title: The cellular source for APOBEC3G's incorporation into HIV-1.
abstract: BACKGROUND
  Human APOBEC3G (hA3G) has been identified as a cellular inhibitor of HIV-1 infectivity. Viral incorporation of hA3G is an essential step for its antiviral activity. Although the mechanism underlying hA3G virion encapsidation has been investigated extensively, the cellular source of viral hA3G remains unclear.
  
  
  RESULTS
  Previous studies have shown that hA3G forms low-molecular-mass (LMM) and high-molecular-mass (HMM) complexes. Our work herein provides evidence that the majority of newly-synthesized hA3G interacts with membrane lipid raft domains to form Lipid raft-associated hA3G (RA hA3G), which serve as the precursor of the mature HMM hA3G complex, while a minority of newly-synthesized hA3G remains in the cytoplasm as a soluble LMM form. The distribution of hA3G among the soluble LMM form, the RA LMM form and the mature forms of HMM is regulated by a mechanism involving the N-terminal part of the linker region and the C-terminus of hA3G. Mutagenesis studies reveal a direct correlation between the ability of hA3G to form the RA LMM complex and its viral incorporation.
  
  
  CONCLUSIONS
  Together these data suggest that the Lipid raft-associated LMM A3G complex functions as the cellular source of viral hA3G.
authors.affiliation: Institute of Medicinal Biotechnology, Chinese Academy of Medical Science, Beijing, PR China.
authors.forename: Jing
authors.initials: J
authors.lastname: Ma
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Li
authors.forename: Jian
authors.initials: J
authors.lastname: Xu
authors.forename: Quan
authors.initials: Q
authors.lastname: Zhang
authors.forename: Zhenlong
authors.initials: Z
authors.lastname: Liu
authors.forename: Pingping
authors.initials: P
authors.lastname: Jia
authors.forename: Jinming
authors.initials: J
authors.lastname: Zhou
authors.forename: Fei
authors.initials: F
authors.lastname: Guo
authors.forename: Xuefu
authors.initials: X
authors.lastname: You
authors.forename: Liyan
authors.initials: L
authors.lastname: Yu
authors.forename: Lixun
authors.initials: L
authors.lastname: Zhao
authors.forename: Jiandong
authors.initials: J
authors.lastname: Jiang
authors.forename: Shan
authors.initials: S
authors.lastname: Cen
mesh_terms: D000071480:APOBEC-3G Deaminase; D003564:Cytidine Deaminase / Q000235:genetics / Q000378:metabolism*; D015497:HIV-1 / Q000502:physiology*; D006801:Humans; D016296:Mutagenesis; D050505:Mutant Proteins / Q000235:genetics / Q000378:metabolism; D019065:Virus Assembly
chemical_list: D050505:Mutant Proteins; D000071480:APOBEC-3G Deaminase; C464924:APOBEC3G protein, human; D003564:Cytidine Deaminase