Evolution and diversification of the nuclear envelope

Eukaryotic cells arose similar to 1.5 billion years ago, with the endomembrane system a central feature, facilitating evolution of intracellular compartments. Endomembranes include the nuclear envelope (NE) dividing the cytoplasm and nucleoplasm. The NE possesses universal features: a double lipid bilayer membrane, nuclear pore complexes (NPCs), and continuity with the endoplasmic reticulum, indicating common evolutionary origin. However, levels of specialization between lineages remains unclear, despite distinct mechanisms underpinning various nuclear activities. Several distinct modes of molecular evolution facilitate organellar diversification and to understand which apply to the NE, we exploited proteomic datasets of purified nuclear envelopes from model systems for comparative analysis. We find enrichment of core nuclear functions amongst the widely conserved proteins to be less numerous than lineage-specific cohorts, but enriched in core nuclear functions. This, together with consideration of additional evidence, suggests that, despite a common origin, the NE has evolved as a highly diverse organelle with significant lineage-specific functionality.

Automated summary

Eukaryotic cells originated around 1.5 billion years ago, with the endomembrane system playing a central role in intracellular evolution. The nuclear envelope, with its universal features such as nuclear pore complexes and double lipid bilayer membrane, shows significant lineage-specific functionality despite a common evolutionary origin. Proteomic analysis of purified nuclear envelopes from model systems reveals a diversity in core nuclear functions across different lineages, indicating the evolution of the nuclear envelope as a highly diverse organelle.