Association of specific cell-surface glycoproteins with a triton X-100-resistant complex of plasma membrane proteins isolated from T-lymphoma cells (P 1798)

1985 ◽  
Vol 156 (1) ◽  
pp. 239-250 ◽  
Author(s):  
Daniel Hoessli ◽  
Elisabeth Rungger-Brändle
1993 ◽  
Vol 265 (6) ◽  
pp. C1588-C1596 ◽  
Author(s):  
L. Feng ◽  
N. Kraus-Friedmann

Studies were carried out to characterize the interaction between inositol 1,4,5-trisphosphate (IP3) receptors and the plasma membrane fraction. Extraction of the membranes with the nonionic detergents Nonidet P-40 and Triton X-100, followed by centrifugation at 100,000 g, resulted in the doubling of the IP3 receptor in the pellets, whereas no detectable binding was found in the supernatants. These data indicate that the detergents did not solubilize the receptor, that it remained associated with membrane particles, and that it is likely to be associated with the cytoskeleton. The cytoskeleton proteins actin, ankyrin, and spectrin were identified in the plasma membrane fraction. However, comparison of the amount of these proteins in different fractions of the detergent, or otherwise treated plasma membrane fractions, showed no direct correlation between the presence of any of these proteins in the plasma membrane fraction and their ability to bind [3H]IP3. This is in contrast to the brain and T-lymphoma cells in which the IP3 receptor is attached to ankyrin (L. Y. W. Bourguigon, H. Jin, N. Iida, N. R. Brandt, and S. H. Zhang. J. Biol. Chem. 268: 6477-6486, 1993; and S. K. Joseph and S. Samanta. J. Biol. Chem 268: 6477-6486, 1993). Thus the hepatic IP3 receptor, which is different from the brain receptor, might attach to the cytoskeleton by anchoring to a different protein. Because cytochalasin D treatment of livers diminishes the ability of IP3 to raise cytosolic free Ca2+ levels, the attachment of the IP3 receptor to the cytoskeleton seems to involve an association with microfilaments.


1989 ◽  
Vol 92 (1) ◽  
pp. 85-91
Author(s):  
W.F. Patton ◽  
M.R. Dhanak ◽  
B.S. Jacobson

The plasma membrane proteins of Dictyostelium discoideum were characterized with respect to their partitioning into the Triton-insoluble cytoskeleton fraction of the cell during concanavalin A-induced capping. Two fractions of plasma membrane-associated concanavalin A were identified; one that immediately associated with the cytoskeleton fraction via cell surface glycoproteins, and one that partitioned with the cytoskeleton only after extensive cell surface glycoprotein cross-linking. Three major classes of polypeptides were found in the plasma membrane that differed with respect to their partitioning properties into the cytoskeleton fraction. The temporal order of association of the polypeptides with the cytoskeleton during concanavalin A-induced capping corresponded to the strength of their association with the cytoskeleton fraction as determined by pH and ionic strength elution from unligated cytoskeletons.


1994 ◽  
Vol 298 (3) ◽  
pp. 661-668 ◽  
Author(s):  
A S Bergman ◽  
S R Carlsson

A glycosylphosphatidylinositol-specific phospholipase D (GPI-PLD) was purified from human serum and used for studies on the release of GPI-anchored Thy-1 glycoprotein from mouse T lymphoma cells Y191. Previous studies have shown that whereas GPI-PLD is highly active against detergent-solubilized GPI-anchored proteins, it is normally unable to release GPI-containing proteins anchored in a lipid bilayer. Confirming these findings, the addition of GPI-PLD to intact Y191 cells did not result in cleavage of Thy-1. However, pretreatment of cells with saponin, a cholesterol-sequestering agent, rendered Thy-1 susceptible to hydrolysis. Very little solubilization of GPI-containing Thy-1 occurred under these conditions. From experiments with reconstituted liposomes it was inferred that the effect of saponin on cells was to aid in the presentation of Thy-1 to GPI-PLD. Furthermore, it was concluded that cholesterol-saponin complexes formed in the membrane were not alone responsible for the effect. Rather, additional molecules in the plasma membrane are possibly involved in the presentation of Thy-1 on saponin-treated cells. This finding may have implications for a physiological role of circulating GPI-PLD in the regulation of GPI-anchored proteins on cells.


1981 ◽  
Vol 91 (3) ◽  
pp. 889-894 ◽  
Author(s):  
L Y Bourguignon ◽  
M L Nagpal ◽  
Y C Hsing

Colchicine induces the clustering of at least three different T-lymphoma surface antigens (T200, Thy-1, and gp 69/71) into a cap structure in the absence of any external ligand. In addition, colchicine induces the intracellular accumulation of actin and myosin directly beneath the surface cap structure. We have discovered that myosin molecules (both heavy and light chains) are closely associated with the plasma membrane of T-lymphoma cells. Most importantly, we have found that the 20,000-dalton light chain of lymphocyte myosin is both phosphorylated and preferentially accumulated in the plasma membrane of colchicine-induced capped cells. It is proposed that myosin light chain is directly involved in the activation of membrane-associated actomyosin required for the collection of surface proteins into a cap structure (analogous to muscle cell sliding filament contraction).


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