Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.30.1 (S1 nuclease)
 3,660 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The rat insulin-like growth factor II (rIGFII) gene produces, in addition to three major mRNA species 3.6 kilobases (kb), 4.6 kb and 3.8 kb in length which represent transcripts from three independent leader-exons, multiple smaller-sized products that distribute broadly in the 1-3 kb region on Northern blots. Structural constituents of these RNAs were analyzed by hybridization with region-specific probes prepared from the entire rIGFII genome. Most of these shorter RNAs contained both 5'-untranslated and coding regions, but only parts of the 3'-untranslated region. At least nine protected sites were mapped within a single 3'-most exon E6 by S1 nuclease analysis. Some but not all of these sites were associated with the upstream polyadenylation signal, AATAAA, or its variants. Since none of the shorter subspecies contained intronic sequences, aberration in splicing is not involved in their generation. Thus, the main parts of submature materials are a collection of discrete species of RNAs, most, if not all, of which are produced by alternative polyadenylation site selection.
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PMID:Multiple polyadenylation sites in a large 3'-most exon of the rat insulin-like growth factor II gene. 247 62

We have characterized the cis-control signals in one of the two promoters of the developmentally regulated rat insulin-like growth factor II gene (rIGF-II) by a combination of in-vivo transient expression, in-vitro transcription, footprinting, gel band-shifting and methylation-interference experiments, using a series of deletion mutant templates. Our results indicate that this simple (minimal) promoter (P2) consists of no more than 128 base-pairs, which include an ATA box and four proximal upstream GC boxes binding the general transcription factor Sp1. Three of the latter sites deviate from the known Sp1 consensus recognition sequence. The two types of cis-acting regulatory signals (GC/ATA motif) of the P2 promoter are inter-dependent and sufficient for transcription. A model for the operation of this type of minimal promoter is discussed. S1 nuclease-hypersensitive sites, localized by in-vitro mapping to the region of the P2 Sp1-binding sites, are also present in vivo and correlate with the transcriptional state of chromatin in the rIGF-II locus. We show that recognition sites for Sp1 binding are a subset of sequences that exhibit hypersensitivity to S1.
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PMID:A promoter of the rat insulin-like growth factor II gene consists of minimal control elements. 335 24

The human insulin-like growth factor II (IGF-II) gene contains four promoters (P1, P2, P3 and P4). In order to determine the mechanism by which the P4 promoter is controlled, the human IGF-II P4 promoter was analyzed in cell lines. DNA sequence analysis of the human IGF-II P4 promoter gene showed that the P4 promoter region contains a TATA-like sequence and several G+C rich regions which are essential for transcription. Analysis of the transcription initiation site by S1 nuclease mapping revealed two transcription start sites; both are located immediately behind TATA-like sequence. To determine the location of sites that may be important for the function of the human IGF-II P4 promoter, we constructed chimeric genes of the human IGF-II P4 promoter fused to the coding region for chloramphenicol acetyltransferase (CAT). These constructs were transfected into HepG2, PLC/PRF/5, G401 and A549 cells, and were examined for CAT activity. All transfected cells showed a similar profile of CAT activity. Sequences responsible for putative enhancer and silencer regions were identified and the 5' flanking sequences of the human IGF-II P4 promoter contain negative regulatory regions (-213 to -174). The 53-base pair fragment located between 111 and 59 base pairs upstream of the start site contains positive regulatory activity. Gel mobility shift assay showed that Sp1 and another proteins might be involved in positive regulation of the human IGF-II P4 promoter.
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PMID:Characterization of the P4 promoter region of the human insulin-like growth factor II gene. 840 33