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Biomedical subjects

F Costanzo

Publications and source records attributed to F Costanzo.

At least 55 records · Page 3Linked to original sources
PubMed1985

Study of herpes simplex virus type 1 populations obtained from recurrences and primary infections.

The analysis of 23 clinical isolates of herpes simplex virus type 1 (HSV-1) showed that 15 of 15 isolates that had undergone a few passages in tissue culture (fresh isolates) and two of eight isolates that had never been passaged (new isolates) were composed of a mixed population with respect to plaque morphology in Vero cells. Cloning and characterization of 10 large plaque viruses (L variants) and nine small plaque viruses (S variants), obtained from seven different isolates, showed the following. BamHI DNA restriction patterns of the L and the S variants from a single isolate differed only with respect to the electrophoretic mobility of the fragments that contain reiteration of specific sequences; they did not differ regarding the presence or the absence of restriction endonuclease cleavage sites. The L and S variants differed with respect to the electrophoretic profiles of infected cell glycoproteins, thermosensitivity of growth and plaquing efficiency at 39 degrees C, and, at least in the case of the two couples of variants that we tested, pathogenicity for the mouse. The hypothesis that the L variants might arise from the S variant during in vivo replication is discussed.

Adult↗
PubMed1984

Cloning and sequencing of a full length cDNA coding for a human apoferritin H chain: evidence for a multigene family.

We have cloned a segment of cDNA from human liver coding for an apoferritin subunit, probably an H chain. Sequence comparison with the available protein sequence shows that our clone corresponds to a ferritin subunit present as a minor species in human spleen and placenta, but as major species in HeLa cells. Northern blot analysis shows the existence of only one band of similar size in human liver, HeLa cells, Daudi lymphoma and Hep3B hepatoma cell lines. In contrast, Southern blot analysis provides evidence for a multigene family.

Amino Acid Sequence↗
PubMed1984

Inhibition of eukaryotic tRNA transcription by potential Z-DNA sequences.

The effect of d(CA/TG)n DNA segments on tRNA transcription has been examined. Alternating purine-pyrimidine tracts were cloned at a long distance from, adjacent to, or within the coding sequence of a tRNAPro gene from Caenorhabditis elegans and shown to be able to assume the A-DNA conformation in vitro in physiological salt concentrations. The transcriptional level of these constructs was compared to that of normal tDNAPro by micro-injection into Xenopus laevis oocytes. Our results show a strong inhibitory effect by potential Z-DNA sequences only when these are placed in the flanking regions of the gene or when they are located between the elements (Box A and Box B) of the split promoter. Transcription was studied in parallel with supercoiled and linear DNA molecules carrying a d(CA/TG) stretch 124-bp long in front of the tRNAPro gene. The results show the same level of inhibition of Po/III transcription regardless of the topological status of the injected DNA.

Animals↗
PubMed1983

Cloning and sequencing of a full length cDNA coding for human retinol-binding protein.

We have isolated and sequenced a cDNA clone coding for human Retinol Binding Protein. The sequence indicates that Retinol Binding Protein is synthesized as a single polypeptide chain precursor which is then matured to the secreted protein by removal of a leader peptide. Southern and Northern blot analysis suggest that the gene is present in one or few copies per haploid genome and is transcribed in a single mRNA species.

Amino Acid Sequence↗
PubMed1983

Sequence of human haptoglobin cDNA: evidence that the alpha and beta subunits are coded by the same mRNA.

We have isolated and sequenced a cDNA clone coding for human haptoglobin. Our sequence shows that haptoglobin is very likely synthesized as a single polypeptide chain which is then cleaved at an Arg residue to generate its two characteristic alpha and beta subunit. Southern blot analysis suggests that there are at least two copies of the haptoglobin gene per haploid genome.

Amino Acid Sequence↗
PubMed1983

Cloning of several cDNA segments coding for human liver proteins.

