Open AccessNested Genes CDA12 and CDA13 Encode Proteins Associated with Membrane Trafficking in the Ciliate Tetrahymena thermophila
Author(s) -
Erica Zweifel,
Joshua Smith,
Daniel P. Romero,
Thomas H. Giddings,
Mark Winey,
Jerry E. Honts,
Jeff Dahlseid,
Brigitte Schneider,
Elliot Cole
Publication year - 2009
Publication title -
eukaryotic cell
Language(s) - English
Resource type - Journals
eISSN - 1535-9778
pISSN - 1535-9786
DOI - 10.1128/ec.00342-08
Subject(s) - cytokinesis , biology , tetrahymena , microbiology and biotechnology , ciliate , endosome , macronucleus , golgi apparatus , rna , gene , cell division , genetics , cell , intracellular , endoplasmic reticulum
We describe a novel pair of nested genes,CDA12 andCDA13 , fromTetrahymena thermophila . Both are implicated in membrane trafficking associated with cell division and conjugation. Green fluorescent protein localization reveals Cda12p decoration of diverse membrane-bound compartments, including mobile, subcortical tubulovesicular compartments; perinuclear vesicles; and candidates for recycling endosomes. Cda13p decorates intracellular foci located adjacent to cortically aligned mitochondria and their neighboring Golgi networks. The expression of antisenseCDA12 RNA in transformants produces defects in cytokinesis, macronuclear segregation, and the processing of pinosomes to downstream compartments. AntisenseCDA13 RNA expression produces a conjugation phenotype, resulting in the failure of mating pairs to separate, as well as failures in postconjugation cytokinesis and macronuclear fission. This study offers insight into the membrane trafficking events linking endosome and Golgi network activities, cytokinesis, and karyokinesis and the unique membrane-remodeling events that accompany conjugation in the ciliateT. thermophila . We also highlight an unusual aspect of genome organization inTetrahymena , namely, the existence of nested, antisense genes.