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Liu L, Yuan S, Yao S, Cao W, Wang L. EPPK1 as a Prognostic Biomarker in Type I Endometrial Cancer and Its Correlation with Immune Infiltration. Int J Gen Med 2024; 17:1677-1694. [PMID: 38706750 PMCID: PMC11067944 DOI: 10.2147/ijgm.s449986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Accepted: 04/19/2024] [Indexed: 05/07/2024] Open
Abstract
Purpose Approximately 20% of patients with type I endometrial cancer (EC) of the uterus experience recurrence and metastasis. However, existing data do not provide sufficient evidence for the utility of protein levels as prognostic biomarkers in type I EC. This study aims to determine whether epiplakin1 (EPPK1) and progesterone receptor (PR) play a role in the recurrence and metastasis of type I EC. Methods Following the Reporting Recommendations for Tumor Marker Prognostic Studies (REMARK) for assessing the quality of biomarker research results, a retrospective analysis was conducted on clinical information and tissue samples of type I EC patients. Protein expression data and clinical data for type I EC were downloaded from The Cancer Proteome Atlas (TCPA) database. We utilized the Kaplan-Meier (K-M) method and Cox proportional hazards regression analyses to evaluate whether epiplakin1 (EPPK1), progesterone receptor (PR) and certain clinical parameters can serve as independent prognostic factors. The Immune Cell Abundance Identifier (ImmuCellAI) and Cancer Immunome Atlas (TCIA) were employed to predict responses to immunotherapy. Immunohistochemistry was carried out to assess the expression of EPPK1 in type I EC. Results Type I EC patients with high EPPK1 and low PR expression had higher International Federation of Gynecology and Obstetrics (FIGO) stage, recurrence, and metastasis rates. Furthermore, EPPK1 was identified as an independent prognostic factor, and low expression of EPPK1 was predominantly observed in the POLE ultramutated (POLEmut) group, indicating a favorable prognosis. Additionally, the high EPPK1 expression group had a lower Immune Prognostic Score (IPS), suggesting that the high-expression group may not benefit from immune checkpoint inhibitors. Conclusion High expression of EPPK1 is an independent prognostic factor in type I EC patients with low PR expression. It can identify a subgroup of patients at high risk of recurrence. A more aggressive treatment approach is recommended for these patients.
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Affiliation(s)
- Lu Liu
- The International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200030, People’s Republic of China
| | - Shuang Yuan
- The International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200030, People’s Republic of China
| | - Shouheng Yao
- The International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200030, People’s Republic of China
| | - Wenjiao Cao
- The International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200030, People’s Republic of China
- Shanghai Key Laboratory of Embryo Original Diseases, Shanghai, 200030, People’s Republic of China
| | - Lihua Wang
- The International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200030, People’s Republic of China
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2
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Yang L, Huang W, Bai X, Wang H, Wang X, Xiao H, Li Y. Androgen dihydrotestosterone promotes bladder cancer cell proliferation and invasion via EPPK1-mediated MAPK/JUP signalling. Cell Death Dis 2023; 14:363. [PMID: 37328487 PMCID: PMC10275919 DOI: 10.1038/s41419-023-05882-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Revised: 03/30/2023] [Accepted: 06/08/2023] [Indexed: 06/18/2023]
Abstract
The incidence of bladder cancer (BLCA) in men is higher than that in women. Differences in androgen levels between men and women are considered the main causes of incidence rate differences. In this study, dihydrotestosterone (DHT) significantly increased the proliferation and invasion of BLCA cells. In addition, BLCA formation and metastatic rates were higher in N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN)-treated male mice than in female and castrated male mice in vivo. However, immunohistochemistry showed that androgen receptor (AR) was expressed at low levels in normal and BLCA tissues of men and women. The classical AR pathway considers that DHT binds to AR and induces it to enter the nucleus, where it functions as a transcription factor. Here, a non-AR combination pathway of androgen that promoted BLCA development was investigated. The EPPK1 protein was bombarded with DHT, as determined by biotinylated DHT-binding pull-down experiments. EPPK1 was highly expressed in BLCA tissues, and EPPK1 knockdown significantly inhibited BLCA cell proliferation and invasion promoted by DHT. Moreover, JUP expression was elevated in DHT-treated high-EPPK1 expressing cells, and JUP knockdown inhibited cell proliferation and invasion. EPPK1 overexpression increased tumour growth and JUP expression in nude mice. Furthermore, DHT increased the expression of the MAPK signals p38, p-p38, and c-Jun, and c-Jun could bind to the JUP promoter. However, the promotion of p38, p-p38, and c-Jun expression by DHT was not observed in EPPK1 knockdown cells, and a p38 inhibitor suppressed the DHT-induced effects, indicating that p38 MAPK may be involved in the regulation of DHT-dependent EPPK1-JUP-promoted BLCA cell proliferation and invasion. The growth of bladder tumours in BBN-treated mice was inhibited by the addition of the hormone inhibitor goserelin. Our findings indicated the potential oncogenic role and mechanism of DHT in BLCA pathogenesis through a non-AR pathway, which may serve as a novel therapeutic target for BLCA.
