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p12 DOC1 , a growth suppressor, associates with DNA polymerase α/primase
Author(s) -
Matsuo Kou,
Shintani Satoru,
Tsuji Takanori,
Nagata Emi,
Lerman Michael,
Mcbride Jim,
Nakahara Yuuji,
Ohyama Hiroe,
Todd Randy,
Wong David T. W.
Publication year - 2000
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.14.10.1318
Subject(s) - primase , dna replication , dna polymerase , biology , microbiology and biotechnology , dna polymerase ii , processivity , primer (cosmetics) , dna , chemistry , biochemistry , gene , reverse transcriptase , polymerase chain reaction , organic chemistry
p12 DOC‐1 is a growth suppressor identified and isolated from normal keratinocytes. Ectopic expression of p12 DOC1 in squamous carcinoma cells led to the reversion of in vitro transformation phenotypes including anchorage independence, doubling time, and morphology. Here we report that p12 DOC1 associates with DNA polymerase α/primase (pol‐α: primase) in vitro and in cells. The pol‐α:primase binding domain in p12 DOC‐1 is mapped to the amino‐terminal six amino acid (MSYKPN). The biological effect of p12 DOC1 on pol‐α:primase was examined using in vitro DNA replication assays. Using the SV40 DNA replication assay, p12 DOC‐1 suppresses DNA rep lication, leveling at —50%. Similar results were obtained using the M13 single‐stranded DNA synthesis assay. Analysis of the DNA replication products revealed that p12 DOC1 affects the initiation step, not the elongation phase. The p12 DOC1 suppression of DNA replication is likely to be mediated either by a direct inhibitory effect on pol‐α:primase or by its effect on cyclin‐dependent kinase 2 (CDK2), a recently identified p12 DOC‐1 ‐associated protein known to stimulate DNA replication by phosphorylating pol‐α:primase. p12 DOC1 suppresses CDK2‐mediated phosphorylation of pol‐α:primase. These data support a role of p12 DOC1 as a regulator of DNA replication by direct inhibition of pol‐α:primase or by negatively regulating the CDK2‐mediated phosphorylation of pol‐α:primase.—Matsuo, K., Shintani, S., Tsuji, T., Nagata, E., Lerman, M., McBride, J., Nakahara, Y., Ohyama, H., Todd, R., Wong, D. T. W. p12 DOC‐1 , a growth suppressor, associates with DNA polymerase α/primase. FASEB J. 14, 1318–1324 (2000)