Theileria parva is an obligate intracellular protozoan parasite which is the causative agent of East Coast fever, an acute, leukemia-like disease of cattle. The intralymphocytic stage of the parasite induces blastogenesis and clonal expansion of quiescent bovid lymphocytes. Experiments in our laboratory have shown a marked increase of casein kinase II- (CK II-) like activity in T. parva-transformed lymphocytes. We have also detected CK II activity in purified T. parva schizonts. To explore the significance of this increase, we used a Drosophila melanogaster CK II α cDNA probe [Saxena et al. (1987) Mol. Cell Biol. 7, 3409-3417] to isolate a T. parva genomic clone encoding a CK II catalytic subunit. The clone contains a 1.3-kb open reading frame coding for a predicted protein of 420 amino acids (Mr 50 200). Northern blot analysis revealed a single transcript of 1.65 kb. The deduced T. parva CK II catalytic subunit sequence shows, over 321 residues comprising the C-terminus of the molecule, extensive identity with CK II α and α′ sequences from both vertebrate and invertebrate organisms. The T. parva CK II subunit amino acid sequence displays 68% identity with the Drosophila a subunit and 67% with the Caenorhabditis elegans a subunit but only 58% and 56% sequence identity with the Saccharomyces cerevisiae α and α′ subunits, respectively. Comparison of the T. parva sequence with higher eukaryotic α and α′ sequences reveals that it is most identical with the α subunit. A unique component of the T. parva CK II α subunit is a 99 amino acid sequence at the N-terminus, which contains a sequence motif with features characteristic of signal peptides.
|Original language||English (US)|
|Number of pages||10|
|State||Published - 1992|
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