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Your search keyword '"Dion, Arnold S."' showing total 103 results
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103 results on '"Dion, Arnold S."'

10. Identification of a previously unknown human collagen chain, alpha-1(XV), characterized by extensive interruptions in the triple-helical region

Author

Myers, Jeanne C., Kivirikko, Sirpa, Gordon, Marion K., Dion, Arnold S., and Pihlajeniemi, Taina

Subjects
Collagen -- Analysis, Polypeptides -- Identification and classification, Glycosylation -- Physiological aspects, Science and technology
Abstract

A human placenta cDNA library yielded a clone, termed PF19, which encoded a previously unknown collagen chain. Sequence analysis showed that PF19 contains an insert which codes for a protein of 709 residues including a NH2-terminal signal sequence. Homology searches indicated that the NH2-terminal domain is collagenous while the COOH-terminal domain is noncollagenous. However, the collagenous sequences are interrupted by sequences which may function in glycosylation. It is proposed that this polypeptide be named the alpha-1 chain of type XV collagen.

Published
1992

13. HIF Regulation of ANK Expression in Nucleus Pulposus Cells: Possible Implications in Controlling Dystrophic Mineralization in the Intervertebral Disc

Author

Skubutyte, Renata, Markova, Dessislava, Freeman, Theresa A., Anderson, D. Greg, Dion, Arnold S., Williams, Charlene J., Shapiro, Irving M., and Risbud, Makarand V.

Subjects
Adult, Aged, 80 and over, Ankyrins, Mice, Knockout, Blotting, Western, Calcinosis, Gene Expression, Middle Aged, Embryo, Mammalian, Hypoxia-Inducible Factor 1, alpha Subunit, Article, Cell Hypoxia, Rats, Mice, Basic Helix-Loop-Helix Transcription Factors, Animals, Humans, Gene Silencing, Hypoxia-Inducible Factor 1, RNA, Messenger, Fluorescent Antibody Technique, Indirect, Intervertebral Disc, Cells, Cultured, Aged
Abstract

Since nucleus pulposus cells reside under conditions of hypoxia, we determined if the expression of ANK, a pyrophosphate transporter, is regulated by the hypoxia-inducible factor (HIF) proteins.Quantitative reverse transcription-polymerase chain reaction and Western blot analyses were used to measure ANK expression in nucleus pulposus cells from rats and humans. Transfections were performed to determine the effect of HIF-1/2 on ANK promoter activity.ANK was expressed in embryonic and mature rat discs. Oxygen-dependent changes in ANK expression in nucleus pulposus cells were minimal. However, silencing of HIF-1α and HIF-2α resulted in increased ANK expression and up-regulation of promoter activity. HIF-mediated suppression of ANK was validated by measuring promoter activity in HIF-1β-null embryonic fibroblasts. Under conditions of hypoxia, there was induction of promoter activity in the null cells as compared with the wild-type cells. Overexpression of HIF-1α and HIF-2α in nucleus pulposus cells resulted in a significant suppression of ANK promoter activity. Since the ANK promoter contains 2 hypoxia-responsive elements (HREs), we performed site-directed mutagenesis and measured promoter activity. We found that HIF-1 can bind to either of the HREs and can suppress promoter activity; in contrast, HIF-2 was required to bind to both HREs in order to suppress activity. Finally, analysis of human nucleus pulposus tissue showed that while ANK was expressed in normal tissue, there was increased expression of ANK along with alkaline phosphatase in the degenerated state.Both HIF-1 and HIF-2 serve as negative regulators of ANK expression in the disc. We propose that baseline expression of ANK in the disc serves to prevent mineral formation under physiologic conditions.

Published
2010

14. Mammary Tumor Viruses

Author

Moore, Dan H., primary, Long, Carole A., additional, Vaidya, Akhil B., additional, Sheffield, Joel B., additional, Dion, Arnold S., additional, and Lasfargues, Etienne Y., additional

Published
1979
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15. P5L mutation in Ank results in an increase in extracellular inorganic pyrophosphate during proliferation and nonmineralizing hypertrophy in stably transduced ATDC5 cells

Author

Zaka, Raihana, Stokes, David, Dion, Arnold S., Kusnierz, Anna, Han, Fei, Williams, Charlene J., Zaka, Raihana, Stokes, David, Dion, Arnold S., Kusnierz, Anna, Han, Fei, and Williams, Charlene J.

