Fission yeast essential nuclear pore protein Nup211 regulates the expression of genes involved in cytokinesis.

Nuclear pore proteins control nucleocytoplasmic transport; however, certain nucleoporins play regulatory roles in activities such as transcription and chromatin organization. The fission yeast basket nucleoporin Nup211 is implicated in mRNA export and is essential for cell viability. Nup211 preferentially associates with heterochromatin, however, it is unclear whether it plays a role in regulating transcription.

Influenza virus mRNAs encode determinants for nuclear export via the cellular TREX-2 complex.

Nuclear export of influenza A virus (IAV) mRNAs occurs through the nuclear pore complex (NPC). Using the Auxin-Induced Degron (AID) system to rapidly degrade proteins, we show that among the nucleoporins localized at the nucleoplasmic side of the NPC, TPR is the key nucleoporin required for nuclear export of influenza virus mRNAs. TPR recruits the TRanscription and EXport complex (TREX)-2 to the NPC for exporting a subset of cellular mRNAs.

Nsp1 protein of SARS-CoV-2 disrupts the mRNA export machinery to inhibit host gene expression.

The ongoing unprecedented severe acute respiratory syndrome caused by the SARS-CoV-2 outbreak worldwide has highlighted the need for understanding viral-host interactions involved in mechanisms of virulence. Here, we show that the virulence factor Nsp1 protein of SARS-CoV-2 interacts with the host messenger RNA (mRNA) export receptor heterodimer NXF1-NXT1, which is responsible for nuclear export of cellular mRNAs. Nsp1 prevents proper binding of NXF1 to mRNA export adaptors and NXF1 docking at the nuclear pore complex.

The novel interaction between microspherule protein Msp58 and ubiquitin E3 ligase EDD regulates cell cycle progression.

Microspherule protein Msp58 (or MCRS1) plays a role in numerous cellular processes including transcriptional regulation and cell proliferation. It is not well understood either how Msp58 mediates its myriad functions or how it is itself regulated. Here, by immunoprecipitation, we identify EDD (E3 identified by differential display) as a novel Msp58-interacting protein.

Ultrastructural nuclear import assay.

Electron microscopy (EM) has been used for several decades to study the mechanisms of nuclear transport. In early studies of nuclear import, gold-conjugated nuclear proteins were microinjected into cells and followed by EM. As the components of the nuclear pore complex (NPC) and soluble mediators of nuclear import were cloned and characterized, gold-conjugated antibodies were utilized to sublocalize the components of the nuclear transport machinery by immuno-EM.

Carrier-independent nuclear import of the transcription factor PU.1 via RanGTP-stimulated binding to Nup153.

PU.1 is a transcription factor of the Ets family with important functions in hematopoietic cell differentiation. Using green fluorescent protein-PU.

Depletion of a single nucleoporin, Nup107, prevents the assembly of a subset of nucleoporins into the nuclear pore complex.

The nuclear pore complex (NPC) is a protein assembly that contains several distinct subcomplexes. The mammalian nucleoporin (Nup)-107 is part of a hetero-oligomeric complex, that also contains Nup160, Nup133, Nup96, and the mammalian homolog of yeast Sec13p. We used transfection of HeLa cells with small interfering RNAs to specifically deplete mRNA for Nup107.