Preliminary study of the enzyme ubiquitin carboxylterminal hydrolase 14 (UBP6) in Giardia intestinalis: structural bioinformatic analysis and transcriptional profile during encystation
This paper presents a combined approach<br />with two aims. The first is to analyze the<br />reported sequence of the enzyme ubiquitin<br />carboxyl-terminal hydrolase 14 of Giardia<br />intestinalis (UBP6) through computational<br />methods to find components related with<br />its hypothetical function. The second is<br />to determine if the protein-coding gene is<br />expressed in G. intestinalis and, if such is<br />the case, also determine its transcription<br />pattern along the life cycle of the parasite. It<br />was established that the protein belongs to<br />the family of Cys-dependent deubiquitinases<br />and more specifically to ubiquitin specific<br />proteases (USPs). Moreover, the catalytic<br />center with the complete triad as well as<br />typical features of the USP motif were also<br />identified. Since the computational findings<br />suggest that the enzyme could be functional,<br />reverse transcription coupled to PCR was<br />used as a first approach to establish if in fact<br />the coding gene is expressed in the parasite.<br />Interestingly, it was found not only that<br />the gene is expressed, but also that there<br />is a transcription variation along the life<br />cycle of the parasite. These two findings are<br />the starting point for further studies since<br />they tentatively suggest that this enzyme<br />could be involved in the protein turnover<br />that occurs during parasite encystation.<br />Although preliminary, this study is the first<br />report concerning the study of a specific<br />deubiquitinating enzyme in the parasite G.<br />intestinalis.