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E Gruenstein

Publications and source records attributed to E Gruenstein.

43 records · Page 3Linked to original sources
PubMed1975

Decrease in membrane-associated actin of fibroblasts after transformation by Rous sarcoma virus.

The actin content of membranes prepared from cultured chick embryo fibroblasts has been measured on polyacrylamide gels. The actin was identified by tryptic peptide mapping. After transformation of the cells by Rous sarcoma virus, the amount of actin associated with the membranes is decreased by 30-50%. This result is not due to infection per se, since infection by a temperature-sensitive strain of the virus decreases membrane-associated actin only at the permissive temperature. A shift from the nonpermissive (41 degrees) to the permissive (36 degrees) temperature results in an increase in the percentage of total cellular protein synthesis devoted to actin production, so that the decrease in membrane-associated actin appears to be a selective displacement from the membrane rather than a general decrease in total cellular actin.

Actins↗
PubMed1975

Actin associated with membranes from 3T3 mouse fibroblast and HeLa cells.

A protein component of membranes isolated from 3T3 mouse fibroblasts and HeLa cells has been identified as actin by peptide mapping. Extensive but apparently not total coincidence was found between the peptide maps of these two nonmuscle membrane-associated actins compared to chick skeletal muscle actin. Between 2 and 4 percent of the total membrane protein appears in the actin band on sodium dodecyl sulfate polyacrylamide gels of 3T3 membranes while about 4 percent of the membrane protein appears as the actin band from HeLa membranes. These values represent approximately the same proportion of actin to total protein found in the cell homogenates. Treatment of intact cells with levels of cytochalasin B sufficient to cause pronounced morphological changes did not change the amount of actin associated with the membrane in either 3T3 or HeLa cells. However, incubation of isolated membranes under conditions favoring conversion of actin from filamentous to monomeric form resulted in dissociation of approximately 80 and 60 percent of the actin from 3T3 and HeLa membranes, respectively. Thus, approximately 20 percent of 3T3 membrane actin and 40 percent of HeLa membrane actin remained associated with the membrane even under actin depolymerizing conditions.

Actins↗