title: Evolution and architecture of the inner membrane complex in asexual and sexual stages of the malaria parasite.
abstract: The inner membrane complex (IMC) is a unifying morphological feature of all alveolate organisms. It consists of flattened vesicles underlying the plasma membrane and is interconnected with the cytoskeleton. Depending on the ecological niche of the organisms, the function of the IMC ranges from a fundamental role as reinforcement system to more specialized roles in motility and cytokinesis. In this article, we present a comprehensive evolutionary analysis of IMC components, which exemplifies the adaptive nature of the IMCs' protein composition. Focusing on eight structurally distinct proteins in the most prominent "genus" of the Alveolata-the malaria parasite Plasmodium-we demonstrate that the level of conservation is reflected in phenotypic characteristics, accentuated in differential spatial-temporal patterns of these proteins in the motile stages of the parasite's life cycle. Colocalization studies with the centromere and the spindle apparatus reveal their discriminative biogenesis. We also reveal that the IMC is an essential structural compartment for the development of the sexual stages of Plasmodium, as it seems to drive the morphological changes of the parasite during the long and multistaged process of sexual differentiation. We further found a Plasmodium-specific IMC membrane matrix protein that highlights transversal structures in gametocytes, which could represent a genus-specific structural innovation required by Plasmodium. We conclude that the IMC has an additional role during sexual development supporting morphogenesis of the cell, which in addition to its functions in the asexual stages highlights the multifunctional nature of the IMC in the Plasmodium life cycle.
authors.affiliation: Department of Molecular Parasitology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany.
authors.forename: Maya
authors.initials: M
authors.lastname: Kono
authors.forename: Susann
authors.initials: S
authors.lastname: Herrmann
authors.forename: Noeleen B
authors.initials: NB
authors.lastname: Loughran
authors.forename: Ana
authors.initials: A
authors.lastname: Cabrera
authors.forename: Klemens
authors.initials: K
authors.lastname: Engelberg
authors.forename: Christine
authors.initials: C
authors.lastname: Lehmann
authors.forename: Dipto
authors.initials: D
authors.lastname: Sinha
authors.forename: Boris
authors.initials: B
authors.lastname: Prinz
authors.forename: Ulrike
authors.initials: U
authors.lastname: Ruch
authors.forename: Volker
authors.initials: V
authors.lastname: Heussler
authors.forename: Tobias
authors.initials: T
authors.lastname: Spielmann
authors.forename: John
authors.initials: J
authors.lastname: Parkinson
authors.forename: Tim W
authors.initials: TW
authors.lastname: Gilberger
mesh_terms: D002460:Cell Line; D021961:Cell Membrane Structures / Q000378:metabolism*; D016764:Cell Polarity; D003599:Cytoskeleton / Q000378:metabolism; D005260:Female; D006801:Humans; D008297:Male; D010802:Phylogeny; D010961:Plasmodium / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D021381:Protein Transport; D015800:Protozoan Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
chemical_list: D015800:Protozoan Proteins