title: Temporal self-regulation of transposition through host-independent transposase rodlet formation.
abstract: Transposons are highly abundant in eukaryotic genomes, but their mobilization must be finely tuned to maintain host organism fitness and allow for transposon propagation. Forty percent of the human genome is comprised of transposable element sequences, and the most abundant cut-and-paste transposons are from the hAT superfamily. We found that the hAT transposase TcBuster from Tribolium castaneum formed filamentous structures, or rodlets, in human tissue culture cells, after gene transfer to adult mice, and ex vivo in cell-free conditions, indicating that host co-factors or cellular structures were not required for rodlet formation. Time-lapsed imaging of GFP-laced rodlets in human cells revealed that they formed quickly in a dynamic process involving fusion and fission. We delayed the availability of the transposon DNA and found that transposition declined after transposase concentrations became high enough for visible transposase rodlets to appear. In combination with earlier findings for maize Ac elements, these results give insight into transposase overproduction inhibition by demonstrating that the appearance of transposase protein structures and the end of active transposition are simultaneous, an effect with implications for genetic engineering and horizontal gene transfer.
authors.affiliation: Department of Veterans Affairs, Nashville, TN 37212, USA and Department of Medicine, Vanderbilt University, Nashville, TN 37232, USA.|Department of Veterans Affairs, Houston, TX 77030, USA and Department of Medicine, Baylor College of Medicine, Houston, TX 77030, USA.
authors.forename: Lauren E
authors.initials: LE
authors.lastname: Woodard
authors.affiliation: Department of Veterans Affairs, Nashville, TN 37212, USA and Department of Medicine, Vanderbilt University, Nashville, TN 37232, USA.
authors.forename: Laura M
authors.initials: LM
authors.lastname: Downes
authors.affiliation: Department of Veterans Affairs, Houston, TX 77030, USA and Department of Medicine, Baylor College of Medicine, Houston, TX 77030, USA.
authors.forename: Yi-Chien
authors.initials: YC
authors.lastname: Lee
authors.affiliation: Department of Veterans Affairs, Houston, TX 77030, USA and Department of Medicine, Baylor College of Medicine, Houston, TX 77030, USA.
authors.forename: Aparna
authors.initials: A
authors.lastname: Kaja
authors.affiliation: Department of Veterans Affairs, Houston, TX 77030, USA and Department of Medicine, Baylor College of Medicine, Houston, TX 77030, USA.
authors.forename: Eyuel S
authors.initials: ES
authors.lastname: Terefe
authors.affiliation: Department of Veterans Affairs, Nashville, TN 37212, USA and Department of Medicine, Vanderbilt University, Nashville, TN 37232, USA matthew.wilson@vanderbilt.edu.|Department of Veterans Affairs, Houston, TX 77030, USA and Department of Medicine, Baylor College of Medicine, Houston, TX 77030, USA.
authors.forename: Matthew H
authors.initials: MH
authors.lastname: Wilson
mesh_terms: D000818:Animals; D004251:DNA Transposable Elements; D005260:Female; D005786:Gene Expression Regulation; D017930:Genes, Reporter; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D019476:Insect Proteins / Q000235:genetics* / Q000378:metabolism; D008156:Luciferases / Q000235:genetics / Q000378:metabolism; D008297:Male; D051379:Mice; D061848:Optical Imaging; D059008:Time-Lapse Imaging; D019895:Transposases / Q000235:genetics* / Q000378:metabolism; D014231:Tribolium
chemical_list: D004251:DNA Transposable Elements; D019476:Insect Proteins; D008156:Luciferases; D019895:Transposases