Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.30.2 (endonuclease)
 18,621 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have cloned double-stranded cDNA copies of a rat preproinsulin messenger RNA in Escherichia coli chi1776, using the unique Pst endonuclease site of plasmid pBR322 that lies in the region encoding amino acids 181-182 of penicillinase. This site was reconstructed by inserting the cDNA with an oligo(dG)-oligo(dC) joining procedure. One of the clones expresses a fused protein bearing both insulin and penicillinase antigenic determinants. The DNA sequence of this plasmid shows that the insulin region is read in phase; a stretch of six glycine residues connects the alanine at position 182 of penicillinase to the fourth amino acid, glutamine, of rat proinsulin.
 ...
PMID:A bacterial clone synthesizing proinsulin. 35 98

We have used a synthetic deoxydecanucleotide to generate an insulin-specific cDNA probe suitable for selecting transformants that contain nearly full-length cDNAs corresponding to the mRNAs coding for rat insulins I and II. Double-stranded cDNA was synthesized from x-ray-induced rat insulinoma poly(A)-RNA, inserted in pBR322 plasmid DNA by the homopolymeric tailing technique, and cloned in Escherichia coli chi 1776. Colony hybridization with oligonucleotide-primed cDNA yielded 16 positive clones of which 7 corresponded to rat insulin I mRNA and 9 to rat insulin II mRNA. Restriction endonuclease maps of representative clones of each group indicated that these contained the complete coding sequences, as was confirmed by nucleotide sequence analysis of the 5' region of the cloned DNA for rat insulin II. Nucleotide sequence analysis also established the amino acid sequence of the prepeptide of rat preproinsulin II. Comparison of the amino acid sequence of the prepeptides of rat preproinsulin I and II shows that three conservative amino acid substitutions have occurred in this region of the molecule.
 ...
PMID:Construction and selection of recombinant plasmids containing full-length complementary DNAs corresponding to rat insulins I and II. 38 27

DNA complementary to preproinsulin messenger RNA from the primate Macaca fascicularis has been cloned into the PstI endonuclease site of the plasmid pBR322. One clone contains the entire preproinsulin coding region as well as 59 nucleotides of the 5'-untranslated region. The results predict an amino acid sequence for the Macaca fascicularis preproinsulin and establish for the first time that the primary structures of human and primate insulins are identical. The two amino acid exchanges between human and primate preproinsulins are restricted to the pre- and the C-peptide, respectively.
 ...
PMID:The nucleotide sequence of cDNA coding for preproinsulin from the primate Macaca fascicularis. 618 62

In rat there are two nonallelic insulins, I and II. We have cloned and sequenced double stranded cDNA copies of both preproinsulin mRNA I and II. Using the cloned sequence as probe, we established by the Southern blotting technique a restriction map of the two chromosomal genes. This map indicates that an intron exists within the insulin II gene. To examine this in more detail, we have isolated both genes from a library of rat DNA cloned in phage lambda. Restriction endonuclease analysis and direct DNA sequencing revealed that gene II contains two introns: a 490 base pair intron between the region encoding amino acids 38 and 39 of proinsulin, and a 119 base pair intron, which is 17 base pairs upstream from the initiation codon. Gene I is not interrupted within the protein coding region, but possesses an intron homologous to the 119 base pair intron of insulin II. We are studying the structure of insulin genes from other species to determine if the 490 base pair intron was lost or inserted in the duplicated gene. We have identified nuclear RNA molecules larger than preproinsulin mRNA which contain the transcribed intronic sequences. These molecules represent a new precursor in insulin biosynthesis.
 ...
PMID:The structure of rat preproinsulin genes. 624 67

A complementary DNA (cDNA) library was prepared from messenger RNA (mRNA) isolated from Syrian hamster islets. Bacterial colonies containing hamster preproinsulin cDNA were identified by cross-hybridization with the human preproinsulin gene. The sequences of two of these established the complete sequence of Syrian hamster preproinsulin mRNA and predicted the sequence of the protein. Hamster preproinsulin is 110 amino acids and possesses 90.0% and 82.7% identity with the corresponding proteins of rats (either I or II) and human beings, respectively. Analysis of the hybridization of hamster preproinsulin cDNA to restriction endonuclease digests of hamster DNA suggests that there is only a single preproinsulin gene in this rodent, in contrast to rats and mice, which possess two nonallelic genes.
 ...
PMID:Sequence of a cDNA encoding Syrian hamster preproinsulin. 636 63

A plasmid containing human preproinsulin cDNA inserted into the endonuclease Pst I site of the ampicillinase gene of plasmid pBR322 was modified by excision of large portions of the ampicillinase-coding region to produce a variety of gene fusion combinations, many of which generated proteins detectable with antisera to insulin or human C peptide. In one case a perfect hybrid of the NH2-terminal half of the leader sequence of ampicillinase (residues -23 to -12) with the human preproinsulin prepeptide beginning at residue -13 was formed; the result was the synthesis and secretion of human proinsulin into the periplasmic space. We have characterized this protein immunologically and also by labeling it biosynthetically or by iodination followed by immunoprecipitation and automated amino acid sequence analysis. It contains the A and B chain regions of insulin as well as specific human C peptide immunodeterminants and is convertible to an insulin-like component by tryptic digestion. These results demonstrate that human proinsulin can be produced by bacteria and that this biosynthetic approach should prove feasible for the production of adequate amounts of human proinsulin for a variety of clinical studies and human insulin for therapeutic purposes.
 ...
PMID:Biosynthesis and periplasmic segregation of human proinsulin in Escherichia coli. 702 34

Many studies support the concept of insulin synthesis in tissues other than the pancreas. Our previous investigations have demonstrated the presence of insulin immunoreactivity in the adrenal medulla of the rat. This immunoreactivity was found to be associated with the chromaffin granule. This study is directed at isolating the messenger ribonucleic acid that encodes for preproinsulin. Reverse transcription coupled with polymerase chain reaction was used. Complementary deoxyribonucleic acid (cDNA) was amplified, extracted and reamplified. It was then subjected to digestion with four different restriction endonuclease enzymes. Its resemblance to the corresponding cDNA that encodes for preproinsulin I in the rat was established. Our results suggest that insulin is synthesized in the rat adrenal gland for autocrine, paracrine, neuromodulation or local physiologic function.
 ...
PMID:Preproinsulin messenger ribonucleic acid in the rat adrenal gland. 750 12