function for the nuclear periphery in repressing endogenous GAL gene expression. Our results do not support a gene-gating model in which GAL gene interaction with the nuclear pore ensures rapid gene expression, but instead they suggest that a repressive environment at the nuclear periphery establishes a negative feedback loop that enables the GAL locus to respond rapidly to changes in environmental conditions.

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Mex67p of Schizosaccharomyces pombeInteracts with Rae1p in Mediating mRNA Export

Molecular and Cellular Biology ◽

10.1128/mcb.20.23.8767-8782.2000 ◽

2000 ◽

Vol 20 (23) ◽

pp. 8767-8782 ◽

Cited By ~ 52

Author(s):

Jin Ho Yoon ◽

Dona C. Love ◽

Anjan Guhathakurta ◽

John A. Hanover ◽

Ravi Dhar

Keyword(s):

Nuclear Export ◽

Rna Binding ◽

Fluorescent Protein ◽

Synthetic Lethality ◽

Sequence Similarity ◽

Mrna Export ◽

Nuclear Periphery ◽

Nuclear Pore ◽

Multicopy Suppressor ◽

Accessory Factor

ABSTRACT We identified the Schizosaccharomyces pombe mex67 gene (spmex67) as a multicopy suppressor of rae1-167 nup184-1 synthetic lethality and the rae1-167 tsmutation. spMex67p, a 596-amino-acid-long protein, has considerable sequence similarity to the Saccharomyces cerevisiae Mex67p (scMex67p) and human Tap. In contrast toscMEX67, spmex67 is essential for neither growth nor nuclear export of mRNA. However, an spmex67 null mutation (Δmex67) is synthetically lethal with therae1-167 mutation and accumulates poly(A)+ RNA in the nucleus. We identified a central region (149 to 505 amino acids) within spMex67p that associates with a complex containing Rae1p that complements growth and mRNA export defects of therae1-167 Δmex67 synthetic lethality. This region is devoid of RNA-binding, N-terminal nuclear localization, and the C-terminal nuclear pore complex-targeting regions. The (149–505)-green fluorescent protein (GFP) fusion is found diffused throughout the cell. Overexpression of spMex67p inhibits growth and mRNA export and results in the redistribution of the diffused localization of the (149–505)-GFP fusion to the nucleus and the nuclear periphery. These results suggest that spMex67p competes for essential mRNA export factor(s). Finally, we propose that the 149–505 region of spMex67p could act as an accessory factor in Rae1p-dependent transport and that spMex67p participates at various common steps with Rae1p export complexes in promoting the export of mRNA.

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Strategies to regulate transcription factor–mediated gene positioning and interchromosomal clustering at the nuclear periphery

The Journal of Cell Biology ◽

10.1083/jcb.201508068 ◽

2016 ◽

Vol 212 (6) ◽

pp. 633-646 ◽

Cited By ~ 31

Author(s):

Carlo Randise-Hinchliff ◽

Robert Coukos ◽

Varun Sood ◽

Michael Chas Sumner ◽

Stefan Zdraljevic ◽

...

Keyword(s):

Transcription Factor ◽

Dna Binding ◽

Binding Sites ◽

Nuclear Periphery ◽

Mitogen Activated Protein Kinase ◽

Nuclear Pore ◽

General Function ◽

Gene Promoters ◽

Protein Levels ◽

Gene Positioning

In budding yeast, targeting of active genes to the nuclear pore complex (NPC) and interchromosomal clustering is mediated by transcription factor (TF) binding sites in the gene promoters. For example, the binding sites for the TFs Put3, Ste12, and Gcn4 are necessary and sufficient to promote positioning at the nuclear periphery and interchromosomal clustering. However, in all three cases, gene positioning and interchromosomal clustering are regulated. Under uninducing conditions, local recruitment of the Rpd3(L) histone deacetylase by transcriptional repressors blocks Put3 DNA binding. This is a general function of yeast repressors: 16 of 21 repressors blocked Put3-mediated subnuclear positioning; 11 of these required Rpd3. In contrast, Ste12-mediated gene positioning is regulated independently of DNA binding by mitogen-activated protein kinase phosphorylation of the Dig2 inhibitor, and Gcn4-dependent targeting is up-regulated by increasing Gcn4 protein levels. These different regulatory strategies provide either qualitative switch-like control or quantitative control of gene positioning over different time scales.

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Npp106p, a Schizosaccharomyces pombe nucleoporin similar to Saccharomyces cerevisiae Nic96p, functionally interacts with Rae1p in mRNA export.

