A proteomic analysis of the mammalian nuclear pore complex (NPC) identified 29 nucleoporins and 18 NPC-associated proteins, revealing that the mammalian NPC contains approximately 30 distinct proteins, similar to the yeast NPC. Six previously unknown nucleoporins and a novel family of WD repeat nucleoporins were identified. One of these WD repeat nucleoporins, ALADIN, is linked to triple-A (AAAS) syndrome. The study also identified several NPC-associated proteins, including importin-α1, importin-β1, TAP, and Ran, which are involved in nucleocytoplasmic transport. The NPC is composed of nucleoporins and associated proteins, with nucleoporins forming the structural framework and NPC-associated proteins playing roles in transport and regulation. The vertebrate NPC is larger and more complex than the yeast NPC, with additional domains and specialized functions. The study used mass spectrometry to identify and classify proteins in the NPC, and found that the NPC is composed of a similar number of proteins to the yeast NPC, suggesting conserved functions. The results provide a comprehensive understanding of the NPC's composition and function, paving the way for further research into its structure and role in cellular processes. The study also highlights the importance of WD repeat nucleoporins in NPC function and the potential role of ALADIN in AAAS. The findings contribute to the understanding of NPC structure, function, and evolution, and have implications for the study of nuclear transport and related diseases.A proteomic analysis of the mammalian nuclear pore complex (NPC) identified 29 nucleoporins and 18 NPC-associated proteins, revealing that the mammalian NPC contains approximately 30 distinct proteins, similar to the yeast NPC. Six previously unknown nucleoporins and a novel family of WD repeat nucleoporins were identified. One of these WD repeat nucleoporins, ALADIN, is linked to triple-A (AAAS) syndrome. The study also identified several NPC-associated proteins, including importin-α1, importin-β1, TAP, and Ran, which are involved in nucleocytoplasmic transport. The NPC is composed of nucleoporins and associated proteins, with nucleoporins forming the structural framework and NPC-associated proteins playing roles in transport and regulation. The vertebrate NPC is larger and more complex than the yeast NPC, with additional domains and specialized functions. The study used mass spectrometry to identify and classify proteins in the NPC, and found that the NPC is composed of a similar number of proteins to the yeast NPC, suggesting conserved functions. The results provide a comprehensive understanding of the NPC's composition and function, paving the way for further research into its structure and role in cellular processes. The study also highlights the importance of WD repeat nucleoporins in NPC function and the potential role of ALADIN in AAAS. The findings contribute to the understanding of NPC structure, function, and evolution, and have implications for the study of nuclear transport and related diseases.