title: Enrichment of phosphatidylinositols with specific acyl chains.
abstract: There are six major species of phospholipids in eukaryotes, each of which plays unique structural and functional roles. One species, phosphatidylinositol (PI) only contributes about 2-10% of the total phospholipid pool. However, they are critical factors in the regulation of several fundamental processes such as in membrane dynamics and signal transduction pathways. Although numerous acyl species exist, PI species are enriched with one specific acyl chain composition at both sn-1 and sn-2 positions. Recent work has identified several enzymes that act on lipids to lead to the formation or interconversion of PI species that exhibit acyl chain specificity. These enzymes contribute to this lipid's enrichment with specific acyl chains. The nature of the acyl chains on signaling lipids has been shown to contribute to their specificity. Here we review some of the critical functions of PI and the multiple pathways in which PI can be produced and metabolized. We also discuss a common motif that may confer arachidonoyl specificity to several of the enzymes involved. This article is part of a Special Issue entitled: Membrane Structure and Function: Relevance in the Cell's Physiology, Pathology and Therapy.
authors.affiliation: Department of Biochemistry and Biomedical Sciences, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada.
authors.forename: Kenneth
authors.initials: K
authors.lastname: D'Souza
authors.affiliation: Department of Biochemistry and Biomedical Sciences, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada. Electronic address: epand@mcmaster.ca.
authors.forename: Richard M
authors.initials: RM
authors.lastname: Epand
mesh_terms: D000215:Acylation; D000818:Animals; D016718:Arachidonic Acid / Q000737:chemistry* / Q000378:metabolism; D002462:Cell Membrane / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D010716:Phosphatidylinositols / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D010716:Phosphatidylinositols; D016718:Arachidonic Acid
keywords: Acyl chain; Arachidonoyl; Lipid signal; Phosphatidylinositol; Phosphatidylinositol cycle