The MSL proteins are essential for elevating transcription of the single X chromosome in the male (X chromosome dosage compensation). Mle, msl-1 and msl-3 are colocalized on the X chromosome. Each of the MSL proteins requires all the other MSLs for wild-type X-chromosome binding. Component of the male-specific lethal (MSL) histone acetyltransferase complex at least composed of mof, msl-1, msl-2 and msl-3. Msl-3 is associated with hundreds of discrete sites along the length of the X chromosome in males and not in females, and is also associated with 10-20 autosomal sites in males.