Protection against fatal Sindbis virus encephalitis by beclin, a novel Bcl-2-interacting protein.
bcl-2, the prototypic cellular antiapoptotic gene, decreases Sindbis virus replication and Sindbis virus-induced apoptosis in mouse brains, resulting in protection against lethal encephalitis. To investigate potential mechanisms by which Bcl-2 protects against central nervous system Sindbis virus infection, we performed a yeast two-hybrid screen to identify Bcl-2-interacting gene products in an adult mouse brain library. We identified a novel 60-kDa coiled-coil protein, Beclin, which we confirmed interacts with Bcl-2 in mammalian cells, using fluorescence resonance energy transfer microscopy. To examine the role of Beclin in Sindbis virus pathogenesis, we constructed recombinant Sindbis virus chimeras that express full-length human Beclin (SIN/beclin), Beclin lacking the putative Bcl-2-binding domain (SIN/beclinDeltaBcl-2BD), or Beclin containing a premature stop codon near the 5' terminus (SIN/beclinstop). The survival of mice infected with SIN/beclin was significantly higher (71%) than the survival of mice infected with SIN/beclinDeltaBcl-2BD (9%) or SIN/beclinstop (7%) (P < 0.001). The brains of mice infected with SIN/beclin had fewer Sindbis virus RNA-positive cells, fewer apoptotic cells, and lower viral titers than the brains of mice infected with SIN/beclinDeltaBcl-2BD or SIN/beclinstop. These findings demonstrate that Beclin is a novel Bcl-2-interacting cellular protein that may play a role in antiviral host defense.
Liang
X H
XH
Departments of Medicine, Columbia University College of Physicians and Surgeons, New York, New York 10032, USA.
Kleeman
L K
LK
Jiang
H H
HH
Gordon
G
G
Goldman
J E
JE
Berry
G
G
Herman
B
B
Levine
B
B
D018354:Alphavirus Infections / Q000209:etiology / Q000517:prevention & control*; D000595:Amino Acid Sequence; D000818:Animals; D000998:Antiviral Agents / Q000737:chemistry / Q000235:genetics / Q000502:physiology; D017209:Apoptosis / Q000235:genetics; D051017:Apoptosis Regulatory Proteins; D000071186:Beclin-1; D002886:Chromosomes, Human, Pair 17 / Q000235:genetics; D018792:Encephalitis, Viral / Q000209:etiology / Q000517:prevention & control*; D005260:Female; D019254:Genes, bcl-2; D006801:Humans; D008297:Male; D008565:Membrane Proteins; D051379:Mice; D008969:Molecular Sequence Data; D009154:Mutation; D011506:Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000502:physiology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics; D012845:Sindbis Virus / Q000187:drug effects* / Q000472:pathogenicity / Q000502:physiology; D014018:Tissue Distribution; D014774:Virulence; D014779:Virus Replication
D000998:Antiviral Agents; D051017:Apoptosis Regulatory Proteins; C491997:BECN1 protein, human; D000071186:Beclin-1; C115010:Becn1 protein, mouse; D008565:Membrane Proteins; D011506:Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger