TY - JOUR
T1 - Membrane bending modulus and adhesion energy of wild-type and mutant cells of Dictyostelium lacking talin or cortexillins
AU - Simson, R.
AU - Wallraft, E.
AU - Faix, J.
AU - Niewohner, J.
AU - Gerisch, G.
AU - Sackmann, E.
PY - 1998
Y1 - 1998
N2 - 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 Dictyostellum discoldeum 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.
AB - 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 Dictyostellum discoldeum 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.
UR - http://www.scopus.com/inward/record.url?scp=0031982879&partnerID=8YFLogxK
U2 - 10.1016/S0006-3495(98)77808-7
DO - 10.1016/S0006-3495(98)77808-7
M3 - Article
C2 - 9449351
AN - SCOPUS:0031982879
SN - 0006-3495
VL - 74
SP - 514
EP - 522
JO - Biophysical Journal
JF - Biophysical Journal
IS - 1
ER -