title: Drosophila male-specific lethal-2 protein: structure/function analysis and dependence on MSL-1 for chromosome association.
abstract: MSL-2 is required for the male-specific assembly of a dosage compensation regulatory complex on the X chromosome of Drosophila melanogaster. 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. Moreover, the pattern of MSL-2 binding corresponds precisely in each case to that of MSL-1, suggesting that the two proteins function together to associate with the X. Consistent with this hypothesis, we isolated EMS-induced loss of function msl-1 and msl-2 alleles in a screen for suppressors of the toxic effects of MSL-2 expression in females. We also used site-directed mutagenesis to determine the importance of the MSL-2 RING finger domain and second cysteine-rich motif. The mutations, including those in conserved zinc coordinating cysteines, confirm that the RING finger is essential for MSL-2 function, while suggesting a less stringent requirement for an intact second motif.
authors.affiliation: Department of Cell Biology, Baylor College of Medicine, Houston, Texas 77030, USA.
authors.forename: L M
authors.initials: LM
authors.lastname: Lyman
authors.forename: K
authors.initials: K
authors.lastname: Copps
authors.forename: L
authors.initials: L
authors.lastname: Rastelli
authors.forename: R L
authors.initials: RL
authors.lastname: Kelley
authors.forename: M I
authors.initials: MI
authors.lastname: Kuroda
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002874:Chromosome Mapping; D003545:Cysteine / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000235:genetics / Q000378:metabolism*; D005260:Female; D008297:Male; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009687:Nuclear Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D013329:Structure-Activity Relationship; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D016335:Zinc Fingers
chemical_list: D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D009687:Nuclear Proteins; D014157:Transcription Factors; C082132:msl-1 protein, Drosophila; C094166:msl-2 protein, Drosophila; D003545:Cysteine