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Plasmodium actin is incompletely folded by heterologous protein‐folding machinery and likely requires the native Plasmodium chaperonin complex to enter a mature functional state
Author(s) -
Olshina Maya A.,
Baumann Hella,
Willison Keith R.,
Baum Jake
Publication year - 2016
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fj.15-276618
Subject(s) - chaperonin , biology , actin , microbiology and biotechnology , heterologous , plasmodium falciparum , heterologous expression , protein folding , native state , plasmodium (life cycle) , chaperone (clinical) , actin binding protein , cytoskeleton , recombinant dna , biochemistry , actin cytoskeleton , parasite hosting , cell , malaria , gene , medicine , pathology , world wide web , computer science , immunology
ABSTRACT Actin filament turnover underpins several processes in the life cycle of the malaria parasite, Plasmodium falciparum. Polymerization and depolymerization are especially important for gliding motility, a substrate‐dependent form of cell movement that underpins the protozoan parasite's ability to disseminate and invade host cells. To date, given difficulties in extraction of native actins directly from parasites, much of our biochemical understanding of malarial actin has instead relied on recombinant protein extracted and purified from heterologous protein expression systems. Here, using in vitro transcription‐translation methodologies and quantitative protein‐binding assays, we explored the folding state of heterologously expressed P. falciparum actin 1 (PfACTI) with the aim of assessing the reliability of current recombinant‐protein‐based data. We demonstrate that PfACTI, when expressed in non‐native systems, is capable of binding to and release from bacterial, yeast, and mammalian chaperonin complexes but appears to be incompletely folded. Characterization of the native Plasmodium folding machinery in silico , the chaperonin containing t‐complex protein‐1 complex, highlights key divergences between the different chaperonin systems that likely underpins this incomplete folded state. These results highlight the importance of characterizing actin's folded state and raise concerns about the interpretation of actin polymerization kinetics based solely on protein derived from heterologous expression systems.—Olshina, M. A., Baumann, H., Willison, K. R., Baum, J. Plasmodium actin is incompletely folded by heterologous protein‐folding machinery and likely requires the native Plasmodium chaperonin complex to enter a mature functional state. FASEB J. 30, 405‐416 (2016). www.fasebj.org