Skip to main content

Moonlighting enzymes in parasitic protozoa


Enzymes moonlight in a non-enzymatic capacity in a diverse variety of cellular processes. The discovery of these non-enzymatic functions is generally unexpected, and moonlighting enzymes are known in both prokaryotes and eukaryotes. Importantly, this unexpected multi-functionality indicates that caution might be needed on some occasions in interpreting phenotypes that result from the deletion or gene-silencing of some enzymes, including some of the best known enzymes from classic intermediary metabolism. Here, we provide an overview of enzyme moonlighting in parasitic protists. Unequivocal and putative examples of moonlighting are discussed, together with the possibility that the unusual biological characteristics of some parasites either limit opportunities for moonlighting to arise or perhaps contribute to the evolution of novel proteins with clear metabolic ancestry.

Corresponding author
*Corresponding author: School of Health and Medicine, Division of Biomedical and Life Sciences, Lancaster University, Lancaster LA1 4YQ, UK. Tel: 01524-593922; Fax: 01524-593192. E-mail:
Hide All
Addis M. F., Rappelli P., Cappuccinelli P. and Fiori P. L. (1997). Extracellular release by Trichomonas vaginalis of a NADP+ dependent malic enzyme involved in pathogenicity. Microbial Pathogenesis 23, 5561.
Albert M. A., Haanstra J. R., Hannaert V., Van Roy J., Opperdoes F. R., Bakker B. M. and Michels P. A. (2005). Experimental and in silico analyses of glycolytic flux control in bloodstream form Trypanosoma brucei. Journal of Biological Chemistry 280, 2830628315.
Alderete J. F., Millsap K. W., Lehker M. W. and Benchimol M. (2001). Enzymes on microbial pathogens and Trichomonas vaginalis: molecular mimicry and functional diversity. Cellular Microbiology 3, 359370.
Alderete J. F., O'Brien J. L., Arroyo R., Engbring J. A., Musatovova O., Lopez O., Lauriano C. and Nguyen J. (1995). Cloning and molecular characterization of two genes encoding adhesion proteins involved in Trichomonas vaginalis cytoadherence. Molecular Microbiology 17, 6983.
Arroyo R., Gonzalez-Robles A., Martinez-Palomo A. and Alderete J. F. (1993). Signalling of Trichomonas vaginalis for amoeboid transformation and adhesion synthesis follows cytoadherence. Molecular Microbiology 7, 299309.
Bakker B. M., Mensonides F. I., Teusink B., van Hoek P., Michels P. A. and Westerhoff H. V. (2000). Compartmentation protects trypanosomes from the dangerous design of glycolysis. Proceedings of the National Academy of Sciences, USA 97, 20872092.
Bakker B. M., Michels P. A., Opperdoes F. R. and Westerhoff H. V. (1999 a). What controls glycolysis in bloodstream form Trypanosoma brucei? Journal of Biological Chemistry 274, 1455114559.
Bakker B. M., Walsh M. C., ter Kuile B. H., Mensonides F. I., Michels P. A., Opperdoes F. R. and Westerhoff H. V. (1999 b). Contribution of glucose transport to the control of the glycolytic flux in Trypanosoma brucei. Proceedings of the National Academy of Sciences, USA 96, 1009810103.
Baum J., Gilberger T. W., Frischknecht F. and Meissner M. (2008). Host-cell invasion by malaria parasites: insights from Plasmodium and Toxoplasma. Trends in Parasitology 24, 557563.
Baum J., Richard D., Healer J., Rug M., Krnajski Z., Gilberger T. W., Green J. L., Holder A. A. and Cowman A. F. (2006). A conserved molecular motor drives cell invasion and gliding motility across malaria life cycle stages and other apicomplexan parasites. Journal of Biological Chemistry 281, 51975208.
