Trypanosoma cruzi: in vitro phosphorylation of tubulin by a protein kinase CK2-like enzyme

Identification of casein kinase 1, casein kinase 2, and cAMP-dependent protein kinase-like activities in Trypanosoma evansi

“…In addition, the parasite CK2 was not purified to homogeneity, and inhibitors' IC 50 values may change according to the purity of the material. Consistently, tubulin has been reported to be the major phosphoprotein in another trypanosome, T. cruzi (Casas et al 2002), and likewise, T. cruzi tubulin has also been shown to be phosphorylated by a CK2-like activity (Casas et al 2002, Uzcanga et al 2003. In T. brucei, an evolutionarily more related parasite, two CK2 genes have been identified: CK2a1 and CK2a2 (Park et al 2002).…”

Divalent cation hinder the solubilization of a tubulin kinase activity from Trypanosoma cruzi epimastigotes

“…As previously shown in Table I, the sum of the kinase activities obtained for S1 and P1 was always higher than the corresponding activities obtained in the original homogenate, under both conditions (data not included), suggesting again the presence of a protein kinase modulator in the whole-cell extract. C K 2 i n h i b i t o r s w e r e e m p l o y e d t o demonstrate that the TubK was the CK2-like activity previously reported to be responsible for phosphorylating tubulin in T. cruzi epimastigotes (Casas et al, 2002). Since divalent cations influenced the compartmentalization of the parasite TubK and fP-Tub, three specific CK2 inhibitors, heparin, 2,3-BPG and GTP (Tuazon & Traugh, 1991) were tested on the TubKenriched fractions originated when the parasites were extracted with Buffer D or E, i.e., the corresponding P1 or S1 fractions, respectively.…”

“…Since Casas et al (2002) have shown that TubK is a protein kinase CK2-like activity in T. cruzi, we also examined the kinase activity of the fractions obtained under the various conditions, using casein as an exogenous substrate. Calabokis et al (2002) have reported soluble CK1-like and CK2-like activities in T. cruzi epimastigotes.…”

“…c r u z i : e p i m a s t i g o t e s , t r y p o m a s t i g o t e s a n d spheromastigotes. The phosphorylation of tubulin was inhibited with heparin, 2,3-bisphosphoglycerate (2,3-BPG), and GTP in a dose dependent manner, indicating that tubulin kinase corresponded to a protein kinase CK2-like activity (Casas et al, 2002). Interestingly, CK1-like and CK2-like activities have been previously shown in T. cruzi epimastigotes .…”

“…Recently, Casas et al (2002) have d e m o n s t r a t e d t h a t t u b u l i n w a s t h e p r e d o m i n a n t p h o s p h o p r o t e i n i n h o m o g e n a t e s o f t h r e e d i f f e r e n t d i f f e r e n t i a t i o n s t a g e s o f T . c r u z i : e p i m a s t i g o t e s , t r y p o m a s t i g o t e s a n d spheromastigotes.…”