This mutant has approximately 665 bp that span nt 1726-2391. As with full length LaTRF, the LaTRF Myb mutant was cloned into the pCR® 2.1 cloning vector (Invitrogen), sequenced and subcloned into a pET28a+ expression
vector. Expression of LaTRF and the deletion mutant LaTRFMyb proteins in E. coli Full length LaTRF and the deletion mutant LaTRF Myb cloned into a pET 28a+ vector, were transformed in E. coli strain BL21 DE3 RP codon plus cells for expression in the presence of 1 mM IPTG. Both proteins were expressed in low amounts and in non-soluble form, preventing them from being purified by affinity chromatography based on the 6× His-tag. To overcome this problem, the SBE-��-CD non-soluble bacterial pellets containing both proteins were solubilized in 7 M urea, sonicated in the presence of 10 U of DNAse I (Sigma) and renatured by dialysis in 50 mM glycine, pH 8.0. The presence of each protein in the extracts was checked by electrophoresis in 10% SDS-PAGE followed by Western blot probed with anti-LaTRF serum and with an anti-His tag monoclonal
antibody (Novagen). Preparation of L. amazonensis total and nuclear extracts Promastigotes in mid-exponential growth were used to obtain both extracts. Nuclear and cytoplasmic extracts were prepared with a Nuclear Extract Kit (Active Motif) adapted for L. amazonensis promastigotes in the presence of phosphatase and protease inhibitors. Total protein extracts were obtained using RIPA buffer (150 mM Tris-HCl pH 7.5, 150 mM click here NaCl, 1% Triton X-100 and 0.1% SDS) in the presence of 10 U of DNase I and 1X protease inhibitor cocktail (Calbiochem) and incubated for 15 min at 4°C. Cell lysates were homogenized by vortexing at maximum speed (5 bursts of 10 s each). Extracts were cleared by centrifugation at 9,300 ×g for 8 min at 4°C, to separate the
Oxalosuccinic acid total protein (supernatant) from the cellular debris (pellet). Both extracts were stored at -80°C and their protein concentrations were measured by the Bradford dye-binding assay, using bovine serum albumin as standard. Western blot analysis Different protein extracts obtained from 107 parasites were separated by SDS-PAGE on 10% check details polyacrylamide gels and transferred to nitrocellulose membranes (BIO-RAD) in Tris-glycine-methanol at 16°C. The membranes were probed with rabbit anti-TRF2 serum raised against the synthetic peptide Nt-APAVTTRKRPRSSDSP-Ct (Sigma). The extracts were also probed with anti-LaRPA-1 serum as a control [23, 32]. In both cases, immunoreactive bands were revealed by using an Amplified Alkaline Phosphatase Immun-Blot Assay Kit, according to the manufacturer’s instructions (BIO-RAD). Indirect immunofluorescence combined with Telomere PNA FISH (fluorescence in situ hybridization) This assay was performed using previously described protocols [32, 33] with minor modifications.