RNA-dependent association of the Drosophila maleless protein with the male X chromosome

Genes Cells. 1996 Mar;1(3):325-36. doi: 10.1046/j.1365-2443.1996.26027.x.


Background: Dosage compensation results in equivalent X-linked gene expression in males (XY) and females (XX). In Drosophila, both X chromosomes are active in females, and the single male X must double its transcriptional activity to allow male development. Four proteins (encoded by the male-specific lethal genes) are required for dosage compensation and associate with the X chromosome in males but not in females.

Results: In this report, we focus on the maleless (MLE) protein. The MLE protein sequence contains motifs common to members of a family of RNA-dependent ATPases. We have found that association of MLE with the male X chromosome is RNase sensitive, and that mutations in the ATPase motifs affect MLE function. Overexpression of MLE or its carboxyl terminus, which includes glycine-rich repeats, reveals an RNase-sensitive affinity for all chromosome arms.

Conclusions: Our results suggest that nascent transcripts or a hypothetical RNA component of chromatin play a critical role in the biochemical mechanism of dosage compensation. The potential relationship between interaction with RNA and transcriptional control of the X chromosome suggests that the mechanism of dosage compensation is distinct from classical models for transcriptional activation.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adenosine Triphosphatases / genetics
  • Animals
  • Animals, Genetically Modified
  • Chromosomal Proteins, Non-Histone*
  • DNA Helicases*
  • DNA-Binding Proteins*
  • Dosage Compensation, Genetic*
  • Drosophila / genetics*
  • Drosophila Proteins*
  • Female
  • Hot Temperature
  • Male
  • Mutation
  • RNA Nucleotidyltransferases / genetics
  • RNA Nucleotidyltransferases / metabolism*
  • RNA, Messenger / metabolism
  • Recombinant Fusion Proteins
  • Ribonuclease, Pancreatic
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*
  • X Chromosome / genetics
  • X Chromosome / metabolism*


  • Chromosomal Proteins, Non-Histone
  • DNA-Binding Proteins
  • Drosophila Proteins
  • RNA, Messenger
  • Recombinant Fusion Proteins
  • Transcription Factors
  • mle protein, Drosophila
  • RNA Nucleotidyltransferases
  • Ribonuclease, Pancreatic
  • Adenosine Triphosphatases
  • RNA-dependent ATPase
  • DNA Helicases