Binding and assembly of actin filaments by plasma membranes from dictyostelium discoideum

Journal Article · Wed Jan 01 04:00:00 EST 1986 · J. Cell Biol.; (United States)

DOI:https://doi.org/10.1083/jcb.102.6.2067· OSTI ID:5563938

Schwartz, M A; Luna, E J

The binding of native, /sup 125/I-Bolton-Hunter-labeled actin to purified Dictyostelium discoideum plasma membranes was measured using a sedimentation assay. Binding was saturable only in the presence of the actin capping protein, gelsolin. The binding curves were sigmoidal, indicating positive cooperativity at low actin concentrations. This cooperativity appeared to be due to actin-actin associations during polymerization, since phalloidin converted the curve to a hyperbolic shape. This membrane-bound actin stained with rhodamine-phalloidin and was cross-linked by m-maleimidobenzoyl succinimide ester, a bifunctional cross-linker, into multimers with the same pattern observed for cross-linked F-actin. The authors conclude that D. discoideum plasma membranes bind actin specifically and saturably and that these membranes organize actin into filaments below the normal critical concentration for polymerization. This interaction probably occurs between multiple binding sites on the membrane and the side of the actin filament, and may be related to the clustering of membrane proteins.

• Research Organization: Harvard Medical School, Boston, MA
• OSTI ID: 5563938
• Journal Information: J. Cell Biol.; (United States), Journal Name: J. Cell Biol.; (United States) Vol. 102; ISSN JCLBA
• Country of Publication: United States
• Language: English

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59 BASIC BIOLOGICAL SCIENCES
ACTIN
ADSORPTION
BETA DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
CELL CONSTITUENTS
CELL MEMBRANES
DAYS LIVING RADIOISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
LABELLED COMPOUNDS
MEMBRANES
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
PLANT CELLS
PROTEINS
RADIOISOTOPES
REACTION KINETICS
SORPTION
STRUCTURE-ACTIVITY RELATIONSHIPS
TRACER TECHNIQUES