title: Identification of a novel Drosophila SMAD on the X chromosome.
abstract: TGF-beta signaling from the cell surface to the nucleus is mediated by the SMAD family of proteins, which have been grouped into three classes based upon sequence identity and function. Receptor-regulated, or pathway-restricted, SMADs (R-SMADs) are phosphorylated by ligand-specific serine/threonine kinase receptors. Phosphorylated R-SMADs oligomerize with the coactivating, or shared, SMAD (Co-SMAD) mediator and translocate to the nucleus where the complex directs transcription of downstream target genes. Inhibitory SMADs (I-SMADs) block receptor-mediated phosphorylation of R-SMADs. In Drosophila, one member of each class of SMAD has been reported: MAD, an R-SMAD, MEDEA, a Co-SMAD, and DAD, an I-SMAD. Here, we report the first identification of a novel Drosophila R-SMAD, which we have named Smox for Smad on X. We have localized the Smox gene to a specific interval on the X chromosome and shown that Smox is transcribed throughout development.
authors.affiliation: Department of Cell Biology and Anatomy, The Johns Hopkins University School of Medicine, Baltimore, Maryland, 21205-2196, USA.
authors.forename: K D
authors.initials: KD
authors.lastname: Henderson
authors.forename: D J
authors.initials: DJ
authors.lastname: Andrew
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D019521:Body Patterning; D002874:Chromosome Mapping; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics*; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000196:embryology / Q000235:genetics*; D004625:Embryo, Nonmammalian / Q000502:physiology; D017403:In Situ Hybridization; D008969:Molecular Sequence Data; D012097:Repressor Proteins; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D051896:Smad Proteins, Receptor-Regulated; D051901:Smad4 Protein; D015534:Trans-Activators / Q000737:chemistry / Q000235:genetics*; D014157:Transcription Factors; D016212:Transforming Growth Factor beta / Q000502:physiology; D014714:Vertebrates; D014960:X Chromosome
chemical_list: D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; C112506:MAD protein, Drosophila; C112504:Med protein, Drosophila; D012097:Repressor Proteins; D051896:Smad Proteins, Receptor-Regulated; D051901:Smad4 Protein; C115826:Smox protein, Drosophila; D015534:Trans-Activators; D014157:Transcription Factors; D016212:Transforming Growth Factor beta