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A Tumolo

Publications and source records attributed to A Tumolo.

6 recordsLinked to original sources

A two-step hybridization method for chemiluminescent detection of single copy genes.

We have developed a technique for the chemiluminescent detection of single copy genes that eliminates the high backgrounds and problems with probe labeling associated with existing methods. The procedure employs a primary hybridization of single-stranded probe DNA to immobilized target DNA, a secondary hybridization with a covalently cross-linked oligonucleotide-alkaline phosphatase conjugate, followed by incubation in the chemiluminescent substrate AMPPD and detection on x-ray film. The key to the success of this method is that the primary probe contains a region complementary to the target DNA as well as to the oligonucleotide sequence of the secondary probe-alkaline phosphatase conjugate. Here we report our results using the two-step hybridization procedure to detect single copy genes from genomic Southern blots.

Actins↗

Structural analysis of the gene for human acidic fibroblast growth factor.

Genomic clones derived from the gene for human acidic fibroblast growth factor (aFGF) have been isolated. Nucleotide sequence analysis of these clones revealed that the coding region of the human aFGF gene is interrupted by two introns, located at precisely homologous locations to introns in four other members of the FGF gene family, strongly indicating a common evolutionary origin for these genes. Northern blot analyses of the multiple aFGF transcripts found in serum-stimulated human foreskin fibroblasts indicated that the aFGF gene also contains a third intron, lying in the 5' untranslated region.

Amino Acid Sequence↗

The structure of the rabbit macrophage defensin genes and their organ-specific expression.

Defensins are a family of microbicidal and cytotoxic peptides abundant in the lysosomal granules of mammalian phagocytes. We present the cDNA and genomic sequences of two rabbit defensins, macrophage cationic peptides MCP-1 and MCP-2. Their cDNA and genomic sequences are highly homologous, reflecting the homology between the two defensins (32 of 33 amino acids). The MCP genes are closely linked (within 13 kb) suggesting that they evolved by a recent tandem gene duplication. Their cDNA sequences indicate that the peptides are synthesized as 95 amino acid prepro-MCPs, consistent with their lysosomal location. The MCP genes are separated into three exons encoding distinct domains: the 5' untranslated region, the prepropeptide domain, and the mature defensin sequence. Fully developed polymorphonuclear leukocytes, short-lived phagocytes with limited capacity for protein and nucleic acid synthesis, contained MCPs but lacked MCP mRNA. MCP mRNA was found in bone marrow and spleen, organs which contained immature polymorphonuclear leukocytes. MCP and MCP mRNA were detected in lung macrophages, but not in macrophages from other organs, nor in monocytes, the putative macrophage precursors. In macrophages, the expression of MCPs appears to be a marker of lung-specific differentiation.

Amino Acid Sequence↗

Nucleotide sequence of a bovine clone encoding the angiogenic protein, basic fibroblast growth factor.

Basic and acidic fibroblast growth factors (FGF's) are potent mitogens for capillary endothelial cells in vitro, stimulate angiogenesis in vivo, and may participate in tissue repair. An oligonucleotide probe for bovine basic FGF was designed from the nucleotide sequence of the amino-terminal exon of bovine acidic FGF, taking into account the 55 percent amino acid sequence homology between the two factors. With this oligonucleotide probe, a full length complementary DNA for basic FGF was isolated from bovine pituitary. Basic FGF in bovine hypothalamus was shown to be encoded by a single 5.0-kilobase messenger RNA; in a human hepatoma cell line, both 4.6- and 2.2-kilobase basic FGF messenger RNA's were present. Both growth factors seem to be synthesized with short amino-terminal extensions that are not found on the isolated forms for which the amino acid sequences have been determined. Neither basic nor acidic FGF has a classic signal peptide.

Angiogenesis Inducing Agents↗

Human basic fibroblast growth factor: nucleotide sequence and genomic organization.

Clones encoding the angiogenic endothelial cell mitogen, basic fibroblast growth factor (FGF), have been isolated from human cDNA libraries made from kidney, fetal heart, fetal liver, term placenta, and a breast carcinoma. Basic FGF cDNA clones are present in these libraries at very low levels when compared to the quantity of the growth factor in the tissues. This observation, combined with the fact that several of the clones represent unspliced transcripts, suggests that cytoplasmic basic FGF mRNA is unstable and that the protein is stored in tissues. The amino acid sequence of human basic FGF, deduced from the sequence of these cDNAs and from genomic clones, is 99% homologous to that of bovine basic FGF, implying a strong selection pressure for maintenance of function and structure. As with the bovine factor, human basic FGF does not appear to have a signal peptide sequence. Southern blot analysis of human genomic DNA and mapping of the cloned gene shows that there is only one basic FGF gene. All of the basic, heparin-binding endothelial cell mitogens of similar amino acid composition that have been described must therefore be products of this single gene.

Amino Acid Sequence↗