Inositol 1,4,5-trisphosphate and the endoplasmic reticulum Ca2+ cycle of a rat insulinoma cell line - PubMed (original) (raw)
. 1985 Aug 5;260(16):9185-90.
- PMID: 2991236
Free article
Inositol 1,4,5-trisphosphate and the endoplasmic reticulum Ca2+ cycle of a rat insulinoma cell line
M Prentki et al. J Biol Chem. 1985.
Free article
Abstract
Regulation of endoplasmic reticulum (ER) Ca2+ cycling by inositol 1,4,5-trisphosphate (IP3) was studied in saponin-permeabilized RINm5F insulinoma cells. Cells were incubated with mitochondrial inhibitors, and medium Ca2+ concentration established by nonmitochondrial pool(s) (presumably the ER) was monitored with a Ca2+ electrode. IP3 degradation accounted for the transience of the Ca2+ response induced by pulse additions of the molecule. To compensate for degradation, IP3 was infused into the medium. This resulted in elevation of [Ca2+] from about 0.2 microM to a new steady state between 0.3 and 1.0 microM, depending on both the rate of IP3 infusion and the ER Ca2+ content. The elevated steady state represented a bidirectional buffering of [Ca2+] by the ER, as slight displacements in [Ca2+], by small aliquots of Ca2+ or the Ca2+ chelator quin 2, resulted in net uptake or efflux of Ca2+ to restore the previous steady state. When IP3 infusion was stopped, [Ca2+] returned to its original low level. Ninety per cent of the Ca2+ accumulated by the ER was released by IP3 when the total Ca2+ content did not exceed 15 nmol/mg of cell protein. Above this high Ca2+ content, Ca2+ was accumulated in an IP3-insensitive, A23187-releasable pool. The maximal amount of Ca2+ that could be released from the ER by IP3 was 13 nmol/mg of cell protein. The data support the concept that in the physiological range of Ca2+ contents, almost all the ER is an IP3-sensitive Ca2+ store that is capable of finely regulating [Ca2+] through independent influx (Ca2+-ATPase) and efflux (IP3-modulated component) pathways of Ca2+ transport. IP3 may continuously modulate Ca2+ cycling across the ER and play an important role in determining the ER Ca2+ content and in regulating cytosolic Ca2+ under both stimulated and possibly basal conditions.
Similar articles
- Inositol 1,4,5-trisphosphate mobilizes intracellular Ca2+ from permeabilized insulin-secreting cells.
Biden TJ, Prentki M, Irvine RF, Berridge MJ, Wollheim CB. Biden TJ, et al. Biochem J. 1984 Oct 15;223(2):467-73. doi: 10.1042/bj2230467. Biochem J. 1984. PMID: 6093775 Free PMC article. - myo-Inositol 1,4,5-trisphosphate mobilizes Ca2+ from isolated adipocyte endoplasmic reticulum but not from plasma membranes.
Delfert DM, Hill S, Pershadsingh HA, Sherman WR, McDonald JM. Delfert DM, et al. Biochem J. 1986 May 15;236(1):37-44. doi: 10.1042/bj2360037. Biochem J. 1986. PMID: 2947569 Free PMC article. - Modulation of intracellular free Ca2+ concentration by IP3-sensitive and IP3-insensitive nonmitochondrial Ca2+ pools.
Schulz I, Thévenod F, Dehlinger-Kremer M. Schulz I, et al. Cell Calcium. 1989 Jul;10(5):325-36. doi: 10.1016/0143-4160(89)90058-4. Cell Calcium. 1989. PMID: 2548726 Review. - Calcium signalling mechanisms in endoplasmic reticulum activated by inositol 1,4,5-trisphosphate and GTP.
Gill DL, Ghosh TK, Mullaney JM. Gill DL, et al. Cell Calcium. 1989 Jul;10(5):363-74. doi: 10.1016/0143-4160(89)90062-6. Cell Calcium. 1989. PMID: 2670240 Review.
Cited by
- Calcium activates Nedd4 E3 ubiquitin ligases by releasing the C2 domain-mediated auto-inhibition.
Wang J, Peng Q, Lin Q, Childress C, Carey D, Yang W. Wang J, et al. J Biol Chem. 2010 Apr 16;285(16):12279-88. doi: 10.1074/jbc.M109.086405. Epub 2010 Feb 19. J Biol Chem. 2010. PMID: 20172859 Free PMC article. - Inositol 1,4,5- trisphosphate receptor function in Drosophila insulin producing cells.
Agrawal N, Padmanabhan N, Hasan G. Agrawal N, et al. PLoS One. 2009 Aug 14;4(8):e6652. doi: 10.1371/journal.pone.0006652. PLoS One. 2009. PMID: 19680544 Free PMC article. - Ca2+/H+ exchange in acidic vacuoles of Trypanosoma brucei.
Vercesi AE, Moreno SN, Docampo R. Vercesi AE, et al. Biochem J. 1994 Nov 15;304 ( Pt 1)(Pt 1):227-33. doi: 10.1042/bj3040227. Biochem J. 1994. PMID: 7998937 Free PMC article. - The mechanism of action of GTP on Ca2+ efflux from rat liver microsomal vesicles.
Dawson AP, Hills G, Comerford JG. Dawson AP, et al. Biochem J. 1987 May 15;244(1):87-92. doi: 10.1042/bj2440087. Biochem J. 1987. PMID: 3499139 Free PMC article.
Publication types
MeSH terms
Substances
LinkOut - more resources
Full Text Sources
Medical
Miscellaneous