|
|
|
|
|
||
|
|||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | |||||
Journal of Cell Science, Vol 114, Issue 7 1283-1295, Copyright © 2001 by Company of Biologists
JOURNAL ARTICLES |
AC Rupper, JM Rodriguez-Paris, BD Grove and JA Cardelli
Department of Microbiology and Immunology, and Feist-Weiller Cancer Center, Louisiana State University Health Sciences Center, Shreveport, Louisiana 71130, USA. jcarde@lsumc.edu
The Dictyostelium p110-related PI 3-kinases, PIK1 and PIK2, regulate the endosomal pathway and the actin cytoskeleton, but do not significantly regulate internalization of particles in D. discoideum. Bacteria internalized into (&Dgr;)ddpik1/ddpik2 cells or cells treated with PI 3-kinase inhibitors remained intact as single particles in phagosomes with closely associated membranes after 2 hours of internalization, while in control cells, bacteria appeared degraded in multi-particle spacious phagosomes. Addition of LY294002 to control cells, after 60 minutes of chase, blocked formation of spacious phagosomes, suggesting PI 3-kinases acted late to regulate spacious phagosome formation. Phagosomes purified from control and drug treated cells contained equivalent levels of lysosomal proteins, including the proton pump complex, and were acidic, but in drug treated cells and (&Dgr;)ddpik1/ddpik2 cells phagosomal pH was significantly more acidic during maturation than the pH of control phagosomes. Inhibition of phagosomal maturation by LY294002 was overcome by increasing phagosomal pH with NH(4)Cl, suggesting that an increase in pH might trigger homotypic phagosome fusion. A pkbA null cell line (PKB/Akt) reproduced the phenotype described for cells treated with PI 3-kinase inhibitors and (&Dgr;)ddpik1/ddpik2 cells. We propose that PI 3-kinases, through a PKB/Akt dependent pathway, directly regulate homotypic fusion of single particle containing phagosomes to form multi-particle, spacious phagosomes, possibly through the regulation of phagosomal pH.
This article has been cited by other articles:
|
|
 |
|
  A. T. Sasaki, C. Janetopoulos, S. Lee, P. G. Charest, K. Takeda, L. W. Sundheimer, R. Meili, P. N. Devreotes, and R. A. Firtel G protein-independent Ras/PI3K/F-actin circuit regulates basic cell motility J. Cell Biol., July 10, 2007; 178(2): 185 - 191. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 X. Xu, A. Muller-Taubenberger, K. E. Adley, N. Pawolleck, V. W. Y. Lee, C. Wiedemann, T. S. Sihra, M. Maniak, T. Jin, and R. S. B. Williams Attenuation of Phospholipid Signaling Provides a Novel Mechanism for the Action of Valproic Acid Eukaryot. Cell, June 1, 2007; 6(6): 899 - 906. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L.-A. H. Allen, J. A. Allgood, X. Han, and L. M. Wittine Phosphoinositide3-kinase regulates actin polymerization during delayed phagocytosis of Helicobacter pylori J. Leukoc. Biol., July 1, 2005; 78(1): 220 - 230. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. Sendide, N. E. Reiner, J. S. I. Lee, S. Bourgoin, A. Talal, and Z. Hmama Cross-Talk between CD14 and Complement Receptor 3 Promotes Phagocytosis of Mycobacteria: Regulation by Phosphatidylinositol 3-Kinase and Cytohesin-1 J. Immunol., April 1, 2005; 174(7): 4210 - 4219. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. Dormann, G. Weijer, S. Dowler, and C. J. Weijer In vivo analysis of 3-phosphoinositide dynamics during Dictyostelium phagocytosis and chemotaxis J. Cell Sci., December 15, 2004; 117(26): 6497 - 6509. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. Decave, D. Rieu, J. Dalous, S. Fache, Y. Brechet, B. Fourcade, M. Satre, and F. Bruckert Shear flow-induced motility of Dictyostelium discoideum cells on solid substrate J. Cell Sci., November 1, 2003; 116(21): 4331 - 4343. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. Harris and J. Cardelli RabD, a Dictyostelium Rab14-related GTPase, regulates phagocytosis and homotypic phagosome and lysosome fusion J. Cell Sci., September 15, 2002; 115(18): 3703 - 3713. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Clarke, J. Kohler, Q. Arana, T. Liu, J. Heuser, and G. Gerisch Dynamics of the vacuolar H+-ATPase in the contractile vacuole complex and the endosomal pathway of Dictyostelium cells J. Cell Sci., July 15, 2002; 115(14): 2893 - 2905. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 E. Harris, N. Wang, W.-l Wu, A. Weatherford, A. De Lozanne, and J. Cardelli Dictyostelium LvsB Mutants Model the Lysosomal Defects Associated with Chediak-Higashi Syndrome Mol. Biol. Cell, February 1, 2002; 13(2): 656 - 669. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Rupper, K. Lee, D. Knecht, and J. Cardelli Sequential Activities of Phosphoinositide 3-Kinase, PKB/Akt, and Rab7 during Macropinosome Formation in Dictyostelium Mol. Biol. Cell, September 1, 2001; 12(9): 2813 - 2824. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Rupper, B. Grove, and J. Cardelli Rab7 regulates phagosome maturation in Dictyostelium J. Cell Sci., January 7, 2001; 114(13): 2449 - 2460. [Abstract] [Full Text] [PDF]
|
|