Benchimol M. (1999). Hydrogenosome autophagy: an ultrastructural and cytochemical study. Biology of the Cell 91, 165174.
Bhowmick I. P., Kumar N., Sharma S., Coppens I. and Jarori G. K. (2009). Plasmodium falciparum enolase: stage-specific expression and sub-cellular localization. Malaria Journal 8, 179.
Blattner J., Helfert S., Michels P. and Clayton C. (1998). Compartmentation of phosphoglycerate kinase in Trypanosoma brucei plays a critical role in parasite energy metabolism. Proceedings of the National Academy of Sciences, USA 95, 1159611600.
Bosch J., Buscaglia C. A., Krumm B., Ingason B. P., Lucas R., Roach C., Cardozo T., Nussenzweig V. and Hol W. G. (2007). Aldolase provides an unusual binding site for thrombospondin-related anonymous protein in the invasion machinery of the malaria parasite. Proceedings of the National Academy of Sciences, USA 104, 70157020.
Boudeau J., Miranda-Saavedra D., Barton G. J. and Alessi D. R. (2006). Emerging roles of pseudokinases. Trends in Cell Biology 16, 443452.
Bringaud F., Stripecke R., Frech G. C., Freedland S., Turck C., Byrne E. M. and Simpson L. (1997). Mitochondrial glutamate dehydrogenase from Leishmania tarentolae is a guide RNA-binding protein. Molecular and Cellular Biology 17, 39153923.
Brugerolle G., Bricheux G. and Coffe G. (2000). Immunolocalization of two hydrogenosomal enzymes of Trichomonas vaginalis. Parasitology Research 86, 3035.
Buscaglia C. A., Coppens I., Hol W. G. and Nussenzweig V. (2003). Sites of interaction between aldolase and thrombospondin-related anonymous protein in Plasmodium. Molecular Biology of the Cell 14, 49474957.
Caetano-Anollés G., Wang M., Caetano-Anollés D. and Mittenthal J. E. (2009 a). The origin, evolution and structure of the protein world. Biochemical Journal 417, 621637.
Caetano-Anollés G., Yafremava L. S., Gee H., Caetano-Anollés D., Kim H. S. and Mittenthal J. E. (2009 b). The origin and evolution of modern metabolism. International Journal of Biochemistry and Cell Biology 41, 285297.
Campbell R. N., Leverentz M. K., Ryan L. A. and Reece R. J. (2008). Metabolic control of transcription: paradigms and lessons from Saccharomyces cerevisiae. Biochemical Journal 414, 177187.
Carlton J. M., Hirt R. P., Silva J. C., Delcher A. L., Schatz M., Zhao Q., Wortman J. R., Bidwell S. L., Alsmark U. C., Besteiro S., Sicheritz-Ponten T., Noel C. J., Dacks J. B., Foster P. G., Simillion C., Van de Peer Y., Miranda-Saavedra D., Barton G. J., Westrop G. D., Müller S., Dessi D., Fiori P. L., Ren Q., Paulsen I., Zhang H., Bastida-Corcuera F. D., Simoes-Barbosa A., Brown M. T., Hayes R. D., Mukherjee M., Okumura C. Y., Schneider R., Smith A. J., Vanacova S., Villalvazo M., Haas B. J., Pertea M., Feldblyum T. V., Utterback T. R., Shu C. L., Osoegawa K., de Jong P. J., Hrdy I., Horvathova L., Zubacova Z., Dolezal P., Malik S. B., Logsdon J. M. Jr., Henze K., Gupta A., Wang C. C., Dunne R. L., Upcroft J. A., Upcroft P., White O., Salzberg S. L., Tang P., Chiu C. H., Lee Y. S., Embley T. M., Coombs G. H., Mottram J. C., Tachezy J., Fraser-Liggett C. M. and Johnson P. J. (2007). Draft genome sequence of the sexually transmitted pathogen Trichomonas vaginalis. Science 315, 207212.
Chambers J. W., Kearns M. T., Morris M. T. and Morris J. C. (2008). Assembly of heterohexameric trypanosome hexokinases reveals that hexokinase 2 is a regulable enzyme. Journal of Biological Chemistry 283, 1496314970.
