Format

Send to

Choose Destination
Biophys J. 1998 Jan;74(1):514-22.

Membrane bending modulus and adhesion energy of wild-type and mutant cells of Dictyostelium lacking talin or cortexillins.

Author information

1
Physics Department, Technische Universität München, Garching, Germany. rsimson@physik.tu-muenchen.de

Abstract

We have employed an interferometric technique for the local measurement of bending modulus, membrane tension, and adhesion energy of motile cells adhering to a substrate. Wild-type and mutant cells of Dictyostelium discoideum were incubated in a flow chamber. The flow-induced deformation of a cell near its adhesion area was determined by quantitative reflection interference contrast microscopy (RICM) and analyzed in terms of the elastic boundary conditions: equilibrium of tensions and bending moments at the contact line. This technique was employed to quantify changes caused by the lack of talin, a protein that couples the actin network to the plasma membrane, or by the lack of cortexillin I or II, two isoforms of the actin-bundling protein cortexillin. Cells lacking either cortexillin I or II exhibited reduced bending moduli of 95 and 160 k(B)T, respectively, as compared to 390 k(B)T, obtained for wild-type cells. No significant difference was found for the adhesion energies of wild-type and cortexillin mutant cells. In cells lacking talin, not only a strongly reduced bending modulus of 70 k(B)T, but also a low adhesion energy one-fourth of that in wild-type cells was measured.

PMID:
9449351
PMCID:
PMC1299403
DOI:
10.1016/S0006-3495(98)77808-7
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Elsevier Science Icon for PubMed Central
Loading ...
Support Center