Role of Kaposi's sarcoma-associated herpesvirus C-terminal LANA chromosome binding in episome persistence.
Kaposi's sarcoma-associated herpesvirus (KSHV) LANA is an 1,162-amino-acid protein that tethers terminal repeat (TR) DNA to mitotic chromosomes to mediate episome persistence in dividing cells. C-terminal LANA self-associates to bind TR DNA. LANA contains independent N- and C-terminal chromosome binding regions. N-terminal LANA binds histones H2A/H2B to attach to chromosomes, and this binding is essential for episome persistence. We now investigate the role of C-terminal chromosome binding in LANA function. Alanine substitutions for LANA residues (1068)LKK(1070) and (1125)SHP(1127) severely impaired chromosome binding but did not reduce the other C-terminal LANA functions of self-association or DNA binding. The (1068)LKK(1070) and (1125)SHP(1127) substitutions did not reduce LANA's inhibition of RB1-induced growth arrest, transactivation of the CDK2 promoter, or C-terminal LANA's inhibition of p53 activation of the BAX promoter. When N-terminal LANA was wild type, the (1068)LKK(1070) and (1125)SHP(1127) substitutions also did not reduce LANA chromosome association or episome persistence. However, when N-terminal LANA binding to chromosomes was modestly diminished, the substitutions in (1068)LKK(1070) and (1125)SHP(1127) dramatically reduced both LANA chromosome association and episome persistence. These data suggest a model in which N- and C-terminal LANA cooperatively associates with chromosomes to mediate full-length LANA chromosome binding and viral persistence.
Kelley-Clarke
Brenna
B
Departments of Medicine, Channing Laboratory, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA.
De Leon-Vazquez
Erika
E
Slain
Katherine
K
Barbera
Andrew J
AJ
Kaye
Kenneth M
KM
D000409:Alanine / Q000235:genetics / Q000378:metabolism; D000956:Antigens, Viral / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D002875:Chromosomes / Q000378:metabolism*; D004279:DNA, Viral / Q000235:genetics / Q000378:metabolism; D019288:Herpesvirus 8, Human / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008938:Mitosis; D009154:Mutation / Q000235:genetics; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D010641:Phenotype; D010957:Plasmids / Q000235:genetics*; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding
D000956:Antigens, Viral; D004279:DNA, Viral; D009687:Nuclear Proteins; C109540:latency-associated nuclear antigen; D000409:Alanine