Isolation and characterization of a XXXX cDNA clone encoding a putative @entity563 / @entity1889 protein kinase.

@entity1 @entity563 @entity535 @entity8026 @entity18258 @entity1889 @entity375 @entity669 @entity3457
@entity3457 ( @entity3457 ) kinases, a closely related family of protein kinases, are involved in cell cycle regulation and differentiation in @entity375 and @entity1 cells. They have not been documented in ciliates. We used PCR to amplify DNA sequences of a ciliated protozoan-- @entity18258 --using primers corresponding to @entity535 sequences that are common to @entity3457 kinases. We isolated and sequenced one putative @entity3457 kinase-like @entity563 / @entity1889 kinase cDNA from @entity18258 . This cDNA, called pcstk1 ( @entity18258 @entity563 / @entity1889 Kinase 1) shared approximately 35% @entity535 identity with @entity3457 kinases from @entity375 . @entity3457 kinases are activated by phosphorylation of specific @entity1889 and @entity669 residues. These two @entity535 residues are conserved in the PCSTK1 sequence at positions Thr 159 and Tyr 161. The PSTAIRE motif, which is characteristic of the CDK2 gene family, cannot be found in ORF of PCSTK1. The highest homology score was to @entity1 @entity8026 , which contains @entity3457 type kinase domains. Comparisons of expression level have shown that pcstk1 is expressed equally in cells at different stages (sexual and asexual). We discussed the possibility, as in other organisms, that a family of @entity3457 kinase genes exists in @entity18258 .
