Rsj. Felleisen et al., A novel EF-hand calcium-binding protein in the flagellum of the protozoan Tritrichomonas suis, PARASITOL, 122, 2001, pp. 125-132
The cloning and characterization of Ts-p41, an EF-hand calcium-binding prot
ein of the protozoan parasite Tritrichomonas suis is described double dagge
r. A T. suis cDNA library was screened with monospecific antibodies affinit
y purified on an immunoreactive 41 kDa antigen in a Triton X-114 membrane-p
rotein fraction. The resulting cDNA fragments turned out to be derived from
2 different genes encoding closely related Ts-p41 variants. The deduced am
ino acid sequences contained 6 EF-hand domains perfectly matching the canon
ical consensus motif and a putative C-terminal prenylation site. Northern a
nd Southern hybridizations revealed that Ts-p41 was highly expressed and en
coded by a gene-family. A cDNA encoding Ts-p41 was expressed as recombinant
protein in Escherichia roll. By overlay with Ca-45 it was demonstrated tha
t the native and recombinant Ts-p41 proteins bind Ca2+. In immunofluorescen
ce, 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 bearin
g calcium-binding proteins might be a common phenomenon associated with fla
gellar motility.