Cloning of p57KIP2, a cyclin-dependent kinase inhibitor with unique domain structure and tissue distribution.

Abstract

Progression through the cell cycle is catalyzed by cyclin-dependent kinases (CDKs) and is negatively controlled by CDK inhibitors (CDIs). We have isolated a new member of the p21aPl/p27 v'~el CDI family and named it p57 ~ea to denote its apparent molecular mass and higher similarity to p27 ~n'l. Three distinct p57 cDNAs were cloned that differ at the start of their open reading frames and correspond to messages generated by the use of distinct splice acceptor sites, p57 is distinguished from p21 and p27 by its unique domain structure. Four distinct domains follow the heterogeneous amino-terminal region and include, in order, a p21/p27-related CDK inhibitory domain, a proline-rich (28% proline) domain, an acidic (36% glutamic or aspartic acid) domain, and a carboxy-terminal nuclear targeting domain that contains a putative CDK phosphorylation site and has sequence similarity to p27 but not to p21. Most of the acidic domain consists of a novel, tandemly repeated 4-amino acid motif, p57 is a potent inhibitor of G1-and S-phase CDKs (cyclin E-cdk2, cyclin D2-cdk4, and cyclin A-cdk2) and, to lesser extent, of the mitotic cyclin B-Cde2. In mammalian cells, p57 localizes to the nucleus, associates with G1 CDK components, and its overexpression causes a complete cell cycle arrest in G1 phase. In contrast to the widespread expression of p21 and p27 in human tissues, p57 is expressed in a tissue-specific manner, as a 1.5-kb species in placenta and at lower levels in various other tissues and a 7-kb mRNA species observed in skeletal muscle and heart. The expression pattern and unique domain structure of p57 suggest that this CDI may play a specialized role in cell cycle control.

Identification of a p130 domain mediating interactions with cyclin A/cdk 2 and cyclin E/cdk 2 complexes

“…Several other cellular proteins which have been shown to stably interact with cyclin/cdk complexes also contain a region that is homologous to the p130 cyclin binding region. Included among these are the highly related p107 protein, the cdk inhibitors p21 cip1 , p27 kip1 , p57 kip2 (ElDeiry et al, 1993;Gu et al, 1993;Harper et al, 1993;Xiong et al, 1993;Polyak et al, 1994;Toyoshima and Hunter, 1994;Lee et al, 1995;Matsuoka et al, 1995) and the transcription factor E2F-1 (Helin et al, 1992;Kaelin et al, 1992;Shan et al, 1992). A similar sequence is found in E2F-2 and -3; however, these proteins have not been demonstrated to interact with the cyclin/cdk complexes (Ivey-Hoyle et al, 1993;Lees et al, 1993).…”

“…An examination of the sequences of various other cyclin/cdk interacting proteins revealed sequences similar to the p130 RRRLFVE motif in several other proteins including E2F-1, 2 and 3, p21 cip1 , p27 kip1 and p57 kip2 (Helin et al, 1992;Kaelin et al, 1992;Shan et al, 1992;El-Deiry et al, 1993;Gu et al, 1993;Harper et al, 1993;Ivey-Hoyle et al, 1993;Lees et al, 1993;Xiong et al, 1993;Polyak et al, 1994;Toyoshima and Hunter, 1994;Lee et al, 1995;Matsuoka et al, 1995) (Figure 5a). As discussed below, each of these proteins has been shown to be present in complexes containing cyclin A or E. In some cases, this particular region has been implicated in the cyclin interactions.…”

The Nuclear Protein p34SEI-1 Regulates the Kinase Activity of Cyclin-Dependent Kinase 4 in a Concentration-Dependent Manner

“…Under our in vitro assay conditions, p34 SEI-1 acts as both an activator and inhibitor of CDK4, which distinguishes p34 SEI-1 from other CDK4-binding proteins. INK4 (5)(6)(7)(8)(9)(10)(11) and KIP proteins (12)(13)(14) only inhibit CDK4; gankyrin functions as a competitor to antagonize INK4 proteins (17), while Tax is competent in activating CDK4 (15,16), quenching p16 (32,33), and affecting cyclin Ds (34). It is important to point out that most of these studies were performed by in vitro or cell-based studies, and their biological relevance remains to be established.…”

“…Many proteins have been found to act as negative or positive kinase regulators of CDK4 and 6 through protein/protein interactions. While binding of D cyclins is required for the full kinase activity (4), INK4 (including p16, p15, p18, and p19) (6)(7)(8)(9)(10)(11) and KIP (including p21, p27, and p57) proteins (5,(12)(13)(14) are inhibitors of CDK4 and 6. Moreover, the oncoprotein Tax from human T-cell leukemia virus 1 (HTLV-1) stimulates the CDK4 activity in infected cells through physical association (15,16), and the oncoprotein gankyrin affects CDK4 by counteracting against the inhibition of p16 and p18 (17).…”

Roles for negative cell regulator 14-3-3σ in control of MDM2 activities

“…Cell lines and cell culture 293T, R1B/L17 (the mink lung epithelial cell line derivative) (Lee et al, 1995), H1299 cells (from ATCC, Manassas, VA, USA) and Rat1-akt cells (Zhou et al, 2001) were maintained in Dulbecco's modified Eagle's medium. An HCT116 14-3-3s þ / þ human colon carcinoma cell line and a derivative HCT116 14-3-3sÀ/À cell line were kindly provided by Dr Bert Vogelstein (John Hopkins Oncology Center, Baltimore, MD, USA).…”