title: Deficiency of the 15-kDa selenoprotein led to cytoskeleton remodeling and non-apoptotic membrane blebbing through a RhoA/ROCK pathway.
abstract: The 15-kDa selenoprotein (Sep15) has been implicated in etiology of some types of cancer. Herein, inducible RNAi cell lines were established and cell morphology and motility were analyzed. The majority of Sep15-deficient cells (>95%) formed membrane blebs in a dynamic manner. Blebbing cells transformed cell morphology from a normal flat spindle shape to a spherical morphology. In blebbing cells, actin fibers moved to the cell periphery, covering and obscuring visualization of α-tubulin. Bleb formation was suppressed by the inhibitors of Rho-associated protein kinase (ROCK), RhoA or myosin light chain (MLC), restoring blebbing cells to wild-type morphology. RhoA activation and phosphorylation of myosin phosphatase target subunit 1 was induced by Sep15 knockdown. Sep15-deficient cells were non-apoptotic, and displayed a distinct relative localization of F-actin and α-tubulin from typical apoptotic blebbing cells. Our data suggest that Sep15 in Chang liver cells regulates the pathway that antagonizes RhoA/ROCK/MLC-dependent non-apoptotic bleb formation.
authors.affiliation: School of Biological Sciences, Seoul National University, Seoul 151-742, Republic of Korea; Interdisciplinary Program in Bioinformatics, Seoul National University, Seoul 151-742, Republic of Korea.
authors.forename: Jeyoung
authors.initials: J
authors.lastname: Bang
authors.affiliation: School of Biological Sciences, Seoul National University, Seoul 151-742, Republic of Korea.
authors.forename: Mihyun
authors.initials: M
authors.lastname: Jang
authors.affiliation: School of Biological Sciences, Seoul National University, Seoul 151-742, Republic of Korea.
authors.forename: Jang Hoe
authors.initials: JH
authors.lastname: Huh
authors.affiliation: School of Biological Sciences, Seoul National University, Seoul 151-742, Republic of Korea.
authors.forename: Ji-Woon
authors.initials: JW
authors.lastname: Na
authors.affiliation: School of Biological Sciences, Seoul National University, Seoul 151-742, Republic of Korea; Institute of Molecular Biology and Genetics, Seoul National University, Seoul 151-742, Republic of Korea.
authors.forename: Myoungsup
authors.initials: M
authors.lastname: Shim
authors.affiliation: Mouse Cancer Genetics Program, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: Bradley A
authors.initials: BA
authors.lastname: Carlson
authors.affiliation: Mouse Cancer Genetics Program, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: Ryuta
authors.initials: R
authors.lastname: Tobe
authors.affiliation: Department of Biological Sciences, Towson University, Towson, MD 21252, USA.
authors.forename: Petra A
authors.initials: PA
authors.lastname: Tsuji
authors.affiliation: Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Vadim N
authors.initials: VN
authors.lastname: Gladyshev
authors.affiliation: Mouse Cancer Genetics Program, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: Dolph L
authors.initials: DL
authors.lastname: Hatfield
authors.affiliation: School of Biological Sciences, Seoul National University, Seoul 151-742, Republic of Korea; Interdisciplinary Program in Bioinformatics, Seoul National University, Seoul 151-742, Republic of Korea; Institute of Molecular Biology and Genetics, Seoul National University, Seoul 151-742, Republic of Korea. Electronic address: imbglmg@snu.ac.kr.
authors.forename: Byeong Jae
authors.initials: BJ
authors.lastname: Lee
mesh_terms: D000577:Amides / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D045744:Cell Line, Tumor; D021961:Cell Membrane Structures / Q000187:drug effects / Q000378:metabolism*; D003599:Cytoskeleton / Q000187:drug effects / Q000378:metabolism*; D055785:Gene Knockdown Techniques; D006801:Humans; D009219:Myosin-Light-Chain Kinase / Q000037:antagonists & inhibitors; D011725:Pyridines / Q000494:pharmacology; D051140:Selenoproteins / Q000172:deficiency* / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D054460:rho-Associated Kinases / Q000378:metabolism*; D020742:rhoA GTP-Binding Protein / Q000378:metabolism*
chemical_list: D000577:Amides; D011725:Pyridines; C495238:SELENOF protein, human; D051140:Selenoproteins; C108830:Y 27632; D054460:rho-Associated Kinases; D009219:Myosin-Light-Chain Kinase; D020742:rhoA GTP-Binding Protein
keywords: 15-kDa selenoprotein; Apoptosis; Cytoskeletal protein; Membrane blebbing; Selenium