title: Class I Phosphoinositide 3-Kinase Exerts a Differential Role on Cell Survival and Cell Trafficking in Retina.
abstract: Phosphoinositide 3-kinases (PI3Ks) are a family of lipid kinases that phosphorylates the 3'OH of the inositol ring of phosphoinositides. They are responsible for coordinating a diverse range of cell functions including proliferation, cell survival, degranulation, vesicular trafficking, and cell migration. The PI 3-kinases are grouped into three distinct classes: I, II, and III. Class III PI3K has been shown to be involved in intracellular protein trafficking, whereas class I PI3K is known to regulate cell survival following activation of cell surface receptors. However, studies from our laboratory and others have shown that class I PI3K may also be involved in photoreceptor protein trafficking. Therefore, to learn more about the role of class I and class III P13K in trafficking and to understand the impact of the lipid content of trafficking cargo vesicles, we developed a methodology to isolate trafficking vesicles from retinal tissue. PI3K class I and III proteins were enriched in our extracted trafficking vesicle fraction. Moreover, levels of ether phosphatidylethanolamine (PE) and ether phosphatidylcholine (PC) were significantly higher in the trafficking vesicle fraction than in total retina. These two lipid classes have been suggested to be involved with fusion/targeting of trafficking vesicles.
authors.affiliation: Departments of Ophthalmology, Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, 608 Stanton L. Young Blvd, 73104, Oklahoma City, OK, USA. Seifollah-azadi@ouhsc.edu.
authors.forename: Seifollah
authors.initials: S
authors.lastname: Azadi
authors.affiliation: Departments of Ophthalmology, Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, 608 Stanton L. Young Blvd, 73104, Oklahoma City, OK, USA. Richard-Brush@ouhsc.edu.
authors.forename: Richard S
authors.initials: RS
authors.lastname: Brush
authors.affiliation: Departments of Ophthalmology and Cell Biology, Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, 608 Stanton L. Young Blvd, 73104, Oklahoma City, OK, USA. robert-anderson@ouhsc.edu.
authors.forename: Robert E
authors.initials: RE
authors.lastname: Anderson
authors.affiliation: Departments of Cell Biology, Physiology and Ophthalmology, Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, 608 Stanton L. Young Blvd, 73104, Oklahoma City, OK, USA. raju-rajala@ouhsc.edu.
authors.forename: Raju V S
authors.initials: RV
authors.lastname: Rajala
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002417:Cattle; D002458:Cell Fractionation / Q000379:methods*; D002470:Cell Survival; D010713:Phosphatidylcholines / Q000378:metabolism; D010714:Phosphatidylethanolamines / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000145:classification / Q000378:metabolism*; D021381:Protein Transport; D012160:Retina / Q000166:cytology / Q000378:metabolism*; D053719:Tandem Mass Spectrometry; D022161:Transport Vesicles / Q000737:chemistry / Q000201:enzymology*
chemical_list: D010713:Phosphatidylcholines; D010714:Phosphatidylethanolamines; C483858:phosphatidylethanolamine; D019869:Phosphatidylinositol 3-Kinases
keywords: Degeneration; Lipid; Phosphoinositide 3-Kinase; Photoreceptors; Retina; Trafficking