NUP - nucleoporin | Elisa - Clia - Antibody - Protein

Background

Nucleoporins (NUPs) are a family of proteins that constitute the nuclear pore complex (NPC), a crucial structure embedded in the nuclear envelope. The NPC regulates the bidirectional transport of macromolecules between the nucleus and the cytoplasm, maintaining cellular function and homeostasis. Each NPC is composed of multiple copies of approximately 30 different NUPs, forming a symmetric structure with distinct components such as the cytoplasmic filaments, the central channel, and the nuclear basket. NUPs are highly conserved across eukaryotes, indicating their fundamental role in cellular processes. The dysfunction of NUPs can lead to severe consequences, including diseases such as cancer and various genetic disorders.

Protein Structure

• General Features: NUPs typically possess structural motifs such as the phenylalanine-glycine (FG) repeats, coiled-coil domains, and β-propeller structures.
• Key NUPs: Examples include NUP62, NUP98, and NUP214, each contributing specific structural and functional roles within the NPC.
• FG Repeats: These regions are critical for selective permeability and interaction with transport receptors.
• Structural Domains: NUPs often have α-helical and β-sheet regions, providing stability and facilitating interactions with other proteins and nucleic acids.

Classification and Subtypes

NUPs can be classified based on their localization within the NPC and their structural features:

• Core Scaffold NUPs: Form the structural backbone of the NPC (e.g., NUP133, NUP107).
• Peripheral NUPs: Include cytoplasmic filaments and nuclear basket components (e.g., NUP214, NUP153).
• Transport NUPs: Involved in the selective transport mechanism (e.g., NUP98, NUP62).

Function and Biological Significance

• Nuclear-Cytoplasmic Transport: NUPs facilitate the transport of proteins, RNAs, and ribonucleoprotein complexes through the NPC.
• Regulation of Gene Expression: Some NUPs are involved in chromatin organization and gene expression regulation.
• Cell Cycle Progression: NUPs play roles in mitosis by ensuring proper nuclear envelope breakdown and reassembly.
• Signal Transduction: NUPs are involved in signaling pathways by regulating the localization and function of signaling molecules.

Clinical Issues

• NUP-Related Diseases: Mutations and alterations in NUPs are linked to various diseases:
• Cancer: NUP98 fusion proteins are associated with acute myeloid leukemia (AML).
• Neurological Disorders: Defects in NUPs can result in neurodevelopmental and neurodegenerative diseases.
• Autoimmune Diseases: Certain autoimmune conditions are associated with the presence of autoantibodies against NUPs.

Summary

Nucleoporins are integral components of the nuclear pore complex, essential for the regulation of nucleocytoplasmic transport. Their diverse structural motifs and specific localization within the NPC contribute to their multifunctional roles in cellular processes such as gene expression, cell cycle regulation, and signal transduction. Disruptions in NUP function can lead to various diseases, including cancer and neurological disorders, highlighting their importance in maintaining cellular homeostasis and health. Research into NUPs continues to provide insights into their complex roles and mechanisms, paving the way for potential therapeutic interventions in NUP-related diseases.