Signaling Inositol Polyphosphate-5-phosphatase

Jefferson, Anne B.; Auethavekiat, Vorachart; Pot, David; Williams, Lewis T.; Majerus, Philip W.

doi:10.1074/jbc.272.9.5983

Cited by 35 publications

(24 citation statements)

References 68 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Another interesting type Π 5-phosphatase is deficient in Lowe's oculocerebrorenal (OCRL) syndrome, a developmental disorder which, as its name suggests, affects the lens, kidney and central nervous system (53,54). Both PtdIns(3,4,5)P 3 and PtdIns(4,5)P 2 are metabolized by the normal OCRL protein more efficiently than are Ins(l,4,5)P 3 and Ins(l,3,4,5)P 4 , the affinities for which are relatively low (K,,, values of 70 μΜ and 30 μΜ, respectively (42,54)). In other words, any defects in ORCL activity are more likely to impact the metabolism of the PtdIns(3,4,5)P 3 and/or PtdIns(4,5)P 2 lipids than the soluble inositol phosphates.…”

mentioning

confidence: 99%

“…Most current interest in this 5-phosphatase is directed at its likely impact on regulating PtdIns(3,4,5)P 3 metabolism. However, it actually metabolizes Ins(l,3,4,5)P 4 with greater catalytic efficiency than the type I and II 5-phosphatases, even though the ΐζ" of the type IV enzyme for Ins(l,3,4,5)P 4 is 16 μΜ (42). Tyrosine phosphorylation of the type IV 5-phosphatase down-regulates its activity (62), so it is possible that this may influence the signaling capacity of Ins(l,3,4,5)P 4 .…”

mentioning

confidence: 99%

“…An intriguing new group of 5-phosphatases (type IV) have been found to hydrolyze Ins(l,3,4,5)P 4 and PtdIns(3,4,5)P 3 , but not Ins(l,4,5)P 3 nor PtdIns(4,5)P 2 (42,60). This 5-phosphatase has an SH2 domain which promotes its association with phosphotyrosines within multimeric signaling complexes, thus it is also known by the acronyms "SHIP" (for SH2-containing inositol phosphatase (61)) and "SIP" (for signaling inositol polyphosphate 5-phosphatase (42)).…”

mentioning

confidence: 99%

“…The 75 kDa (type 2) Ins(l,4,5)P 3 5-phosphatase also attacks Ins(l,4,5)P 3 (1^ approx 20 μΜ) and Ins(l,3,4,5)P 4 (1^ approx 10 μΜ), but in addition both PtdIns(3,4,5)P 3 and PtdIns(4,5)P 2 are substrates (40,43). Type ΙΠ 5-phosphatases are grouped together by virtue of their only dephosphorylating PtdIns(3,4,5)P 3 (43), and type IV 5-phosphatases hydrolyze Ins(l,3,4,5)P 4 and PtdIns(3,4,5)P 3 (42). We will concentrate here on the enzymes that dephosphorylate Ins(l,4,5)P 3 and/or Ins(l,3,4,5)P 4 .…”

mentioning

confidence: 99%

“…These enzymes have been subdivided into four distinct groups (42), on the basis of their size and substrate specificity. The 43 kDa (type I) 5-phosphatase hydrolyzes both Ins(l,4,5)P 3 04 approx 5-10 μΜ) and Ins(l,3,4,5)P 4 (Κ" approx 1 μΜ) (38,41).…”

mentioning

confidence: 99%

See 4 more Smart Citations

The Structural and Functional Versatility of Inositol Phosphates

Caffrey

Safrany

Yang

et al. 1998

ACS Symposium Series

View full text Add to dashboard Cite

This review presents a summary of our current knowledge of inositol phosphate turnover in animal cells. In the Figure 1, the various metabolic reactions are sub-divided into several distinct groups; each of these is discussed in turn in this review, in an effort to illustrate the functional versatility of these polyphosphates.The Ins(l,4,5)P 3 / Ins(l,3,4,5)P 4 cycleThe discovery of inositol phosphate-mediated cellular Ca 2+ mobilization was a pivotal development in the field of signal transduction (/), but this breakthrough also owes much to the persistence of some other workers who had the foresight to develop and promote the idea of receptor-activated inositide signaling. It was the Hokins who first discovered that muscarinic agonists accelerate the turnover of Ptdlns in tissue slices from brain and pancreas (2). It was unfortunate that their dedication to characterizing this effect over the following 20 years did not lead them to ascribe its biological function. Indeed, there was little general interest in this so-called "phosphoinositide effect", until Michell (3) proposed that it might drive receptor-dependent Ca 2+ influx into the cell. Later, Michell and his colleagues showed mat an accelerated PtdIns(4,5)P 2 turnover immediately followed receptor-occupation by Ca 2+ -mobilizing hormones (4,5). The modem era of inositide research was now bom: Berridge (6) recognized that the Ins(l,4,5)P 3 formed by hydrolysis of PtdIns(4,5)P 2 was a candidate intracellular signal, and so it was discovered that Ins(l,4,5)/\ released Ca 2+ from endoplasmic reticulum (ER) (7). This intracellular release of Ca was found to be co-ordinated with an increase in the rate of Ca 2+ influx into the cell (7) -which finally confirmed the essence of the original idea (3) that inositol lipid turnover regulated Ca 2+ entry.Ins(l,4,5)P 3 -induced Ca 2+ release mediates an abundance of cellular responses as diverse as fertilization, cell growth and differentiation, neuronal signaling, secretion, and phototransduction. The distinct signaling requirements of individual cells are served by cell-and agonist-specific spatiotemporal patterns of Ca 2+ signaling. These arise not just from the binding of Ins(l,4,5)P 3 to its receptor, but also by modulation of this ligand/protein interaction by both cytosolic and ER-luminal Ca 2+ , and there is also input from the process of Ca 2+ entry, and Ins(l,4,5)P 3 metabolism (8). There is also regulatory diversity between the three major forms of the Ins(l,4,5)P 3 receptors that are currently recognized (see reference 9 for a review).

show abstract

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 3 more Smart Citations