Commichau F. M., Rothe F. M., Herzberg C., Wagner E., Hellwig D., Lehnik-Habrink M., Hammer E., Völker U. and Stülke J. (2009). Novel activities of glycolytic enzymes in Bacillus subtilis: interactions with essential proteins involved in mRNA processing. Molecular and Cellular Proteomics 8, 13501360.
Davids B. J., Palm J. E. D., Housley M. P., Smith J. R., Anderson Y. S., Martin M. G., Hendrickson B. A., Johansen F.-E., Svärd S. G., Gillin F. D. and Eckmann L. (2006). Polymeric immunoglobulin receptor in intestinal immune defense against the lumen-dwelling protozoan parasite Giardia. Journal of Immunology 177, 62816290.
Demarse N. A., Ponnusamy S., Spicer E. K., Apohan E., Baatz J. E., Ogretmen B. and Davies C. (2009). Direct binding of glyceraldehyde 3-phosphate dehydrogenase to telomeric DNA protects telomeres against chemotherapy-induced rapid degradation. Journal of Molecular Biology 394, 789803.
Engbring J. A. and Alderete J. F. (1998). Three genes encode distinct AP33 proteins involved in Trichomonas vaginalis cytoadherence. Molecular Microbiology 28, 305313.
Feo S., Arcuri D., Piddini E., Passantino R. and Giallongo A. (2000). ENO1 gene product binds to the c-myc promoter and acts as a transcriptional repressor: relationship with Myc promoter-binding protein 1 (MBP-1). FEBS Letters 473, 4752.
Ferguson D. J., Parmley S. F. and Tomavo S. (2002). Evidence for nuclear localisation of two stage-specific isoenzymes of enolase in Toxoplasma gondii correlates with active parasite replication. International Journal for Parasitology 32, 13991410.
Furuya T., Kessler P., Jardim A., Schnaufer A., Crudder C. and Parsons M. (2002). Glucose is toxic to glycosome-deficient trypanosomes. Proceedings of the National Academy of Sciences, USA 99 1417714182.
Gancedo C. and Flores C. L. (2008). Moonlighting proteins in yeasts. Microbiology and Molecular Biology Reviews 72, 197210.
Garcia A. F., Chang T. H., Benchimol M., Klumpp D. J., Lehker M. W. and Alderete J. F. (2003). Iron and contact with host cells induce expression of adhesins on surface of Trichomonas vaginalis. Molecular Microbiology 47, 12071224.
Ginger M. L., McFadden G. I. and Michels P. A. (2010). Rewiring and regulation of cross-compartmentalised metabolism in protists. Philosophical Transaction of the Royal Society Series B Biological Sciences 365, 831845.
Haanstra J. R., van Tuijl A., Kessler P., Reijnders W., Michels P. A., Westerhoff H. V., Parsons M. and Bakker B. M. (2008). Compartmentation prevents a lethal turbo-explosion of glycolysis in trypanosomes. Proceedings of the National Academy of Sciences, USA 105, 1771817723.
Helfert S., Estévez A. M., Bakker B., Michels P. and Clayton C. (2001). Roles of triosephosphate isomerase and aerobic metabolism in Trypanosoma brucei. Biochemical Journal 357, 117125.
Herman M., Pérez-Morga D., Schtickzelle N. and Michels P. A. (2008). Turnover of glycosomes during life-cycle differentiation of Trypanosoma brucei. Autophagy 4, 294308.
Hirt R. P., Noel C. J., Sicheritz-Ponten T., Tachezy J. and Fiori P. L. (2007). Trichomonas vaginalis surface proteins: a view from the genome. Trends in Parasitology 23, 540547.
Hittinger C. T. and Carroll S. B. (2007). Gene duplication and the adaptive evolution of a classic genetic switch. Nature 449, 677681.
Hjort K., Goldberg A. V., Tsaousis A. D., Hirt R. P. and Embley T. M. (2010). Diversity and reductive evolution of mitochondria among microbial eukaryotes. Philosophical Transaction of the Royal Society Series B Biological Sciences 365, 713727.
Hrdy I., Hirt R. P., Dolezal P., Bardonová L., Foster P. G., Tachezy J. and Embley T. M. (2004). Trichomonas hydrogenosomes contain the NADH dehydrogenase module of mitochondrial complex I. Nature 432, 618622.