A human cDNA library was constructed using M13 derivative vectors. The simple and rapid procedures for sequencing single-stranded DNA by the dideoxy chain termination method allowed a screening of individual clones directly by DNA sequence analysis. Some of these clones were identified as coding for: serum albumin, alpha1-antitrypsin, retinol-binding protein, prothrombin, haptoglobin, and metallothionein. Furthermore, a clone coding for aldolase B was tentatively identified on the basis of high sequence homology with rabbit muscle aldolase.

Amino Acid Sequence↗
PubMed1983

Modified nucleosides in body fluids of tumor-bearing patients.

The catabolism of nucleic acids, particularly tRNA, produces a variety of modified nucleosides which are not reutilized by mammalian cells. Investigation of these compounds in body fluids, mainly urine, has recently provided evidence of altered metabolic situations in tumor-bearing patients. The factors involved in the alterations of modified nucleosides formation are connected with altered tRNA-modifying enzymes and/or altered turnover of subpopulations of tRNA. A common pattern in tumor cells or tissues is the presence of isoaccepting tRNA species containing aberrant nucleoside modifications. Several modified nucleosides have been detected and quantitated by HPLC analysis of the urine of normal subjects and cancer patients. Results obtained, in the authors' laboratory, among others, indicate a possible correlation between urinary excretion of these compounds and the course of the disease, with implications for the follow-up of therapeutic treatment. Particular reference should be made to psi, which appears to be a suitable marker for monitoring these subjects. The data from the authors' laboratory also show that the analysis of modified nucleosides in blood may be considered a useful tool in the search for proper markers associated with the cancer status. In this respect psi is suggested as a biochemical indicator for cancer patients.

Chromatography, High Pressure Liquid↗
PubMed1983

Common and interchangeable elements in the promoters of genes transcribed by RNA polymerase iii.

We have shown that the 34 bp internal control region of the somatic 5S RNA gene from Xenopus borealis can be split into two separable components. A maxigene carrying an insertion between nucleotide 71 and nucleotide 74 of the coding region is actively transcribed in the nucleus of X. laevis oocytes, giving rise to a maxitranscript with initiation and termination points identical with those of the wild-type transcript. The first 11 bases of the 5S RNA gene promoter are shown to be structurally and functionally homologous with the first component (box A) of the promoter for tRNA genes. This was shown by constructing hybrid 5S RNA-tRNAPro and tRNAPro-5S RNA genes that were efficiently transcribed in the X. laevis oocytes. Initiation of transcription appears to be a complex phenomenon in which both components of the internal promoter play a role.

Animals↗
PubMed1983

N-acetylgalactosaminyltransferase activity involved in O-glycosylation of herpes simplex virus type 1 glycoproteins.

We report on N-acetylgalactosaminyltransferase (UDPacetylgalactosamine--protein acetylgalactosaminyltransferase; EC 2.4.1.41) activity in herpes simplex virus type 1 (HSV-1)-infected BHK and RicR14 cells, a line of ricin-resistant BHK cells defective in N-acetylglucosaminyltransferase I. The enzyme catalyzed the transfer of [14C]N-acetylgalactosamine (GalNAc) from UDP-[14C]GalNAc into HSV glycoproteins, as identified by immunoprecipitation. The sugar was selectively incorporated into the immature forms of herpesvirus glycoproteins pgC, pgD, and gA-pgB, which are known to contain N-linked glycans of the high-mannose type. The high incorporation of [14C]GalNAc into endogenous acceptors of HSV-1-infected RicR14 cells was consistent with the accumulation of immature forms of HSV glycoproteins which occurs in these cells. Mild alkaline borohydride treatment of glycoproteins labeled via GalNAc transferase showed that the transferred GalNAc was O-linked and represented the first sugar added to the peptide backbone.

Acetylgalactosamine↗
PubMed1982

A prokaryotic tRNATyr gene, inactive in Xenopus laevis oocytes, is activated by recombination with an eukaryotic tRNAPro gene.

