The Drosophila Pioneer Factor Zelda Modulates the Nuclear Microenvironment of a Dorsal Target Enhancer to Potentiate Transcriptional Output

Shigehiro Yamada, Peter H. Whitney, Shao Kuei Huang, Elizabeth C. Eck, Hernan G. Garcia, Christine A. Rushlow

Research output: Contribution to journalArticle

Abstract

Connecting the developmental patterning of tissues to the mechanistic control of RNA polymerase II remains a long-term goal of developmental biology. Many key elements have been identified in the establishment of spatial-temporal control of transcription in the early Drosophila embryo, a model system for transcriptional regulation. The dorsal-ventral axis of the Drosophila embryo is determined by the graded distribution of Dorsal (Dl), a homolog of the nuclear factor κB (NF-κB) family of transcriptional activators found in humans [1, 2]. A second maternally deposited factor, Zelda (Zld), is uniformly distributed in the embryo and is thought to act as a pioneer factor, increasing enhancer accessibility for transcription factors, such as Dl [3–9]. Here, we utilized the MS2 live imaging system to evaluate the expression of the Dl target gene short gastrulation (sog) to better understand how a pioneer factor affects the kinetic parameters of transcription. Our experiments indicate that Zld modifies probability of activation, the timing of this activation, and the rate at which transcription occurs. Our results further show that this effective rate increase is due to an increased accumulation of Dl at the site of transcription, suggesting that transcription factor “hubs” induced by Zld [10] functionally regulate transcription.

Original languageEnglish (US)
Pages (from-to)1387-1393.e5
JournalCurrent Biology
Volume29
Issue number8
DOIs
StatePublished - Apr 22 2019

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Keywords

  • Zelda
  • enhancer mode
  • microenvironment
  • morphogen gradient
  • pioneer
  • transcription

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)
  • Agricultural and Biological Sciences(all)

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