Jeffery C. J. (1999). Moonlighting proteins. Trends in Biochemical Sciences 24, 8–11.
Jeffery C. J. (2005). Mass spectrometry and the search for moonlighting proteins. Mass Spectrometry Reviews 24, 772782.
Jeffery C. J. (2009). Moonlighting proteins – an update. Molecular Biosystems 5, 345350.
Jewett T. J. and Sibley L. D. (2003). Aldolase forms a bridge between cell surface adhesins and the actin cytoskeleton in apicomplexan parasites. Molecular Cell 11, 885894.
Krishnamurthy G., Vikram R., Singh S. B., Patel N., Agarwal S., Mukhopadhyay G., Basu S. K. and Mukhopadhyay A. (2005). Hemoglobin receptor in Leishmania is a hexokinase located in the flagellar pocket. Journal of Biological Chemistry 280, 58845891.
Kumar R., Gupta S., Srivastava R., Sahasrabuddhe A. A. and Gupta C. M. (2009). Expression of a PTS2-truncated hexokinase produces glucose toxicity in Leishmania donovani. Molecular and Biochemical Parasitology 170, 4144.
Lama A., Kucknoor A., Mundodi V. and Alderete J. F. (2009). Glyceraldehyde-3-phosphate dehydrogenase is a surface-associated, fibronectin-binding protein of Trichomonas vaginalis. Infection and Immunity 77, 27032711.
Lukeš J., Guilbride D. L., Votýpka J., Ziková A., Benne R. and Englund P. T. (2002). Kinetoplast DNA network: evolution of an improbable structure. Eukaryotic Cell 1, 495502.
Lyda T. A., Dodson H. C., Coley A. F., Morris M. T., Michels P. A. M. and Morris J. C. (2009). Identification of a C-terminal Flagellar Targeting Sequence in Trypanosoma brucei Hexokinase. Woods Hole 3rd Kinetoplastid Meeting. Abstract 235B.
Ma B. G., Chen L., Ji H. F., Chen Z. H., Yang F. R., Wang L., Qu G., Jiang Y. Y., Ji C. and Zhang H. Y. (2008). Characters of very ancient proteins. Biochemical and Biophysical Research Communications 366, 607611.
Michels P. A., Bringaud F., Herman M. and Hannaert V. (2006). Metabolic functions of glycosomes in trypanosomatids. Biochimica et Biophysica Acta 1763, 14631477.
Moreno-Brito V., Yáñez-Gómez C., Meza-Cervantez P., Avila-González L., Rodriguez M. A., Ortega-López J., González-Robles A. and Arroyo R. (2005). A Trichomonas vaginalis 120 kDa protein with identity to hydrogenosome pyruvate:ferredoxin oxidoreductase is a surface adhesin induced by iron. Cellular Microbiology 7, 245258.
Morris M. T., DeBruin C., Yang Z., Chambers J. W., Smith K. S. and Morris J. C. (2006). Activity of a second Trypanosoma brucei hexokinase is controlled by an 18-amino-acid C-terminal tail. Eukaryotic Cell 5, 20142023.
Mundodi V., Kucknoor A. S. and Alderete J. F. (2008). Immunogenic and plasminogen-binding surface-associated alpha-enolase of Trichomonas vaginalis. Infection and Immunity 76, 523531.
Painter H. J., Morrisey J. M., Mather M. W. and Vaidya A. B. (2007). Specific role of mitochondrial electron transport in blood-stage Plasmodium falciparum. Nature 446, 8891.
Pal-Bhowmick I., Vora H. K. and Jarori G. K. (2007). Sub-cellular localization and post-translational modifications of the Plasmodium yoelii enolase suggest moonlighting functions. Malaria Journal 6, 45.
Paris Z., Rubio M. A., Lukeš J. and Alfonzo J. D. (2009). Mitochondrial tRNA import in Trypanosoma brucei is independent of thiolation and the Rieske protein. RNA 15, 13981406.
Pascual-García A., Abia D., Méndez R., Nido G. S. and Bastolla U. (2009). Quantifying the evolutionary divergence of protein structures: The role of function change and function conservation. Proteins 78, 181196.
