The cells of any living being can divide by means of two mechanisms: through mitosis, which is the way cells divide during cell growth of the majority of living organisms, and by meiosis, the process by which sex or germ cells are formed. For scientists, precise knowledge of the way living cells divide is of vital importance for understanding anomalous functioning in the growth of tumoral and carcinogenic cells.

In this study, published today by the journal Nature, the UPF researchers identified, in cells of the fission yeast Schizosaccharomyces pombe, a new mechanism regulating the activity of a cyclin , Rem1. Cyclins are a type of protein that is indispensable for cell division. They are the essential engine causing the cells to divide.

RNA synthesis is an intermediary step in the transmission of the genetic information in DNA and the proteins resulting from its transcription and subsequent translation. The UPF researchers' work shows that, in the expression of the Rem1 gene , the synthesis of RNA and its subsequent processing are two coupled procedures directed by the same gene, which, depending on how the genetic information is processed, may perform various functions in the control of cell division. If Rem1 is produced during mitosis, cell division is blocked; however, this same cyclin is indispensable in meiotic cell division.

The director of the study, José Ayté, says that "cyclins are the motor that makes eukaryotic cells divide and when they lose the mechanisms that control the activity of the cyclins, the cells proliferate indiscriminately, hence the importance of controlling their activity at various levels". "In this article we have proposed a new mechanism for regulating the activity of the cyclins and de-activating them when one does not want cell division to take place", Ayté concluded.

Reference article:

Alberto Moldón, Jordi Malapeira, Natalia Gabrielli, Madelaine Gogol, Blanca Gómez-Escoda, Tsvetomira Ivanova, Chris Seidel and José Ayté, "Promoter-driven splicing regulation in fission yeast", Nature, doi: 10.1038/nature07325.