Nuclear inositides: inconsistent consistencies

It is now clear that phosphoinositides, which play a major role in the regu lation of a variety of cellular processes in the cytoplasm, are found withi n the nucleus. Their role in this subcellular compartment is still contenti ous; however, data has suggested that nuclear inositides generate substrate s, such as PtdIns(4,5)P2, utilised by a number of nuclear signalling pathwa ys: for example, nuclear phospholipase C and the PtdIns 3-kinase cascade. T here is also evidence that PtdIns(4,5)P2 may play a role in the localisatio n and regulation of a number of nuclear proteins such as the BAF complex, w hich is involved in the regulation of chromatin structure. Although the pre sence of nuclear inositides has been demonstrated in a number of different cell types, suggesting that it is ubiquitous, there are many inconsistencie s within the literature concerning the locations and isotypes of enzymes th at are involved in their regulation and in the potential second messengers which are generated by them. This review aims to highlight some of these in consistencies in order to focus on areas that need further characterisation .