Eukaryotic tDNA promoters are composed of two essential regions contained within the coding sequence (Box A and Box B). Due to the highly conserved structure of prokaryotic and eukaryotic tRNA, most prokaryotic tRNA genes are expected to be active templates in eukaryotic transcriptional systems. In this paper we show that Escherichia coli tDNATyr is not transcribed in the nucleus of Xenopus laevis oocytes. By in vitro construction of hybrid molecules between inactive prokaryotic tDNATyr from E. coli, and active eukaryotic tDNAPro from Caenorhabditis elegans, we show that tDNATyr can be made into an active gene if its first third, including the Box A region, is replaced by that of the eukaryotic tDNA . These results suggest that an improper Box A sequence is responsible for the inactivity of the E. coli tRNATyr gene, and argue against the role of secondary and tertiary DNA conformations in RNA polymerase III transcription.

Animals↗
PubMed1980

Restriction of herpes simplex virus by Ama 1 cells. An analysis of viral macromolecule synthesis.

Ama 1 cells, and alpha-amanitin-resistant subline of CHO cells, restricted herpes simplex virus-1 and -2 replication. The infection was characterized by i) induction of typical cytopathology; ii) appearance of all the major virus proteins, glycoproteins and DNA earlier than in HEp-2 cells, followed by shut off of virus macromolecule synthesis; iii) defective maturation of viral particles, i.e. scarce assembly and lack of envelopment. The early shut off of viral DNA and protein synthesis, and the altered glycoprotein pattern may account for herpes simplex virus restriction.

Amanitins↗
PubMed1979

Influence of genetic and physiological properties of the host cell on the cytopathic expression of herpes simplex virus.

Two plaque morphology variants, a cell aggregating variant and a syncytial variant, were isolated from MDBK cells infected with the MP mutant of herpes simplex virus, type 1. The variants differed in the polypeptides produced in infected MDBK cells. The properties of the variants were stable on passage in cells and both variants produced only syncytia in KB and Hep-2 cells. The physiological state of MDBK cells influenced the cytopathological expression of the infecting virus, so that, under certain conditions, each variant could shift from one type of plaque morphology to the other. However, attempts to correlate this plaque morphology shift with a difference in the glycopolypeptides synthesized in the infected cells were unsuccessful.

Animals↗
PubMed1977

Evidence that herpes simplex virus DNA is transcribed by cellular RNA polymerase B.

In herpes simplex virus type 1 (HSV-1)-infected HEp-2 cells, amanitin added before or at various times after infection always reduced viral multiplication. Also, the three waves of transcription of HSV-1 DNA, which led to the synthesis of alpha, beta-, and gamma-polypeptides, were all sensitive to amanitin in HEp-2 cells, and the amanitin-sensitive RNA polymerase activities of isolated nuclei were equally sensitive to the inhibitor before and during the infection. On the contrary, HSV-1 DNA transcription was totally unaffected by amanitin in AR1/9-5B cells, a mutant subline of CHO cells that possesses an amanitin-resistant RNA polymerase B. Together, these results strongly suggest that HSV-1 DNA utilizes for its transcription a polymerase undistinguishable from host cell RNA polymerase B with respect to its sensitivity to amanitin.

Amanitins↗
PubMed1976

Effect of non-permissive temperature on protein synthesis of frog virus 3 infected cells.

In the present paper we describe the kinetics of virus specific protein synthesis in FV3-infected BHK cells incubated at the non-permissive temperature of 33 degrees C. Some quantitative differences were detected, in comparison with proteins synthesized at permissive temperature (26 degrees C). Thereafter we studied the fate of polypeptides pulse labelled at non-permissive temperature, by shifting the infected cells to permissive temperature. In such experimental conditions infectious virus is readily produced; however the profiles of electrophoretically separated polypeptides did not differ remarkably from those obtained from cells maintained at 33 degrees C.

Animals↗
PubMed1975

Modifications of cellular RNA-polymerase II after infection with frog virus 3.

RNA-polymerase II extracted from FV3-infected and uninfected BHK cells were compared by measuring their abilities to bind [3-H]-amanitin and ribonucleoside triphosphates. Binding sites for [3-H]-amanitin and the dissociation constant of the complex between [3H]-amanitin and RNA-polymerase II were significantly modified following FV3 infection. The apparent Km's for ribonucleoside triphosphates remained unchanged.

Adenosine Triphosphate↗