The RNA export factor, Nxt1, is required for tissue specific transcriptional regulation

PLoS Genet. 2013 Jun;9(6):e1003526. doi: 10.1371/journal.pgen.1003526. Epub 2013 Jun 6.

Abstract

The highly conserved, Nxf/Nxt (TAP/p15) RNA nuclear export pathway is important for export of most mRNAs from the nucleus, by interacting with mRNAs and promoting their passage through nuclear pores. Nxt1 is essential for viability; using a partial loss of function allele, we reveal a role for this gene in tissue specific transcription. We show that many Drosophila melanogaster testis-specific mRNAs require Nxt1 for their accumulation. The transcripts that require Nxt1 also depend on a testis-specific transcription complex, tMAC. We show that loss of Nxt1 leads to reduced transcription of tMAC targets. A reporter transcript from a tMAC-dependent promoter is under-expressed in Nxt1 mutants, however the same transcript accumulates in mutants if driven by a tMAC-independent promoter. Thus, in Drosophila primary spermatocytes, the transcription factor used to activate expression of a transcript, rather than the RNA sequence itself or the core transcription machinery, determines whether this expression requires Nxt1. We additionally find that transcripts from intron-less genes are more sensitive to loss of Nxt1 function than those from intron-containing genes and propose a mechanism in which transcript processing feeds back to increase activity of a tissue specific transcription complex.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Active Transport, Cell Nucleus / genetics
  • Animals
  • Cell Survival / genetics
  • Drosophila Proteins / genetics*
  • Drosophila melanogaster / genetics*
  • Introns / genetics
  • Male
  • Nuclear Pore / genetics
  • Nucleocytoplasmic Transport Proteins / genetics*
  • Organ Specificity / genetics
  • RNA, Messenger / genetics*
  • RNA, Messenger / metabolism
  • Spermatocytes / cytology
  • Spermatocytes / growth & development
  • Testis / growth & development
  • Testis / metabolism
  • Transcription, Genetic*

Substances

  • Drosophila Proteins
  • Nucleocytoplasmic Transport Proteins
  • Nxt1 protein, Drosophila
  • RNA, Messenger