EBNA-LP associates with cellular proteins including DNA-PK and HA95.
EBNA-LP-associated proteins were identified by sequencing proteins that immunoprecipitated with Flag epitope-tagged EBNA-LP (FLP) from lymphoblasts in which FLP was stably expressed. The association of EBNA-LP with Hsp70 (72/73) was confirmed, and sequences of DNA-PK catalytic subunit (DNA-PKcs), HA95, Hsp27, prolyl 4-hydroxylase alpha-1 subunit, alpha-tubulin, and beta-tubulin were identified. The fraction of total cellular HA95 that associated with FLP was very high, while progressively lower fractions of the total DNA-PKcs, Hsp70, Hsp 27, alpha-tubulin, and beta-tubulin specifically associated with EBNA-LP as determined by immunoblotting with antibodies to these proteins. EBNA-LP bound to two domains in the DNA-PKcs C terminus and DNA-PKcs associated with the EBNA-LP repeat domain. DNA-PKcs that was bound to EBNA-LP phosphorylated p53 or EBNA-LP in vitro, and the phosphorylation of EBNA-LP was inhibited by Wortmannin, a specific in vitro inhibitor of DNA-PKcs.
Han
I
I
Channing Laboratory, Harvard Medical School, Boston, Massachusetts 02445, USA.
Harada
S
S
Weaver
D
D
Xue
Y
Y
Lane
W
W
Orstavik
S
S
Skalhegg
B
B
Kieff
E
E
D051747:DNA-Activated Protein Kinase; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D020031:Epstein-Barr Virus Infections / Q000821:virology*; D004854:Herpesvirus 4, Human / Q000378:metabolism*; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D016393:Lymphoma, B-Cell; D009687:Nuclear Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D009842:Oligopeptides; D010455:Peptides / Q000378:metabolism; D011233:Precipitin Tests; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism; D014407:Tumor Cells, Cultured; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
C490117:AKAP8L protein, human; D004268:DNA-Binding Proteins; C402640:EBNA-LP protein, Human herpesvirus 4; D047908:Intracellular Signaling Peptides and Proteins; D009687:Nuclear Proteins; D009842:Oligopeptides; D010455:Peptides; D011506:Proteins; D014764:Viral Proteins; C085706:FLAG peptide; D051747:DNA-Activated Protein Kinase; C497263:PRKDC protein, human; D017346:Protein Serine-Threonine Kinases