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APOBEC-1 and AID are nucleo-cytoplasmic trafficking proteins but APOBEC3G cannot traffic

Ryan P Bennett1, Elie Diner, Mark P Sowden

  • 1Department of Biochemistry, Box 712, University of Rochester, 601 Elmwood Avenue, Rochester, NY 14642, USA.

Biochemical and Biophysical Research Communications
|September 27, 2006
PubMed

Insights

Human APOBEC3G (hA3G) acts as an antiviral factor against HIV-1 by mutating viral DNA. This study reveals hA3G is retained in the cytoplasm, unlike related proteins, via its N and C-terminal regions.

Area of Science:

  • Biochemistry
  • Virology
  • Molecular Biology

Background:

  • Human APOBEC3G (hA3G) is a cytidine deaminase involved in innate immunity.
  • hA3G defends against retrotransposons and viruses like HIV-1 by deaminating viral DNA.
  • Its cellular localization and function compared to related proteins are not fully understood.

Purpose of the Study:

  • To investigate the cellular localization and retention mechanisms of human APOBEC3G (hA3G).
  • To determine if hA3G exhibits nucleo-cytoplasmic shuttling.
  • To elucidate the role of hA3G's N and C-terminal regions in its localization.

Main Methods:

  • Cellular localization studies of hA3G.
  • Analysis of hA3G's interaction with cellular compartments.
  • Investigating the contribution of N and C-terminal regions to hA3G localization.

Main Results:

  • hA3G mutagenic activity is restricted to the cytoplasm.
  • hA3G is not a nucleo-cytoplasmic shuttling protein.
  • Both N and C-terminal regions of hA3G are involved in its cytoplasmic retention.

Conclusions:

  • hA3G's antiviral activity against HIV-1 is cytoplasmically localized.
  • hA3G's subcellular localization is actively regulated, preventing nuclear entry.
  • The N and C-terminal regions are critical for maintaining hA3G in the cytoplasm.

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