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Affiliation(s)
- Long Yang
- Department of Urology, Tianjin Medical University General Hospital, Tianjin, China
| | - Wen Huang
- Department of Urology, Tianjin Medical University General Hospital, Tianjin, China
| | - Xiaoyu Bai
- Department of Pathology, Tianjin Medical University Cancer Institute & Hospital, Tianjin, China
| | - Haoyu Wang
- Department of Urology, Tianjin Medical University General Hospital, Tianjin, China
| | - Xiaolei Wang
- Department of Urology, Tianjin Medical University General Hospital, Tianjin, China
| | - Huiyuan Xiao
- Department of Urology, Tianjin Medical University General Hospital, Tianjin, China
| | - Yanlei Li
- Department of Pathology, Tianjin Medical University, Tianjin, China.
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3
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Ratajczyk S, Drexler C, Windoffer R, Leube RE, Fuchs P. A Ca 2+-Mediated Switch of Epiplakin from a Diffuse to Keratin-Bound State Affects Keratin Dynamics. Cells 2022; 11:cells11193077. [PMID: 36231039 PMCID: PMC9563781 DOI: 10.3390/cells11193077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 09/19/2022] [Accepted: 09/23/2022] [Indexed: 11/16/2022] Open
Abstract
Keratins exert important structural but also cytoprotective functions. They have to be adaptable to support cellular homeostasis. Epiplakin (EPPK1) has been shown to decorate keratin filaments in epithelial cells and to play a protective role under stress, but the mechanism is still unclear. Using live-cell imaging of epithelial cells expressing fluorescently tagged EPPK1 and keratin, we report here an unexpected dynamic behavior of EPPK1 upon stress. EPPK1 was diffusely distributed throughout the cytoplasm and not associated with keratin filaments in living cells under standard culture conditions. However, ER-, oxidative and UV-stress, as well as cell fixation, induced a rapid association of EPPK1 with keratin filaments. This re-localization of EPPK1 was reversible and dependent on the elevation of cytoplasmic Ca2+ levels. Moreover, keratin filament association of EPPK1 led to significantly reduced keratin dynamics. Thus, we propose that EPPK1 stabilizes the keratin network in stress conditions, which involve increased cytoplasmic Ca2+.
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Affiliation(s)
- Sonia Ratajczyk
- Max Perutz Labs, Department of Biochemistry and Cell Biology, University of Vienna, Vienna Biocenter Campus (VBC), A-1030 Vienna, Austria
- Vienna Biocenter PhD Program, A Doctoral School of the University of Vienna and Medical University of Vienna, A-1030 Vienna, Austria
| | - Corinne Drexler
- Max Perutz Labs, Department of Biochemistry and Cell Biology, University of Vienna, Vienna Biocenter Campus (VBC), A-1030 Vienna, Austria
- Vienna Biocenter PhD Program, A Doctoral School of the University of Vienna and Medical University of Vienna, A-1030 Vienna, Austria
| | - Reinhard Windoffer
- Institute of Molecular and Cellular Anatomy, RWTH Aachen University, Wendlingweg 2, 52074 Aachen, Germany
| | - Rudolf E. Leube
- Institute of Molecular and Cellular Anatomy, RWTH Aachen University, Wendlingweg 2, 52074 Aachen, Germany
| | - Peter Fuchs
- Max Perutz Labs, Department of Biochemistry and Cell Biology, University of Vienna, Vienna Biocenter Campus (VBC), A-1030 Vienna, Austria
- Correspondence: ; Tel.: +43-1-4277-52855
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4
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Qiao Z, Dai C, Wang Z, Wang Z, Wang Z, Zhang T, Niu W, Ma X. Epiplakin1 promotes the progression of esophageal squamous cell carcinoma by activating the PI3K-AKT signaling pathway. Thorac Cancer 2022; 13:1117-1125. [PMID: 35238170 PMCID: PMC9013648 DOI: 10.1111/1759-7714.14366] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 02/09/2022] [Accepted: 02/10/2022] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Epiplakin1 (EPPK1) has been associated with disease progression and unfavorable prognosis of many cancers, but its functional involvement in esophageal squamous cell carcinoma (ESCC) remains to be uncovered. METHODS The Quantitative Real-time PCR (qPCR) assay was employed to determine the expression of EPPK1 in ESCC tissues and cells. CCK-8 assay, colony forming assay, wound healing assay, and transwell invasion assay were utilized to evaluate the effects of EPPK1 on cell proliferation, migration, and invasion capacity in ESCC cells using small interfering ribonucleic acids. Flow cytometry was performed to estimate the cell apoptotic rate caused by silencing of EPPK1. The proteins related to epithelial-to-mesenchymal transition (EMT), apoptosis, and activation of the phosphatidylinositol 3-kinase/serine threonine protein kinase 1 (PI3K/AKT) signaling pathway were measured by western blot. RESULTS The expression of EPPK1 was dramatically increased in ESCC tissues and cells compared to that in relative controls. Additionally, silencing of EPPK1 suppressed ESCC cell growth, colony formation, migration, invasion, and EMT, while promoting ESCC cell apoptosis. Furthermore, EPPK1 induced ESCC cell progression via mediating the PI3K/AKT signaling pathway. CONCLUSION EPPK1 promotes ESCC progression by modulating the PI3K/AKT signaling pathway and could serve as a potential target for ESCC treatment.
