HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Biden, T. J. Articles by Wollheim, C. B. Search for Related Content PubMed PubMed Citation Articles by Biden, T. J. Articles by Wollheim, C. B. Social Bookmarking                      What's this?

J. Biol. Chem., Vol. 261, Issue 26, 11931-11934, Sep, 1986

Ca2+ regulates the inositol tris/tetrakisphosphate pathway in intact and broken preparations of insulin-secreting RINm5F cells

TJ Biden and CB Wollheim

The two-step isomerization of inositol 1,4,5-trisphosphate (Ins-1,4,5- P3) to Ins-1,3,4-P3 via the intermediate inositol 1,3,4,5- tetrakisphosphate (Ins-P4) was studied in intact RINm5F cells and in subcellular fractions. Muscarinic stimulation with carbamylcholine leads to a rapid (2 s) rise in both Ins-1,4,5-P3 and Ins-P4, whereas Ins-1,3,4-P3 was produced only after a lag of at least 5 s. In cells with depleted Ca2+ stores, the rinse in Ins-1,4,5-P3 was nearly tripled, and that of Ins-1,3,4-P3 markedly diminished as compared to control cells. Raising the free Ca2+ concentration from 10(-7) to 10(- 5) M increased inositol 1,4,5-triphosphate-3-kinase activity in cytosolic fractions by 2 1/2-fold (EC50 for Ca2+ approximately 0.8 microM) but had no effect on the activity of inositol 1,4,5- triphosphate-5-phosphomonoesterase. At 10(-7) M Ca2+ these two enzymes displayed comparable activity when assayed at concentrations of Ins- 1,4,5-P3 occurring in stimulated cells; however, at 10(-5) M Ca2+, kinase activity predominates. These results suggest that Ins-1,4,5-P3 counter-regulates its own levels through the activity of inositol 1,4,5- trisphosphate 3-kinase and that the increase in [Ca2+]i may account for the transience of the rise in Ins-1,4,5-P3 seen during muscarinic stimulation of RINm5F cells.
CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				A. SPAT and L. HUNYADY Control of Aldosterone Secretion: A Model for Convergence in Cellular Signaling Pathways Physiol Rev, April 1, 2004; 84(2): 489 - 539. [Abstract] [Full Text] [PDF]

				P. Gilon and J.-C. Henquin Mechanisms and Physiological Significance of the Cholinergic Control of Pancreatic {beta}-Cell Function Endocr. Rev., October 1, 2001; 22(5): 565 - 604. [Abstract] [Full Text] [PDF]

				W. Abebe and S. J. Mustafa A1 adenosine receptor-mediated Ins(1,4,5)P3 generation in allergic rabbit airway smooth muscle Am J Physiol Lung Cell Mol Physiol, November 1, 1998; 275(5): L990 - L997. [Abstract] [Full Text] [PDF]

				C. E. Sims and N. L. Allbritton Metabolism of Inositol 1,4,5-Trisphosphate and Inositol 1,3,4,5-Tetrakisphosphate by the Oocytes of Xenopus laevis J. Biol. Chem., February 13, 1998; 273(7): 4052 - 4058. [Abstract] [Full Text] [PDF]

				M.R. Hanley, T.R. Jackson, W.T. Cheung, M. Dreher, A. Gatti, P. Hawkins, S.I. Patterson, M. Vallejo, A.P. Dawson, and O. Thastrup Molecular Mechanisms of Phospholipid Signaling Pathways in Mammalian Nerve Cells Cold Spring Harb Symp Quant Biol, January 1, 1988; 53(0): 435 - 445. [Abstract] [PDF]

				A.T. Harootunian, J.P.Y. Kao, and R.Y. Tsien Agonist-induced Calcium Oscillations in Depolarized Fibroblasts and Their Manipulation by Photoreleased Ins(l,4,5)P3, and Ca++, and Ca++ Buffer Cold Spring Harb Symp Quant Biol, January 1, 1988; 53(0): 935 - 943. [Abstract] [PDF]