Abstract
The nuclear lipid cycle and how it is regulated are areas of active investigation (see Irvine). The generation of specific lipid species in the nucleus may play a key role in recruiting and activating lipid-dependent enzymes such as members of the protein kinase C (PKC) family. Deacon et al. suggest that the formation of the tetraunsaturated diacylglycerol species, 1-stearoyl, 2-arachidonyl glycerol (SAG), may be a key element for the localization and activation of PKC βII, a classical PKC isoform that is regulated by calcium and diacylgycerol. PKC βII translocated to the nucleus during the G2 to M phase of the cell cycle and was presumably activated by its association with the membrane. Furthermore, the concentration of SAG was selectively increased in the nuclei of cells at G2-M. SAG activated PKC βII and PKC α in vitro. Thus, the localized increase in nuclear SAG may be sufficient to recruit and activate specific PKC isoforms during the G2-M phase of the cell cycle.
R. Irvine, Nuclear lipid signaling. Science's STKE (2000), http://stke.sciencemag.org/cgi/content/full/OC_sigtrans;2000/48/re1 [Abstract] [Full Text]
E. M. Deacon, T. R. Pettitt, P. Webb, T. Cross, H. Chahal, M. J. O. Wakelan, J. M. Lord, Generation of duacylglycerol molecular species through the cell cycle: a role for 1-stearoyl, 2-arachidonyl glycerol in the activation of nuclear protein kinase C-βII at G2/M. J. Cell Sci. 115, 983-989 (2002). [Online Journal]