Protein sex-lethal

Protein information

  • Protein ID: P19339
  • Protein Name : Protein sex-lethal
  • Gene : Sxl
  • Organism : Drosophila melanogaster
  • Status : reviewed
  • Function : Sex determination switch protein which controls sexual development by sex-specific splicing. Regulates dosage compensation in females by suppressing hyperactivation of X-linked genes. Expression of the embryo-specific isoform is under the control of primary sex-determining signal which depends on the ratio of X chromosomes relative to autosomes (X:A ratio). Expression occurs in 2X:2A cells but not in X:2A cells. The X:A ratio seems to be signaled by the relative concentration of the X-linked transcription factors SIS-A and SIS-B. As a result the embryo-specific product is expressed early only in female embryos and specifies female-adult specific splicing; in the male where it is not expressed the default splicing gives rise to a truncated non-functional protein. The female-specific isoform specifies the splicing of its own transcript thereby initiating a positive autoregulatory feedback loop leading to female development pathway. The female-specific isoform controls the sex-specific splicing of transformer (TRA); acts as a translational repressor for male-specific lethal-2 (MSL-2) and prevents male-less (MLE) MSL-1 and MSL-3 proteins from associating with the female X chromosome.

Protein Sequence

  • MYGNNNPGSNNNNGGYPPYGYNNKSSGGRGFGMSHSLPSGMSRYAFSPQDTEFSFPSSSSRRGYNDFPGCGGSGGNGGSANNLGGGNMCHLPPMASNNSLNNLCGLSLGSGGSDDLMNDPRASNTNLIVNYLPQDMTDRELYALFRAIGPINTCRIMRDYKTGYSFGYAFVDFTSEMDSQRAIKVLNGITVRNKRLKVSYARPGGESIKDTNLYVTNLPRTITDDQLDTIFGKYGSIVQKNILRDKLTGRPRGVAFVRYNKREEAQEAISALNNVIPEGGSQPLSVRLAEEHGKAKAAHFMSQMGVVPANVPPPPPQPPAHMAAAFNMMHRGRSIKSQQRFQNSHPYFDAKKFI

RRM domains in this Protein - 2 

RRM Entryname RRM Sequence range Pfam ID
P19339_RRM1 127 - 197 PF00076
P19339_RRM2 213 - 281 PF00076

RRM domain Linkers in this Protein - 1 

Linker Name Linker Sequence range
P19339_linker1 198 - 212

Experiments retrieved for this Protein - 5 

Experiment ID Experiment Type PubMed ID
Exp_1B7F X-ray Diffraction 10217141
Exp_1SXL NMR 7524663
Exp_2SXL NMR 9299339
Exp_3SXL X-ray Diffraction 10220389
Exp_4QQB X-ray Diffraction 25209665

Ligands tested for Binding - 4 

Ligand ID Ligand Type Ligand Sequence
Lig209 RNA UUUUUUUGAGCACGUGAA
Lig3 RNA GUUGUUUUUUUU
Lig209 RNA UUUUUUUGAGCACGUGAA
Lig3 RNA GUUGUUUUUUUU