Submitted on May 2, 2001
Revised on August 27, 2001
Accepted on September 4, 2001

"The cyclin B1 Gene is Actively Transcribed During Mitosis in HeLa Cells".

¹ Dipartimento di Oncologia Sperimentale, Istituto Regina Elena, Via delle Messi D'Oro 156, 00158 Rome, Italy
² Laboratory of Molecular Growth Regulation, NICHD, NIH, Bethesda, MD 20892, USA

^* To whom correspondence should be addressed. E-mail: piaggio@ifo.it

In mammalian cells, the expression level of the cyclin B1 gene plays a critical role in the progression through mitosis. Here we demonstrate that the transcriptional activity of the human cyclin B1 promoter, as well as the rate of gene transcription, is high during mitosis. Indeed, the cyclin B1 promoter maintains an open chromatin configuration at the mitotic stage. Consistent with this, we show that the cyclin B1 promoter is occupied and bound to NF-Y during mitosis in vivo . Our results provide the first example of RNA polymerase II-dependent transcription during mitosis in mammalian cells.

1. Frenster JH, Landrum SR, Masek MA, Nakatsu SL, and Wilson LS, "Comparison of DNA Helix Openings During In-Vivo Mitosis of Normal and Neoplastic Human Cells", Proc. Am. Assoc. Cancer Res. 19: p. 1 (March, 1978).

2. Frenster JH, "Activation of DNA Transcription Within Repressed Chromatin", 14th John Innes Symposium, September 5-8, 2001.