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pubmed:abstractText |
Plk (polo-like kinase) is a serine-threonine kinase that appears to function in mitotic control in mammalian cells. We demonstrated previously that PLK mRNA expression is low at the G1-S transition, increases during S phase, and is maximally expressed during G2-M. In the present study, we have cloned the human PLK gene and analyzed the structure and function of 2 kilobases of its 5'-flanking region. Using synchronized cultures of HeLa cells transfected with PLK promoter/luciferase constructs, we show that the promoter of PLK is activated at S phase and is maximal at G2-M phase. Using various PLK promoter/luciferase constructs, we show that three activating regions are located between 35 and 93 base pairs upstream of the transcription initiation site. We identified a repressor element (CDE/CHR) in the region of the transcription start site, and mutations within this element diminished cell cycle regulation of transcription.
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pubmed:affiliation |
Laboratory of Leukocyte Biology, Division of Cancer Treatment, National Cancer Institute, Frederick Cancer Research and Development Center, Frederick, Maryland 21702-1201, USA.
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