Faculty Opinions recommendation of Sus1, Cdc31, and the Sac3 CID region form a conserved interaction platform that promotes nuclear pore association and mRNA export.

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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Quantifying tagged mRNA export flux via nuclear pore complexes in single live cells

Biochemical and Biophysical Research Communications ◽

10.1016/j.bbrc.2021.01.049 ◽

2021 ◽

Vol 545 ◽

pp. 138-144

Author(s):

Yueyue Jing ◽

Yilin Lv ◽

Jingya Ye ◽

Longfang Yao ◽

Liwen Chen ◽

...

Keyword(s):

Mrna Export ◽

Live Cells ◽

Nuclear Pore ◽

Nuclear Pore Complexes ◽

Export Flux ◽

Pore Complexes

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A role for Gle1, a regulator of DEAD-box RNA helicases, at centrosomes and basal bodies

Molecular Biology of the Cell ◽

10.1091/mbc.e16-09-0675 ◽

2017 ◽

Vol 28 (1) ◽

pp. 120-127 ◽

Cited By ~ 23

Author(s):

Li-En Jao ◽

Abdalla Akef ◽

Susan R. Wente

Keyword(s):

Mrna Export ◽

Nuclear Pore ◽

Nuclear Pore Complexes ◽

Rna Helicases ◽

Microtubule Organization ◽

Developmental Defects ◽

Dead Box ◽

Pericentriolar Material ◽

Pore Complexes ◽

And Function

Control of organellar assembly and function is critical to eukaryotic homeostasis and survival. Gle1 is a highly conserved regulator of RNA-dependent DEAD-box ATPase proteins, with critical roles in both mRNA export and translation. In addition to its well-defined interaction with nuclear pore complexes, here we find that Gle1 is enriched at the centrosome and basal body. Gle1 assembles into the toroid-shaped pericentriolar material around the mother centriole. Reduced Gle1 levels are correlated with decreased pericentrin localization at the centrosome and microtubule organization defects. Of importance, these alterations in centrosome integrity do not result from loss of mRNA export. Examination of the Kupffer’s vesicle in Gle1-depleted zebrafish revealed compromised ciliary beating and developmental defects. We propose that Gle1 assembly into the pericentriolar material positions the DEAD-box protein regulator to function in localized mRNA metabolism required for proper centrosome function.

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An agent-based model for mRNA export through the nuclear pore complex

Molecular Biology of the Cell ◽

10.1091/mbc.e14-06-1065 ◽

2014 ◽

Vol 25 (22) ◽

pp. 3643-3653 ◽

Cited By ~ 16

Author(s):

Mohammad Azimi ◽

Evgeny Bulat ◽

Karsten Weis ◽

Mohammad R. K. Mofrad

Keyword(s):

Nuclear Pore Complex ◽

Mrna Export ◽

Nuclear Pore ◽

Central Channel ◽

Agent Based Model ◽

Agent Based ◽

Transport Dynamics ◽

Rate Limiting Step ◽

Limiting Step ◽

Rate Limiting

mRNA export from the nucleus is an essential step in the expression of every protein- coding gene in eukaryotes, but many aspects of this process remain poorly understood. The density of export receptors that must bind an mRNA to ensure export, as well as how receptor distribution affects transport dynamics, is not known. It is also unclear whether the rate-limiting step for transport occurs at the nuclear basket, in the central channel, or on the cytoplasmic face of the nuclear pore complex. Using previously published biophysical and biochemical parameters of mRNA export, we implemented a three-dimensional, coarse-grained, agent-based model of mRNA export in the nanosecond regime to gain insight into these issues. On running the model, we observed that mRNA export is sensitive to the number and distribution of transport receptors coating the mRNA and that there is a rate-limiting step in the nuclear basket that is potentially associated with the mRNA reconfiguring itself to thread into the central channel. Of note, our results also suggest that using a single location-monitoring mRNA label may be insufficient to correctly capture the time regime of mRNA threading through the pore and subsequent transport. This has implications for future experimental design to study mRNA transport dynamics.

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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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