Inositol 1,2,3-trisphosphate and inositol 1,2- and/or 2,3-bisphosphate are normal constituents of mammalian cells

C. J. Barker, P. J. French, A. J. Moore, T. Nilsson, P. O. Berggren, C. M. Bunce, C. J. Kirk, R. H. Michell*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

27 Citations (Scopus)


1. An inositol trisphosphate (InsP3) distinct from Ins(1,4,5)P3 and Ins(1,3,4)P3, which we previously observed in myeloid and lymphoid cells, is present in WRK1 rat mammary tumour cells and pancreatic endocrine β-cells. 2. It has been identified as Ins(1,2,3)P3 by a combination of oxidation to ribitol, a structurally diagnostic polyol, and ammoniacal hydrolysis to identified inositol monophosphates. 3. Ins(1,2,3)P3 concentration in HL60 cells changed little during stimulation by ATP or fMetLeuPhe or during neutrophilic or monocytic differentiation, and Ins(1,2,3)P3 was unresponsive to vasopressin in WRK1 cells. 4. Ins(1,2,3)P3 was usually more abundant than Ins(1,4,5)P3, often being present at concentrations between ~ 1 μM and ~ 10 μM. 5. HL60, WRK-1 and lymphoid cells also contain Ins(1,2)P2 or Ins(2,3)P2, or a mixture of these two enantiomers, as a major InsP2 species. 6. Ins(1,2,3)P2 and Ins(1,2)P2/Ins(2,3)P2 are readily detected in cells labelled for long periods, but not in acutely labelled cells. This behaviour resembles that of InsP6, the most abundant cellular inositol polyphosphate that includes the 1,2,3-trisphosphate motif, which also achieves isotopic equilibrium with inositol only slowly. 7. Ins(1,2,3)P3 is the major InsP3 that accumulates during metabolism of InsP6 by WRK-1 cell homogenates. 8. Possible metabolic relationships between Ins(1,2,3)P3, Ins(1,2)P2/Ins(2,3)P2 and other inositol polyphosphates in cells, and a possible role for Ins(1,2,3)P3 in cellular iron handling, are considered.

Original languageEnglish
Pages (from-to)557-564
Number of pages8
JournalBiochemical Journal
Issue number2
Publication statusPublished - 1 Jan 1995

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology


Dive into the research topics of 'Inositol 1,2,3-trisphosphate and inositol 1,2- and/or 2,3-bisphosphate are normal constituents of mammalian cells'. Together they form a unique fingerprint.

Cite this