title: Nuclear phospholipase C beta1 and cellular differentiation.
abstract: Phosphoinositides (PI) are the most extensively studied lipids involved in cell signaling pathways. The bulk of PI is found in membranes where they are substrates for enzymes, such as kinases, phosphatases and phospholipases, which respond to the activation by cell-surface receptors. The outcome of the majority of signaling pathways involving lipid second messengers results in nuclear responses finally driving the cell into differentiation, proliferation or apoptosis. Some of these pathways are well established, such as that of PI-specific phospholipase C (PI-PLC), which cleaves phosphatidylinositol-4,5-bisphosphate (PIP2) into the two second messengers diacylglycerol (DAG) and inositol-1,4,5-trisphosphate (IP3). Two independent cycles of PI are present inside the cell. One is localized at the plasma membrane, while the most recently discovered PI cycle is found inside the nuclear compartment. The regulation of the nuclear PI pool is totally independent from the plasma membrane counterpart, suggesting that the nucleus constitutes a functionally distinct compartment of inositol lipids metabolism. In this report we will focus on the signal transduction-related metabolism of nuclear PI and review the most convincing evidence that the PI cycle is involved in differentiation programs in several cell systems.
authors.affiliation: Cellular Signaling Laboratory, Department of Anatomical Sciences, University of Bologna, 40126 Bologna, Italy.
authors.forename: Irene
authors.initials: I
authors.lastname: Faenza
authors.forename: Lisa
authors.initials: L
authors.lastname: Bregoli
authors.forename: Giulia
authors.initials: G
authors.lastname: Ramazzotti
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Gaboardi
authors.forename: Matilde Y
authors.initials: MY
authors.lastname: Follo
authors.forename: Sara
authors.initials: S
authors.lastname: Mongiorgi
authors.forename: Anna Maria
authors.initials: AM
authors.lastname: Billi
authors.forename: Lucia
authors.initials: L
authors.lastname: Manzoli
authors.forename: Alberto M
authors.initials: AM
authors.lastname: Martelli
authors.forename: Lucio
authors.initials: L
authors.lastname: Cocco
mesh_terms: D000818:Animals; D002453:Cell Cycle; D002454:Cell Differentiation; D002467:Cell Nucleus / Q000201:enzymology*; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D004915:Leukemia, Erythroblastic, Acute / Q000378:metabolism; D008954:Models, Biological; D009132:Muscles / Q000378:metabolism; D054799:Phospholipase C beta / Q000378:metabolism / Q000502:physiology*; D020033:Protein Isoforms; D015398:Signal Transduction; D014157:Transcription Factors / Q000378:metabolism
chemical_list: D020033:Protein Isoforms; D014157:Transcription Factors; D054799:Phospholipase C beta