Abstract
Skeletal muscle triads are possessing the whole set of enzymes of the phosphatidylinositol (PI)-linked signal generating pathway, PI-kinase, PI(4)P-kinase, and PI(4,5)P2-phospholipase C (PLC). The activities of these enzymes are comparable to those found in other cell types for which a functional role of the PI-pathway in intracellular signal transduction has been established. For skeletal muscle an unequivocal function and an initiating signal for Ins(1,4,5)P3-liberation is still unknown. However, the observed Ca-dependency of PLC activity suggests that here Ins(1,4,5)P3 production is a consequence rather than a cause of increasing cytosolic Ca2+. Recently, the glycolytic enzyme aldolase, whose activity can be modulated by inositol polyphosphates, has been localized in the triadic structure. The enzyme which has a high affinity to Ins(1,4)P2, Ins(1,4,5)P3 and Ins(1,3,4,5)P4, seems to be compartmentalized to the junctional foot structure from which it is released upon binding of these molecules. This phenomenon could reflect a capability for regulation of the glycolytic flux even for aldolase, especially if a non steady-state situation in the junctional gap is considered. Meanwhile we have accumulated evidence for the operation of a partial glycolytic sequence in the junctional region established by the enzymes aldolase, glyceraldehyde-3-P (GAP) dehydrogenase and phosphoglycerate kinase. This system is able to produce ATP upon oxidation of GAP and could be, because of the inositol polyphosphate-sensing abilities of aldolase, a target for the membrane associated PI-pathway. The ATP production is however transient which indicates the coupling to an ATP hydrolyzing reaction. Thus, it appears that the ATP produced by the membrane associated system is effectively utilized by an ATP consuming membrane localized system like PI-metabolism or protein kinases. There are indications that exogeneously added ATP does not equilibrate with the ATP synthesized in the junctional region which suggests an effective structural or kinetical compartmentalization of this system. Therefore it is hypothesized that the ATP synthesized by the membrane associated glycolytic sequence is utilized in membrane localized reactions.
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Bergmeyer HU: Methoden der enzymatischen Analyse. Vol. 3. Verlag Chemie, Weinheim/Bergstraße. 1974
Berridge MJ: In: K Fuxe, LF Agnati (eds) Receptor-receptor Interactions: A New Intermembrane Integrative Mechanism. enner-Gren Center International Symposium Series. Vol 48, MacMillan, London, 1987, pp 145–161
Block BA, Furagawa T, Campbell KP, Franzini-Armstrong C: J Cell Biol 107: 2587–2600, 1988
Brunschwig J-P, Brandt NR, Caswell AH, Lukeman DS: J Cell Biol 93: 533–542, 1982
Koppitz B, Vogel F, Mayr GW: Eur J Biochem 161: 421–433, 1986
Mayr G: Biochem J 259: 463–470, 1989
Pullman ME: In: RW Eskebrook, ME Pullman Methods in Enzymology, Vol 10, Academic Press, New York, 1967, pp 57–60
Rios E, Brum G: Nature (Lond) 325: 717–720, 1987
Thieleczek R, Heilmeyer LMG jr: Biochem Biophys Res Comm 135: 662–669, 1986
Thieleczek R, Behle G, Messer A, Varsanyi M, Heilmeyer LMG jr, Drenckhahn D: Eur J Cell Biol 44: 333–340, 1987
Thieleczek R, Mayr GW, Brandt NR: J Biol Chem 264: 7349–7356, 1989
Varsanyi M, Messer M, Brandt NR: Eur J Biochem 179: 473–479, 1989
Volpe P, di Virgilio F, Pozan T: TIBS 12: 139–140, 1987
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Heilmeyer, L.M.G., Han, JW., Thieleczek, R. et al. Relation of phosphatidylinositol metabolism to glycolytic pathway in skeletal muscle membranes. Mol Cell Biochem 99, 111–116 (1990). https://doi.org/10.1007/BF00230340
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DOI: https://doi.org/10.1007/BF00230340