Limits...
Identification of Giardia lamblia DHHC proteins and the role of protein S-palmitoylation in the encystation process.

Merino MC, Zamponi N, Vranych CV, Touz MC, Rópolo AS - PLoS Negl Trop Dis (2014)

Bottom Line: With bioinformatics tools, we found nine DHHC proteins, potential protein acyltransferases, in the Giardia proteome.These proteins displayed a conserved structure when compared to different organisms and are distributed in different monophyletic clades.Our findings disclosed some important issues regarding the role of DHHC proteins and palmitoylation during Giardia encystation.

View Article: PubMed Central - PubMed

Affiliation: Instituto de Investigación Médica Mercedes y Martín Ferreyra, INIMEC - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de Córdoba, Córdoba, Argentina.

ABSTRACT
Protein S-palmitoylation, a hydrophobic post-translational modification, is performed by protein acyltransferases that have a common DHHC Cys-rich domain (DHHC proteins), and provides a regulatory switch for protein membrane association. In this work, we analyzed the presence of DHHC proteins in the protozoa parasite Giardia lamblia and the function of the reversible S-palmitoylation of proteins during parasite differentiation into cyst. Two specific events were observed: encysting cells displayed a larger amount of palmitoylated proteins, and parasites treated with palmitoylation inhibitors produced a reduced number of mature cysts. With bioinformatics tools, we found nine DHHC proteins, potential protein acyltransferases, in the Giardia proteome. These proteins displayed a conserved structure when compared to different organisms and are distributed in different monophyletic clades. Although all Giardia DHHC proteins were found to be present in trophozoites and encysting cells, these proteins showed a different intracellular localization in trophozoites and seemed to be differently involved in the encystation process when they were overexpressed. dhhc transgenic parasites showed a different pattern of cyst wall protein expression and yielded different amounts of mature cysts when they were induced to encyst. Our findings disclosed some important issues regarding the role of DHHC proteins and palmitoylation during Giardia encystation.

Show MeSH

Related in: MedlinePlus

Differential expression of Giardia dhhc genes in growing and encysting parasites.Expression of gla_8619, gla_1908, gla_8711, EAA36893, gla_9529, gla_16928, gla_6733, gla_96562, gla_2116 transcripts from 48 h encysting parasites (white bars) relative to the expression in growing parasites (black bars). The data are the means and SEM of three separate experiments, and each experiment was carried out in triplicate. The qRT-PCR analysis of dhhc genes was performed as described in Methods. The asterisks indicate that there was significant difference compared with growing parasites (Student's t test: * p<0.05; **p<0.01; ***p<0.001).
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4109852&req=5

pntd-0002997-g006: Differential expression of Giardia dhhc genes in growing and encysting parasites.Expression of gla_8619, gla_1908, gla_8711, EAA36893, gla_9529, gla_16928, gla_6733, gla_96562, gla_2116 transcripts from 48 h encysting parasites (white bars) relative to the expression in growing parasites (black bars). The data are the means and SEM of three separate experiments, and each experiment was carried out in triplicate. The qRT-PCR analysis of dhhc genes was performed as described in Methods. The asterisks indicate that there was significant difference compared with growing parasites (Student's t test: * p<0.05; **p<0.01; ***p<0.001).

Mentions: Semi-quantitative RT-PCR indicated that all the dhhc genes were expressed in trophozoites and in encysting parasites (Figure S6). This prompted us to explore further the expression levels of these genes in growing and encysting parasites by performing qRT-PCR analysis of mRNA expression from these cells. As shown in figure 6, many of the dhhc transcripts were present at relatively constant levels, but gla_8619, gla_1908, and EAA36893 were downregulated in encysting parasites while gla_2116 was upregulated in 48 h encysting cells. Considering that Giardia contains minimal systems, either as a result of reductive processes associated with a parasitic lifestyle, as a reflection of basic evolutionary characteristics, or both [85], [86], the fact that the nine dhhc genes found by bioinformatics were expressed in vegetative and encysting parasites suggests that protein palmitoylation and the PATs themselves may be playing a key role during the entire life cycle of this parasite.


