The signature organelle of eukaryotic cells is the cell nucleus, which houses the genome and serves as the site of DNA and RNA synthesis, transcription, processing, and repair, as well as ribosome biogenesis. The nucleus is bound by a double membrane called the nuclear envelope (NE). The outer nuclear membrane is continuous with the endoplasmic reticulum, while the inner nuclear membrane is coated with a filamentous meshwork of nucleus-specific proteins, the lamins, held in place by pores and numerous inner nuclear membrane proteins. To ensure a smooth flow from genetic information to cellular function, a major interchange of proteins, nucleic acids and small molecules must take place between the nucleus and the cytoplasm. This communication is mediated by nuclear pore complexes (NPCs), which punctuate the NE at sites where inner and outer nuclear membrane fuse. A failure at any step or intermediary molecule in the flow from gene to protein function can have fatal consequences for normal cellular function and in turn, organismal health.

FEBS Letters proudly presents two new special issues on the NE and NPCs.

The collection entitled Structure and function of the nuclear envelope and nuclear pores, guest-edited by Susan Gasser and Birthe Fahrenkrog, focusses on NPC quality control mechanisms [1-3], and explores how nucleoporins affect gene expression [4], or how nucleoporin mutants can lead to hereditary disorders [5]. In addition, several Reviews discuss how NPCs and the NE (and the lamins in particular) play essential roles in organising the genome inside the nucleus [6-9]. Last but not least, Gasser and Stutz discuss the impact of posttranslational modification by the Small Ubiquitin-related Modifier (SUMO) on DNA repair and transcription, through locus positioning at the NE and NPCs [10].

The Special Issue Biomedical implications of nuclear transport, guest-edited by Nathalie Arhel and Mark Field, explores some of the latest findings and insights into the role of NPCs in essential biological pathways, and the assembly of these fascinating molecular structures. Two Reviews address fundamental concepts of NPC and NE structure and composition throughout eukaryotic evolution, and explain how understanding their function can help unravel specific pathologies [11-12]. Other reviews delve into NPC assembly and explain how defects in NPC assembly or homeostasis can lead to neurodegenerative disease [13-15]. Finally, by providing a magnified view of individual NPCs, Fichtman and Harel showcase recent advances in field emission scanning electron microscopy [16].

FEBS Letters thanks the guest editors for their input and dedication in curating the publication of these two excellent special issues, which offer a comprehensive overview of the roles of the NE and NPCs in health, disease and evolution. We join the editors in inviting the readers to embark on this journey and explore the frontiers of cell biology, where the nucleus and its gatekeepers hold the keys to understanding many aspects of the complexity of life.

References

[1] Penzo, A. & Palancade, B. (2023) Puzzling out nuclear pore complex assembly, FEBS Lett. DOI: 10.1002/1873-3468.14713.

[2]  Boyle, E. & Wilfling, F. (2023) Autophagy as a caretaker of nuclear integrity, FEBS Lett. DOI: 10.1002/1873-3468.14719.

[3]  Veldsink, A. C., Gallardo, P., Lusk, C. P. & Veenhoff, L. M. (2023) Changing the guard-nuclear pore complex quality control, FEBS Lett. DOI: 10.1002/1873-3468.14739.

[4] Capelson, M. (2023) You are who your friends are-nuclear pore proteins as components of chromatin-binding complexes, FEBS Lett. DOI: 10.1002/1873-3468.14728.

[5] Jühlen, R. & Fahrenkrog, B. (2023) From the sideline: tissue-specific nucleoporin function in health and disease, an update, FEBS Lett.

[6] Kiseleva, A. A. & Poleshko, A. (2023) The secret life of chromatin tethers, FEBS Lett. DOI: 10.1002/1873-3468.14685.

[7]  Buxboim, A., Kronenberg-Tenga, R., Salajkova, S., Avidan, N., Shahak, H., Thurston, A. & Medalia, O. (2023) Scaffold, mechanics and functions of nuclear lamins, FEBS Lett. DOI: 10.1002/1873-3468.14750.

[8] Alagna, N.S., Thomas T.I., Wilson K.L. & Reddy, K.L. (2023) Choreography of Lamina Associated Domains: Structure Meets Dynamics, FEBS Lett.

[9]  King, M. C. (2023) Dynamic regulation of LINC complex composition and function across tissues and contexts, FEBS Lett. DOI: 10.1002/1873-3468.14757.

[10]  Gasser, S. M. & Stutz, F. (2023) SUMO in the regulation of DNA repair and transcription at nuclear pores, FEBS Lett. DOI: 10.1002/1873-3468.14751.

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[16] Fichtman B and Harel A (2023) The magnified view:from ancient trinkets to single nuclear pore complexes.FEBS Lett597, 2590–2596