scholarly journals CAD Gene

2020 ◽  
Author(s):  
Keyword(s):  
Cad Gene

Localization of the Chinese Hamster CAD Gene Reveals Homology between Human Chromosome 2p and Chinese Hamster 7q

Genomics ◽  
1993 ◽  
Vol 16 (3) ◽  
pp. 779-781 ◽  
Author(s):  
Livia Bertoni ◽  
Carmen Attolini ◽  
Silvana Simi ◽  
Elena Giulotto
Keyword(s):  
Human Chromosome ◽  
Chinese Hamster ◽  
Cad Gene

Transcriptional regulation of the human CAD gene during myeloid differentiation

1987 ◽  
Vol 7 (5) ◽  
pp. 1961-1966
Author(s):  
G N Rao ◽  
E S Buford ◽  
J N Davidson
Keyword(s):  
Gene Expression ◽  
De Novo ◽  
Morphological Changes ◽  
Transcriptional Level ◽  
Carbamoyl Phosphate ◽  
Aspartate Transcarbamylase ◽  
Trans Retinoic Acid ◽  
Beta Actin ◽  
Cad Gene ◽  
Cad Protein

CAD codes for a trifunctional protein involved in the catalysis of the first three enzymatic activities in the de novo pyrimidine biosynthetic pathway, namely, carbamoyl-phosphate synthetase II (EC 6.3.5.5), aspartate transcarbamylase (EC 2.1.3.2), and dihydroorotase (EC 3.5.2.3). CAD regulation was studied in the human promyelocyte leukemic line HL-60 as it differentiated into monocytic or granulocytic lineages after induction by 12-O-tetradecanoylphorbol-13-acetate or trans-retinoic acid and dibutyryl cyclic AMP, respectively. Within 12 h of induction of HL-60 cells with either inducer, total cellular levels of CAD RNA essentially disappeared. On the other hand, no apparent decreases in beta-actin RNA levels were seen even 48 h after HL-60 cells were induced, as compared with untreated cells. With nuclear runoff assays, it was clearly shown that the inactivation of CAD gene expression during the induction of HL-60 cells with either inducer was at the transcriptional level. The nuclear runoff experiments also demonstrated that the CAD gene expression was shut down in less than 4 h after induction, well before morphological changes were observed in these cells. At the enzymatic level, the activity of aspartate transcarbamylase, one of the three enzymes encoded by the CAD gene, decreased by about half within 24 h of induction, suggesting a CAD protein half-life of 24 h in differentiating HL-60 cells. Nevertheless, this means that significant levels of aspartate transcarbamylase activity remained even after the cells have stopped proliferating. From the RNA data, it is clear that CAD gene expression is rapidly turned off as promyelocytes begin to terminally differentiate into macrophages and granulocytes. We suspect that the inactivation of the CAD gene in induced HL-60 cells is a consequence of the differentiating cells leaving the cell cycle and becoming nonproliferating.

Analysis of CAD Gene Amplification Using a Combined Approach of Molecular Genetics and Cytogenetics

1984 ◽  
pp. 319-345 ◽  
Author(s):  
Geoffrey M. Wahl ◽  
Virginia Allen ◽  
Suzanne Delbruck ◽  
Walter Eckhart ◽  
Judy Meinkoth ◽  
...  
Keyword(s):  
Molecular Genetics ◽  
Gene Amplification ◽  
Combined Approach ◽  
Cad Gene

scholarly journals Evolution and stability of chromosomal DNA coamplified with the CAD gene.

1989 ◽  
Vol 9 (6) ◽  
pp. 2445-2452 ◽  
Author(s):  
I Saito ◽  
R Groves ◽  
E Giulotto ◽  
M Rolfe ◽  
G R Stark
Keyword(s):  
Syrian Hamster ◽  
Copy Number ◽  
High Copy Number ◽  
Second Step ◽  
Chromosomal Dna ◽  
Average Amount ◽  
Large Domain ◽  
Cad Gene ◽  
The Stability ◽  
Striking Contrast

We have compared clones of Syrian hamster cells selected for the first amplification of the CAD gene with clones selected for further amplification. The large domain amplified initially was not reamplified as an intact unit. Instead, subregions were reamplified preferentially, and parts of the initial array were often lost. These events reduced the average amount of coamplified DNA accompanying each copy of the selected gene. The degree of amplification was small in the first step (about three extra copies of CAD per cell), but second-step amplifications to a high copy number (up to 60 extra copies per cell) occurred frequently. After several separate steps of amplification, highly condensed arrays that brought many CAD genes close together were formed. In striking contrast to the stability of these highly amplified arrays, the low-copy chromosomal arrays formed early were quite unstable and were often lost completely within 1 or 2 months of growth without selection. The results suggest that different mechanisms may be involved in the first step of amplification and in the later evolution of an already amplified array.

