pubmed.ncbi.nlm.nih.gov

Widespread occurrence of lysine methylation in Plasmodium falciparum proteins at asexual blood stages - PubMed

  • ️Fri Jan 01 2016

Widespread occurrence of lysine methylation in Plasmodium falciparum proteins at asexual blood stages

Inderjeet Kaur et al. Sci Rep. 2016.

Abstract

Post-transcriptional and post-translational modifications play a major role in Plasmodium life cycle regulation. Lysine methylation of histone proteins is well documented in several organisms, however in recent years lysine methylation of proteins outside histone code is emerging out as an important post-translational modification (PTM). In the present study we have performed global analysis of lysine methylation of proteins in asexual blood stages of Plasmodium falciparum development. We immunoprecipitated stage specific Plasmodium lysates using anti-methyl lysine specific antibodies that immunostained the asexual blood stage parasites. Using liquid chromatography and tandem mass spectrometry analysis, 570 lysine methylated proteins at three different blood stages were identified. Analysis of the peptide sequences identified 605 methylated sites within 422 proteins. Functional classification of the methylated proteins revealed that the proteins are mainly involved in nucleotide metabolic processes, chromatin organization, transport, homeostatic processes and protein folding. The motif analysis of the methylated lysine peptides reveals novel motifs. Many of the identified lysine methylated proteins are also interacting partners/substrates of PfSET domain proteins as revealed by STRING database analysis. Our findings suggest that the protein methylation at lysine residues is widespread in Plasmodium and plays an important regulatory role in diverse set of the parasite pathways.

PubMed Disclaimer

Figures

Figure 1
Figure 1. Extensive lysine methylation occurs at asexual blood stages of P. falciparum.

Anti-methyl-lysine specific antibodies recognize the proteins from three different blood stages of P. falciparum. (A) Representative western blot showing extent of lysine methylation at ring, trophozoite and schizont stages when the parasite lysates were probed with anti-methyl-lysine specific antibody. (B) The same antibodies also immuno-stained the asexual blood stages of the parasite as examined through immuno-fluorescence assay. The representative confocal microscopy images are shown above. DIC- bright field, DAPI-stained nucleus (blue), immunofluorescent cells labeled with anti-Methyl lysine antibody (green), and merged images.

Figure 2
Figure 2. Lysine methylated proteins of Plasmodiun falciparum.

Anti-methyl-lysine antibodies were used to immunoprecipitate stage specific lysine methylated proteins from P. falciparum lysates. N = number of proteins, MK, K = Proteins immunoprecipitated by anti-monomethyl lysine antibody, TMK, TK = Proteins immunoprecipitated by anti-trimethyl lysine antibody.

Figure 3
Figure 3. Analysis of identified lysine-methylated proteins for the presence of known motifs.

(A) Motif representation of methylated lysine sites along with a consensus sequence logo in P. falciparum. All the 605 confirmed sites were examined to know the presence of conserved motifs. (B) Motif representation of previously reported sites in other organisms.

Figure 4
Figure 4. Western blot confirms the presence of methylated lysine proteins in immuno precipitates.

Representative western blots (A) with anti-PfP12 and (B) anti-PfTSN antisera validating the LC-MS/MS results of immunoprecipitation experiments.

Figure 5
Figure 5. Classification of lysine methylated proteins in P. falciparum.

(A) based on cellular components and (B) based on function and (C) on the basis of conserved domains. The 570 identified lysine methylated proteins were categorized based on their known or likely functions and cellular localization. Proteins with no annotations in PlasmoDB were categorized as unknown proteins. A pie chart shows the distribution of the proteins based on domain super families.

Similar articles

Cited by

References

    1. Guerra C. A. et al.. The limits and intensity of Plasmodium falciparum transmission: implications for malaria control and elimination worldwide. PLoS medicine 5, e38, 10.1371/journal.pmed.0050038 (2008). - DOI - PMC - PubMed
    1. Le Roch K. G. et al.. A systematic approach to understand the mechanism of action of the bisthiazolium compound T4 on the human malaria parasite, Plasmodium falciparum. BMC Genomics 9, 513, 10.1186/1471-2164-9-513 (2008). - DOI - PMC - PubMed
    1. Hoffman M. D., Sniatynski M. J. & Kast J. Current approaches for global post-translational modification discovery and mass spectrometric analysis. Analytica chimica acta 627, 50–61, 10.1016/j.aca.2008.03.032 (2008). - DOI - PubMed
    1. Doerig C., Rayner J. C., Scherf A. & Tobin A. B. Post-translational protein modifications in malaria parasites. Nat Rev Microbiol 13, 160–172, 10.1038/nrmicro3402 (2015). - DOI - PubMed
    1. Solyakov L. et al.. Global kinomic and phospho-proteomic analyses of the human malaria parasite Plasmodium falciparum. Nat Commun 2, 565 (2011). - PubMed

Publication types

MeSH terms

Substances

LinkOut - more resources