Studies on calmodulin-binding proteins (CaMBPs) in the cilia of Tetrahymena.
As a first step to elucidate the involvement of calmodulin in Ca2+-dependent regulation of ciliary motility, molecular species and properties of calmodulin-binding proteins (CaMBPs) in Tetrahymena cilia were investigated by a modified [125I]calmodulin overlay method. At least 36 kinds of CaMBPs were detected. All the CaMBPs bound to calmodulin in Ca2+-dependent and calmodulin-specific manners, but they showed different Ca2+-dependencies. Several of CaMBPs bound to calmodulin in the presence of 100 microM trifluoperazine, several did in the presence of 8 M urea, and a few of them were highly sensitive to trypsin digestion. Among these CaMBPs, we noticed a 95 000-dalton (D) CaMBP present in the outerdoublet microtubule fraction, which possessed some attributes of the calmodulin counterpart suggested from the results of our previous paper [12]. We discussed a possibility that this protein might correspond to one of the protein components of the interdoublet link.
Hirano
J
J
Watanabe
Y
Y
D000818:Animals; D002118:Calcium / Q000494:pharmacology; D002147:Calmodulin / Q000378:metabolism; D002148:Calmodulin-Binding Proteins; D002923:Cilia / Q000032:analysis / Q000378:metabolism*; D008870:Microtubules / Q000032:analysis / Q000378:metabolism*; D008970:Molecular Weight; D010749:Phosphoprotein Phosphatases / Q000032:analysis / Q000378:metabolism*; D013768:Tetrahymena / Q000032:analysis / Q000378:metabolism* / Q000648:ultrastructure; D014268:Trifluoperazine / Q000494:pharmacology; D014357:Trypsin; D014508:Urea
D002147:Calmodulin; D002148:Calmodulin-Binding Proteins; D014268:Trifluoperazine; D014508:Urea; D010749:Phosphoprotein Phosphatases; D014357:Trypsin; D002118:Calcium