Pomel S., Luk F. C. and Beckers C. J. (2008). Host cell egress and invasion induce marked relocations of glycolytic enzymes in Toxoplasma gondii tachyzoites. PLoS Pathogens 4, e1000188.
Quiñones W., Peña P., Domingo-Sananes M., Cáceres A., Michels P. A. M., Avilan L. and Concepción J. L. (2007). Leishmania mexicana: molecular cloning and characterisation of enolase. Experimental Parasitology 116, 241251.
Rigden D. J., Michels P. A. and Ginger M. L. (2009). Autophagy in protists: Examples of secondary loss, lineage-specific innovations, and the conundrum of remodeling a single mitochondrion. Autophagy 5, 784794.
Ringqvist E., Palm J. E. D., Skarin H., Hehl A. B., Weiland M., Davids B. J., Reiner D. S., Griffiths W. J., Eckmann L., Gillin F. D. and Svärd S. G. (2008). Release of metabolic enzymes by Giardia in response to interaction with intestinal epithelial cells. Molecular and Biochemical Parasitology 159, 8591.
Robinson D., Beattie P., Sherwin T. and Gull K. (1991). Microtubules, tubulin, and microtubule-associated proteins of trypanosomes. Methods in Enzymology 196, 285299.
Simpson L., Sbicego S. and Aphasizhev R. (2003). Uridine insertion/deletion RNA editing in trypanosome mitochondria: a complex business. RNA 9, 265276.
Sirover M. A. (2005). New nuclear functions of the glycolytic protein, glyceraldehyde-3-phosphate dehydrogenase, in mammalian cells. Journal of Cellular Biochemistry 95, 4552.
Soldati D., Foth B. J. and Cowman A. F. (2004). Molecular and functional aspects of parasite invasion. Trends in Parasitology 20, 567574.
Starnes G. L., Coincon M., Sygusch J. and Sibley L. D. (2009). Aldolase is essential for energy production and bridging adhesin-actin cytoskeletal interactions during parasite invasion of host cells. Cell Host and Microbe 5, 353364.
Stuart K. D., Schnaufer A., Ernst N. L. and Panigrahi A. K. (2005). Complex management: RNA editing in trypanosomes. Trends in Biochemical Sciences 30, 97–105.
Vanegas G., Quiñones W., Carrasco-López C., Concepción J. L., Albericio F. and Avilán L. (2007). Enolase is a plasminogen binding protein in Leishmania mexicana. Parasitology Research 101, 15111516.
Vanhollebeke B., de Muylder G., Nielsen M. J., Pays A., Tebabi P., Dieu M., Raes M., Moestrup S. K. and Pays E. (2008). A haptoglobin-hemoglobin receptor conveys innate immunity to Trypanosoma brucei in humans. Science 320, 677681.
Willert E. K., Fitzpatrick R. and Phillips M. A. (2007). Allosteric regulation of an essential trypanosome polyamine biosynthetic enzyme by a catalytically dead homolog. Proceedings of the National Academy of Sciences, USA 104, 82758280.
Williams K., Lowe P. N. and Leadlay P. F. (1987). Purification and characterization of pyruvate: ferredoxin oxidoreductase from the anaerobic protozoon Trichomonas vaginalis. Biochemical Journal 246, 529536.
Yang H. W., Yong T. S., Lee J. H., Im K. I. and Park S. J. (2002). Characterization of two glyceraldehyde 3-phosphate dehydrogenase genes in Giardia lamblia. Parasitology Research 88, 646650.
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

  • ISSN: 0031-1820
  • EISSN: 1469-8161
  • URL: /core/journals/parasitology
Please enter your name
Please enter a valid email address
Who would you like to send this to? *



Full text views

Total number of HTML views: 22
Total number of PDF views: 36 *
Loading metrics...

Abstract views

Total abstract views: 294 *
Loading metrics...

* Views captured on Cambridge Core between September 2016 - 21st January 2018. This data will be updated every 24 hours.