An in vitro1H-MRS Model of Oncogene Transfection

1997 ◽  
Vol 38 (6) ◽  
pp. 1083-1086
Author(s):  
T. Nakai ◽  
R. Ishima ◽  
H. Sakahara ◽  
K. Endo ◽  
J. Konishi ◽  
...  

Purpose: Malignancy is an abnormality of cell division and differentiation based on abnormal expression of oncogenes. This note describes the in vitro1H-NMR spectral features of oncogene-transfected NIH3T3 fibroblast cells compared to non-transfected cells Material and Methods: 1H-NMR spectra of cultured NIH3T3 cells and c-erbB-2 or c-Ha-ras gene-transfected cells were obtained by 400 MHz high resolution NMR. the peaks were assigned by 2D HOHAHA spectra of the cell suspension and the spectral changes were evaluated in 1D and 1D differential spectra Results: the 1H spectra obtained from both transfected cell lines were broadened over all peaks, suggesting reduced mobility in plasma membrane lipid molecules. No other differential spectra for characterizing metabolic change was detected Conclusion: Broadened 1H spectra observed after c-erbB-2 or c-Ha-ras transfection suggest changes of plasma membrane viscosity, which may be related to the oncogene expression

2006 ◽  
Vol 17 (1) ◽  
pp. 56-66 ◽  
Author(s):  
John H. Evans ◽  
Diana Murray ◽  
Christina C. Leslie ◽  
Joseph J. Falke

The C2 domain of protein kinase Cα (PKCα) controls the translocation of this kinase from the cytoplasm to the plasma membrane during cytoplasmic Ca2+ signals. The present study uses intracellular coimaging of fluorescent fusion proteins and an in vitro FRET membrane-binding assay to further investigate the nature of this translocation. We find that Ca2+-activated PKCα and its isolated C2 domain localize exclusively to the plasma membrane in vivo and that a plasma membrane lipid, phosphatidylinositol-4,5-bisphosphate (PIP2), dramatically enhances the Ca2+-triggered binding of the C2 domain to membranes in vitro. Similarly, a hybrid construct substituting the PKCα Ca2+-binding loops (CBLs) and PIP2 binding site (β-strands 3–4) into a different C2 domain exhibits native Ca2+-triggered targeting to plasma membrane and recognizes PIP2. Conversely, a hybrid containing the CBLs but lacking the PIP2 site translocates primarily to trans-Golgi network (TGN) and fails to recognize PIP2. Similarly, PKCα C2 domains possessing mutations in the PIP2 site target primarily to TGN and fail to recognize PIP2. Overall, these findings demonstrate that the CBLs are essential for Ca2+-triggered membrane binding but are not sufficient for specific plasma membrane targeting. Instead, targeting specificity is provided by basic residues on β-strands 3–4, which bind to plasma membrane PIP2.


1990 ◽  
Vol 10 (3) ◽  
pp. 263-270 ◽  
Author(s):  
J. Pascal Zimmer ◽  
Hans A. Lehr ◽  
Christoph Hübner ◽  
Stephan G. Lindner ◽  
Ralf Ramsperger ◽  
...  

Although most non-human primates, except the chimpanzee and the gibbon in vivo are not infectible by HIV-1, lymphocytes of several of these species can be infected by HIV-1 in vitro.In order to investigate whether the in vitro infectibility of primate lymphocytes might be attributed to plasma membrane adaptation processes or to serum factors, we compared HIV-1 infectibility of cultivated peripheral blood lymphocytes of macaques and of baboons on day one and on day ten of cultivation. These data were correlated to plasma membrane lipid composition and membrane fluidity.We found a correlation between increased HIV-1 in vitro infectibility and changes in plasma membrane lipid composition resulting in decreased membrane fluidity of cultured primate lymphocytes.


Hepatology ◽  
1981 ◽  
Vol 1 (2) ◽  
pp. 137-145 ◽  
Author(s):  
Bruce F. Scharschmidt ◽  
Emmet B. Keeffe ◽  
Donald A. Vessey ◽  
Nancy M. Blankenship ◽  
Robert K. Ockner

Lipids ◽  
1988 ◽  
Vol 23 (9) ◽  
pp. 829-833 ◽  
Author(s):  
Michael W. Hamm ◽  
Anna Sekowski ◽  
Roni Ephrat

1986 ◽  
Vol 126 (3) ◽  
pp. 379-388 ◽  
Author(s):  
Brian J. Del Buono ◽  
Patrick L. Williamson ◽  
Robert A. Schlegel

2003 ◽  
Vol 4 (2) ◽  
pp. 69 ◽  
Author(s):  
W. Jessup ◽  
K. Gaus ◽  
L. Kritharides ◽  
A. Boettcher ◽  
W. Drobnik ◽  
...  

1995 ◽  
Vol 23 (4) ◽  
pp. 254-263 ◽  
Author(s):  
M Marutaka ◽  
H Iwagaki ◽  
K Mizukawa ◽  
N Tanaka ◽  
K Orita

The time-course of changes in the plasma-membrane lipid bilayer induced by tumour necrosis factor-α (TNF) were investigated in cultured cells using spin-label electron-spin-resonance techniques. Treatment of K 562 cells, a human chronic myelocytic leukaemia cell line, in suspension culture with TNF for up to 6 h caused an initial increase in cell-membrane fluidity, which returned to the control level after 12 h of treatment. After 24 h of treatment, the cell-membrane fluidity had decreased and this decrease was maintained after 48 h of treatment. In Daudi cells, a human malignant lymphoma cell line, TNF, did not induce any changes in cell-membrane fluidity, indicating that the effect of TNF on membrane structure is cell-specific. The early and transient change in membrane fluidity in K 562 cells is probably related to signal generation, while the later, persistent change may reflect the phenotype of TNF-treated cells, in particular, changes in the plasma membrane-cytoplasmic complex. Histochemical electron microscopic studies indicated that the membrane fluidity changes induced by TNF have an ultrastructural correlate.


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