title: Vacuolar-type H+-ATPase E subunit is required for embryogenesis and yolk transfer in Caenorhabditis elegans.
abstract: Vacuolar H(+)-ATPases (V-ATPases) are ATP-dependent proton pumps localized at membranes of intracellular acidic organelles and plasma membranes of various cell types. By virtue of its regulation in acidification, V-ATPase is required for many intracellular processes such as receptor-mediated endocytosis and protein sorting. Here we report the molecular characterization of the E subunit of V-ATPase in Caenorhabditis elegans. This subunit is one of the most well conserved subunits sharing approximately 57% identity with the human homologue, ATP6E. Green fluorescent protein (GFP) and whole-mount immunostaining analyses showed that V-ATPase E subunit (vha-8) is abundantly expressed in the H-shaped excretory cell, consistent with the expression patterns observed for other V-ATPase subunits. Double-stranded RNAs (or RNAi) targeted to vha-8 resulted in embryonic and larval lethality for the first filial generation, indicating that vha-8 is essential during early developmental processes. In addition, accumulation of abnormal endomitotic oocytes and defects in receptor-mediated endocytosis were observed in parental animals. These findings suggest that multiple phenotypes caused by the disruption of pH homeostasis are due to the defective V-ATPase. In summary, vha-8 encoding the E subunit of V-ATPase in C. elegans is essential for embryogenesis and receptor-mediated endocytosis.
authors.affiliation: Department of Life Science, Kwangju Institute of Science and Technology (K-JIST), Kwangju 500-712, South Korea.
authors.forename: Kyu Yeong
authors.initials: KY
authors.lastname: Choi
authors.forename: Yon Ju
authors.initials: YJ
authors.lastname: Ji
authors.forename: Bijaya Kumar
authors.initials: BK
authors.lastname: Dhakal
authors.forename: Jae-Ran
authors.initials: JR
authors.lastname: Yu
authors.forename: Chunghee
authors.initials: C
authors.lastname: Cho
authors.forename: Woo Keun
authors.initials: WK
authors.lastname: Song
authors.forename: Joohong
authors.initials: J
authors.lastname: Ahnn
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017173:Caenorhabditis elegans / Q000196:embryology / Q000201:enzymology* / Q000235:genetics; D004530:Egg Yolk / Q000378:metabolism*; D004625:Embryo, Nonmammalian / Q000201:enzymology / Q000648:ultrastructure; D047108:Embryonic Development; D005260:Female; D018507:Gene Expression Regulation, Developmental; D015971:Gene Expression Regulation, Enzymologic; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D008297:Male; D008856:Microscopy, Fluorescence; D016253:Microscopy, Immunoelectron; D008969:Molecular Sequence Data; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism; D034622:RNA Interference; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012098:Reproduction / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D025262:Vacuolar Proton-Translocating ATPases / Q000235:genetics / Q000378:metabolism*
chemical_list: D008164:Luminescent Proteins; D021122:Protein Subunits; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; D025262:Vacuolar Proton-Translocating ATPases