Probing phosphatidylinositolphosphates and adenosinenucleotides on talin nucleated actin polymerization.
We have investigated the binding of PI, PIP and PIP2 to talin and the effect of phosphoinositides and adenosinenucleotides on talin-induced actin polymerization. At physiological salt concentrations, talin coprecipitates with liposomes when containing phosphoinositides but not when containing PI. The nucleating effect of talin as reflected by a twofold increase of fluorescence during the polymerization of actin labelled with NBD is not inhibited by phosphoinositides. The polymerization of ADP-actin versus ATP-actin was investigated in the presence and absence of talin by NBD fluorescence. ADP-actin nucleation induced by talin is comparably efficient as with ATP-actin. These experimental findings in summary have implications when evaluating the role of talin during cell activation.
Isenberg
G
G
Technical University of Munich, Biophysics, Garching, Germany.
Niggli
V
V
Pieper
U
U
Kaufmann
S
S
Goldmann
W H
WH
D000199:Actins / Q000737:chemistry*; D000244:Adenosine Diphosphate / Q000031:analogs & derivatives* / Q000737:chemistry; D000255:Adenosine Triphosphate / Q000031:analogs & derivatives* / Q000737:chemistry; D001704:Biopolymers; D006801:Humans; D008081:Liposomes / Q000378:metabolism; D019269:Phosphatidylinositol 4,5-Diphosphate / Q000378:metabolism / Q000494:pharmacology; D018129:Phosphatidylinositol Phosphates / Q000378:metabolism / Q000494:pharmacology; D010716:Phosphatidylinositols / Q000378:metabolism / Q000494:pharmacology*; D013050:Spectrometry, Fluorescence; D016608:Talin / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*
C042634:ADP-G-actin; C022920:ATP-G-actin; D000199:Actins; D001704:Biopolymers; D008081:Liposomes; D019269:Phosphatidylinositol 4,5-Diphosphate; D018129:Phosphatidylinositol Phosphates; D010716:Phosphatidylinositols; D016608:Talin; C037178:phosphatidylinositol 4-phosphate; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate