Extrachromosomal DNA DNA in a variety of different organisms. Extrachromosomal DNA Extrachromosomal DNA is any DNA that is found outside the nucleus of a cell. It is also referred to as extranuclear DNA or cytoplasmic DNA. Most DNA in an individual genome is found in chromosomes but DNA found outside the nucleus also serves important biological functions. In prokaryotes, nonviral extrachromosomal DNA is primarily found in plasmids whereas in eukaryotes extrachromosomal DNA is primarily found in organelles. Mitochondrial DNA is a main source of this extrachromosomal DNA in eukaryotes. The fact that this organelle contains its own DNA supports the hypothesis that
Calcium signaling in cell division cell lines, that the G2/M checkpoint is regulated by CaMKII and MAPK crosstalk. Here, CaMKII activates MEK/ERK, which degrades the cell cycle arresting p27 protein In general, transformed cells proliferate in a calcium-independent manner, whereas non-transformed cells show high sensitivity to extra-cellular calcium concentration, suggesting oncogenic growth may include disruption of calcium signaling. Condensation of chromatin is a vital step in cell division, allowing cells to equally distribute chromosomes to the daughter cells. Recent work has suggested that Ca is required for enabling chromatin condensation in prometaphase. Calcium was found to concentrate on condensed DNA to much higher levels compared