Functional characterization of the Bari1 transposition system.
The transposons of the Bari family are mobile genetic elements widespread in the Drosophila genus. However, despite a broad diffusion, virtually no information is available on the mechanisms underlying their mobility. In this paper we report the functional characterization of the Bari elements transposition system. Using the Bari1 element as a model, we investigated the subcellular localization of the transposase, its physical interaction with the transposon, and its catalytic activity. The Bari1 transposase localized in the nucleus and interacted with the terminal sequences of the transposon both in vitro and in vivo, however, no transposition activity was detected in transposition assays. Profiling of mRNAs expressed by the transposase gene revealed the expression of abnormal, internally processed transposase transcripts encoding truncated, catalytically inactive transposase polypeptides. We hypothesize that a post-transcriptional control mechanism produces transposase-derived polypeptides that effectively repress transposition. Our findings suggest further clues towards understanding the mechanisms that control transposition of an important class of mobile elements, which are both an endogenous source of genomic variability and widely used as transformation vectors/biotechnological tools.
Dipartimento di Biologia, Università di Bari, Bari, Italy.
Antonio
A
Palazzo
Simona
S
Marconi
Valeria
V
Specchia
Maria Pia
MP
Bozzetti
Zoltán
Z
Ivics
Ruggiero
R
Caizzi
René Massimiliano
RM
Marsano
D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D004251:DNA Transposable Elements; D004330:Drosophila / Q000235:genetics* / Q000378:metabolism*; D029721:Drosophila Proteins / Q000235:genetics; D006360:Heat-Shock Proteins / Q000235:genetics; D006801:Humans; D042541:Intracellular Space / Q000378:metabolism; D055029:Inverted Repeat Sequences; D008297:Male; D008969:Molecular Sequence Data; D009154:Mutation; D009690:Nucleic Acid Conformation; D011485:Protein Binding; D021381:Protein Transport; D012326:RNA Splicing; D016415:Sequence Alignment; D014158:Transcription, Genetic; D019895:Transposases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
D004251:DNA Transposable Elements; D029721:Drosophila Proteins; D006360:Heat-Shock Proteins; C089272:Hsp83 protein, Drosophila; D019895:Transposases