Despite extensive data demonstrating that immature retroviral particle assembly can take place either at the plasma membrane or at a distinct location within the cytoplasm, targeting of viral precursor proteins to either assembly site still remains poorly understood. Biochemical data presented here suggest that Tctex-1, a light chain of the molecular motor dynein, is involved in the intracellular targeting of Mason-Pfizer monkey virus (M-PMV) polyproteins to the cytoplasmic assembly site. Comparison of the three-dimensional structures of M-PMV wild-type matrix protein (wt MA) with a single amino acid mutant (R55F), which redirects assembly from a cytoplasmic site to the plasma membrane, revealed different mutual orientations of their C- and N-terminal domains. This conformational change buries a putative intracellular targeting motif located between both domains in the hydrophobic pocket of the MA molecule, thereby preventing the interaction with cellular transport mechanisms.

• MeSH
• Models, Biological MeSH
• Biological Transport MeSH
• Cell Membrane metabolism   virology   MeSH
• Chlorocebus aethiops MeSH
• COS Cells MeSH
• Cytoplasm metabolism   MeSH
• Dyneins metabolism   MeSH
• Phenotype MeSH
• t-Complex Genome Region MeSH
• Nuclear Proteins chemistry   metabolism   physiology   MeSH
• Humans MeSH
• Mason-Pfizer monkey virus metabolism   MeSH
• Mutation MeSH
• Microtubule-Associated Proteins chemistry   metabolism   physiology   MeSH
• Retroviridae metabolism   MeSH
• Protein Structure, Tertiary MeSH
• Binding Sites MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Dyneins MeSH
• Nuclear Proteins MeSH
• Microtubule-Associated Proteins MeSH