Phosphoinositides cell regulation

Cousin MA, Robinson PJ (2001) The dephosphins dephosphorylation by calcineurin triggers synaptic vesicle endocytosis. Trends Neurosci 24 659-65 Craxton M (2004) Synaptotagmin gene content of the sequenced genomes. BMC Genomics 5 43 Di Paolo G, De Camilli P (2006) Phosphoinositides in cell regulation and membrane dynamics. Nature 443 651-7... 

Aldose reductase is present in the Schwann cell body but not in the axon. Activation of the polyol pathway depletes myo-inositol and inactivates Na/K-ATPase activity of nerve cells, leading to a reduction in the nerve conduction velocity, at least in diabetic animals, myo-inositol is important for the phosphoinositide-mediated regulation of... 

Di Paolo G, de Camilli P (2006) Phosphoinositides in cell regulation and membrane dynamics. Nature 443 651-657... 

Domin J, Harper L, Aubyn D, et al. The class II phosphoinositide 3-kinase PI3K-C2beta regulates cell migration by a PtdIns(3)P dependent mechanism. J Cell Physiol 2005 205(3) 452 162. 

Weinkove D, Neufeld TP, Twardzik T, Waterfield MD, Leevers SJ 1999 Regulation of imaginal disc cell size, cell number and organ size by Drosophila class IA phosphoinositide 3-kinase and its adaptor. Curr Biol 9 1019-1029... 

Phorbol esters are promoters that interact with cellular receptors and activate protein kinase C. Usually protein kinase C is activated by Ca++ and diacylglycerol, both of which result from the hydrolysis of phosphoinositides catalyzed by phospholipase C. Phospholipase C is normally activated by several different growth factors. Thus phorbol esters bypass a tightly regulated step in the control of cell growth. Since protein kinase C phosphorylates various proteins, it is not known how this activity participates in establishing a cancerous line of cells. 

Expression of the cloned receptors in Chinese hamster ovary cells, other mammalian cells and Xenopus oocytes has demonstrated differential coupling of these receptors to cellular responses. In general the Mb M3 and M5 receptors regulate phosphoinositide hydrolysis by stimulating PLC. This occurs through selective coupling of the receptor to the pertussis-toxin-insensitive G protein Gq/11,... 

Hormonal actions on target neurons are classified in terms of cellular mechanisms of action. Hormones act either via cell-surface or intracellular receptors. Peptide hormones and amino-acid derivatives, such as epinephrine, act on cell-surface receptors that do such things as open ion-channels, cause rapid electrical responses and facilitate exocytosis of hormones or neurotransmitters. Alternatively, they activate second-messenger systems at the cell membrane, such as those involving cAMP, Ca2+/ calmodulin or phosphoinositides (see Chs 20 and 24), which leads to phosphorylation of proteins inside various parts of the target cell (Fig. 52-2A). Steroid hormones and thyroid hormone, on the other hand, act on intracellular receptors in cell nuclei to regulate gene expression and protein synthesis (Fig. 52-2B). Steroid hormones can also affect cell-surface events via receptors at or near the cell surface. 

Figure 6. Regulation of cell cycling and survival by phosphoinositids.

Sawyer C, Sturge J, Bennett DC et al (2003) Regulation of breast cancer cell chemotaxis by the phosphoinositide 3-kinase pllOdelta. Cancer Res 63 1667-1675... 

Protein kinase B (Akt) is a serine/threonine, mitogen-regulated protein kinase involved in the protection of cells from apoptosis as well as the promotion of cell proliferation and diverse metabolic responses. It is activated upon binding of phospholipids and phosphorylation at residues Thr and Ser by upstream kinases such as phosphoinositide-dependent protein kinase 1 and 2 (M15). Activation of... 

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