HIGH-MOLECULAR-WEIGHT PROTEINS ASSOCIATED WITH THE BASAL BODY IN AFRICAN TRYPANOSOMES

Immunoblots of protein preparations from Trypanosoma brucei were probe d with monoclonal antibodies directed against basal-body associated pr oteins in Tetrahymena called tetrins. An antibody recognizing tetrin 4 in Tetrahymena. mAb11C7, blotted a double band at about 300 kDa in to tal cell protein preparations and in detergent-extracted cytoskeletons of T. brucei. Immunofluorescence preparations using triple labeling w ith antitubulin, mAb11C7, and DAPI showed that mAb11C7 stains three sm all dots close to the kinetoplast very brightly. Immunogold preparatio ns of both whole mount and thin sections of cytoskeletons examined wit h the electron microscope showed that the mAb11C7-positive material is located in the dense cloud of material surrounding the flagellar basa l body. The same results were obtained with other African trypanosomes , but similar high molecular weight (HMW) proteins were not found by t hese procedures in South American forms. Evidence is presented indicat ing that the tetrin-related proteins in T. brucei are heavily phosphor ylated.