TY - JOUR
T1 - Eukaryote-conserved methylarginine is absent in diplomonads and functionally compensated in Giardia
AU - Emery-Corbin, Samantha J.
AU - Hamey, Joshua J.
AU - Ansell, Brendan R.E.
AU - Balan, Balu
AU - Tichkule, Swapnil
AU - Stroehlein, Andreas J.
AU - Cooper, Crystal
AU - McInerney, Bernie V.
AU - Hediyeh-Zadeh, Soroor
AU - Vuong, Daniel
AU - Crombie, Andrew
AU - Lacey, Ernest
AU - Davis, Melissa J.
AU - Wilkins, Marc R.
AU - Bahlo, Melanie
AU - Svard, Staffan G.
AU - Gasser, Robin B.
AU - Jex, Aaron R.
PY - 2020/12/1
Y1 - 2020/12/1
N2 - Methylation is a common posttranslational modification of arginine and lysine in eukaryotic proteins. Methylproteomes are best characterized for higher eukaryotes, where they are functionally expanded and evolved complex regulation. However, this is not the case for protist species evolved from the earliest eukaryotic lineages. Here, we integrated bioinformatic, proteomic, and drug-screening data sets to comprehensively explore the methylproteome of Giardia duodenalis—a deeply branching parasitic protist. We demonstrate that Giardia and related diplomonads lack arginine-methyltransferases and have remodeled conserved RGG/RG motifs targeted by these enzymes. We also provide experimental evidence for methylarginine absence in proteomes of Giardia but readily detect methyllysine. We bioinformatically infer 11 lysine-methyltransferases in Giardia, including highly diverged Su(var)3-9, Enhancer-of-zeste and Trithorax proteins with reduced domain architectures, and novel annotations demonstrating conserved methyllysine regulation of eukaryotic elongation factor 1 alpha. Using mass spectrometry, we identify more than 200 methyllysine sites in Giardia, including in species-specific gene families involved in cytoskeletal regulation, enriched in coiled-coil features. Finally, we use known methylation inhibitors to show that methylation plays key roles in replication and cyst formation in this parasite. This study highlights reduced methylation enzymes, sites, and functions early in eukaryote evolution, including absent methylarginine networks in the Diplomonadida. These results challenge the view that arginine methylation is eukaryote conserved and demonstrate that functional compensation of methylarginine was possible preceding expansion and diversification of these key networks in higher eukaryotes.
AB - Methylation is a common posttranslational modification of arginine and lysine in eukaryotic proteins. Methylproteomes are best characterized for higher eukaryotes, where they are functionally expanded and evolved complex regulation. However, this is not the case for protist species evolved from the earliest eukaryotic lineages. Here, we integrated bioinformatic, proteomic, and drug-screening data sets to comprehensively explore the methylproteome of Giardia duodenalis—a deeply branching parasitic protist. We demonstrate that Giardia and related diplomonads lack arginine-methyltransferases and have remodeled conserved RGG/RG motifs targeted by these enzymes. We also provide experimental evidence for methylarginine absence in proteomes of Giardia but readily detect methyllysine. We bioinformatically infer 11 lysine-methyltransferases in Giardia, including highly diverged Su(var)3-9, Enhancer-of-zeste and Trithorax proteins with reduced domain architectures, and novel annotations demonstrating conserved methyllysine regulation of eukaryotic elongation factor 1 alpha. Using mass spectrometry, we identify more than 200 methyllysine sites in Giardia, including in species-specific gene families involved in cytoskeletal regulation, enriched in coiled-coil features. Finally, we use known methylation inhibitors to show that methylation plays key roles in replication and cyst formation in this parasite. This study highlights reduced methylation enzymes, sites, and functions early in eukaryote evolution, including absent methylarginine networks in the Diplomonadida. These results challenge the view that arginine methylation is eukaryote conserved and demonstrate that functional compensation of methylarginine was possible preceding expansion and diversification of these key networks in higher eukaryotes.
KW - Diplomonadida
KW - Giardia
KW - Metamonada
KW - Methylarginine
KW - Methyllysine
KW - Methylproteome
UR - http://www.scopus.com/inward/record.url?scp=85098674763&partnerID=8YFLogxK
U2 - 10.1093/molbev/msaa186
DO - 10.1093/molbev/msaa186
M3 - Article
C2 - 32702104
AN - SCOPUS:85098674763
SN - 0737-4038
VL - 37
SP - 3525
EP - 3549
JO - Molecular Biology and Evolution
JF - Molecular Biology and Evolution
IS - 12
ER -