Phosphoinositide-specific phospholipase

Rhee SG, Bae YS (1997) Regulation of phosphoinositide-specific phospholipase Isozymes. J Biol Chem 272 15045-15048... 

S. G., McLaughlin, S., Effect of monolayer surface pressure on the activities of phosphoinositide-specific phospholipase C-beta 1, -gamma 1, and -delta 1, Biochemistry 1994, 33, 3032-3037. 

The characteristics of the four major classes of histamine receptors are summarized. Question marks indicate suggestions from the literature that have not been confirmed. AA, arachidonic acid DAG, diacylglycerol Iko,2+, calcium-activated potassium current IP3, inositol 1,4,5-trisphosphate NHE, sodium-proton exchange, PKC, protein kinase C NO, nitric oxide PTPLC, phosphoinositide-specific phospholipase C TXA2, thromboxane A2. Has brain-penetrating characteristics after systemic administration. 

H linked intracellular messengers. Activated H receptors are known to activate a pertussis-toxin-insensitive G protein, Gq, that stimulates phosphoinositide-specific phospholipase C (PI-PLC), with the subsequent generation of inositol 1,4,5-trisphosphate (IP3) and diacylglyc-erol (DAG). These two mediators are known to elevate intracellular Ca2+ concentrations and to activate PKC,... 

Genebankaccession numbers are for human clones. fPI-PLC = phosphoinositide-specific phospholipase C. 

The family of heterotrimeric G proteins is involved in transmembrane signaling in the nervous system, with certain exceptions. The exceptions are instances of synaptic transmission mediated via receptors that contain intrinsic enzymatic activity, such as tyrosine kinase or guanylyl cyclase, or via receptors that form ion channels (see Ch. 10). Heterotrimeric G proteins were first identified, named and characterized by Alfred Gilman, Martin Rodbell and others close to 20 years ago. They consist of three distinct subunits, a, (3 and y. These proteins couple the activation of diverse types of plasmalemma receptor to a variety of intracellular processes. In fact, most types of neurotransmitter and peptide hormone receptor, as well as many cytokine and chemokine receptors, fall into a superfamily of structurally related molecules, termed G-protein-coupled receptors. These receptors are named for the role of G proteins in mediating the varied biological effects of the receptors (see Ch. 10). Consequently, numerous effector proteins are influenced by these heterotrimeric G proteins ion channels adenylyl cyclase phosphodiesterase (PDE) phosphoinositide-specific phospholipase C (PI-PLC), which catalyzes the hydrolysis of phosphatidylinositol 4,5-bisphosphate (PIP2) and phospholipase A2 (PLA2), which catalyzes the hydrolysis of membrane phospholipids to yield arachidonic acid. In addition, these G proteins have been implicated in... 

Phosphoinositides are cleaved by a family of phosphoinositide-specific phospholipase C isozymes 350... 

Katan, M. Families of phosphoinositide-specific phospholipase C structure and function. Biochim. Biophys. Acta 1436 5-17,1998. 

Phosphoinositase C (i.e. phosphoinositide-specific phospholipase C [PLC]) enzymes are found in the vast majority of mammalian cells. Molecular cloning of these enzymes, analysis of their predicted amino acid sequences and immunological cross-reactivity indicate that at least three major forms of the enzyme exist PLC-/I, -8 and -y. Each of these enzyme types is encoded by a distinct gene. More recent experiments using the polymerase chain reaction and molecular cloning have revealed even greater enzyme di-... 

Essen, L.-O., Peiisic, O., Cheung, R., Katan, M., and Wilhams, R.L., 1996, Crystal structure ofamammahan phosphoinositide-specific phospholipase C. Nature 380 595-602. 

Rhee, S. G. (2001). Regulation of phosphoinositide-specific phospholipase C. Annu. Rev. Biochem. 70, 281-312. 

The Ca2+-phosphoinositide signaling pathway. Key proteins include hormone receptors (R), a G protein (G), a phosphoinositide-specific phospholipase C (PLC), protein kinase C substrates of the kinase (S), calmodulin (CaM), and calmodulin-binding enzymes (E), including kinases, phosphodiesterases, etc. (PIP2, phosphatidylinositol-4,5-bisphosphate DAG, diacylglycerol. Asterisk denotes activated state. Open arrows denote regulatory effects.)... 

The G protein complexes related to thyrotrophs TRH receptors affect phosphoinositide-specific phospholipase C, which increases intracellular cytoplasmic free calcium, thereby stimulating TSH secretion. 

Blank, J.L., Ross, A.H., and Exton, J.H. 1991. Purification and characterization of two G-proteins that activate the beta 1 isozyme of phosphoinositide-specific phospholipase C. Identification as members of the Gq class. J. Biol. Chem. 266 18206-18216. 

Heinz, D.W., Essen, L.O., and Williams, R.L., 1998, Structural and mechanistic comparison of prokaryotic and eukaryotic phosphoinositide-specific phospholipases C. J. Mol. Biol. 275 635-650. 

Wu, Y., Perisic, O., Williams, R.L., Katan, M., and Roberts, M.F., 1997, Phosphoinositide-specific phospholipase C 81 activity toward micellar substrates, inositol 1,2-cyclic phosphate, and other water-soluble substrates A sequential mechanism and allosteric activation. Biochemistry 36 11223-11233. 

Figure 4. Linear representation of the Arabidopsis PIPKs and PLCs. The Arabidopsis PtdlnsP 5-kinases are most similar to the human type I PtdlnsP 5-kinases. There are 11 putative type I /I/PtdlnsP 5-kinases in Arabidopsis arranged in two subfamilies based on size. Subfamily B contains X/PIPK1-9, all of which contain membrane occupation and recognition nexus (MORN) repeats. /1/PIPK10-11 are in Subfamily A with molecular weights less than that of the members of subfamily B and contain no MORN repeats. The Arabidopsis phosphoinositide specific phospholipase C family is most similar to the animal PLC . There are seven functional PI-PLCs in Arabidopisis (Hunt et al., 2004). All isoforms contain EF-hand motifs, the X and Y catalytic domains characteristic of PI-PLCs and a C2 lipid-binding domain.

Mueller-Roeber, B., and Pical, C., 2002, Inositol phospholipid metabolism in Arabidopsis. Characterized and putative isoforms of inositol phospholipid kinase and phosphoinositide-specific phospholipase C. Plant Physiol. 130 22—46. 

Staxen, I., Pical, C., Montgomery, L.T., Gray, J.E., Hetherington, A.M., and McAinsh, M.R., 1999, Abscisic acid induces oscillations in guard-cell cytosolic free calcium that involve phosphoinositide-specific phospholipase C. Proc. Natl. Acad. Sci. U.S.A. 96 1779-1784. 

Song, F. and Goodman, R.M., 2002, Molecular cloning and characterization of a rice phosphoinositide-specific phospholipase C gene, OsPI-PLCl, that is activated in systemic acquired resistance. Physiol. Mol. Plant Pathol. 61 31-40. 

Hirayama, T., Mitsukawa, N., Shibata, D., and Shinozaki, K., 1997, AtPLC2, a gene encoding phosphoinositide-specific phospholipase C, is constitutively expressed in vegetative and floral tissues in Arabidopsis thaliana. Plant Mol. Biol. 34 175-180. 

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