Deletions or mutations of the retinoblastoma gene, RB1, are common features of many
tumors and tumor cell lines. Recently, the RB1 gene product, p105-RB, has been shown to
form stable protein/protein complexes with the oncoproteins of two DNA tumor viruses, the …

The association of cdk4 with D-type cyclins to form functional kinase complexes is
comparatively inefficient. This has led to the suggestion that assembly might be a regulated
step. In this report we demonstrate that the CDK inhibitors p21 (CIP), p27 (KIP), and p57 …

One of the cellular targets implicated in the process of transformation by the adenovirus E1A
proteins is a 105K cellular protein. Previously, this protein had been shown to form stable
protein/protein complexes with the E1A polypeptides but its identity was unknown. Here, we …

The E7 proteins encoded by the human papillomaviruses (HPVs) associated with anogenital
lesions share significant amino acid sequence homology. The E7 proteins of these different
HPVs were assessed for their ability to form complexes with the retinoblastoma tumor …

Thirty hybridomas that secrete immunoglobulins against the simian virus 40 tumor antigens
were isolated and cloned. Of these, 28 produced antibodies which bound to simian virus 40
large-T, and 2 produced antibodies which bound to the host 53,000-dalton protein. As in …

Abstract p105-RB is the product of the retinoblastoma tumor suppressor gene. It is a nuclear
phosphoprotein hypothesized to act as an inhibitor of cellular proliferation, yet surprisingly it
is present in actively dividing cells. To look for changes in p105-RB that may regulate its …

The key cell-cycle regulator Cdc2 belongs to a family of cyclin-dependent kinases in higher
eukaryotes. Dominant-negative mutations were used to address the requirement for kinases
of this family in progression through the human cell cycle. A dominant-negative Cdc2 mutant …

The coordinated action of cell cycle progression and cell growth (an increase in cell size and
cell mass) is critical for sustained cellular proliferation, yet the biochemical signals that
control cell growth are poorly defined, particularly in mammalian systems. We find that cell …

The p34cdc2 protein kinase is known to regulate important transitions in the eukaryotic cell
cycle. We have identified 10 human protein kinases based on their structural relation to
p34cdc2. Seven of these kinases are novel and the products of five share greater than 50 …