Nuclear Pore Markers

Nuclear pore complexes (NPCs) are huge, multiprotein structures that stud the nuclear envelope and regulate the exchange of materials between the nucleus and cytoplasm. They are some of the largest protein assemblies found in eukaryotic cells, comprising over 500 individual proteins in Saccharomyces cerevisiae and 1,000 proteins in human cells. NPCs form a selective channel through the double layer of the nuclear envelope, compartmentalizing the genome within the nuclear interior and physically separating the processes of transcription and translation. The outer diameter of NPCs ranges from 120–130 nm, while the central channel has a diameter of 40–60 nm. NPCs feature a distinctive 8-fold rotational symmetry and consist of three layers of concentric rings: a cytoplasmic-facing ring with associated cytoplasmic filaments, the central channel and scaffold, and the nuclear ring with associated nuclear basket. These structures are made up of a family of proteins called nucleoporins (NUPs), of which dozens have been identified. The cytoplasmic ring and nuclear ring are based on multiprotein structures called Y complexes, which resemble the English alphabet letter ‘Y’. The complex is composed of a conserved set of proteins – in yeast, these include Nup84, Nup85, Nup120, Seh1, and others. A heterotrimer of Nups (in yeast, Nup49, Nup57, and Nsp1) forms the selective transport channel at the heart of NPCs. These proteins prominently feature intrinsically disordered domains, rich in phenylalanine-glycine (FG) repeats, that face into the channel. They are involved in determining the size, shape, charge, and directionality of molecules destined for transport through the NPC. While molecules less than 40 kDa can diffuse freely through the NPC, larger materials are actively shepherded through the central pore by nuclear transport receptors – including karyopherins and NTF2 proteins – which rely on the small GTPase Ran. The de novo assembly of NPCs in mitotic cells is an area of extensive research. At the end of mitosis, interactions between NUPs and the newly forming nuclear envelope initiate NPC formation. NPCs are extruded through the nuclear envelope from the nuclear interior. As a result, channel formation requires fusion between the inner and outer nuclear membranes. In addition to regulating nuclear transport, NPCs have been implicated in mitosis, gene expression, chromatin organization, and DNA repair. Mutations in nucleoporins have been linked to various diseases such as cancer, neurodegenerative diseases, and developmental disorders. We offer a range of nuclear pore markers including NUP98 antibodies that are validated for multiple applications including western blotting (WB), immunocytochemistry (ICC), immunohistochemistry (IHC), and enzyme-linked immunosorbent assay (ELISA).