Protein and mRNA content of TcDHH1‐containing mRNPs in Trypanosoma cruzi

In trypanosomatids, the regulation of gene expression occurs mainly at the post‐transcriptional level. Previous studies have revealed nontranslated mRNA in the Trypanosoma cruzi cytoplasm. Previously, we have identified and cloned the TcDHH1 protein, a DEAD box RNA helicase. It has been reported that Dhh1 is involved in multiple RNA‐related processes in various eukaryotes. It has also been reported to accumulate in stress granules and processing bodies of yeast, animal cells, Trypanosoma brucei and T. cruzi. TcDHH1 is localized to discrete cytoplasmic foci that vary depending on the life cycle status and nutritional conditions. To study the composition of mRNPs containing TcDHH1, we carried out immunoprecipitation assays with anti‐TcDHH1 using epimastigote lysates. The protein content of mRNPs was determined by MS and pre‐immune serum was used as control. We also carried out a ribonomic approach to identify the mRNAs present within the TcDHH1 immunoprecipitated complexes. For this purpose, competitive microarray hybridizations were performed against negative controls, the nonprecipitated fraction. Our results showed that mRNAs associated with TcDHH1 in the epimastigote stage are those mainly expressed in the other forms of the T. cruzi life cycle. These data suggest that mRNPs containing TcDHH1 are involved in mRNA metabolism, regulating the expression of at least epimastigote‐specific genes. Structured digital abstract MINT‐7909478 : DHH1 (uniprotkb: Q4DIE1 ) physically interacts ( MI:0915 ) with PABP2 (uniprotkb: Q27335 ) by anti bait coimmunoprecipitation ( MI:0006 ) MINT‐7909338 : DHH1 (uniprotkb: Q4DIE1 ) physically interacts ( MI:0914 ) with ATP‐dependent DEAD/H RNA helicase, putative (uniprotkb: Q4DIE1 ), Actin, putative (uniprotkb: Q4D7A6 ), Actin, putative (uniprotkb: Q4CLA9 ), Chaperonin HSP60, mitochondrial (uniprotkb: Q4DYP6 ), ATP‐dependent Clp protease subunit, heat shock protein 100 (HSP100), putative (uniprotkb: Q4CNM5 ), Elongation factor 2, putative (uniprotkb: Q4D5X0 ), Elongation factor 1‐alpha (EF‐1‐alpha), putative (uniprotkb: Q4CU73 ), Heat shock protein 85, putative (uniprotkb: Q4CQS6 ), Glutamate dehydrogenase, putative (uniprotkb: Q4DWV8 ), Putative uncharacterized protein (uniprotkb: Q4CNI8 ), 40S ribosomal protein S11, putative (uniprotkb: Q4CRH9 ), Sterol 24‐c‐methyltransferase, putative (uniprotkb: Q4CMB7 ), Heat shock protein 70 (HSP70), putative (uniprotkb: Q4DTM9 ), Glutamate dehydrogenase, putative (uniprotkb: Q4D5C2 ) and Calpain‐like cysteine peptidase, putative (uniprotkb: Q4CYU3 ) by anti bait coimmunoprecipitation ( MI:0006 ) MINT‐7909469 : DHH1 (uniprotkb: Q4DIE1 ) physically interacts ( MI:0915 ) with PABP1 (uniprotkb: Q4E4I9 ) by anti bait coimmunoprecipitation ( MI:0006 )