Phenothiazine binding by a homolog of calpactin, the pp60src tyrosine kinase substrate.
Microvilli isolated from 13762 mammary ascites tumor cells contain a major calcium-sensitive protein (AMV-p35) that can be isolated with microvillar microfilament cores prepared by Triton X-100 extraction in the presence but not absence of calcium. AMV-p35 can be readily purified from ethylene glycol bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid extracts of the microfilament cores by chromatography on an anion exchange column, to which it does not bind. Immunoblot analysis indicates that AMV-p35 is related to calpactin I, the pp60src tyrosine kinase substrate. In the presence of calcium, AMV-p35 binds approximately 4 mol of chlorpromazine per mole of protein in a binding process showing apparent positive cooperativity, similar to calmodulin; however, in contrast to calmodulin, AMV-p35 also binds phenothiazine in the absence of calcium.
Carraway
K L
KL
Liu
Y
Y
Puett
D
D
Carraway
K L
KL
Carraway
C A
CA
D000818:Animals; D002118:Calcium / Q000502:physiology; D002460:Cell Line; D002746:Chlorpromazine / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D007158:Immunologic Techniques; D008325:Mammary Neoplasms, Experimental / Q000378:metabolism*; D008840:Microfilament Proteins / Q000302:isolation & purification / Q000378:metabolism*; D008871:Microvilli / Q000378:metabolism*; D008970:Molecular Weight; D009363:Neoplasm Proteins / Q000302:isolation & purification / Q000378:metabolism*; D010640:Phenothiazines / Q000378:metabolism*; D011485:Protein Binding
D008840:Microfilament Proteins; D009363:Neoplasm Proteins; D010640:Phenothiazines; C053369:ascites microvillar protein p35; D002118:Calcium; D002746:Chlorpromazine