Study traces transcriptional regulatory activity to an intrinsic property of transposase proteins

Transposons — repetitive DNA sequences capable of moving within genomes — were first described by Barbara McClintock as 'controlling elements' because of their influence on gene expression. The molecular basis for this regulatory activity has remained poorly defined. A preprint posted to bioRxiv on 27 August 2026 addresses this longstanding question using the model plant Arabidopsis thaliana.

The authors show that transcriptional regulatory activity is an intrinsic property of transposase (TPase) proteins — the enzymes that catalyse transposon movement. Specifically, the Arabidopsis AtMu1 TPase was found to be sufficient to induce sequence-specific transcriptional activation of cognate transposon copies, revealing a pre-existing cis-regulatory network embedded in the transposon family. The team further demonstrate that TnpA, a transcriptional regulator encoded by the Spm transposon and long known to modulate gene expression, evolved from an ancestral TPase.

The findings provide a mechanistic account of how transposons can function as controlling elements and contribute to an understanding of how transposable elements have shaped gene regulation across eukaryotic genomes. The work is relevant to researchers studying genome evolution, gene regulation, and the domestication of transposon-derived sequences by host genomes. The preprint has not been peer-reviewed.