A novel EF-hand calcium-binding protein in the flagellum of the protozoan Tritrichomonas suis.
The cloning and characterization of Ts-p41, an EF-hand calcium-binding protein of the protozoan parasite Tritrichomonas suis is described. A T. suis cDNA library was screened with monospecific antibodies affinity purified on an immunoreactive 41 kDa antigen in a Triton X-114 membrane-protein fraction. The resulting cDNA fragments turned out to be derived from 2 different genes encoding closely related Ts-p41 variants. The deduced amino acid sequences contained 6 EF-hand domains perfectly matching the canonical consensus motif and a putative C-terminal prenylation site. Northern and Southern hybridizations revealed that Ts-p41 was highly expressed and encoded by a gene-family. A cDNA encoding Ts-p41 was expressed as recombinant protein in Escherichia coli. By overlay with 45Ca it was demonstrated that the native and recombinant Ts-p41 proteins bind Ca2+. In immunofluorescence, epitopes recognized by anti-Ts-p41 antibodies were distributed as well on the anterior flagella as on the recurrent flagellum of the parasite. Our findings with the parabasalid T. suis suggest that multiple EF-hand bearing calcium-binding proteins might be a common phenomenon associated with flagellar motility.
Institute of Parasitology, University of Bern, Switzerland.
R S
RS
Felleisen
A
A
Hemphill
B
B
Gottstein
D000595:Amino Acid Sequence; D000818:Animals; D002118:Calcium / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D004591:Electrophoresis, Polyacrylamide Gel; D005407:Flagella / Q000737:chemistry; D005455:Fluorescent Antibody Technique; D008969:Molecular Sequence Data; D019105:Random Amplified Polymorphic DNA Technique; D011993:Recombinant Fusion Proteins / Q000737:chemistry; D014318:Tritrichomonas / Q000737:chemistry* / Q000235:genetics
D002135:Calcium-Binding Proteins; D011993:Recombinant Fusion Proteins; C426723:flagellum protein 41-kDa, Tritrichomonas suis; D002118:Calcium