Intracellular structure and nucleocytoplasmic transport

Area of Science:

• Cell biology
• Molecular transport mechanisms

Background:

• Intracellular movement follows solution-phase (diffusionist) or solid-state interaction schemes.
• Nucleocytoplasmic transport involves pore complexes, nucleoskeleton, and cytoskeleton.

Purpose of the Study:

• To evaluate the dominant mechanisms of nucleocytoplasmic transport.
• To assess the roles of the nucleoskeleton and cytoskeleton in macromolecular transport.
• To explore solid-state mechanisms for mRNA transport.

Main Methods:

• Review and evaluation of existing evidence on intracellular transport.
• Comparative analysis of diffusionist and solid-state models.
• Examination of data on viral protein effects on RNA processing and migration.

Main Results:

• The balance of evidence favors solid-state mechanisms for nucleocytoplasmic transport.
• Ribosomal subunits likely migrate via solid-state pathways, unlike proteins and tRNAs.
• Recent data support solid-state models, particularly concerning viral protein impacts on RNA.

Conclusions:

• Solid-state models provide a better explanation for observed intracellular movements than diffusion alone.
• Diffusion theory, even enhanced computationally, is insufficient to explain cellular material transport.
• Nucleocytoplasmic transport likely involves solid-state interactions, highlighting the importance of the nucleoskeleton and cytoskeleton.