Molecular and Cellular Biology ◽

10.1128/mcb.17.12.7047 ◽

1997 ◽

Vol 17 (12) ◽

pp. 7047-7060 ◽

Cited By ~ 19

Author(s):

J H Yoon ◽

W A Whalen ◽

A Bharathi ◽

R Shen ◽

R Dhar

Keyword(s):

Saccharomyces Cerevisiae ◽

Schizosaccharomyces Pombe ◽

Fluorescent Protein ◽

Synthetic Lethality ◽

Mrna Export ◽

Nuclear Periphery ◽

Simian Virus 40 ◽

Nuclear Pore ◽

Significant Similarity ◽

Synthetically Lethal

To identify components of the mRNA export machinery in Schizosaccharomyces pombe, a screen was developed to identify mutations that were synthetically lethal with the conditional mRNA export allele rae1-167. Mutations defining three complementation groups were isolated, and here we report the characterization of npp106 (for nuclear pore protein of 106 kDa). This gene encodes a predicted protein that has significant similarity to the Nic96p nucleoporin of Saccharomyces cerevisiae. Consistent with Npp106p being a nucleoporin, a functional green fluorescent protein (GFP)-tagged Npp106p localized to the nuclear periphery. In contrast to NIC96, the npp106 gene is not essential. Moreover, a delta npp106 mutant did not show cytoplasmic mislocalization of a simian virus 40 nuclear localization signal-GFP-LacZ reporter protein, and a fraction of cells had accumulation of poly(A)+ RNA in the nucleus. A consequence of the synthetic lethality between rae1-167 and npp106-1 was the accumulation of poly(A)+ RNA in the nucleus when cells were grown under synthetic lethal conditions. In addition to npp106-1, which is a nonsense mutation that truncates the protein at amino acid 292, the delta npp106 mutation was synthetically lethal with rae1-167, suggesting that the synthetic lethality is a consequence of the loss of a function of npp106. We further demonstrate that a region between amino acids 74 and 348 of Npp106p is required for complementation of the synthetic lethality. These results uncover a potential direct or indirect involvement of Npp106p in mRNA export.

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Subnuclear positioning and interchromosomal clustering of the GAL1-10 locus are controlled by separable, interdependent mechanisms

Molecular Biology of the Cell ◽

10.1091/mbc.e16-03-0174 ◽

2016 ◽

Vol 27 (19) ◽

pp. 2980-2993 ◽

Cited By ~ 22

Author(s):

Donna Garvey Brickner ◽

Varun Sood ◽

Evelina Tutucci ◽

Robert Coukos ◽

Kayla Viets ◽

...

Keyword(s):

Molecular Mechanism ◽

Nuclear Pore Complex ◽

Molecular Mechanisms ◽

Nuclear Periphery ◽

Gene Clustering ◽

Nuclear Pore ◽

Cis Acting ◽

Gene Positioning ◽

Gal Genes ◽

Necessary And Sufficient

On activation, the GAL genes in yeast are targeted to the nuclear periphery through interaction with the nuclear pore complex. Here we identify two cis-acting “DNA zip codes” from the GAL1-10 promoter that are necessary and sufficient to induce repositioning to the nuclear periphery. One of these zip codes, GRS4, is also necessary and sufficient to promote clustering of GAL1-10 alleles. GRS4, and to a lesser extent GRS5, contribute to stronger expression of GAL1 and GAL10 by increasing the fraction of cells that respond to the inducer. The molecular mechanism controlling targeting to the NPC is distinct from the molecular mechanism controlling interchromosomal clustering. Targeting to the nuclear periphery and interaction with the nuclear pore complex are prerequisites for gene clustering. However, once formed, clustering can be maintained in the nucleoplasm, requires distinct nuclear pore proteins, and is regulated differently through the cell cycle. In addition, whereas targeting of genes to the NPC is independent of transcription, interchromosomal clustering requires transcription. These results argue that zip code–dependent gene positioning at the nuclear periphery and interchromosomal clustering represent interdependent phenomena with distinct molecular mechanisms.

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A nuclear envelope protein linking nuclear pore basket assembly, SUMO protease regulation, and mRNA surveillance

The Journal of Cell Biology ◽

10.1083/jcb.200702154 ◽

2007 ◽

Vol 178 (5) ◽

pp. 813-827 ◽

Cited By ~ 71

Author(s):

Alaron Lewis ◽

Rachael Felberbaum ◽

Mark Hochstrasser

Keyword(s):

Nuclear Envelope ◽

Nuclear Pore Complex ◽

Envelope Protein ◽

Mrna Export ◽

Nuclear Periphery ◽

Nuclear Pore ◽

Nucleocytoplasmic Trafficking ◽

Sumo Protease ◽

Mrna Surveillance ◽

Regulatory Event

The nuclear pore complex (NPC) is both the major conduit for nucleocytoplasmic trafficking and a platform for organizing macromolecules at the nuclear envelope. We report that yeast Esc1, a non-NPC nuclear envelope protein, is required both for proper assembly of the nuclear basket, a structure extending into the nucleus from the NPC, and for normal NPC localization of the Ulp1 SUMO protease. In esc1Δ cells, Ulp1 and nuclear basket components Nup60 and Mlp1 no longer distribute broadly around the nuclear periphery, but co-localize in a small number of dense-staining perinuclear foci. Loss of Esc1 (or Nup60) alters SUMO conjugate accumulation and enhances ulp1 mutant defects. Similar to previous findings with Mlp1, both Esc1 and Ulp1 help retain unspliced pre-mRNAs in the nucleus. Therefore, these proteins are essential for proper nuclear basket function, which includes mRNA surveillance and regulation of SUMO protein dynamics. The results raise the possibility that NPC-localized protein desumoylation may be a key regulatory event preventing inappropriate pre-mRNA export.

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