THE ADENOVIRUS-E1A-ASSOCIATED 130-KD PROTEIN IS ENCODED BY A MEMBER OF THE RETINOBLASTOMA GENE FAMILY AND PHYSICALLY INTERACTS WITH CYCLIN-A AND CYCLIN-E

The adenovirus E1A proteins form complexes with a group of cellular pr oteins, including a protein of 130 kD. E1A-associated p130 was purifie d through coimmunoprecipitation with E1A, and sequence data from four tryptic peptides was obtained. Oligonucleotides derived from the pepti de sequences were used to clone a 4.85-kb cDNA. The cDNA contained an 1139-amino-acid open reading frame with homology to the retinoblastoma protein and E1A-associated p107 but was more closely related to p107. In vitro-translated p130 bound to E1A, and anti-p130 antibodies detec ted p130 in immunoblots of E1A immunoprecipitates. p130 was also detec ted in immunoprecipitates of cyclins A and E and was an efficient subs trate in vitro for kinase activities associated with these cyclins. Th e p130 gene mapped to chromosome 16q12.2-13, a region that undergoes a llelic loss in several types of tumors, including hepatocellular, pros tate, and breast carcinomas.