Disease relevance of l(2)35Bg

• Synthetic poly[d(A-T)].poly[d(A-T)] and poly(dA).poly(dT) duplexes effectively compete in vitro with A + T-rich D. melanogaster satellite DNAs for binding to D1, whereas total Escherichia coli DNA is an extremely poor competitor [1].

High impact information on l(2)35Bg

• Using many deficiency mutants and in situ hybridization, we mapped the Drosophila J kappa RBP gene in a region containing two recessive lethal mutations, i.e., br26 and br7, which shows the dominant Suppressor of Hairless (Su(H)) phenotype in heterozygotes [2].
• The P9 polyamide, which binds the X-chromosome 1.688 g/cm3 satellite III (SAT III), displaces the D1 protein [3].
• Furthermore, using a modification of a protein blotting technique in which proteins are not exposed to dodecyl sulfate denaturation, we have found that D1 preferentially binds to A + T-rich double-stranded DNA in vitro, and it is apparently the only abundant nuclear protein in cultured D. melanogaster cells that possesses this property [1].
• Possible functions of D1 protein include compaction of A + T-rich heterochromatin and participation in microtubule-centromere interactions in mitosis [1].
• These findings strongly suggest that D1 is a specific component of A + T-rich, tandemly repeated, heterochromatic regions, which constitute up to 15-20% of the total D. melanogaster genome [1].

Biological context of l(2)35Bg

• The 1.705 density simple satellite (sequence-AAGAG-) is also found in nucleosomes, in a radically different subset from those of the -AATAT- DNA sequence. -AAGAG- nucleosomes do not contain D1 protein, but appear to be enriched in ubiquitinated core histone H2A [4].

Associations of l(2)35Bg with chemical compounds

• Nucleosomes have been fractionated on nondenaturing polyacrylamide gels, and nucleosome subtypes containing the Drosophila melanogaster specific protein D1 and ubiquitinated core histone H2A were identified by solubility in 0.1 M NaCl before nucleoprotein gel electrophoresis [4].

References