Posttranslational modifications are one of the most effective ways
by which evolution has increased the versatility in protein function.
In eukaryotic cells, SUMOylation of highly conserved proteins
occurs. In the intestinal parasite G. lamblia we showed that gSentrin
protein localize mainly in the cytoplasm of Giardia trophozoites,
though also surrounding the nuclei, even inside it. By Western Blot we observed several sumoylated proteins but, at this time, only Arginine Deiminase (gADI) was confirmed as a sumoylated substrate. gADI is an important enzyme in the survival and differentiation of the parasite. During the differentiation process, gADI translocated to the nuclei and the production of cysts was reduced. Recently, we demonstrated that in the nuclei gADI citrullinates histones. Moreover, when the enzyme had mutations in the site of sumoylation, the translocation to the nuclei did not occur, nor the citrullination of histones and the number of cysts produced were similar to wild type trophozoites. The characterization of SUMOylation and citrulination in Giardia are crucial to understand
the role of these posttranslational modifications in the evolution history.
protein localize mainly in the cytoplasm of Giardia trophozoites,
though also surrounding the nuclei, even inside it. By Western Blot we observed several sumoylated proteins but, at this time, only Arginine Deiminase (gADI) was confirmed as a sumoylated substrate. gADI is an important enzyme in the survival and differentiation of the parasite. During the differentiation process, gADI translocated to the nuclei and the production of cysts was reduced. Recently, we demonstrated that in the nuclei gADI citrullinates histones. Moreover, when the enzyme had mutations in the site of sumoylation, the translocation to the nuclei did not occur, nor the citrullination of histones and the number of cysts produced were similar to wild type trophozoites. The characterization of SUMOylation and citrulination in Giardia are crucial to understand
the role of these posttranslational modifications in the evolution history.
though also surrounding the nuclei, even inside it. By Western Blot
we observed several sumoylated proteins but, at this time, only
Arginine Deiminase (gADI) was confirmed as a sumoylated
substrate. gADI is an important enzyme in the survival and
differentiation of the parasite. During the differentiation process,
gADI translocated to the nuclei and the production of cysts was
reduced. Recently, we demonstrated that in the nuclei gADI
citrullinates histones. Moreover, when the enzyme had mutations in
the site of sumoylation, the translocation to the nuclei did not occur,
nor the citrullination of histones and the number of cysts produced
were similar to wild type trophozoites. The characterization of
SUMOylation and citrulination in Giardia are crucial to understand
the role of these posttranslational modifications in the evolution history.
the role of these posttranslational modifications in the evolution
history.
