Quantitation of O6-methylguanine-DNA methyltransferase in HeLa cells

R. S. Foote; B. C. Pal; S. Mitra

doi:10.1016/0165-7992(83)90164-1

Quantitation of O⁶-methylguanine-DNA methyltransferase in HeLa cells

R. S. Foote, B. C. Pal, S. Mitra

Research output: Contribution to journal › Article › peer-review

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Abstract

A synthetic DNA polymer containing [8-³H]O⁶-methylguanine m⁶G) was used as a substrate to assay the in situ demethylation of the alkylated base by an activity in HeLa cell extracts. The repair activity appears to be similar to the O⁶-methylguanine-DNA methyltransferase of E. coli and to be inactivated by reaction with the substrate. Extracts of a methylation-repair proficient (Mer⁺) cell strain, HeLa CCL2, were found to contain m⁶G repair activity equivalent to approx. 100 000 molecules of methyltransferase per cell, assuming that each molecule can demethylate one m⁶G residue. No activity could be detected in the extract of a repair deficient (Mer^-) cell strain, HeLa S3, and there is no evidence of an inhibitor of repair activity in this strain.

Original language	English (US)
Pages (from-to)	221-228
Number of pages	8
Journal	Mutation Research Letters
Volume	119
Issue number	3-4
DOIs	https://doi.org/10.1016/0165-7992(83)90164-1
State	Published - Mar 1983

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General Medicine

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10.1016/0165-7992(83)90164-1

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title = "Quantitation of O6-methylguanine-DNA methyltransferase in HeLa cells",

abstract = "A synthetic DNA polymer containing [8-3H]O6-methylguanine m6G) was used as a substrate to assay the in situ demethylation of the alkylated base by an activity in HeLa cell extracts. The repair activity appears to be similar to the O6-methylguanine-DNA methyltransferase of E. coli and to be inactivated by reaction with the substrate. Extracts of a methylation-repair proficient (Mer+) cell strain, HeLa CCL2, were found to contain m6G repair activity equivalent to approx. 100 000 molecules of methyltransferase per cell, assuming that each molecule can demethylate one m6G residue. No activity could be detected in the extract of a repair deficient (Mer-) cell strain, HeLa S3, and there is no evidence of an inhibitor of repair activity in this strain.",

author = "Foote, \{R. S.\} and Pal, \{B. C.\} and S. Mitra",

note = "Funding Information: *Research sponsored by the Office of Health and Environmental Research, U.S. Department of Energy, under contract W-7405-eng-26 with the Union Carbide Corporation and National Cancer Institute under Interagency Agreement Y02-CP-00200. Copyright: Copyright 2014 Elsevier B.V., All rights reserved.",

year = "1983",

month = mar,

doi = "10.1016/0165-7992(83)90164-1",

language = "English (US)",

volume = "119",

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journal = "Mutation Research Letters",

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T1 - Quantitation of O6-methylguanine-DNA methyltransferase in HeLa cells

AU - Foote, R. S.

AU - Pal, B. C.

AU - Mitra, S.

N1 - Funding Information: *Research sponsored by the Office of Health and Environmental Research, U.S. Department of Energy, under contract W-7405-eng-26 with the Union Carbide Corporation and National Cancer Institute under Interagency Agreement Y02-CP-00200. Copyright: Copyright 2014 Elsevier B.V., All rights reserved.

PY - 1983/3

Y1 - 1983/3

N2 - A synthetic DNA polymer containing [8-3H]O6-methylguanine m6G) was used as a substrate to assay the in situ demethylation of the alkylated base by an activity in HeLa cell extracts. The repair activity appears to be similar to the O6-methylguanine-DNA methyltransferase of E. coli and to be inactivated by reaction with the substrate. Extracts of a methylation-repair proficient (Mer+) cell strain, HeLa CCL2, were found to contain m6G repair activity equivalent to approx. 100 000 molecules of methyltransferase per cell, assuming that each molecule can demethylate one m6G residue. No activity could be detected in the extract of a repair deficient (Mer-) cell strain, HeLa S3, and there is no evidence of an inhibitor of repair activity in this strain.

AB - A synthetic DNA polymer containing [8-3H]O6-methylguanine m6G) was used as a substrate to assay the in situ demethylation of the alkylated base by an activity in HeLa cell extracts. The repair activity appears to be similar to the O6-methylguanine-DNA methyltransferase of E. coli and to be inactivated by reaction with the substrate. Extracts of a methylation-repair proficient (Mer+) cell strain, HeLa CCL2, were found to contain m6G repair activity equivalent to approx. 100 000 molecules of methyltransferase per cell, assuming that each molecule can demethylate one m6G residue. No activity could be detected in the extract of a repair deficient (Mer-) cell strain, HeLa S3, and there is no evidence of an inhibitor of repair activity in this strain.

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AN - SCOPUS:0020654385

SN - 0165-7992

VL - 119

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EP - 228

JO - Mutation Research Letters

JF - Mutation Research Letters

IS - 3-4

ER -

Quantitation of O⁶-methylguanine-DNA methyltransferase in HeLa cells

Abstract

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