Herpes simplex virus encodes a virion-associated protein which promotes long cellular processes in over-expressing cells

Genes Cells. 2001 Nov;6(11):955-66. doi: 10.1046/j.1365-2443.2001.00475.x.


Background: Herpes simplex virus (HSV) possesses a number of accessory genes which are dispensable for replication in cell culture. A previous study showed that the UL21 gene product of HSV type 1 is a virion component that is not necessary for viral replication. The function of the gene product remains unknown.

Results: We found that the HSV-1 UL21 gene product, a capsid-associated tegument protein with an apparent molecular mass of 62 kDa, promotes the outgrowth of long cellular processes when it is over-expressed in non-neural cells. The UL21 protein co-localizes and physically associates with microtubules in the long processes. Analysis using mutant proteins implicates a proline-rich region in promotion of the processes.

Conclusions: The results suggest that the UL21 protein, like tau and other MAPs, promotes the process by directly or indirectly interacting with microtubules and facilitates the intracellular transport of the virus.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • Blotting, Western
  • Capsid
  • DNA Primers
  • Fluorescent Antibody Technique
  • Immune Sera
  • Molecular Sequence Data
  • Mutation
  • Precipitin Tests
  • Sequence Homology, Amino Acid
  • Simplexvirus / genetics*
  • Transfection
  • Viral Proteins / chemistry
  • Viral Proteins / genetics*
  • Viral Proteins / immunology
  • Viral Proteins / physiology*
  • Virion / genetics*


  • DNA Primers
  • Immune Sera
  • Viral Proteins
  • UL21 protein, herpes simplex virus 1