High impact information on mle

• We have found that in females, Sxl functions to prevent mle from binding to the two X chromosomes [1].
• Regulation of the sex-specific binding of the maleless dosage compensation protein to the male X chromosome in Drosophila [1].
• The maleless (mle) gene is one of four known regulatory loci required for increased transcription (dosage compensation) of X-linked genes in D. melanogaster males [2].
• Molecular analyses of nap and mle mutations indicate that mle+, nap+, and napts activities are encoded by the same open reading frame and suggest that napts is due to a single amino acid substitution [3].
• napts is a recessive mutation that affects the level of sodium channel activity and, at high temperature, causes paralysis associated with a loss of action potentials [3].

Biological context of mle

• A delayed onset of binding of the MSLs in male progeny of homozygous mutant msl-1 or mle mothers coupled with the previous finding that such males have an earlier lethal phase supports the idea that msl-mediated dosage compensation begins early in embryogenesis [4].
• Other results show that the maleless (MLE) protein on embryo and larval chromosomes differs in its reactivity with antibodies; the functional significance of this finding remains to be explored [4].
• We also show that, for the whole DEAH family, only MLE and its metazoan orthologs have acquired new protein domains since the fungi/animals split [5].
• An analysis of maleless and histone H4 acetylation in Drosophila melanogaster spermatogenesis [6].
• We have analyzed the expression pattern and localization of MLE, the other MSLs and acetylated isoforms of histone H4 in male germ cells to address whether dosage compensation and/or X inactivation occur in the Drosophila germline [6].

Anatomical context of mle

• The Sciara mle gene produces a single transcript, encoding a helicase, which is present in both male and female larvae and adults and in testes and ovaries [7].
• Maleless (mle) is essential in Drosophila melanogaster males both in somatic cells and in germ cells [6].
• Polyclonal antibodies against Drosophila MLE recognized RNA helicase A in crude nuclear extracts of HeLa cells as well as the purified protein [8].
• It was also found that parats1 and napts mutations, like the sodium channel blocker tetrodotoxin, do not affect the morphological differentiation and survival of central nervous system neurons in culture [9].
• The upstream sequences are also required for maximal binding of factors to the 5' splice site, cross-linking of U2AF to precursor RNA, and assembly of the active spliceosome, suggesting that sequences upstream of the branch point influence events at both ends of the small mle intron [10].

Associations of mle with chemical compounds

• Three of these proteins, MLE, MSL-1 and histone H4 acetylated at lysine 16 (H4Ac16), have recently been shown to be located almost exclusively on the male X chromosome in interphase (polytene) cells [11].
• Overexpression of MLE or its carboxyl terminus, which includes glycine-rich repeats, reveals an RNase-sensitive affinity for all chromosome arms [12].

Other interactions of mle

• We found that MSL-2 binds in a reproducible, partial pattern to the male X chromosome in the absence of MLE or MSL-3, or when ectopically expressed at a low level in females [13].
• The NTPase/helicase activities of Drosophila maleless, an essential factor in dosage compensation [14].
• Recent work showed that three of the Drosophila msls (msl-3, mof, and mle) have an ancient origin [15].
• MLE functions as a transcriptional regulator of the roX2 gene [16].
• When combined with para or mle mutations, Khe mutations cause synthetic lethality and a synergistic enhancement of TS-paralysis [17].

Analytical, diagnostic and therapeutic context of mle

• Molecular cloning of the gene encoding nuclear DNA helicase II. A bovine homologue of human RNA helicase A and Drosophila Mle protein [18].
• To explore the function of NDH II, we studied the intracellular distribution of NDH II of different mammalian species by immunofluorescence and compared these findings with the known role of the Drosophila homologue MLE that is involved in sex-specific gene dosage compensation [19].
• Immunohistochemistry was also performed on napts and seits1, two mutant Drosophila strains known to be defective in sodium channel activity [20].
• In previous work it was shown that parats (paralyzed, temperature-sensitive, 1-53.9) and napts (no action potential, temperature-sensitive, 2-56.2), two temperature-sensitive paralytic mutations that block nerve conduction at restrictive temperatures, interact synergistically in double mutants causing unconditional lethality [21].
• An allelism test has ascertained that mle-Co is allelic to mle, a male-specific mutation described by Fukunaga et al., 1975 [22].

References