scholarly journals Demethylation of specific sites in the 5' region of the inactive X-linked human phosphoglycerate kinase gene correlates with the appearance of nuclease sensitivity and gene expression.

1988 ◽  
Vol 8 (11) ◽  
pp. 4692-4699 ◽  
Author(s):  
R S Hansen ◽  
N A Ellis ◽  
S M Gartler
Keyword(s):  
Cell Lines ◽  
X Chromosome ◽  
Transcriptional Activation ◽  
Hybrid Cell ◽  
Methylation Status ◽  
Phosphoglycerate Kinase ◽  
Kinase Gene ◽  
Inactive X Chromosome ◽  
Phosphoglycerate Kinase Gene ◽  
Hypoxanthine Guanine Phosphoribosyltransferase

X8/6T2, a hamster-human hybrid cell line which contains an inactive human X chromosome, was treated with 5-azacytidine and selected for derepression of hypoxanthine-guanine phosphoribosyltransferase. Clones were examined for coreactivation of the phosphoglycerate kinase gene (Pgk). Of 68 of these hybrids, approximately 20% expressed measurable human phosphoglycerate kinase (PGK) activity. A 600-base-pair region of the Pgk 5' CpG cluster was examined for the methylation status of eight CCGG sites (site 1 being 5'-most) in a number of PGK-negative and PGK-positive cell lines. The inactive X chromosome is normally methylated at all eight sites, and this was also true for the majority of X8/6T2 cells. However, several PGK-negative hybrids were demethylated in the site 3 to site 6 region. PGK activity correlated with demethylation at both sites 6 and 7. The data for PGK-positive and -negative hybrids indicate that demethylation at or near site 7 was necessary for reactivation of Pgk. Chromatin sensitivity to MspI digestion in the nuclei of male lymphoblastoid cells and several PGK-positive and PGK-negative hybrids was examined. PGK-positive cell lines were hypersensitive to digestion, while PGK-negative hybrids were resistant. Cleavage at sites 6 and 7 was observed in all PGK-positive cell lines at each MspI concentration examined. Sites 7 and 8 were less accessible to digestion than site 6. Cleavage in the site 2 to site 5 region was observable at the lowest MspI concentration. In most PGK-positive hybrids, a nonspecific endogenous nuclease detected the presence of a hypersensitive region spanning at least 450 base pairs, bounded at the 3' end near HpaII site 6. Nuclease hypersensitivity appears to be related to promoter activity, because sites 7 and 8 are in transcribed regions of the gene. These data indicate that specific sites within the CpG cluster have a dominant controlling influence over the Pgk promoter conformation and the transcriptional activation of Pgk.

Demethylation of specific sites in the 5' region of the inactive X-linked human phosphoglycerate kinase gene correlates with the appearance of nuclease sensitivity and gene expression

1988 ◽  
Vol 8 (11) ◽  
pp. 4692-4699
Author(s):  
R S Hansen ◽  
N A Ellis ◽  
S M Gartler
Keyword(s):  
Cell Lines ◽  
X Chromosome ◽  
Transcriptional Activation ◽  
Hybrid Cell ◽  
Methylation Status ◽  
Phosphoglycerate Kinase ◽  
Kinase Gene ◽  
Inactive X Chromosome ◽  
Phosphoglycerate Kinase Gene ◽  
Hypoxanthine Guanine Phosphoribosyltransferase

X8/6T2, a hamster-human hybrid cell line which contains an inactive human X chromosome, was treated with 5-azacytidine and selected for derepression of hypoxanthine-guanine phosphoribosyltransferase. Clones were examined for coreactivation of the phosphoglycerate kinase gene (Pgk). Of 68 of these hybrids, approximately 20% expressed measurable human phosphoglycerate kinase (PGK) activity. A 600-base-pair region of the Pgk 5' CpG cluster was examined for the methylation status of eight CCGG sites (site 1 being 5'-most) in a number of PGK-negative and PGK-positive cell lines. The inactive X chromosome is normally methylated at all eight sites, and this was also true for the majority of X8/6T2 cells. However, several PGK-negative hybrids were demethylated in the site 3 to site 6 region. PGK activity correlated with demethylation at both sites 6 and 7. The data for PGK-positive and -negative hybrids indicate that demethylation at or near site 7 was necessary for reactivation of Pgk. Chromatin sensitivity to MspI digestion in the nuclei of male lymphoblastoid cells and several PGK-positive and PGK-negative hybrids was examined. PGK-positive cell lines were hypersensitive to digestion, while PGK-negative hybrids were resistant. Cleavage at sites 6 and 7 was observed in all PGK-positive cell lines at each MspI concentration examined. Sites 7 and 8 were less accessible to digestion than site 6. Cleavage in the site 2 to site 5 region was observable at the lowest MspI concentration. In most PGK-positive hybrids, a nonspecific endogenous nuclease detected the presence of a hypersensitive region spanning at least 450 base pairs, bounded at the 3' end near HpaII site 6. Nuclease hypersensitivity appears to be related to promoter activity, because sites 7 and 8 are in transcribed regions of the gene. These data indicate that specific sites within the CpG cluster have a dominant controlling influence over the Pgk promoter conformation and the transcriptional activation of Pgk.

