Isolation of the Rb-related p130 through its interaction with CDK2 and cyclins.

Abstract

A two-hybrid protein interaction screen was used to isolate cDNAs encoding human proteins that can interact with human CDK2 in yeast. A new member of the retinoblastoma susceptibility gene family, Rbr-2 (Rb-related), was obtained. The sequence of the Rbr-2 protein shares -50% identity with p107 and homology to Rb within the pocket domain. Several lines of evidence indicate that Rbr-2 is the adenovirus E1A-associated p130. Like Rb and p107, p130 Rbr-2 can bind to viral oncoproteins, SV40 large T antigen, and adenovirus E1A through its pocket domain. Although p130 Rbr'2 does not bind to CDK2 in vitro, it can interact with cyclins, with a clear preference for D-type cyclins. Because both CDK2 and p130 Rbr'2 show affinity for cyclins, we suggest that p130 Rbr'2 and CDK2 interacted through a yeast-derived cyclin bridge in the two-hybrid screen. The gene encoding p130 Rbr'2 mapped to 16q13, a region of frequent genomic alteration in human tumors.

Retinoblastoma family proteins as key targets of the small DNA virus oncoproteins

“…RB is the founder of the RB family of genes and proteins, since two other factors structurally and functionally related, namely p107 (RBL1) (Ewen et al, 1991;Zhu et al, 1993) and Rb2/p130 (RBL2) (Hannon et al, 1993;Li et al, 1993;Mayol et al, 1993), have been subsequently identified. The RB family proteins share a considerable structural homology, primarily at the level of the 'pocket' domain, a complex structure subdivided in A-domain, spacer and B-domain.…”

“…The subsequent characterization of these proteins first identified p105 as the product of the RB gene (Whyte et al, 1988), and then p60 as cyclin A (Giordano et al, 1989;Pines and Hunter, 1990). Later, genes encoding p107 (Ewen et al, 1991;Zhu et al, 1993) and pRb2/p130 (Hannon et al, 1993;Li et al, 1993;Mayol et al, 1993) were cloned using different strategies. Finally p300, together with CBP, defines a family of transcriptional adaptor proteins that are specifically targeted by the E1A oncoprotein (Arany et al, 1995).…”

“…Also, the other two members of the retinoblastoma family, p107 and pRb2/ p130, were first discovered through their association to E1A Herrmann et al, 1991). Later, they were cloned and identified as pocket proteins (Ewen et al, 1991;Hannon et al, 1993;Li et al, 1993;Mayol et al, 1993;Zhu et al, 1993).…”

Interaction of retinoblastoma protein family members with large T-antigen of primate polyomaviruses

“…Molecular cloning of the p107 cellular protein that forms specific complexes with E1A and large T-antigen revealed that it possessed significant homology to pRb (Ewen et al, 1991). Similarly, the p130 cellular protein, which binds to viral oncoproteins, has been cloned and is also sometimes referred to as pRb2 (Hannon et al, 1993;Li et al, 1993;Mayol et al, 1993; see also Genovese et al, in this issue).…”

“…Interaction involves the same 10 amino-acid LXCXE domain that is involved in pRb binding. Similarly, the p130 cellular protein, pRb2 binds to large T-antigen (Hannon et al, 1993;Li et al, 1993;Mayol et al, 1993). Mutations in the 10 amino-acid LXCXE domain abrogate p107 and pRb2/p130 binding as well as pRb.…”