Intermediates in adenovirus assembly

Area of Science:

• Virology
• Molecular Biology
• Cell Biology

Background:

• Adenovirus assembly involves distinct intermediate stages.
• Understanding these intermediates is crucial for deciphering viral replication mechanisms.

Purpose of the Study:

• To characterize the properties and polypeptide composition of three adenovirus assembly intermediates.
• To elucidate the sequential processing of viral proteins during adenovirus assembly.

Main Methods:

• Differential gradient centrifugation (Ficoll and CsCl) to separate intermediates.
• Pulse-chase labeling and tryptic peptide mapping to analyze polypeptide processing.
• Cell fractionation to localize intermediates within cellular compartments.

Main Results:

• Nuclear intermediates are fragile, heterogeneous, and contain precursor polypeptides (pVI, pVII).
• Young virions are stable, nuclear, and contain both precursor and cleaved polypeptides.
• Mature virions are cytoplasmic and contain final mature polypeptides.
• Polypeptide pVI is the precursor to VI; 26K polypeptide partially accounts for VIII.

Conclusions:

• The three defined intermediates represent sequential stages in adenovirus assembly.
• Protein processing and localization changes mark the progression through these assembly stages.
• This provides a framework for understanding adenovirus morphogenesis.