title: The C-terminal domain of PLD2 participates in degradation of protein kinase CKII β subunit in human colorectal carcinoma cells.
abstract: Elevated phospholipase D (PLD) expression prevents cell cycle arrest and apoptosis. However, the roles of PLD isoforms in cell proliferation and apoptosis are incompletely understood. Here, we investigated the physiological significance of the interaction between PLD2 and protein kinase CKII (CKII) in HCT116 human colorectal carcinoma cells. PLD2 interacted with the CKIIβ subunit in HCT116 cells. The C-terminal domain (residues 578-933) of PLD2 and the N-terminal domain of CKIIβ were necessary for interaction between the two proteins. PLD2 relocalized CKIIβ to the plasma membrane area. Overexpression of PLD2 reduced CKIIβ protein level, whereas knockdown of PLD2 led to an increase in CKIIβ expression. PLD2-induced CKIIβ reduction was mediated by ubiquitin-dependent degradation. The C-terminal domain of PLD2 was sufficient for CKIIβ degradation as the catalytic activity of PLD2 was not required. Taken together, the results indicate that the C-terminal domain of PLD2 can regulate CKII by accelerating CKIIβ degradation in HCT116 cells.
authors.affiliation: School of Life Sciences and Biotechnology, College of Natural Sciences, Kyungpook National University, Daegu 702-701, Korea.
authors.forename: Young-Hoon
authors.initials: YH
authors.lastname: Lee
authors.forename: Jong-Su
authors.initials: JS
authors.lastname: Uhm
authors.forename: Soo-Hyun
authors.initials: SH
authors.lastname: Yoon
authors.forename: Ji-Young
authors.initials: JY
authors.lastname: Kang
authors.forename: Eun-Kyung
authors.initials: EK
authors.lastname: Kim
authors.forename: Beom Sik
authors.initials: BS
authors.lastname: Kang
authors.forename: Do Sik
authors.initials: do S
authors.lastname: Min
authors.forename: Young-Seuk
authors.initials: YS
authors.lastname: Bae
mesh_terms: D047390:Casein Kinase II / Q000378:metabolism*; D015179:Colorectal Neoplasms / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology; D045325:HCT116 Cells; D006801:Humans; D010739:Phospholipase D / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000378:metabolism; D025801:Ubiquitin / Q000378:metabolism
chemical_list: D034741:RNA, Small Interfering; D025801:Ubiquitin; D047390:Casein Kinase II; C105606:phospholipase D2; D010739:Phospholipase D