Complementary DNA

About: Complementary DNA is a research topic. Over the lifetime, 55301 publications have been published within this topic receiving 2752650 citations. The topic is also known as: cDNA & DNA, Complementary.

Expression of the c-fos gene and of an fos-related gene is stimulated by platelet-derived growth factor

Abstract: Complementary DNA clones of genes induced by platelet-derived growth factor (PDGF) in BALB/c-3T3 cells were isolated; one such clone contains a domain having nucleotide sequence homology with the third exon of c-fos. This nucleotide sequence homology is reflected in the predicted amino acid sequences of the gene products. Under low stringency conditions, the mouse v-fos gene cross-hybridizes with the PDGF-inducible complementary DNA clone. However, the messenger RNA transcripts of mouse c-fos and the new fos-related gene can be distinguished by gel electrophoresis and by S1 nuclease analysis. Expression of the authentic c-fos gene is induced by PDGF and superinduced by the combination of PDGF and cycloheximide.

Regulation of the apolipoprotein AI gene by ARP-1, a novel member of the steroid receptor superfamily

Abstract: Apolipoprotein AI (apoAI) is a lipid-binding protein that participates in the transport of cholesterol and other lipids in the plasma. A complementary DNA clone for a protein that bound to regulatory elements of the apoAI gene was isolated. This protein, designated apoAI regulatory protein-1 (ARP-1), is a novel member of the steroid hormone receptor superfamily. ARP-1 bound to DNA as a dimer, and its dimerization domain was localized to the COOH-terminal region. ARP-1 also bound to a thyroid hormone-responsive element and to regulatory regions of the apoB, apoCIII, insulin, and ovalbumin genes. In cotransfection experiments, ARP-1 downregulated the apoAI gene. The involvement of ARP-1 in the regulation of apoAI gene expression suggests that it may participate in lipid metabolism and cholesterol homeostasis.

A soluble form of the HLA-G antigen is encoded by a messenger ribonucleic acid containing intron 4.

Abstract: The HLA-G primary transcript is alternatively spliced to yield mRNAs encoding three alternative membrane bound proteins. In addition to these forms, a soluble HLA-G protein has been described which is not encoded directly by any of the three alternative mRNAs. To explain the process which might lead to the expression of a soluble HLA-G Ag, we investigated the potential roles proteolytic processing and additional alternative splicing of HLA-G RNA might play. By generating transfected cells with HLA-G cDNA expression driven by a retroviral promoter, it was possible to rule out proteolytic processing of the membrane-bound HLA-G as a mechanism of generating soluble HLA-G, resulting in our focus on alternative splicing as an explanation. Analysis of PCR-amplified cDNA revealed a relatively abundant transcript present in all samples examined which consisted of the full length HLA-G mRNA sequence interrupted by intron 4 sequence. The open reading frame in this mRNA continues into intron 4 terminating 21 amino acids after the alpha 3 domain, thus excluding the transmembrane encoding region and yielding a protein with a highly charged carboxyl terminus. Transfection of the intron 4 containing cDNA, inserted into a retroviral expression vector, into LCL .221 followed by comparison of the class I protein to native soluble G by two dimensional isoelectric focusing/SDS-PAGE analysis, demonstrated this message encoded the soluble HLA-G protein. In addition, a similar intron containing message derived from the HLA-G2 mRNA was found, suggesting the existence of a soluble form of this alternative HLA-G protein. These findings are discussed in relation to other soluble class I molecules and with regard to potential functions of the soluble HLA-G Ag.

Cloning and sequencing of cDNA encoding human DNA topoisomerase II and localization of the gene to chromosome region 17q21-22.

Abstract: Two overlapping cDNA clones encoding human DNA topoisomerase II were identified by two independent methods. In one, a human cDNA library in phage lambda was screened by hybridization with a mixed oligonucleotide probe encoding a stretch of seven amino acids found in yeast and Drosophila DNA topoisomerase II; in the other, a different human cDNA library in a lambda gt11 expression vector was screened for the expression of antigenic determinants that are recognized by rabbit antibodies specific to human DNA topoisomerase II. The entire coding sequences of the human DNA topoisomerase II gene were determined from these and several additional clones, identified through the use of the cloned human TOP2 gene sequences as probes. Hybridization between the cloned sequences and mRNA and genomic DNA indicates that the human enzyme is encoded by a single-copy gene. The location of the gene was mapped to chromosome 17q21-22 by in situ hybridization of a cloned fragment to metaphase chromosomes and by hybridization analysis with a panel of mouse-human hybrid cell lines, each retaining a subset of human chromosomes.