Phosphatidylinositol transfer proteins and cellular nanoreactors for lipid signaling

2006 ◽  
Vol 2 (11) ◽  
pp. 576-583 ◽  
Author(s):  
Kristina E Ile ◽  
Gabriel Schaaf ◽  
Vytas A Bankaitis
Keyword(s):  
Lipid Signaling ◽  
Phosphatidylinositol Transfer ◽  
Phosphatidylinositol Transfer Proteins

scholarly journals Phosphatidylinositol transfer proteins and functional specification of lipid signaling pools

2007 ◽  
Vol 47 (1) ◽  
pp. 27-40 ◽  
Author(s):  
Vytas A. Bankaitis ◽  
Patrick Vincent ◽  
Maria Merkulova ◽  
Kim Tyeryar ◽  
Yang Liu
Keyword(s):  
Lipid Signaling ◽  
Functional Specification ◽  
Phosphatidylinositol Transfer ◽  
Phosphatidylinositol Transfer Proteins

An essential role for phosphatidylinositol transfer protein in phospholipase C-Mediated inositol lipid signaling

Cell ◽  
1993 ◽  
Vol 74 (5) ◽  
pp. 919-928 ◽  
Author(s):  
Geraint M.H. Thomas ◽  
Emer Cunningham ◽  
Amanda Fensome ◽  
Andrew Ball ◽  
Nicholas F. Totty ◽  
...  
Keyword(s):  
Phospholipase C ◽  
Essential Role ◽  
Lipid Signaling ◽  
Transfer Protein ◽  
Phosphatidylinositol Transfer Protein ◽  
Phosphatidylinositol Transfer

Phosphatidylinositol transfer proteins and protein kinase C make separate but non-interacting contributions to the phosphorylation state necessary for secretory competence in rat mast cells

2001 ◽  
Vol 356 (1) ◽  
pp. 287-296 ◽  
Author(s):  
Jef A. PINXTEREN ◽  
Bastien D. GOMPERTS ◽  
Danise ROGERS ◽  
Scott E. PHILLIPS ◽  
Peter E. R. TATHAM ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Mast Cells ◽  
Protein Kinase ◽  
Aminoglycoside Antibiotic ◽  
Pleckstrin Homology Domain ◽  
Kinase C ◽  
Streptolysin O ◽  
Regulatory Machinery ◽  
Phosphatidylinositol Transfer ◽  
Phosphatidylinositol Transfer Proteins

Mast cells permeabilized by streptolysin O undergo exocytosis when stimulated with Ca2+ and guanosine 5′-[γ-thio]triphosphate but become progressively refractory to this stimulus if it is delayed. This run-down of responsiveness occurs over a period of 20–30min, during which the cells leak soluble and tethered proteins. We show here that withdrawal of ATP during the process of run-down is strongly inhibitory but that as little as 25μM ATP can extend responsiveness significantly; this effect is maximal at 50μM. When phosphatidylinositol transfer proteins (PITPs) are provided to cells at the time of permeabilization, run-down is retarded. We conclude that in the presence of ATP they convey substrates for phosphorylation that are essential for exocytosis and thus interact with the regulatory machinery. Furthermore, we show that PITPα and PITPβ have additive effects in this mechanism, suggesting that they are not functionally redundant. Alternatively, secretion from run-down cells can be inhibited by the aminoglycoside antibiotic neomycin, which is understood to bind to phosphoinositide headgroups, and by a PH (pleckstrin homology) domain polypeptide that binds phosphoinositides. The apparent displacement of neomycin by exogenous PITPs suggests that these proteins screen essential lipids. Secretion from run-down cells is also inhibited by 1-O-hexadecyl-2-O-methyl-rac-glycerol (AMG-C16), an inhibitor of protein kinase C. The lack of synergy between neomycin and AMG-C16 suggests that protein kinase C independently provides a second essential component through protein phosphorylation and that there are two independent phosphorylation pathways necessary for secretion competence.

Functional Analysis of Phosphatidylinositol Transfer Proteins

1996 ◽  
pp. 327-338 ◽  
Author(s):  
Brian G. Kearns ◽  
James G. Alb ◽  
Robert T. Cartee ◽  
Vytas A. Bankaitis
Keyword(s):  
Functional Analysis ◽  
Phosphatidylinositol Transfer ◽  
Phosphatidylinositol Transfer Proteins

scholarly journals Purification and cloning of phosphatidylinositol transfer proteins from Dictyostelium discoideum: homologues of both mammalian PITPs and Saccharomyces cerevisiae Sec14p are found in the same cell

2000 ◽  
Vol 347 (3) ◽  
pp. 837-843 ◽  
Author(s):  
Philip SWIGART ◽  
Robert INSALL ◽  
Andrew WILKINS ◽  
Shamshad COCKCROFT
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Phospholipase C ◽  
Dictyostelium Discoideum ◽  
Mammalian Cells ◽  
Hl60 Cells ◽  
Single Organism ◽  
Membrane Compartment ◽  
Phosphatidylinositol Transfer ◽  
Cloned Cdna ◽  
Phosphatidylinositol Transfer Proteins

Soluble phosphatidylinositol transfer proteins (PITPs) have important roles in lipid-mediated signalling as well as in membrane traffic. Two PITPs (α and β) have been cloned from mammalian cells, which are unrelated in sequence to yeast PITP (the product of the SEC14 gene). However, all three PITPs can perform interchangeably to reconstitute function in mammalian cells. We have now purified the major PITP from the cytoplasm of Dictyostelium discoideum and cloned the gene. This protein, DdPITP1, is homologous with mammalian PITPα and PITPβ. We have also cloned a second gene (DdPITP2) related in sequence to DdPITP1. In addition, an independently cloned cDNA encodes a relative of the SEC14 family of yeast PITPs. DdPITP1, DdPITP2 and DdSec14 proteins were all able to mediate the transfer of PtdIns from one membrane compartment to another; they thus exhibited the hallmark of PITPs. Secondly, all three PITPs were able to rescue phospholipase C-mediated phosphoinositide hydrolysis in PITP-depleted HL60 cells, indicating that all three PITPs were capable of stimulating phosphoinositide synthesis. The identification of PITPs related to both mammalian PITPs and yeast Sec14p in a single organism will provide a unique opportunity to examine the functions of this class of protein with genetic approaches.

Sign in / Sign up

Export Citation Format

Share Document