Abstract

Ank is a multipass transmembrane protein that regulates the cellular transport of inorganic pyrophosphate. In the progressive ankylosis (ank) mouse, a premature termination mutation at glutamic acid 440 results in a phenotype characterized by inappropriate deposition of basic calcium phosphate crystals in skeletal tissues. Mutations in the amino terminus of ANKH, the human homolog of Ank, result in familial calcium pyrophosphate dihydrate deposition disease. It has been hypothesized that these mutations result in a gain-of-function with respect to the elaboration of extracellular inorganic pyrophosphate. To explore this issue in a mineralization-competent system, we stably transduced ATDC5 cells with wild-type Ank as well as with familial chondrocalcinosis-causing Ank mutations. We evaluated the elaboration of inorganic pyrophosphate, the activity of pyrophosphate-modulating enzymes, and the mineralization in the transduced cells. Expression of transduced protein was confirmed by quantitative real-time PCR and by ELISA. Levels of inorganic pyrophosphate were measured, as were the activities of nucleotide pyrophosphatase phosphodiesterase and alkaline phosphatase. We also evaluated the expression of markers of chondrocyte maturation and the nature of the mineralization phase elaborated by transduced cells. The cell line expressing the proline to leucine mutation at position 5 (P5L) consistently displayed higher levels of extracellular inorganic pyrophosphate and higher phosphodiesterase activity than the other transduced lines. During hypertrophy, however, extracellular inorganic pyrophosphate levels were modulated by alkaline phosphatase activity in this cell system, resulting in the deposition of basic calcium phosphate crystals only in all transduced cell lines. Cells overexpressing wild-type Ank displayed a higher level of expression of type X collagen than cells transduced with mutant Ank. Other markers of hypertrophy and terminal differentiation, such as alkali

Published
2006

28. Related Glycoproteins from Normal Secretory and Malignant Breast Cells.

Author

Ishida, Masao, Major, Pierre P., Ura, Yasuaki, and Dion, Arnold S.

Abstract

Monoclonal antibody MA5 [ 1 ] recognizes an epitope present on the surface and in the cytoplasm of human breast cancer cells [2] and on the human milk fat globule membrane (MFGM). These immunoreactive determinants are found on tumor-associated glycoproteins with apparent molecular weights of 280 and 300 kdaltons, whereas the cross-related milk fat globule membrane antigen appears larger (330 kdaltons). Comparative electrophoretic migration analyses following neuraminidase digestion, as well as differential binding to various lectins, established that these molecules are extensively sialylated, and that the tumor antigens were sialylated to a greater extent than normal antigen. Immunoaffinity purification of this class of differentiation antigens from tumor and MFGM demonstrated similar size distributions, lectin affinities and buoyant densities as their respective crude antigens. Copyright © 1989 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Published
1989
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31. Isolation and Characterization of RNA-Directed DNA Polymerase from a B-Type RNA Tumor Virus

Author

Dion, Arnold S., Vaidya, Akhil B., Fout, Garland S., and Moore, Dan H.

Abstract

RNA-directed DNA polymerase was isolated from milk-borne B-type murine mammary tumor virus of the RIII mouse strain. The several hundred-fold-purified enzyme sediments at 5.5 to 5.7Swith an average molecular weight of approximately 100,000. The purified enzyme is completely template dependent and responds to RNA, DNA, and synthetic templates. Stability studies indicate differential lability dependent on the exogenous template used to monitor activity.

Published
1974
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32. Polyamines in the Synthesis of Bacteriophage Deoxyribonucleic Acid II. Requirement for Polyamines in T4 Infection of a Polyamine Auxotroph

Author

Dion, Arnold S. and Cohen, Seymour S.

Abstract

Polyamine depletion produced by exogenous arginine in Escherichia coliK-12cultures defective in agmatine ureohydrolase activity resulted in a marked inhibition of the rates of growth and nucleic acid synthesis. Addition of putrescine or spermidine to such depleted cultures restored the control rate of growth and nucleic acid accumulation. The omission of lysine resulted in a further decrease in the rates of growth and nucleic acid synthesis in polyamine-depleted cells. The addition of exogenous cadaverine increased the rates of growth and ribonucleic acid synthesis to those observed in lysine-supplemented cultures, suggesting that lysine or a derivative of lysine serves a function similar to cadaverine. Addition of lysine to polyamine-depleted cultures at neutral pH results in the synthesis of cadaverine and a new spermidine analogue, both containing lysine carbon. This new metabolite has been isolated and identified as N-3-aminopropyl-1, 5-diaminopentane. T4D infection of the polyamine-depleted mutant resulted in a very low rate of DNA synthesis and phage maturation. The addition of putrescine or spermidine 15 min before infection restored phage DNA synthesis and phage maturation to control rates, i.e., rates observed in infected cells grown in the absence of arginine.

Published
1972
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33. Polyamines in the Synthesis of Bacteriophage Deoxyribonucleic Acid. I. Lack of Dependence of Polyamine Synthesis on Bacteriophage Deoxyribonucleic Acid Synthesis

Author

Dion, Arnold S. and Cohen, Seymour S.

Abstract

To determine whether polyamine synthesis is dependent on deoxyribonucleic acid (DNA) synthesis, polyamine levels were estimated after infection of bacterial cells with ultraviolet-irradiated T4 or T4 amN 122, a DNA-negative mutant. Although phage DNA accumulation was restricted to various degrees in comparison to cells infected with T4D, nearly commensurate levels of putrescine and spermidine synthesis were observed after infection, regardless of the rate of phage DNA synthesis. We conclude from these data that polyamine synthesis after infection is independent of phage DNA synthesis.

Published
1972
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