Phosphatidylinositol-hydrolysing enzymes in blowfly salivary glands

Irvine, Robin F.; Berridge, M. J.; Letcher, Andrew J.; Dawson, R. M. C.

doi:10.1042/bj2040361

Cited by 12 publications

(3 citation statements)

References 17 publications

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“…Ins(l,4,5)P3-3-kinase activity is also localised primarily in the cytosolic fractions of bovine brain [54] and rat liver [551 and guinea pig peritoneal macrophages [56]. The apparent K, (0.42 pM) of the purified muscle Ins(1,4,5)P3 3-kinase for Ins (1,4,5)P3 is similar to that reported in other tissues (0.21-0.70 pM) [54,[57][58][59][60]. The conversion of Ins( 1,4,5)P, to Ins( 1 ,3,4,5)P4 may be a secondary pathway for Ins(1,4,5)P3 metabolism, with the main function of Ins( 1,4,5)P, 3-kinase being to regulate the relationship between 1ns(1,4,5)P3 and Ins(1,3,4,5)P4, whose roles in Ca2+ signalling may be closely associated [61].…”

Section: Kinetics Of Ins( 145)p3 and Ins(1345)p4 Metabolismsupporting

confidence: 72%

The metabolism of d‐myo‐inositol 1,4,5‐trisphosphate and d‐myo‐inositol 1,3,4,5‐tetrakisphosphate by porcine skeletal muscle

Foster

Hogan

Hansbro

et al. 1994

European Journal of Biochemistry

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and 11-myo-inosito1 1,3,4,S-tetrakisphosphate [Ins( l,3,4,5)P4] are metabolised stepwise to inositol.Ins (l,4,5)P3 is rapidly dephosphorylated to D-myo-inositol 1,4-bisphosphate then to D-myo-inositol 4-phosphate and finally inositol. In soluble extracts Ins( 1 ,3,4,5)P4 is dephosphorylated to D-myoinositol 1,3,4-trisphosphate then sequentially to D-WZyO-inOsitOl 3,4-bisphosphate, u-myo-inositol 3-phosphate and inositol, while in particulate extracts D-mZ~O-inOsitol 1,3-bisphosphate is the predominant inositol bisphosphate formed. Dephosphorylation of these inositol polyphosphates is Mg2+ dependent and inhibited by ~-2,3-bisphosphoglyceric acid. Ins( 1,4,5)P, is also phosphorylated to form Ins(1 ,3,4,5)P4 in soluble extracts by Ins(l,4,5)P, 3-kinase. Ins(1 ,4,S)P3 3-kinase activity is Mgz+ and ATP dependent and is stimulated by Ca2+ and calmodulin. Particulate (sarcotubular) inositol polyphosphate 5-phosphatase (5-phosphatase) is found in membranes which are intimately involved in excitation-contraction coupling and the generation of the primary Ca2+ signal of muscle cells. Particulate 5-phosphatase had the highest specific activity in the transverse-tubule membrane, when compared to the terminal cisternae and longitudinal-tubule membranes of the sarcoplasmic reticulum. Particulate Ins( 1 ,3,4,5)P4-3-phosphatase activity was alfo detected after fractionation of solubilised sarcotubular membranes by DEAE-Sephacel. Particulate 5-phosphatase activity was punfied 25600-fold to a specific activity of 25.6 pmol Ins(1,4,5)P3 hydrolysed . min-' . mg protein-', after DEAE-Sephacel and novel affinity chromatography using ~-2,3-bisphosphoglycerate/agarose and Sepharose-4 B-immobilised Ins( 1 ,4,5)P3-analog matrices. Purified particulate 5-phosphatase had apparent K , of 46.3 pM and 1.9 pM and V,,, of 115 and 0.046 pmol substrate hydrolysed . min-' . mg protein-', for Ins(1,4,5)P, and Ins(1 ,3,4,5)P4, respectively. In contrast, purified soluble type I 5-phosphatase had apparent K,,, of 8.9 pM and 1.1 pM and V,,, of 3.55 and 0.13 pmol substrate hydrolysed . min ' . mg protein-', for Ins(1,4,5)P, and Ins(1,3,4,5)P4, respectively. As in other cells, muscle 5-phosphatases have a lower affinity, but a higher capacity to metabolise Ins( 1,4,S)P, than Ins(1,3,4,S)P4. Soluble type I 5-phosphatase may have a functional role in the metabolism of both inositol polyphosphates, while particulate 5-phosphatasc may primarily metabolise Ins(1,4,S)P3. Purified Ins(1,4,5)P3 3-kinase had an apparent K, of 0.42 pM and a V,,,,, of 4.12 nmol Ins(l,4,5

