The claudin-like megatrachea is essential in septate junctions for the epithelial barrier function in Drosophila.
Vertebrate claudin proteins are integral components of tight junctions, which function as paracellular diffusion barriers in epithelia. We identified Megatrachea (Mega), a Drosophila transmembrane protein homologous to claudins, and show that it acts in septate junctions, the corresponding structure of invertebrates. Our analysis revealed that Mega has transepithelial barrier function similar to the claudins. Also, Mega is necessary for normal tracheal cell morphogenesis but not for apicobasal polarity or epithelial integrity. In addition, we present evidence that Mega is essential for localization of the septate junction protein complex Coracle/Neurexin. The results indicate that claudin-like proteins are functionally conserved between vertebrates and Drosophila.
Behr
Matthias
M
Abteilung Molekulare Entwicklungsbiologie, Max-Planck-Institut für Biophysikalische Chemie, Am Fassberg, 37077 Göttingen, Germany.
Riedel
Dietmar
D
Schuh
Reinhard
R
D000595:Amino Acid Sequence; D000818:Animals; D057167:Claudins / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D003911:Dextrans / Q000378:metabolism; D004330:Drosophila; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D004625:Embryo, Nonmammalian / Q000166:cytology / Q000378:metabolism; D005314:Embryonic and Fetal Development; D004848:Epithelium / Q000502:physiology; D005260:Female; D005455:Fluorescent Antibody Technique / Q000379:methods; D017403:In Situ Hybridization; D019476:Insect Proteins / Q000378:metabolism; D008297:Male; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D008854:Microscopy, Electron; D008954:Models, Biological; D008969:Molecular Sequence Data; D009024:Morphogenesis / Q000235:genetics; D009154:Mutation; D040681:Structural Homology, Protein; D013347:Subcellular Fractions; D019108:Tight Junctions / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D014132:Trachea / Q000166:cytology / Q000378:metabolism* / Q000648:ultrastructure
D057167:Claudins; D003911:Dextrans; D029721:Drosophila Proteins; D019476:Insect Proteins; D008565:Membrane Proteins; C577157:pck protein, Drosophila