bims-nucpor 2021-12-12 papers

Issue of 2021–12–12
four papers selected by
Sara Mingu, Johannes Gutenberg University

J Cell Biol. 2022 Feb 07. pii: e202101049. [Epub ahead of print]221(2):

Reticulon-like REEP4 at the inner nuclear membrane promotes nuclear pore complex formation.

Banafsheh Golchoubian, Andreas Brunner, Helena Bragulat-Teixidor, Annett Neuner, Busra A Akarlar, Nurhan Ozlu, Anne-Lore Schlaitz.

Nuclear pore complexes (NPCs) are channels within the nuclear envelope that mediate nucleocytoplasmic transport. NPCs form within the closed nuclear envelope during interphase or assemble concomitantly with nuclear envelope reformation in late stages of mitosis. Both interphase and mitotic NPC biogenesis require coordination of protein complex assembly and membrane deformation. During early stages of mitotic NPC assembly, a seed for new NPCs is established on chromatin, yet the factors connecting the NPC seed to the membrane of the forming nuclear envelope are unknown. Here, we report that the reticulon homology domain protein REEP4 not only localizes to high-curvature membrane of the cytoplasmic endoplasmic reticulum but is also recruited to the inner nuclear membrane by the NPC biogenesis factor ELYS. This ELYS-recruited pool of REEP4 promotes NPC assembly and appears to be particularly important for NPC formation during mitosis. These findings suggest a role for REEP4 in coordinating nuclear envelope reformation with mitotic NPC biogenesis.

DOI: https://doi.org/10.1083/jcb.202101049

BMC Genomics. 2021 Dec 05. 22(1): 876

Nuclear transport genes recurrently duplicate by means of RNA intermediates in Drosophila but not in other insects.

Ayda Mirsalehi, Dragomira N Markova, Mohammadmehdi Eslamieh, Esther Betrán.

BACKGROUND: The nuclear transport machinery is involved in a well-known male meiotic drive system in Drosophila. Fast gene evolution and gene duplications have been major underlying mechanisms in the evolution of meiotic drive systems, and this might include some nuclear transport genes in Drosophila. So, using a comprehensive, detailed phylogenomic study, we examined 51 insect genomes for the duplication of the same nuclear transport genes.
RESULTS: We find that most of the nuclear transport duplications in Drosophila are of a few classes of nuclear transport genes, RNA mediated and fast evolving. We also retrieve many pseudogenes for the Ran gene. Some of the duplicates are relatively young and likely contributing to the turnover expected for genes under strong but changing selective pressures. These duplications are potentially revealing what features of nuclear transport are under selection. Unlike in flies, we find only a few duplications when we study the Drosophila duplicated nuclear transport genes in dipteran species outside of Drosophila, and none in other insects.
CONCLUSIONS: These findings strengthen the hypothesis that nuclear transport gene duplicates in Drosophila evolve either as drivers or suppressors of meiotic drive systems or as other male-specific adaptations circumscribed to flies and involving a handful of nuclear transport functions.

Keywords: Drosophila; Gene turnover; Genetic conflict; Nuclear transport; Recurrent gene duplication

DOI: https://doi.org/10.1186/s12864-021-08170-4

Sci Rep. 2021 Dec 08. 11(1): 23586

Nuclear Transport Factor 2 (NTF2) suppresses WM983B metastatic melanoma by modifying cell migration, metastasis, and gene expression.

Lidija D Vuković, Pan Chen, Sampada Mishra, Karen H White, Jason P Gigley, Daniel L Levy.

While changes in nuclear structure and organization are frequently observed in cancer cells, relatively little is known about how nuclear architecture impacts cancer progression and pathology. To begin to address this question, we studied Nuclear Transport Factor 2 (NTF2) because its levels decrease during melanoma progression. We show that increasing NTF2 expression in WM983B metastatic melanoma cells reduces cell proliferation and motility while increasing apoptosis. We also demonstrate that increasing NTF2 expression in these cells significantly inhibits metastasis and prolongs survival of mice. NTF2 levels affect the expression and nuclear positioning of a number of genes associated with cell proliferation and migration, and increasing NTF2 expression leads to changes in nuclear size, nuclear lamin A levels, and chromatin organization. Thus, ectopic expression of NTF2 in WM983B metastatic melanoma abrogates phenotypes associated with advanced stage cancer both in vitro and in vivo, concomitantly altering nuclear and chromatin structure and generating a gene expression profile with characteristics of primary melanoma. We propose that NTF2 is a melanoma tumor suppressor and could be a novel therapeutic target to improve health outcomes of melanoma patients.

DOI: https://doi.org/10.1038/s41598-021-02803-0