Cell surface control of differentiation in Acanthamoeba.
Acanthamoeba castellanii (Neff) is a free-living soil amoeba with close relatives that are opportunistic pathogens. Trophozoites differentiate into cysts when deprived of nutrients; cysts convert into trophozoites, leaving the wall behind, in the presence of nutrients. The data presented here, which includes immunoaffinity purification of the receptor, indicate that cell surface molecular signals also control Acanthamoeba differentiation in both directions. Monoclonal antibodies that bind specifically to a 40 kD trophozoite protein initiate the encystment of trophozoites. When bound to cysts the same monoclonal antibodies prevent excystment. Washing away the antibody allows both trophozoites and cysts to resume normal activity. One of these monoclonal antibodies inhibits pinocytosis, while another has no effect on pinocytosis.
Yang
S
S
Department of Molecular Biology, University of Wyoming, Laramie 82071-3944.
Villemez
C
C
D000048:Acanthamoeba / Q000166:cytology* / Q000276:immunology / Q000378:metabolism* / Q000502:physiology*; D000818:Animals; D000911:Antibodies, Monoclonal; D000913:Antibodies, Protozoan; D002454:Cell Differentiation; D015800:Protozoan Proteins / Q000378:metabolism*; D011956:Receptors, Cell Surface / Q000502:physiology
D000911:Antibodies, Monoclonal; D000913:Antibodies, Protozoan; D015800:Protozoan Proteins; D011956:Receptors, Cell Surface