The yemanuclein-alpha: a new Drosophila DNA binding protein specific for the oocyte nucleus.
The Drosophila yG 4.5 gene (now called yemanuclein-alpha gene), which maps at 98F, is a member of the yema gene cluster isolated in a search for differentially expressed maternal genes. The yemanuclein-alpha transcript (formerly yT 4.5) is specifically expressed in the female germ cells at early oogenic stages and displays a graded distribution along the antero-posterior axis of the oocyte. These provocative features are reminiscent of that of K10, bicoid and Bicaudal-D gene transcripts and lead us to hypothesize that the yemanuclein-alpha gene plays a key role in egg organization. We show in the present work that the yemanuclein-alpha is a nuclear protein highly specific for the oocyte nucleus. The sequence analysis of the 5696 bp EcoRI fragment containing the yemanuclein-alpha gene, and of 5 overlapping cDNAs, reveals a 3006 nucleotides long open reading frame (ORF) flanked by long untranslated 5' and 3' sequences. This ORF predicts a 109,215 kDa protein which is basic (pHi: 8.57), and serine rich (12.08%). It contains a 40 amino acid acidic domain in the first third of the protein with a potential alpha-helix organization; this domain has some similarity with the nucleolin acidic domain. Parts of the yemanuclein-alpha sequence are likely to form secondary structures known to interact with DNA. We demonstrate the DNA binding activity of the yemanuclein-alpha by affinity chromatography experiments. Our data indicate that the yemanuclein-alpha shares some of the features which are characteristic of genuine transcriptional activators.
Aït-Ahmed
O
O
Laboratoire de Génétique et Biologie Cellulaires, C.N.R.S., Centre Universitaire Marseille-Luminy, France.
Bellon
B
B
Capri
M
M
Joblet
C
C
Thomas-Delaage
M
M
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002467:Cell Nucleus / Q000378:metabolism; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000502:physiology; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000196:embryology / Q000235:genetics*; D005260:Female; D005796:Genes; D008297:Male; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics* / Q000502:physiology; D009865:Oocytes / Q000378:metabolism*; D009866:Oogenesis; D016366:Open Reading Frames; D010053:Ovary / Q000378:metabolism; D011487:Protein Conformation; D012689:Sequence Homology, Nucleic Acid; D014157:Transcription Factors / Q000235:genetics* / Q000502:physiology
D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D009687:Nuclear Proteins; D014157:Transcription Factors; C075160:yem protein, Drosophila; D004247:DNA