title: Multimerization properties of PiggyMac, a domesticated piggyBac transposase involved in programmed genome rearrangements.
abstract: During sexual processes, the ciliate Paramecium eliminates 25-30% of germline DNA from its somatic genome. DNA elimination includes excision of ∼45 000 short, single-copy internal eliminated sequences (IESs) and depends upon PiggyMac (Pgm), a domesticated piggyBac transposase that is essential for DNA cleavage at IES ends. Pgm carries a core transposase region with a putative catalytic domain containing three conserved aspartic acids, and a downstream cysteine-rich (CR) domain. A C-terminal extension of unknown function is predicted to adopt a coiled-coil (CC) structure. To address the role of the three domains, we designed an in vivo complementation assay by expressing wild-type or mutant Pgm-GFP fusions in cells depleted for their endogenous Pgm. The DDD triad and the CR domain are essential for Pgm activity and mutations in either domain have a dominant-negative effect in wild-type cells. A mutant lacking the CC domain is partially active in the presence of limiting Pgm amounts, but inactive when Pgm is completely absent, suggesting that presence of the mutant protein increases the overall number of active complexes. We conclude that IES excision involves multiple Pgm subunits, of which at least a fraction must contain the CC domain.
authors.affiliation: Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France.
authors.forename: Emeline
authors.initials: E
authors.lastname: Dubois
authors.affiliation: Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Mathy
authors.affiliation: Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France.|Université Paris Diderot, Sorbonne Paris Cité, Paris, France.
authors.forename: Vinciane
authors.initials: V
authors.lastname: Régnier
authors.affiliation: Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France.
authors.forename: Julien
authors.initials: J
authors.lastname: Bischerour
authors.affiliation: Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France.
authors.forename: Céline
authors.initials: C
authors.lastname: Baudry
authors.affiliation: Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France.
authors.forename: Raphaëlle
authors.initials: R
authors.lastname: Trouslard
authors.affiliation: Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France.
authors.forename: Mireille
authors.initials: M
authors.lastname: Bétermier
mesh_terms: D001483:Base Sequence; D053837:DNA Cleavage; D016678:Genome; D009154:Mutation; D016805:Paramecium tetraurelia / Q000235:genetics; D000072417:Protein Domains; D055503:Protein Multimerization; D017384:Sequence Deletion; D019076:Transgenes; D019895:Transposases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism
chemical_list: D019895:Transposases