Alternative names for MEDEA antibody
Med,LD22279p, SMAD4, CG1775
Dot blot (Dot), Enzyme Immunoassay (E), Western blot / Immunoblot (WB), Immunocytochemistry/Immunofluorescence (ICC/IF)
Background of MEDEA antibody
The fly Drosophila melanogaster is one of the most intensively studied organisms in biology and serves as a model system for the investigation of many developmental and cellular processes common to higher eukaryotes, including humans. Approximately 120 mb euchromatic portion of the fly genome ha been sequenced using a shotgun sequencing approach. The entire fly genome encodes for approximately 13,600 genes with vast functional diversity. The dorsal ventral patterning in vertebrate embryos is regulated by members of TGF-beta family of growth and differentiation factors. The receptors for ligands in theTGF-beta superfamily are kinases but not much is known about their down stream components. In drosophila the decapentaplegic protein (dpp), a homolog of vertebrate BMP2 and BMP4 is involved in dorsal ventral axial patterning. Several downstream component of dpp signaling are characterized including MAD and MEDEA that codes a unique predicted cytoplasmic with no identifiable functional domain. Phenotypic analysis of the new Medea mutations indicates that Medea, like Mad, is required for both embryonic and imaginal disc patterning. Complete elimination of maternal and zygotic Medea activity in the early embryo results in a ventralized phenotype identical to that of null dpp mutants, indicating that Medea is required for all dpp-dependent signaling in embryonic dorsal-ventral patterning (1).
Two Smads have been identified in Drosophila. Mothers against dpp (Mad) is a pathway-specific Smad, whereas Daughters against dpp (Dad) is an inhibitory Smad genetically shown to antagonize Dpp signaling.
The protein coded by Medea has a striking sequence similarities to human SMAD4. Medea (SMAD4)AD forms heteromeric complexes with Drosophila SMAD4 (Medea) upon phosphorylation by thickvein (Tkv), a type 1 receptor for Dpp (2). Like dpp, Medea is essential for embryonic dorsal/ventral patterning. However, Mad is essential in the germline for oogenesis whereas Medea is dispensable (3). MEDEA is localized in the cytoplasm, is not regulated by phosphorylation, and requires physical association with MAD for nuclear translocation. The Medea protein is a 745 amino acid (MW 87-89kDa) cytosolic protein expressed during early developmental stages of fly. The mammalian counter parts of Medea is SMAD4 acting as a down-stream transcriptional activators. SMAD2 and SMAD3 are phosphorylated as a result of the canonical cascade through ligand binding and receptor kinase activation. These phosphorylated SMADs (pSMAD) associate with SMAD4, a co-SMAD, and transcriptionally activate TGFbeta-mediated genes. In drosophila Medea is not phosphorylatedon during either development or by its physiological ations.
1. Hudson JB, Podos SD, Keith K, Simpson SL, Ferguson EL. Thomsen GH. The Drosophila Medea gene is required
downstream of dpp and encodes a functional homolog of human Smad4. Xenopus mothers against decapentaplegic is an embryonic ventralizing agent
that acts downstream of the BMP-2/4 receptor. Development. 1998 Apr;125(8):1407-20.
2. Inoue H, Imamura T, Ishidou Y, Takase M, Udagawa Y, Oka Y, Tsuneizumi K, Tabata T, Miyazono K, Kawabata M.Interplay of signal mediators of
decapentaplegic (Dpp): molecular characterization of mothers against dpp, Medea, and daughters against dpp. Mol Biol Cell. 1998 Aug;9(8):2145-56.