Identification of Giardia lamblia DHHC proteins and the role of protein S-palmitoylation in the encystation process.

Merino MC, Zamponi N, Vranych CV, Touz MC, Rópolo AS - PLoS Negl Trop Dis (2014)

Differential expression of Giardia dhhc genes in growing and encysting parasites.Expression of gla_8619, gla_1908, gla_8711, EAA36893, gla_9529, gla_16928, gla_6733, gla_96562, gla_2116 transcripts from 48 h encysting parasites (white bars) relative to the expression in growing parasites (black bars). The data are the means and SEM of three separate experiments, and each experiment was carried out in triplicate. The qRT-PCR analysis of dhhc genes was performed as described in Methods. The asterisks indicate that there was significant difference compared with growing parasites (Student's t test: * p<0.05; **p<0.01; ***p<0.001).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4109852&req=5

pntd-0002997-g006: Differential expression of Giardia dhhc genes in growing and encysting parasites.Expression of gla_8619, gla_1908, gla_8711, EAA36893, gla_9529, gla_16928, gla_6733, gla_96562, gla_2116 transcripts from 48 h encysting parasites (white bars) relative to the expression in growing parasites (black bars). The data are the means and SEM of three separate experiments, and each experiment was carried out in triplicate. The qRT-PCR analysis of dhhc genes was performed as described in Methods. The asterisks indicate that there was significant difference compared with growing parasites (Student's t test: * p<0.05; **p<0.01; ***p<0.001).
Mentions: Semi-quantitative RT-PCR indicated that all the dhhc genes were expressed in trophozoites and in encysting parasites (Figure S6). This prompted us to explore further the expression levels of these genes in growing and encysting parasites by performing qRT-PCR analysis of mRNA expression from these cells. As shown in figure 6, many of the dhhc transcripts were present at relatively constant levels, but gla_8619, gla_1908, and EAA36893 were downregulated in encysting parasites while gla_2116 was upregulated in 48 h encysting cells. Considering that Giardia contains minimal systems, either as a result of reductive processes associated with a parasitic lifestyle, as a reflection of basic evolutionary characteristics, or both [85], [86], the fact that the nine dhhc genes found by bioinformatics were expressed in vegetative and encysting parasites suggests that protein palmitoylation and the PATs themselves may be playing a key role during the entire life cycle of this parasite.

Bottom Line: With bioinformatics tools, we found nine DHHC proteins, potential protein acyltransferases, in the Giardia proteome.These proteins displayed a conserved structure when compared to different organisms and are distributed in different monophyletic clades.Our findings disclosed some important issues regarding the role of DHHC proteins and palmitoylation during Giardia encystation.

View Article: PubMed Central - PubMed

Affiliation: Instituto de Investigación Médica Mercedes y Martín Ferreyra, INIMEC - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de Córdoba, Córdoba, Argentina.

ABSTRACT
Protein S-palmitoylation, a hydrophobic post-translational modification, is performed by protein acyltransferases that have a common DHHC Cys-rich domain (DHHC proteins), and provides a regulatory switch for protein membrane association. In this work, we analyzed the presence of DHHC proteins in the protozoa parasite Giardia lamblia and the function of the reversible S-palmitoylation of proteins during parasite differentiation into cyst. Two specific events were observed: encysting cells displayed a larger amount of palmitoylated proteins, and parasites treated with palmitoylation inhibitors produced a reduced number of mature cysts. With bioinformatics tools, we found nine DHHC proteins, potential protein acyltransferases, in the Giardia proteome. These proteins displayed a conserved structure when compared to different organisms and are distributed in different monophyletic clades. Although all Giardia DHHC proteins were found to be present in trophozoites and encysting cells, these proteins showed a different intracellular localization in trophozoites and seemed to be differently involved in the encystation process when they were overexpressed. dhhc transgenic parasites showed a different pattern of cyst wall protein expression and yielded different amounts of mature cysts when they were induced to encyst. Our findings disclosed some important issues regarding the role of DHHC proteins and palmitoylation during Giardia encystation.

Show MeSH
Related in: MedlinePlus