Nucleocytoplasmic transport: cargo trafficking across the border

Area of Science:

• Molecular Biology
• Cell Biology
• Biochemistry

Background:

• Nuclear transport is essential for cellular function, involving the movement of molecules between the cytoplasm and nucleus.
• This process is mediated by specific transport receptors that interact with the nuclear pore complex (NPC).
• Key transport receptor families include importin-beta, Mex67/Tap, and nuclear transport factor 2 (NFT2).

Purpose of the Study:

• To elucidate the mechanisms of macromolecule transport between the cytoplasm and nucleus.
• To investigate the interactions between nuclear transport factors and the nuclear pore complex.
• To understand the regulation of RNA export and its coupling with processing.

Main Methods:

• Kinetic and structural analyses of transport receptor-NPC interactions.
• Biochemical and genetic studies of RNA export pathways.
• Investigation of phenylalanine/glycine-rich NPC components.

Main Results:

• Identified three main classes of soluble transport receptors: importin-beta family, Mex67/Tap family, and NFT2.
• Demonstrated bidirectional traversal of the nuclear pore complex by transport factors via interactions with FG-rich NPC components.
• Revealed novel insights into the details of these molecular interactions through kinetic and structural studies.
• Advanced understanding of mRNA and ribosomal RNA export, highlighting a strong link between RNA processing and transport.

Conclusions:

• Nuclear transport is a complex process mediated by distinct receptor families interacting with the NPC.
• Detailed understanding of these interactions and RNA export mechanisms has been significantly advanced.
• A tight coupling exists between RNA processing and its subsequent transport out of the nucleus.