Noncoding transcription by alternative RNA polymerases dynamically regulates an auxin-driven chromatin loop

ARIEL, FD; JEGU, T; LATRASSE, D; ROMERO-BARRIOS, N; CHRIST, A; BENHAMED, M; CRESPI, M

MOLECULAR CELL

CELL PRESS

Lugar: United States; Año: 2014 vol. 55 p. 383 - 396

1097-2765

The eukaryotic epigenome is shaped by the genome topology in three-dimensional space. Dynamic reversible variations in this epigenome structure directly influence the transcriptional responses to developmental cues. Here, we show that the Arabidopsislong intergenic noncoding RNA (lincRNA) APOLO is transcribed by RNA polymerases II and V in response to auxin, a phytohormone controlling numerous facets of plant development. This dual APOLO transcription regulates the formation of a chromatin loop encompassing the promoter of its neighboring gene PID, a key regulator of polar auxin transport. Altering APOLO expression affects chromatin loop formation, whereas  RNA-dependent DNA methylation, active DNA demethylation, and Polycomb complexes control loop dynamics. This dynamic chromatin topology determines PID expression patterns. Hence, the dual transcription of a lincRNA influences local chromatin topology and directs dynamic auxin-controlled developmental outputs on neighboring genes. This mechanism likely underscores the adaptive success of plants in diverse environments and may be widespread in eukaryotes.