1
|
Bang J, Huh JH, Na JW, Lu Q, Carlson BA, Tobe R, Tsuji PA, Gladyshev VN, Hatfield DL, Lee BJ. Cell Proliferation and Motility Are Inhibited by G1 Phase Arrest in 15-kDa Selenoprotein-Deficient Chang Liver Cells. Mol Cells 2015; 38:457-65. [PMID: 25728752 PMCID: PMC4443288 DOI: 10.14348/molcells.2015.0007] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Revised: 01/08/2015] [Accepted: 01/09/2015] [Indexed: 01/08/2023] Open
Abstract
The 15-kDa selenoprotein (Sep15) is a selenoprotein residing in the lumen of the endoplasmic reticulum (ER) and implicated in quality control of protein folding. Herein, we established an inducible RNAi cell line that targets Sep15 mRNA in Chang liver cells. RNAi-induced Sep15 deficiency led to inhibition of cell proliferation, whereas cell growth was resumed after removal of the knockdown inducer. Sep15-deficient cells were arrested at the G1 phase by upregulating p21 and p27, and these cells were also characterized by ER stress. In addition, Sep15 deficiency led to the relocation of focal adhesions to the periphery of the cell basement and to the decrease of the migratory and invasive ability. All these changes were reversible depending on Sep15 status. Rescuing the knockdown state by expressing a silent mutant Sep15 mRNA that is resistant to siRNA also reversed the phenotypic changes. Our results suggest that SEP15 plays important roles in the regulation of the G1 phase during the cell cycle as well as in cell motility in Chang liver cells, and that this selenoprotein offers a novel functional link between the cell cycle and cell motility.
Collapse
Affiliation(s)
- Jeyoung Bang
- School of Biological Sciences, Seoul National University, Seoul, 151-742
Korea
- Interdisciplinary Program in Bioinformatics, Seoul National University, Seoul, 151-742
Korea
| | - Jang Hoe Huh
- School of Biological Sciences, Seoul National University, Seoul, 151-742
Korea
| | - Ji-Woon Na
- School of Biological Sciences, Seoul National University, Seoul, 151-742
Korea
| | - Qiao Lu
- School of Biological Sciences, Seoul National University, Seoul, 151-742
Korea
| | - Bradley A. Carlson
- Mouse Cancer Genetics Program, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Ryuta Tobe
- Mouse Cancer Genetics Program, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Petra A. Tsuji
- Department of Biological Sciences, Towson University, Towson, MD 21252
| | - Vadim N. Gladyshev
- Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115,
USA
| | - Dolph L. Hatfield
- Mouse Cancer Genetics Program, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Byeong Jae Lee
- School of Biological Sciences, Seoul National University, Seoul, 151-742
Korea
- Interdisciplinary Program in Bioinformatics, Seoul National University, Seoul, 151-742
Korea
- Institute of Molecular Biology and Genetics, Seoul National University, Seoul, 151-742
Korea
| |
Collapse
|
2
|
Bang J, Jang M, Huh JH, Na JW, Shim M, Carlson BA, Tobe R, Tsuji PA, Gladyshev VN, Hatfield DL, Lee BJ. Deficiency of the 15-kDa selenoprotein led to cytoskeleton remodeling and non-apoptotic membrane blebbing through a RhoA/ROCK pathway. Biochem Biophys Res Commun 2015; 456:884-90. [PMID: 25529450 PMCID: PMC4758352 DOI: 10.1016/j.bbrc.2014.12.059] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Accepted: 12/11/2014] [Indexed: 01/20/2023]
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.
Collapse
Affiliation(s)
- Jeyoung Bang
- 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
| | - Mihyun Jang
- School of Biological Sciences, Seoul National University, Seoul 151-742, Republic of Korea
| | - Jang Hoe Huh
- School of Biological Sciences, Seoul National University, Seoul 151-742, Republic of Korea
| | - Ji-Woon Na
- School of Biological Sciences, Seoul National University, Seoul 151-742, Republic of Korea
| | - Myoungsup Shim
- 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
| | - Bradley A Carlson
- Mouse Cancer Genetics Program, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Ryuta Tobe
- Mouse Cancer Genetics Program, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Petra A Tsuji
- Department of Biological Sciences, Towson University, Towson, MD 21252, USA
| | - Vadim N Gladyshev
- Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Dolph L Hatfield
- Mouse Cancer Genetics Program, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Byeong Jae Lee
- 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.
| |
Collapse
|