title: Suppression of the ER-localized AAA ATPase NgCDC48 inhibits tobacco growth and development.
abstract: CDC48 is a member of the AAA ATPase superfamily. Yeast CDC48 and its mammalian homolog p97 are implicated in diverse cellular processes, including mitosis, membrane fusion, and ubiquitin-dependent protein degradation. However, the cellular functions of plant CDC48 proteins are largely unknown. In the present study, we performed virus-induced gene silencing (VIGS) screening and found that silencing of a gene encoding a tobacco CDC48 homolog, NgCDC48, resulted in severe abnormalities in leaf and shoot development in tobacco. Furthermore, transgenic tobacco plants (35S:anti-NgCDC48), in which the NgCDC48 gene was suppressed using the antisense RNA method, exhibited severely aberrant development of both vegetative and reproductive organs, resulting in arrested shoot and leaf growth and sterile flowers. Approximately 57-83% of 35S:anti-NgCDC48 plants failed to develop mature organs and died at early stage of development. Scanning electron microscopy showed that both adaxial and abaxial epidermal pavement cells in antisense transgenic leaves were significantly smaller and more numerous than those in wild type leaves. These results indicate that NgCDC48 is critically involved in cell growth and development of tobacco plants. An in vivo targeting experiment revealed that NgCDC48 resides in the endoplasmic reticulum (ER) in tobacco protoplasts. We consider the tantalizing possibility that CDC48-mediated degradation of an as-yet unidentified protein(s) in the ER might be a critical step for cell growth and expansion in tobacco leaves.
authors.affiliation: Department of Biology, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749, Korea.
authors.forename: Hansol
authors.initials: H
authors.lastname: Bae
authors.forename: Soo Min
authors.initials: SM
authors.lastname: Choi
authors.forename: Seong Wook
authors.initials: SW
authors.lastname: Yang
authors.forename: Hyun-Sook
authors.initials: HS
authors.lastname: Pai
authors.forename: Woo Taek
authors.initials: WT
authors.lastname: Kim
mesh_terms: D000251:Adenosine Triphosphatases / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D002338:Carotenoids / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D002734:Chlorophyll / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000201:enzymology*; D018506:Gene Expression Regulation, Plant; D055785:Gene Knockdown Techniques; D008855:Microscopy, Electron, Scanning; D008969:Molecular Sequence Data; D010802:Phylogeny; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure; D010940:Plant Proteins / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified; D011523:Protoplasts / Q000378:metabolism; D016372:RNA, Antisense / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D014026:Nicotiana / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D000074405:Valosin Containing Protein; D024341:Xanthophylls / Q000378:metabolism
chemical_list: D018797:Cell Cycle Proteins; D010940:Plant Proteins; D016372:RNA, Antisense; D024341:Xanthophylls; D002734:Chlorophyll; D002338:Carotenoids; D000251:Adenosine Triphosphatases; D000074405:Valosin Containing Protein