title: The Drosophila cell survival gene discs lost encodes a cytoplasmic Codanin-1-like protein, not a homolog of tight junction PDZ protein Patj.
abstract: The Drosophila gene discs lost (dlt) has been reported to encode a homolog of the vertebrate tight junction PDZ protein Patj, and was thought to play a role in cell polarity. Using rescue experiments and sequence analyses, we show that dlt mutations disrupt the Drosophila Codanin-1 homolog, a cytoplasmic protein, and not the PDZ protein. Mutations in human Codanin-1 are associated with congenital dyserythropoietic anemia type I (CDA I). In Drosophila, the genomic organization of dlt is unusual. dlt shares its first untranslated exon with alpha-spectrin, and both genes are coexpressed throughout development. We show that dlt is not required for cell polarity but is needed for cell survival and cell cycle progression. Finally, we present evidence that the PDZ protein previously thought to be encoded by dlt is not required for viability. We propose to rename this PDZ protein after its vertebrate homolog, Patj (Pals-associated tight junction protein).
authors.affiliation: Institut für Neurobiologie, Universität Münster, Badestrasse 9, D-48149 Münster, Germany.
authors.forename: Jan
authors.initials: J
authors.lastname: Pielage
authors.forename: Tobias
authors.initials: T
authors.lastname: Stork
authors.forename: Ingrid
authors.initials: I
authors.lastname: Bunse
authors.forename: Christian
authors.initials: C
authors.lastname: Klämbt
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002455:Cell Division / Q000502:physiology; D002470:Cell Survival / Q000502:physiology; D017124:Conserved Sequence; D003593:Cytoplasm / Q000378:metabolism; D004330:Drosophila / Q000196:embryology / Q000235:genetics*; D029721:Drosophila Proteins / Q000235:genetics* / Q000378:metabolism*; D004847:Epithelial Cells / Q000166:cytology / Q000502:physiology; D005136:Eye Proteins; D005260:Female; D018507:Gene Expression Regulation, Developmental; D006023:Glycoproteins / Q000235:genetics*; D008297:Male; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism*; D008969:Molecular Sequence Data; D009687:Nuclear Proteins; D010641:Phenotype; D034622:RNA Interference; D017386:Sequence Homology, Amino Acid; D013049:Spectrin / Q000235:genetics; D062725:Tight Junction Proteins; D019108:Tight Junctions / Q000502:physiology; D014714:Vertebrates
chemical_list: C470477:CDAN1 protein, human; D029721:Drosophila Proteins; D005136:Eye Proteins; D006023:Glycoproteins; D008565:Membrane Proteins; D009687:Nuclear Proteins; C107903:PATJ protein, human; D062725:Tight Junction Proteins; C118488:dlt protein, Drosophila; D013049:Spectrin