CDP/cut is the DNA-binding subunit of histone gene transcription factor HiNF-D: a mechanism for gene regulation at the G1/S phase cell cycle transition point independent of transcription factor E2F.

Abstract

Transcription of the genes for the human.histone proteins H4, H3,.H2A, H2B, and Hi is activated at the G1/S phase transition of the cell cycle. We have previously shown that the promoter complex HiNF-D, which interacts with cell cycle control elements in multiple histone genes, contains the key cell cycle factors cyclin A, CDC2, and a retinoblastoma (pRB) protein-related protein. However, an intrinsic DNA-binding subunit for HiNF-D was not identified.Many genes that are up-regulated at the G1/S phase boundary are controlled by E2F, a transcription factor that associates with cyclin-, cyclin-dependent kinase-, and pRB-related proteins. Using gel-shift immunoassays, DNase I protection, and oligonucleotide competition analyses, we show that the homeodomain protein CDP/cut, not E2F, is the DNA-binding subunit of the HiNF-D complex. The HiNF-D (CDP/cut) complex with the H4 promoter is immunoreactive with antibodies against CDP/cut and pRB but not p107, whereas the CDP/cut complex with a nonhistone promoter (gp9l-phox) reacts only with CDP and p107 antibodies. Thus, CDP/cut complexes at different gene promoters can associate with distinct pRB-related proteins. Transient coexpression assays show that CDP/cut modulates H4 promoter activity via the HiNF-D-binding site. Hence, DNA replication-dependent histone H4 genes are regulated by an E2F-independent mechanism involving a complex of CDP/cut with cyclin A/CDC2/ RB-related proteins.Cell proliferation is initiated by a sequential series of growth factor-dependent events that activate cyclin-dependent kinases (CDKs), which mediate the onset of the cell cycle and progression into S phase (1, 2). There are two functional components to the G1/S phase transition point during the cell cycle. First, initiation of DNA replication necessitates adjustments in the activities of enzymes involved in nucleotide metabolism and DNA synthesis. Second, progression into early S phase requires induction of histone gene expression, because de novo synthesis of histone nucleosomal proteins is essential for the ordered packaging of newly replicated DNA into chromatin (3).Many genes that are functionally linked to cell cycle progression appear to be regulated by the E2F class of transcription factors, including genes encoding enzymes and regulatory factors involved in DNA synthesis (e.g., refs. 4-13). E2F factors are heterodimers composed of different pairs of E2F/DP proteins that are capable of forming higher order complexes with multiple cell cycle regulators including retinoblastoma protein (pRB)-related proteins (pRB/plO5, pRB-

Expression of N‐terminally truncated isoforms of CDP/CUX is increased in human uterine leiomyomas

“…Nuclear extracts from selected samples of pairs of uterine leiomyomas and matched normal myometrium were prepared as described in Material and Methods and analyzed by EMSA with oligonucleotides containing a CDP/Cut consensus-binding site (CGATATCGAT). DNA and proteins were incubated either with no antibody (lanes 1-10) or with the indicated antibodies (lanes [11][12][13][14]. The diagram shows a schematic representation of the CDP/Cux proteins with their conserved domains and the regions recognized by the respective antibodies.…”

“…However, this notion contradicts results of DNA binding studies in tissue culture systems. CUTL1 encodes for the CDP/Cux protein, which was characterized independently as the CDP and the DNA binding subunit of the HiNF-D. [12][13][14] The DNA binding activity of HiNF-D was upregulated in S phase in normal cells but constitutively activated in tumor cell lines. [15][16][17][18] CDP/Cux is a transcription factor that contains 4 DNA binding domains and whose expression has been associated with cellular proliferation, the repression of genes that are turned on in terminally differentiated cells and the regulation of MARs.…”

“…CDP/Cux is a component of HiNF-D, whose presence on various histone promoters coincides with their upregulation in the cell cycle. 12,13,15,20,21 Moreover, one of the CDP/Cux DNA binding activities is upregulated as normal cells progress into S phase and inhibited in G 2 following phosphorylation of the Cut homeodomain by cyclin A/CDK1. 15,22,23 Upregulation of CDP/Cux DNA binding activity at the G 1 /S transition involves proteolytic processing of p200 CDP/Cux into an Nterminally truncated isoform of 110 kDa.…”

CUX1, a haploinsufficient tumour suppressor gene overexpressed in advanced cancers

“…It is not possible to evaluate the experimental evidence, as the gene list was not provided. Certainly, the idea that CUX1 represses genes that are involved in cell cycle progression runs contrary to the bulk of the evidence showing that CUX1 stimulates expression of histone genes and many genes involved in DNA replication, while repressing expression of the cyclin-dependent kinase inhibitors p21 and p27 (REFS 15,41,60,62,(68)(69)(70)(71)(72)(73)(74)(75). Moreover, in cell-based assays, MEFs from Cux1-knockout mice showed a longer G1 phase and proliferated more slowly than their wild-type counterparts; whereas, in many cell types, ectopic expression of p110 CUX1 accelerated S phase entry and stimulated proliferation 21,22 .…”

YY1 Binds Five cis-Elements and Trans-activates the Myeloid Cell-restricted gp91 Promoter

“…CDP-binding sites have also been identified in many other promoters and enhancers for which competing transcriptional activators have not been identified (41,42,49,(53)(54)(55)(56)(57). In some cases CDP may not directly compete with activators for binding, and CDP-mediated transcriptional repression may be mediated via a carboxyl-terminal repressor domain (58).…”