Multiple genes encode nuclear factor 1-like proteins that bind to the promoter for 3-hydroxy-3-methylglutaryl-coenzyme A reductase.

Abstract

Among the factors that regulate transcription of eukaryotic genes is a family of proteins known as nuclear factor 1 (NF1), CCAAT-box-binding transcription factor (CTF), or CCAATbox-binding protein (1)(2)(3)(4). These proteins are related in that they all bind to double-stranded sequences containing TGG and its complement, CCA making contact with the adjacent guanosines (4). NFl-like pNroteins bind to the promoters of many genes, including the gene for 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMG-CoA reductase), the rate-determining enzyme in cholesterol synthesis (5).NF1 binds to a TGG-containing sequence in adenovirus and thereby stimulates its replication (6, 7). The same protein (designated NF1/CTF) binds to the CCAAT box, making contact with TGG on the opposite strand and activating transcription of the human a-globin gene (1). NF1/CTF binds with highest affinity to sequences that contain the inverted repeat TGGN7CCA. It also binds to "half-sites" that contain only one copy of TGG. Purified NF1/CTF consists of a family of proteins in the molecular weight range of 55,000-62,000. Santoro et al. (3) isolated three cDNAs for NF1/CTF proteins from human HeLa cells. All of the mRNAs were derived from a single gene by alternative splicing and differed by the presence or absence of an insertion in the middle ofthe protein and the presence of various COOH termini. All three proteins, when produced in Escherichia coli, bound to the NF1/CTF recognition sequence, and at least two of them stimulated replication of adenovirus in vitro.Another member of the NF1/CTF family is the TGGCAbinding protein, which was described in chicken liver (8) and believed to have a molecular weight in the 30,000 range. The cDNA for this protein, designated pNF1/L, was isolated from rat liver (9). It encodes a protein of 505 amino acids, which was proteolyzed during its isolation. The first 175 amino acids of the rat TGGCA-binding protein show 98% identity with the NH2 terminus of human NF1/CTF, and the remaining portion shows an identity of "50% (3, 9).The 5' flanking region of the reductase gene contains the information necessary for transcription of the gene as well as for feedback repression by sterols. This region contains eight sequences that bind nuclear proteins as revealed by DNase I protection assays (10). We have purified (5) a protein doublet of 33 and 35 kDa, designated reductase promoter factor (RPF) that produces six of the eight footprints. The two proteins were active as monomers, and both recognized all six footprinted sequences. The only sequence shared by all six footprinted regions is the trinucleotide TGG. Methylation-interference analysis showed that both of the adjacent guanosines in this sequence made contact with RPF (5).The HMG-CoA reductase sequence that binds RPF with highest affinity (designated footprint 2B) contains the inverted repeat TGGN7CCA (5). The other five RPF-binding sites contain only half-sites. We speculated that RPF belonged to the NF1 family, and we demonstrated by gel retardation assays t...

A conserved family of nuclear phosphoproteins localized to sites of polymerase II transcription.

“…PCR Amplification, Cloning, Sequencing, and In Situ Hybridization to Pblytene Chromosomes Degenerate 14-base oligonucleotides corresponding to short stretches of amino acids on either end of fragment C, not including the central seven nucleotides, were used to amplify the genomic DNA sequence encoding the protein (Gil et al ., 1988) . The reactions contained 0.1 ug of each oligonucleotide (one of two was labeled at the 5' end with [32 p]), 1 gg of Drosophila genomic DNA, 50 mM KCI, 10 mM Tris, pH 8.3, 1 .5 MM M9C12, 200 AM each of dATP, dTTP, dCTP, and dGTP, and 2 .5 U of AmpliTaq polymerase (United States Biochemical) in a total volume of 25 A1 .…”

A1F‐B, a novel CCAAT‐binding transcription activator that interacts with the aldolase B promoter

“…Distribution of these contact sites is somewhat different from those of other characterized factors (e.g. CTF/NF-1 [3] and CP2…”

“…For example, human CP2 is composed of two different subunits that can be separated through phosphocellulose chromatography [6]. Furthermore, the size of AlF-B, 70 kDa, differed from those of known factors such as C/EBP family (2542 kDa) [16,17], CTF/NF-1 (52-66 kDa) [2,3], NF-Y/CBF/CPl/ACF (37 kDa and 4043 kDa subunits) [5], YB-1 and the related factors (about 35 kDa) [9], and CDP (180 kDa and 190 kDa) [lo]. Fig.…”

“…Several mammalian factors that recognize a CCAAT motif have been identified, e.g. NFl/CTF [2,3], C/EBP [4], NF-Y/CBF/CP-l/ACF…”

The concerted regulatory functions of the transcription factors nuclear factor-1 and upstream stimulatory factor on a composite element in the promoter of the hepatocyte growth factor gene

“…To test whether these transcription factors indeed regulate the activity of the HGF promoter, we cotransfected the expression vectors encoding these transcription factors with the 0.7 HGF-CAT construct and its mutated forms. NF1 represents a family of sequencespeci®c DNA-binding proteins, which includes heterogeneous species resulting from either alternative splicing events of a single gene (Kruse and Sippel, 1994;Santoro et al, 1988) or transcription of multiple genes (Gil et al, 1988). More than a dozen NF1 isoforms have been cloned to date (Kruse and Sippel, 1994).…”