Interaction of annexins IV and VI with ATP. An alternative mechanism by which a cellular function of these calcium- and membrane-binding proteins is regulated.
Annexin VI from porcine liver can be photoaffinity-labeled with 8-azido-[gamma-32P]ATP in a concentration-dependent, saturable manner. The extent of labeling varied with the concentration of calcium. The dissociation constant for the nucleotide was found to be in the range reported for ATP-binding proteins. The ATP analog, 2'-(or 3')-O-(2,4,6-trinitrophenyl)-adenosine 5'-triphosphate, also bound to AnxVI, as indicated by shift in its fluorescence spectra in the presence of protein. Any significant 8-azido-ATP or TNP-ATP binding was not observed with AnxIV. ATP modulated the binding of AnxVI to erythrocyte membrane and increased the Ca2+ concentration required for half-maximal binding of AnxVI to F-actin.
Bandorowicz-Pikuła
J
J
Department of Cellular Biochemistry, Nencki Institute of Experimental Biology, Warsaw, Poland. bandor@necki.gov.pl
Awasthi
Y C
YC
D000199:Actins / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000031:analogs & derivatives / Q000378:metabolism* / Q000502:physiology; D000345:Affinity Labels; D000818:Animals; D017314:Annexin A4 / Q000378:metabolism* / Q000502:physiology; D017317:Annexin A6 / Q000378:metabolism* / Q000502:physiology; D001386:Azides; D002118:Calcium / Q000097:blood; D002462:Cell Membrane / Q000378:metabolism / Q000502:physiology; D004910:Erythrocyte Membrane / Q000378:metabolism; D005456:Fluorescent Dyes; D006801:Humans; D012685:Sepharose / Q000031:analogs & derivatives / Q000378:metabolism; D013552:Swine
C030548:ATP-sepharose; D000199:Actins; D000345:Affinity Labels; D017314:Annexin A4; D017317:Annexin A6; D001386:Azides; D005456:Fluorescent Dyes; C017040:8-azidoadenosine 5'-triphosphate; C045674:2',3'-O-(2,4,6-trinitro-cyclohexadienylidine)adenosine 5'-triphosphate; D000255:Adenosine Triphosphate; D012685:Sepharose; D002118:Calcium