Murine cytomegalovirus US22 protein pM140 protects its binding partner, pM141, from proteasome-dependent but ubiquitin-independent degradation

J Virol. 2010 Feb;84(4):2164-8. doi: 10.1128/JVI.01739-09. Epub 2009 Dec 2.


Stable assembly of murine cytomegalovirus (MCMV) virions in differentiated macrophages is dependent upon the expression of US22 family gene M140. The M140 protein (pM140) exists in complex with products of neighboring US22 genes. Here we report that pM140 protects its binding partner, pM141, from ubiquitin-independent proteasomal degradation. Protection is conferred by a stabilization domain mapping to amino acids 306 to 380 within pM140, and this domain is functionally independent from the region that confers binding of pM140 to pM141. The M140 protein thus contains multiple domains that collectively confer a structure necessary to function in virion assembly in macrophages.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Autophagy
  • Genes, Viral
  • Mice
  • Multiprotein Complexes
  • Muromegalovirus / genetics
  • Muromegalovirus / metabolism*
  • Muromegalovirus / physiology
  • NIH 3T3 Cells
  • Proteasome Endopeptidase Complex / metabolism
  • Protein Binding
  • Protein Stability
  • Protein Structure, Tertiary
  • Ubiquitin / metabolism
  • Viral Proteins / chemistry
  • Viral Proteins / genetics
  • Viral Proteins / metabolism*
  • Virus Assembly


  • Multiprotein Complexes
  • Ubiquitin
  • Viral Proteins
  • Proteasome Endopeptidase Complex