Glycerophosphoinositols (GP06) / phosphates (GP07-09)

From LipidomicsWiki

Revision as of 14:18, 14 August 2008 by Katharina Rübsaamen (Talk | contribs)
(diff) ←Older revision | Current revision (diff) | Newer revision→ (diff)
Jump to: navigation, search


Contents

Basics

A crucial role for plasma membrane phosphoinositides in controlling the processes of membrane retrieval and insertion has been established.

Structure

Diacylglycerophosphoinositol
Diacylglycerophosphoinositol

Formula: C11H17O13PR2 (GP06)

Diacylglycerophosphoinositol monophosphate
Diacylglycerophosphoinositol monophosphate

Formula: C6H13O9P (GP07)

Diacylglycerophosphoinositol bisphosphate
Diacylglycerophosphoinositol bisphosphate

Formula: C11H19O19P3R2 (GP08)

Glycerophosphoinositol trisphosphate
Glycerophosphoinositol trisphosphate

Formula: C11H20O22P4R2 (GP08)

LIPID MAPS Glycerophospholipid classes and subclasses

Natural sources

Phosphatidylinositol and related lipids

Nomenclature

Synonyms

GP06

  • 1-Phosphatidyl-D-myo-inositol
  • 1-Phosphatidyl-1D-myo-inositol
  • 1-Phosphatidyl-myo-inositol
  • Phosphatidyl-1D-myo-inositol
  • (3-Phosphatidyl)-1-D-inositol
  • 1,2-Diacyl-sn-glycero-3-phosphoinositol

GP07

  • Inositol 1-phosphate
  • myo-Inositol 1-phosphate
  • 1D-myo-Inositol 1-phosphate
  • D-myo-Inositol 1-phosphate
  • 1D-myo-Inositol 1-monophosphate

GP08

  • 1-Phosphatidyl-D-myo-inositol 4,5-bisphosphate
  • 1-Phosphatidyl-1D-myo-inositol 4,5-bisphosphate
  • Phosphatidyl-myo-inositol 4,5-bisphosphate
  • Phosphatidylinositol-4,5-bisphosphate
  • 1,2-Diacyl-sn-glycero-3-phospho-(1'-myo-inositol-4',5'-bisphosphate)

GP09

  • Phosphatidylinositol-3,4,5-trisphosphate
  • 1-Phosphatidyl-1D-myo-inositol 3,4,5-trisphosphate
  • 1,2-Diacyl-sn-glycero-3-phospho-(1'-myo-inositol-3',4',5'-bisphosphate)

IUPAC

Glycerophospholipids and subclasses

Biophysical properties

Species and and their roles in metabolic pathways

Derivatives of phosphatidylinositol (PtdIns) are phosphorylated at one or more positions on the inositol headgroup. The major species of these lipids occurred on the cytoplasmic side of the plasma membrane bilayer, i.e. PtdIns itself, PtdIns(4,5)P2, PtdIns(3,4,5)P3 and PtdIns(3,4)P2 (Vanhaesebroeck et al. 2001). Consistent with the concept that different phosphoinositides play different roles in driving the dynamics of these distinct endosomal trafficking pathways, these lipid species are distributed in a highly asymmetric disposition within the various membrane compartments. PtdIns(4,5)P2 appears to be concentrated in the plasma membrane of a variety of cell types (Stauffer et al. 1998) and it appears to be more concentrated in highly localized regions of the plasma membrane associated with membrane ruffles and F-actin (Tall et al. 2000). Moreover, substantial evidence also indicates that PtdIns(4,5)P2 is localized in lipid rafts within the plasma membrane, perhaps in association with proteins such as GAP43 that regulate raft localization and function (Caron et al. 2001). The high levels of PtdIns(4,5)P2 in plasma membranes of unstimulated cells appear to be consistent with a permissive role in regulating downstream processes such as actin polymerization and membrane retrieval and insertion (Insall et al. 2001).

A regulated signalling role for phosphoinositides would seem to require the ability to undergo acute changes in concentration in response to stimuli. Thus, PtdIns(4,5)P2 concentrations appear to rapidly change in localized regions of the plasma membrane (Tall et al. 2000). Such decreases in plasma membrane PtdIns(4,5)P2 can also be highly localized is exemplified by the process of phagocytosis in macrophages, where rapid decreases in PtdIns(4,5)P2 present in phagosomes correlate with the activation of phospholipase C-gamma and generation of diacylglycerol (Botelho et al. 2000). Taken together, these and other data suggest that the dynamics of PtdIns(4,5)P2 turnover in the plasma membrane can include localized increases, as well as decreases, in response to physiological stimuli and that concentration gradients of PtdIns(4,5)P2 are almost certainly present at the cell surface. Thus, PtdIns(4,5)P2 and other phosphoinositides are candidates for a second messenger role in membrane retrieval and insertion. Inositol 1,4,5-trisphosphate (IP3) receptors are tetrameric intracellular Ca++ channels, the opening of which is regulated by both IP3 and Ca++. The elevated Ca++ concentration in turn has several effects on cellular signal transduction pathways.

Biology / biochemistry

Biochemical synthesis

Metabolism

Enzymes/gene lists

Associated biological processes

Technology

Analysis methods

Chemical synthesis

Personal tools
Create a book