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Structural changes in human cytomegalovirus cytoplasmic assembly sites in the absence of UL97 kinase activity

Maysa Azzeh1, Alik Honigman, Albert Taraboulos

  • 1Department of Clinical Microbiology and Infectious Diseases, Hadassah University Hospital, Jerusalem, Israel 91120.

Virology
|July 29, 2006
PubMed

Insights

Human cytomegalovirus (HCMV) UL97 kinase is crucial for viral assembly. Its absence alters viral protein distribution and Golgi remodeling, impacting cytoplasmic assembly sites.

Area of Science:

  • Virology
  • Molecular Biology
  • Cell Biology

Background:

  • Human cytomegalovirus (HCMV) UL97 kinase plays a known role in viral DNA replication, capsid maturation, and nuclear egress.
  • The precise function of UL97 kinase in the cytoplasmic assembly stages of HCMV remains largely uncharacterized.

Purpose of the Study:

  • To investigate the role of HCMV UL97 kinase activity in the cytoplasmic assembly of viral particles.
  • To determine how the absence of UL97 kinase affects the subcellular localization of viral structural proteins and cellular organelles.

Main Methods:

  • Utilized a human cytomegalovirus (HCMV) UL97 kinase deletion mutant (DeltaUL97) and a specific UL97 kinase inhibitor (NGIC-I).
  • Analyzed the subcellular distribution of viral structural proteins using microscopy.
  • Assessed the reorganization of Golgi-related structures (WGA-positive) and nuclear architecture during infection.

Main Results:

  • Absence of UL97 kinase activity led to diffuse perinuclear distribution of viral assembly sites, unlike the compact nuclear-associated structures seen in wild-type infections.
  • Large vacuoles were observed within the modified assembly sites in DeltaUL97 infections.
  • Both wild-type and DeltaUL97 HCMV infections induced significant reorganization of Golgi-related structures, but this remodeling was notably altered in the absence of UL97 kinase activity.

Conclusions:

  • HCMV UL97 kinase activity is implicated in organizing viral cytoplasmic assembly sites.
  • UL97 kinase influences the subcellular localization of viral components and contributes to the remodeling of host cell organelles during viral assembly.

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