scholarly journals Role of class III phosphatidylinositol 3-kinase during programmed nuclear death ofTetrahymena thermophila

Autophagy ◽  
2013 ◽  
Vol 10 (2) ◽  
pp. 209-225 ◽  
Author(s):  
Takahiko Akematsu ◽  
Yasuhiro Fukuda ◽  
Rizwan Attiq ◽  
Ronald E Pearlman
Keyword(s):  
Class Iii ◽  
Phosphatidylinositol 3 Kinase ◽  
Phosphatidylinositol 3

scholarly journals Distinct roles of class I and class III phosphatidylinositol 3-kinases in phagosome formation and maturation

2001 ◽  
Vol 155 (1) ◽  
pp. 19-26 ◽  
Author(s):  
Otilia V. Vieira ◽  
Roberto J. Botelho ◽  
Lucia Rameh ◽  
Saskia M. Brachmann ◽  
Tsuyoshi Matsuo ◽  
...  
Keyword(s):  
Functional Role ◽  
Fluorescent Proteins ◽  
Class I ◽  
Class Iii ◽  
Phosphatidylinositol 3 Kinase ◽  
Intracellular Parasites ◽  
Selective Ablation ◽  
Phagosomal Membrane ◽  
Phosphatidylinositol 3

Phagosomes acquire their microbicidal properties by fusion with lysosomes. Products of phosphatidylinositol 3-kinase (PI 3-kinase) are required for phagosome formation, but their role in maturation is unknown. Using chimeric fluorescent proteins encoding tandem FYVE domains, we found that phosphatidylinositol 3-phosphate (PI[3]P) accumulates greatly but transiently on the phagosomal membrane. Unlike the 3′-phosphoinositides generated by class I PI 3-kinases which are evident in the nascent phagosomal cup, PI(3)P is only detectable after the phagosome has sealed. The class III PI 3-kinase VPS34 was found to be responsible for PI(3)P synthesis and essential for phagolysosome formation. In contrast, selective ablation of class I PI 3-kinase revealed that optimal phagocytosis, but not maturation, requires this type of enzyme. These results highlight the differential functional role of the two families of kinases, and raise the possibility that PI(3)P production by VPS34 may be targeted during the maturation arrest induced by some intracellular parasites.

The class III phosphatidylinositol 3-kinase Vps34 in Saccharomyces cerevisiae

2017 ◽  
Vol 398 (5-6) ◽  
pp. 677-685 ◽  
Author(s):  
Christina Reidick ◽  
Fahd Boutouja ◽  
Harald W. Platta
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Functional Role ◽  
Protein Sorting ◽  
Endocytic Trafficking ◽  
Class Iii ◽  
Phosphatidylinositol 3 Kinase ◽  
Lipid Kinase ◽  
Vacuolar Protein ◽  
Phosphatidylinositol 3

Abstract The class III phosphatidylinositol 3-kinase Vps34 (vacuolar protein sorting 34) catalyzes for the formation of the signaling lipid phosphatidylinositol-3-phopsphate, which is a central factor in the regulation of autophagy, endocytic trafficking and vesicular transport. In this article, we discuss the functional role of the lipid kinase Vps34 in Saccharomyces cerevisiae.

scholarly journals Class II phosphatidylinositol 3-kinase isoforms in vesicular trafficking

2021 ◽  
Author(s):  
Kazuaki Yoshioka
Keyword(s):  
Class Ii ◽  
Vesicular Trafficking ◽  
Class Iii ◽  
Phosphatidylinositol 3 Kinase ◽  
Cellular Processes ◽  
Endosomal Signaling ◽  
Lipid Kinases ◽  
Reported Data ◽  
Phosphatidylinositol 3

Phosphatidylinositol 3-kinases (PI3Ks) are critical regulators of many cellular processes including cell survival, proliferation, migration, cytoskeletal reorganization, and intracellular vesicular trafficking. They are a family of lipid kinases that phosphorylate membrane phosphoinositide lipids at the 3′ position of their inositol rings, and in mammals they are divided into three classes. The role of the class III PI3K Vps34 is well-established, but recent evidence suggests the physiological significance of class II PI3K isoforms in vesicular trafficking. This review focuses on the recently discovered functions of the distinct PI3K-C2α and PI3K-C2β class II PI3K isoforms in clathrin-mediated endocytosis and consequent endosomal signaling, and discusses recently reported data on class II PI3K isoforms in different physiological contexts in comparison with class I and III isoforms.

scholarly journals Role of phosphatidylinositol 3-kinase in oxidative stress-induced disruption of tight junctions. Vol. 278 (2003) 49239-49245