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Affiliation(s)
- Zhongshi Qiao
- Cancer Center, The Affiliated Qingdao Central Hospital of Qingdao UniversityThe Second Affiliated Hospital of Medical College of Qingdao UniversityQingdaoShandongChina
| | - Chengcheng Dai
- Cancer Center, The Affiliated Qingdao Central Hospital of Qingdao UniversityThe Second Affiliated Hospital of Medical College of Qingdao UniversityQingdaoShandongChina
| | - Zhiqian Wang
- Cancer Center, The Affiliated Qingdao Central Hospital of Qingdao UniversityThe Second Affiliated Hospital of Medical College of Qingdao UniversityQingdaoShandongChina
| | - Zifan Wang
- Cancer Center, The Affiliated Qingdao Central Hospital of Qingdao UniversityThe Second Affiliated Hospital of Medical College of Qingdao UniversityQingdaoShandongChina
| | - Zheng Wang
- Cancer Center, The Affiliated Qingdao Central Hospital of Qingdao UniversityThe Second Affiliated Hospital of Medical College of Qingdao UniversityQingdaoShandongChina
| | - Tongsong Zhang
- Cancer Center, The Affiliated Qingdao Central Hospital of Qingdao UniversityThe Second Affiliated Hospital of Medical College of Qingdao UniversityQingdaoShandongChina
| | - Wenjing Niu
- Cancer Center, The Affiliated Qingdao Central Hospital of Qingdao UniversityThe Second Affiliated Hospital of Medical College of Qingdao UniversityQingdaoShandongChina
| | - Xuezhen Ma
- Cancer Center, The Affiliated Qingdao Central Hospital of Qingdao UniversityThe Second Affiliated Hospital of Medical College of Qingdao UniversityQingdaoShandongChina
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Tian Z, Wong W, Wu Q, Zhou J, Yan K, Chen J, Zhang Z. Elevated Expressions of BTN3A1 and RhoB in Psoriasis Vulgaris Lesions by an Immunohistochemical Study. Appl Immunohistochem Mol Morphol 2022; 30:119-125. [PMID: 34545848 DOI: 10.1097/pai.0000000000000977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 08/25/2021] [Indexed: 11/25/2022]
Abstract
Psoriasis is a chronic, immune-mediated inflammatory disease which pathogenesis is closely linked to γδ T cells. Recently, a critical role for butyrophilin 3A1 (BTN3A1) in mediating the activation of Vγ9Vδ2 T cells, which are reported to redistribute from blood to the perturbed skin lesions in psoriasis, has been proposed. Additional molecular partners, including RhoB and periplakin, have also been speculated to interact with BTN3A1 in modulating Vγ9Vδ2 T-cell activation. Immunohistochemical staining was performed to examine the expressions of BTN3A1, RhoB, and the plakin family members, including periplakin, epiplakin, and envoplakin in the psoriasis vulgaris lesions as compared with the normal control. The expressions of BTN3A1 and RhoB were found significantly upregulated in the psoriatic lesions. Besides, a downregulation of periplakin and an upregulation of epiplakin were noticed in the psoriasis vulgaris lesions. Our data suggest that BTN3A1 and RhoB might participate in the pathogenesis of psoriasis through Vγ9Vδ2 T-cell responses. In addition, a potential involvement of the plakin protein family, especially periplakin and epiplakin, in psoriasis pathology was proposed.