The testis-specific phosphoglycerate kinase gene pgk-2 is a recruited retroposon

1987 ◽  
Vol 7 (9) ◽  
pp. 3107-3112
Author(s):  
P H Boer ◽  
C N Adra ◽  
Y F Lau ◽  
M W McBurney
Keyword(s):  
Nucleotide Sequence ◽  
Gene Duplication ◽  
X Chromosome ◽  
Phosphoglycerate Kinase ◽  
Sperm Cells ◽  
Kinase Gene ◽  
Evolutionary Diversification ◽  
Key Enzyme ◽  
Phosphoglycerate Kinase Gene ◽  
Kinase A

In both humans and mice, two genes encode phosphoglycerate kinase, a key enzyme in the glycolytic pathway. The pgk-1 gene is expressed in all somatic cells, is located on the X chromosome, and contains 10 introns. The pgk-2 gene is expressed only in sperm cells, is located on an autosome, and has no introns. The nucleotide sequence of the pgk-2 gene suggests that it arose from pgk-1 more than 100 million years ago by RNA-mediated gene duplication. The pgk-2 gene may, then, be a transcribed retroposon. Thus, gene duplication by retroposition may have been used as a mechanism for evolutionary diversification.

Restriction site polymorphism in the phosphoglycerate kinase gene on the X chromosome

1984 ◽  
Vol 66 (2-3) ◽  
pp. 217-219 ◽  
Author(s):  
Mara H. Hutz ◽  
A. M. Michelson ◽  
S. E. Antonarakis ◽  
S. H. Orkin ◽  
H. H. Kazazian
Keyword(s):  
X Chromosome ◽  
Restriction Site ◽  
Phosphoglycerate Kinase ◽  
Kinase Gene ◽  
Restriction Site Polymorphism ◽  
Phosphoglycerate Kinase Gene

Clonality in hepatocellular carcinoma: Analysis of methylation pattern of polymorphic X–chromosome-linked phosphoglycerate kinase gene in females

Hepatology ◽  
1995 ◽  
Vol 22 (1) ◽  
pp. 112-117
Author(s):  
Shigenobu Kawai ◽  
Fumio Imazeki ◽  
Osamu Yokosuka ◽  
Masao Ohto ◽  
Shuichiro Shina ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
X Chromosome ◽  
Phosphoglycerate Kinase ◽  
Methylation Pattern ◽  
Kinase Gene ◽  
Phosphoglycerate Kinase Gene

scholarly journals The testis-specific phosphoglycerate kinase gene pgk-2 is a recruited retroposon.

1987 ◽  
Vol 7 (9) ◽  
pp. 3107-3112 ◽  
Author(s):  
P H Boer ◽  
C N Adra ◽  
Y F Lau ◽  
M W McBurney
Keyword(s):  
Nucleotide Sequence ◽  
Gene Duplication ◽  
X Chromosome ◽  
Phosphoglycerate Kinase ◽  
Sperm Cells ◽  
Kinase Gene ◽  
Evolutionary Diversification ◽  
Key Enzyme ◽  
Phosphoglycerate Kinase Gene ◽  
Kinase A

In both humans and mice, two genes encode phosphoglycerate kinase, a key enzyme in the glycolytic pathway. The pgk-1 gene is expressed in all somatic cells, is located on the X chromosome, and contains 10 introns. The pgk-2 gene is expressed only in sperm cells, is located on an autosome, and has no introns. The nucleotide sequence of the pgk-2 gene suggests that it arose from pgk-1 more than 100 million years ago by RNA-mediated gene duplication. The pgk-2 gene may, then, be a transcribed retroposon. Thus, gene duplication by retroposition may have been used as a mechanism for evolutionary diversification.

scholarly journals Differential activation of the hprt gene on the inactive X chromosome in primary and transformed Chinese hamster cells.

1989 ◽  
Vol 9 (4) ◽  
pp. 1635-1641 ◽  
Author(s):  
S G Grant ◽  
R G Worton
Keyword(s):  
Cell Lines ◽  
X Chromosome ◽  
Gene Activation ◽  
Chinese Hamster ◽  
Fibroblast Cell ◽  
Dna Demethylation ◽  
Hprt Gene ◽  
Primary Fibroblast ◽  
Chinese Hamster Cells ◽  
Inactive X Chromosome

We have investigated the genetic activation of the hprt (hypoxanthine-guanine phosphoribosyltransferase) gene located on the inactive X chromosome in primary and transformed female diploid Chinese hamster cells after treatment with the DNA methylation inhibitor 5-azacytidine (5azaCR). Mutants deficient in HPRT were first selected by growth in 6-thioguanine from two primary fibroblast cell lines and from transformed lines derived from them. These HPRT- mutants were then treated with 5azaCR and plated in HAT (hypoxanthine-methotrexate-thymidine) medium to select for cells that had reexpressed the hprt gene on the inactive X chromosome. Contrary to previous results with primary human cells, 5azaCR was effective in activating the hprt gene in primary Chinese hamster fibroblasts at a low but reproducible frequency of 2 x 10(-6) to 7 x 10(-6). In comparison, the frequency in independently derived transformed lines varied from 1 x 10(-5) to 5 x 10(-3), consistently higher than in the nontransformed cells. This increase remained significant when the difference in growth rates between the primary and transformed lines was taken into account. Treatment with 5azaCR was also found to induce transformation in the primary cell lines but at a low frequency of 4 x 10(-7) to 8 x 10(-7), inconsistent with a two-step model of transformation followed by gene activation to explain the derepression of hprt in primary cells. Thus, these results indicate that upon transformation, the hprt gene on the inactive Chinese hamster X chromosome is rendered more susceptible to action by 5azaCR, consistent with a generalized DNA demethylation associated with the transformation event or with an increase in the instability of an underlying primary mechanism of X inactivation.

scholarly journals Nucleotide Sequence of a Wheat Chloroplastic Phosphoglycerate Kinase Gene

1995 ◽  
Vol 107 (4) ◽  
pp. 1483-1484 ◽  
Author(s):  
P. G. Jones ◽  
C. A. Raines ◽  
J. C. Lloyd
Keyword(s):  
Nucleotide Sequence ◽  
Phosphoglycerate Kinase ◽  
Kinase Gene ◽  
Phosphoglycerate Kinase Gene
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