2004 ◽  
Vol 279 (7) ◽  
pp. 6204
Author(s):  
Parimal Sheth ◽  
Shyamali Basuroy ◽  
Chunying Li ◽  
Anjaparavanda P. Naren ◽  
Radhakrishna K. Rao
Keyword(s):  
Oxidative Stress ◽  
Tight Junctions ◽  
Phosphatidylinositol 3 Kinase ◽  
Phosphatidylinositol 3

scholarly journals Novel Role of Phosphatidylinositol 3-Kinase in CD28-mediated Costimulation

2000 ◽  
Vol 276 (12) ◽  
pp. 9003-9008 ◽  
Author(s):  
Yohsuke Harada ◽  
Eri Tanabe ◽  
Ryosuke Watanabe ◽  
Bonnie D. Weiss ◽  
Akira Matsumoto ◽  
...  
Keyword(s):  
Phosphatidylinositol 3 Kinase ◽  
Phosphatidylinositol 3

scholarly journals cAMP-stimulated Na+ transport in H441 distal lung epithelial cells: role of PKA, phosphatidylinositol 3-kinase, and sgk1

2004 ◽  
Vol 287 (4) ◽  
pp. L843-L851 ◽  
Author(s):  
Christie P. Thomas ◽  
Jason R. Campbell ◽  
Patrick J. Wright ◽  
Russell F. Husted
Keyword(s):  
Apical Cell ◽  
P38 Map Kinase ◽  
Lung Epithelial Cells ◽  
Epithelial Cell Line ◽  
Phosphatidylinositol 3 Kinase ◽  
Transport Pathway ◽  
Early Effect ◽  
Sustained Effect ◽  
Phosphatidylinositol 3

H441 cells, a bronchiolar epithelial cell line, develop a cAMP-regulated benzamil-sensitive Na+ transport pathway on permeable supports (Itani OA, Auerbach SD, Husted RF, Volk KA, Ageloff S, Knepper MA, Stokes JB, Thomas CP. Am J Physiol Lung Cell Mol Physiol 282: L631–L641, 2002). To understand the molecular basis for the stimulation of Na+ transport, we delineated the role of specific intracellular pathways and examined the effect of cAMP on αβγ-epithelial Na+ channel (ENaC) and sgk1 expression. Na+ transport increases within 5 min of cAMP stimulation and is sustained for >24 h. The sustained effect of cAMP on Na+ transport is abolished by LY-294002, an inhibitor of phosphatidylinositol 3-kinase, by H89, an inhibitor of PKA, or by SB-202190, an inhibitor of p38 MAP kinase. The sustained effect of cAMP was associated with increases in α-ENaC mRNA and protein but without a detectable increase in βγ-ENaC and sgk1. The early effect of cAMP on Na+ transport is brefeldin sensitive and is mediated via PKA. These results are consistent with a model where the early effect of cAMP is to increase trafficking of Na+ channels to the apical cell surface whereas the sustained effect requires the synthesis of α-ENaC.

scholarly journals PI(4,5)P2 controls slit diaphragm formation and endocytosis in Drosophila nephrocytes

2021 ◽  
Author(s):  
Max Gass ◽  
Sarah Borkowsky ◽  
Marie-Luise Lotz ◽  
Rita Schroeter ◽  
Pavel Nedvetsky ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Model System ◽  
Dominant Negative ◽  
Slit Diaphragm ◽  
Phosphatidylinositol 3 Kinase ◽  
Ectopic Activation ◽  
Phosphatidylinositol 4 ◽  
Asymmetrically Distributed ◽  
Phosphatidylinositol 3

Drosophila nephrocytes are an emerging model system for mammalian podocytes and podocyte-associated diseases. Like podocytes, nephrocytes exhibit characteristics of epithelial cells, but the role of phospholipids in polarization of these cells is yet unclear. In epithelia phosphatidylinositol(4,5)bisphosphate (PI(4,5)P2) and phosphatidylinositol(3,4,5)-trisphosphate (PI(3,4,5)P3) are asymmetrically distributed in the plasma membrane and determine apical-basal polarity. Here we demonstrate that both phospholipids are present in the plasma membrane of nephrocytes, but only PI(4,5)P2 accumulates at slit diaphragms. Knockdown of Skittles, a phosphatidylinositol(4)phosphate 5-kinase, which produces PI(4,5)P2, abolished slit diaphragm formation and led to strongly reduced endocytosis. Notably, reduction in PI(3,4,5)P3 by overexpression of PTEN or expression of a dominant-negative phosphatidylinositol-3-Kinase did not affect nephrocyte function, whereas enhanced formation of PI(3,4,5)P3 by constitutively active phosphatidylinositol-3-Kinase resulted in strong slit diaphragm and endocytosis defects by ectopic activation of the Akt/mTOR pathway. Thus, PI(4,5)P2 but not PI(3,4,5)P3 is essential for slit diaphragm formation and nephrocyte function. However, PI(3,4,5)P3 has to be tightly controlled to ensure nephrocyte development.

Sign in / Sign up

Export Citation Format

Share Document