Single-copy and amplified CAD genes in Syrian hamster chromosomes localized by a highly sensitive method for in situ hybridization

1982 ◽  
Vol 2 (3) ◽  
pp. 308-319
Author(s):  
G M Wahl ◽  
L Vitto ◽  
R A Padgett ◽  
G R Stark
Keyword(s):  
In Situ Hybridization ◽  
Syrian Hamster ◽  
Specific Radioactivity ◽  
Large Chromosome ◽  
Hybridization Technique ◽  
Wild Type ◽  
Aspartate Transcarbamylase ◽  
Metaphase Chromosomes ◽  
Cad Gene

Syrian hamster cells resistant to N-(phosphonacetyl)-L-aspartate (PALA), a specific inhibitor of the aspartate transcarbamylase activity of the multifunctional protein CAD, overproduce this protein as a result of amplification of the CAD gene. We have used a sensitive in situ hybridization technique to localize CAD genomes in spreads of metaphase chromosomes from several independent PALA-resistant lines and from wild-type PALA-sensitive cells. The amplified genes were always found within chromosomes, usually in an expanded region of the short arm of chromosome B9. In wild-type cells, the CAD gene was also on the short arm of chromosome B9. In one mutant line, 90 to 100 CAD genes were found within an expanded B9 chromosome and 10 to 15 more were near the distal end of one arm of several different chromosomes. Another line contained most the genes in a telomeric chromosome or large chromosome fragment. The amplified genes were in chromosomal regions that were stained in a banded pattern by trypsin-Giemsa. A few double minute chromosomes were observed in a very small fraction of the total spreads examined. The it situ hybridizations were performed in the presence of 10% dextral sulfate 500, which increases the signal by as much as 100-fold. Using recombinant DNA plasmids nick-translated with [125I]dCTP to high specific radioactivity, 10 CAD genes in a single chromosomal region were revealed after 1 week of autoradiographic exposure, and the position of the unique gene could be seen after 1 month.

Structure of the gene for CAD, the multifunctional protein that initiates UMP synthesis in Syrian hamster cells

1982 ◽  
Vol 2 (3) ◽  
pp. 293-301
Author(s):  
R A Padgett ◽  
G M Wahl ◽  
G R Stark
Keyword(s):  
Electron Microscopy ◽  
Syrian Hamster ◽  
Specific Inhibitor ◽  
Aspartate Transcarbamylase ◽  
Multifunctional Protein ◽  
Intervening Sequences ◽  
Multiple Copies ◽  
Cad Gene ◽  
Polyadenylated Rnas ◽  
Ump Synthesis

Two adjacent fragments of genomic DNA spanning the gene for CAD, which encodes the first three enzymes of UMP biosynthesis, were cloned from a mutant Syrian hamster cell line containing multiple copies of this gene. The mutant was selected for resistance to N-(phosphonacetyl)-L-aspartate, a potent and specific inhibitor of aspartate transcarbamylase, the second enzyme in the pathway. The sizes and positions of about 37 intervening sequences within the 25-kilobase CAD gene were mapped by electron microscopy, and the locations of the 5' and 3' ends of the 7.9-kilobase CAD mRNA were established by electron microscopy and by other hybridization methods. The coding sequences are small (100 to 400 bases), as are most of the intervening sequences (50 to 300 bases). However, there are also several large intervening sequences of up to 5,000 bases each. Two small cytoplasmic polyadenylated RNAs are transcribed from a region just beyond the 5' end of the CAD gene, and their abundance reflects the degree of gene amplification.

scholarly journals Structure of DNA formed in the first step of CAD gene amplification.

1986 ◽  
Vol 5 (9) ◽  
pp. 2115-2121 ◽  
Author(s):  
E. Giulotto ◽  
I. Saito ◽  
G.R. Stark
Keyword(s):  
Gene Amplification ◽  
Cad Gene

Induction of CAD gene amplification by restriction endonucleases in V79,B7 Chinese hamster cells

1989 ◽  
Vol 225 (1-2) ◽  
pp. 61-64 ◽  
Author(s):  
P. Cavolina ◽  
C. Agnese ◽  
A. Maddalena ◽  
G. Sciandrello ◽  
A. Di Leonardo
Keyword(s):  
Gene Amplification ◽  
Chinese Hamster ◽  
Restriction Endonucleases ◽  
Chinese Hamster Cells ◽  
Cad Gene
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