A unique ribonucleoprotein complex assembles preferentially on ecdysone-responsive sites in Drosophila melanogaster.
The protein on ecdysone puffs (PEP) is associated preferentially with active ecdysone-inducible puffs on Drosophila polytene chromosomes and contains sequence motifs characteristic of transcription factors and RNA-binding proteins (S. A. Amero, S. C. R. Elgin, and A. L. Beyer, Genes Dev. 5:188-200, 1991). PEP is associated with RNA in vivo, as demonstrated here by the sensitivity of PEP-specific chromosomal immunostaining in situ to RNase digestion and by the immunopurification of PEP in Drosophila cell extract with heterogeneous nuclear ribonucleoprotein (hnRNP) complexes. As revealed by sequential immunostaining, PEP is found on a subset of chromosomal sites bound by the HRB (heterogeneous nuclear RNA-binding) proteins, which are basic Drosophila hnRNPs. These observations lead us to suggest that a unique, PEP-containing hnRNP complex assembles preferentially on the transcripts of ecdysone-regulated genes in Drosophila melanogaster presumably to expedite the transcription and/or processing of these transcripts.
Amero
S A
SA
Department of Molecular and Cellular Biochemistry, Stritch School of Medicine, Loyola University Chicago, Maywood, Illinois 60153.
Matunis
M J
MJ
Matunis
E L
EL
Hockensmith
J W
JW
Raychaudhuri
G
G
Beyer
A L
AL
D000818:Animals; D002843:Chromatin / Q000648:ultrastructure; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000235:genetics*; D004440:Ecdysone / Q000494:pharmacology*; D005786:Gene Expression Regulation / Q000187:drug effects*; D007301:Insect Hormones / Q000378:metabolism*; D009687:Nuclear Proteins; D012260:Ribonucleases / Q000494:pharmacology; D012261:Ribonucleoproteins / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic; D016335:Zinc Fingers
D002843:Chromatin; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D007301:Insect Hormones; D009687:Nuclear Proteins; D012261:Ribonucleoproteins; D014157:Transcription Factors; C067400:PEP protein, Drosophila; D004440:Ecdysone; D012260:Ribonucleases