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Section: Kinetics Of Ins( 145)p3 and Ins(1345)p4 Metabolismsupporting

confidence: 72%

The metabolism of d‐myo‐inositol 1,4,5‐trisphosphate and d‐myo‐inositol 1,3,4,5‐tetrakisphosphate by porcine skeletal muscle

Foster

Hogan

Hansbro

et al. 1994

European Journal of Biochemistry

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“…The ability of this PLB to hydrolyse PE is probably a major reason why expression of this protein in E. coli is compromised. It has also been previously reported that the salivary glands of adult blowflies (Calliphora erythrocephala) contain enzymes that deacylate PI, PC and PE, and were secreted in the saliva [40]. The presence of a signal sequence together with the knowledge that a …”

Section: Discussionmentioning

confidence: 99%

Identification of phospholipase B from Dictyostelium discoideum reveals a new lipase family present in mammals, flies and nematodes, but not yeast

Morgan

Insall

Haynes

et al. 2004

Biochemical Journal

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The social amoeba Dictyostelium discoideum exhibits high activities of phospholipase and lysophospholipase [Ferber, Munder, Fischer and Gerisch (1970) Eur. J. Biochem. 14, 253-257]. We assayed Dictyostelium lysates to demonstrate the presence of a highly active phospholipase B (PLB) enzyme that removed both fatty-acid chains from phosphatidylcholine and produced the water-soluble glycerophosphorylcholine. We purified the PLB activity from Dictyostelium cytosol using standard agarose media (size exclusion and ion exchange), and combined this with an affinity purification step using myristoylated ARF1 (ADP-ribosylation factor 1), a protein which has a single fatty acid at its N-terminus. Two proteins co-purified (48 kDa and 65 kDa), and the 48 kDa protein was digested with trypsin, peptide fragments were separated by reverse-phase chromatography, and the resultant peptides were sequenced by Edman degradation. From the peptide sequences obtained, database searches revealed a gene which encodes a protein of 65 kDa with unknown function. The 48 kDa protein therefore appears to be a fragment of the fulllength 65 kDa product. Expression of the gene in Escherichia coli confirmed that it encodes a PLB. Characterization of its substrate specificity indicated that, in addition to phosphatidylcholine deacylation, the enzyme also hydrolysed phosphatidylinositol and phosphatidylethanolamine. The PLB identified in the present study is not related to existing PLBs found in bacteria, fungi or mammals. There are, however, genes similar to Dictyostelium PLB in mammals, flies, worms and Giardia, but not in yeast. We therefore have identified a novel family of intracellular PLBs.

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“…These iso-enzymes have different substrate specificity with respect to Ins(l,4,5)P3 and lns(1 ,3,4,5)P4. The kinase that phosphorylates Ins(1,4,5)P3 at the 3-position is present in a soluble form in virtually all mammalian cells [229,258,2591 and is activated in most if not all tissues by Ca2+/calmodulin [260,261]. Moreover, Ins(1 ,4,5)P3 3-kinase and 5-phosphatase activities may be stimulated by agents that activate protein kinases A and C, respectively [262,2631.…”

Section: Adenylate Cyclase Pathwaymentioning

confidence: 99%

Sensory transduction in eukaryotes

Haastert

Janssens

Erneux³

1991

European Journal of Biochemistry

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The organization of multicellular organisms depends on cell–cell communication. The signal molecules are often soluble components in the extracellular fluid, but also include odors and light. A large array of surface receptors is involved in the detection of these signals. Signals are then transduced across the plasma membrane so that enzymes at the inner face of the membrane are activated, producing second messengers, which by a complex network of interactions activate target proteins or genes [1]. Vertebrate cells have been used to study hormone and neurotransmitter action, vision, the regulation of cell growth and differentiation. Sensory transduction in lower eukaryotes is predominantly used for other functions, notably cell attraction for mating and food seeking. By comparing sensory transduction in lower and higher eukaryotes general principles may be recognized that are found in all organisms and deviations that are present in specialised systems. This may also help to understand the differences between cell types within one organism and the importance of a particular pathway that may or may not be general. In a practical sense, microorganisms have the advantage of their easy genetic manipulation, which is especially advantageous for the identification of the function of large families of signal transducing components.

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Phosphatidylinositol-hydrolysing enzymes in blowfly salivary glands

Cited by 12 publications

References 17 publications

The metabolism of d‐myo‐inositol 1,4,5‐trisphosphate and d‐myo‐inositol 1,3,4,5‐tetrakisphosphate by porcine skeletal muscle

The metabolism of d‐myo‐inositol 1,4,5‐trisphosphate and d‐myo‐inositol 1,3,4,5‐tetrakisphosphate by porcine skeletal muscle

Identification of phospholipase B from Dictyostelium discoideum reveals a new lipase family present in mammals, flies and nematodes, but not yeast

Sensory transduction in eukaryotes

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