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

In attempts to isolate human elastin cDNAs, a human placental lambda gt11 cDNA library was screened with a 1.3 kilobase sheep genomic DNA subclone, corresponding to the 3'-end of the elastin mRNA. The four largest clones, the largest being approximately 3 kilobase, were characterized by Northern transfer analyses, restriction endonuclease digestions and dideoxy nucleotide sequencing. Northern transfer analyses of poly(A)+RNA revealed hybridization to mRNA transcripts in the region of 3.5 kilobase. Restriction endonuclease mapping and nucleotide sequencing demonstrated distinct domains characteristic of elastin, and identified areas of variability which apparently reflects alternative splicing of the primary elastin transcripts. To demonstrate the utilization of these cDNAs for studies on elastin gene expression in human cells, elastin mRNA was examined in fibroblast cultures established from the skin of several individuals of varying ages. Northern transfer analyses and slot blot hybridizations demonstrated that elastin gene expression is initiated early during fetal development, and continues at a relatively constant level through several decades. The lowest abundance of elastin mRNA was noted in the cell cultures established for the oldest individual studied (61-year-old female). Demonstration of elastin gene expression in cultured fibroblasts provides a system to study diseases affecting the elastic fibers.
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PMID:Isolation and characterization of human elastin cDNAs, and age-associated variation in elastin gene expression in cultured skin fibroblasts. 283 31

The identity of the primary in vitro translation products of fetal sheep nuchal ligament elastin mRNA was confirmed as two distinct polypeptides of 63 Kdal and 65 Kdal in both rabbit reticulocyte and wheat germ extract cell-free translation systems. Both polypeptides were co-translationally processed by a microsomal membrane signal peptidase, with the removal of 20-25 amino acid residues. A single (3,5 kb) RNA species encodes both tropoelastin polypeptides. Restriction endonuclease mapping of sheep genomic DNA by hydridization with two radiolabelled genomic DNA fragments containing sequences coding for sheep tropoelastin (pSE1-1,3 and pSE1-0.7,) indicated the presence of a single elastin gene. The elastin gene copy number was further quantitated by comparison of hybridisation of pSE1-1.3 and pSE1-0.7 to slot-blots and Southern transfers of sheep genomic DNA and to standard curves constructed with each clone. These results clearly demonstrate that each of these sequences is represented only once per haploid genome, suggesting that the two tropoelastin polypeptides are products of a single elastin gene.
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PMID:The gene coding for tropoelastin is represented as a single copy sequence in the haploid sheep genome. 360 4

A sheep genomic library containing sheep DNA in the bacteriophage vector Charon 4A was screened for elastin-gene sequences with partially purified, 32P-labelled elastin mRNA (mRNAE). A recombinant containing a 9.9-kb (kilobase) insert was selected from several positive clones by secondary and tertiary screening for further characterization. Positive identification of this elastin clone, designated SE1, was made with radiolabelled mRNAE by hydridization-selected translation and Southern blotting of restriction-enzyme fragments of SE1 DNA. Hybridization of either mRNAE or elastin complementary DNA to restriction fragments of SE1 showed that most of these fragments of SE1 contained elastin-coding sequences. Orientation of the insert was established by preferential hybridization of a short complementary elastin DNA to restriction fragments adjacent to the right arm of Charon 4A. Reciprocal hybridizations of nick-translated SE1 and sheep genomic DNA on Southern blots showed that two restriction fragments of SE1 contained sequence elements which were repeated at high frequency in a restriction-endonuclease-EcoR1 digest of total sheep genomic DNA. In the accompanying paper [Davidson, Shibahara, Boyd, Mason, Tolstoshev & Crystal (1984) Biochem. J. 220, 653-663], it is shown that a subcloned fragment of this elastin gene quantitatively and specifically hybridized to mRNAE sequences in sheep tissue RNA. Electron microscopy of SE1-mRNAE hybrids indicated the presence of at least seven large R-loops. Measurements of these structures indicated that SE1 is likely to contain less than 2 kb of coding sequence and more than 8 kb of intervening sequence, with an average exon size of 120 base-pairs. Thus the elastin gene is distributed over an extended region of the sheep genome and contains numerous intervening and coding sequences.
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PMID:Sheep elastin genes. Isolation and preliminary characterization of a 9.9-kilobase genomic clone. 654 35