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Affiliation(s)
- Zhen Tian
- Department of Dermatology, Huashan Hospital, Shanghai Medical College of Fudan University
| | - Wenghong Wong
- Department of Dermatology, Huashan Hospital, Shanghai Medical College of Fudan University
| | - Qiong Wu
- Department of Dermatology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University
| | - Jiaqing Zhou
- Department of Dermatology, Huashan Hospital, Shanghai Medical College of Fudan University
| | - Kexiang Yan
- Department of Dermatology, Huashan Hospital, Shanghai Medical College of Fudan University
| | - Jia Chen
- Department of Dermatopathology, Shanghai Skin Disease Hospital, School of Medicine, Tongji University, Shanghai, People's Republic of China
| | - Zhenghua Zhang
- Department of Dermatology, Huashan Hospital, Shanghai Medical College of Fudan University
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6
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Fuchs P, Drexler C, Ratajczyk S, Eckhart L. Comparative genomics reveals evolutionary loss of epiplakin in cetaceans. Sci Rep 2022; 12:1112. [PMID: 35064199 PMCID: PMC8782857 DOI: 10.1038/s41598-022-05087-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 01/06/2022] [Indexed: 12/14/2022] Open
Abstract
The adaptation of vertebrates to different environments was associated with changes in the molecular composition and regulation of epithelia. Whales and dolphins, together forming the clade cetaceans, have lost multiple epithelial keratins during or after their evolutionary transition from life on land to life in water. It is unknown whether the changes in keratins were accompanied by gain or loss of cytoskeletal adapter proteins of the plakin family. Here we investigated whether plakin proteins are conserved in cetaceans and other vertebrates. Comparative analysis of genome sequences showed conservation of dystonin, microtubule actin crosslinking factor 1 (MACF1), plectin, desmoplakin, periplakin and envoplakin in cetaceans. By contrast, EPPK1 (epiplakin) was disrupted by inactivating mutations in all cetaceans investigated. Orthologs of EPPK1 are present in bony and cartilaginous fishes and tetrapods, indicating an evolutionary origin of EPPK1 in a common ancestor of jawed vertebrates (Gnathostomes). In many vertebrates, EPPK1 is flanked by an as-yet uncharacterized gene that encodes protein domains homologous to the carboxy-terminal segment of MACF1. We conclude that epiplakin, unlike other plakins, was lost in cetaceans.
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Affiliation(s)
- Peter Fuchs
- Max Perutz Labs, Department of Biochemistry and Cell Biology, University of Vienna, Vienna Biocenter Campus (VBC), Vienna, Austria.
| | - Corinne Drexler
- Max Perutz Labs, Department of Biochemistry and Cell Biology, University of Vienna, Vienna Biocenter Campus (VBC), Vienna, Austria
| | - Sonia Ratajczyk
- Max Perutz Labs, Department of Biochemistry and Cell Biology, University of Vienna, Vienna Biocenter Campus (VBC), Vienna, Austria
| | - Leopold Eckhart
- Skin Biology Laboratory, Department of Dermatology, Medical University of Vienna, Vienna, Austria.
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7
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Ueo D, Furuhashi M, Sasaki T, Kudoh J, Parry DAD, Winter DJ, Sasaki T, Hashimoto T, Tsuruta D, Fujiwara S. Intragenic copy number variation in mouse epiplakin 1 (Eppk1) and the conservation of the repeat structures in the lower vertebrates. J Dermatol Sci 2021; 103:186-189. [PMID: 34275721 DOI: 10.1016/j.jdermsci.2021.07.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2021] [Revised: 07/03/2021] [Accepted: 07/06/2021] [Indexed: 10/20/2022]
Affiliation(s)
- Daisuke Ueo
- Department of Dermatology, Faculty of Medicine, Oita University, Oita, Japan
| | - Mie Furuhashi
- Laboratory of Gene Medicine, Keio University School of Medicine, Tokyo, Japan
| | - Takashi Sasaki
- Center for Supercentenarian Medical Research, Keio University School of Medicine, Tokyo, Japan
| | - Jun Kudoh
- Laboratory of Gene Medicine, Keio University School of Medicine, Tokyo, Japan
| | - David A D Parry
- Department of Biophysics, School of Fundamental Sciences, Massey University, Palmerston North, New Zealand
| | - David J Winter
- Department of Computational Genomics, School of Fundamental Sciences, Massey University, Palmerston North, New Zealand
| | - Takako Sasaki
- Department of Matrix Biology, Faculty of Medicine, Oita University, Oita, Japan
| | - Takashi Hashimoto
- Department of Dermatology, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Daisuke Tsuruta
- Department of Dermatology, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Sakuhei Fujiwara
- Department of Dermatology, Faculty of Medicine, Oita University, Oita, Japan; Department of Dermatology, Osaka City University Graduate School of Medicine, Osaka, Japan.
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8
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Wesley T, Berzins S, Kannourakis G, Ahmed N. The attributes of plakins in cancer and disease: perspectives on ovarian cancer progression, chemoresistance and recurrence. Cell Commun Signal 2021; 19:55. [PMID: 34001250 PMCID: PMC8127266 DOI: 10.1186/s12964-021-00726-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Accepted: 02/20/2021] [Indexed: 02/06/2023] Open
Abstract
The plakin family of cytoskeletal proteins play an important role in cancer progression yet are under-studied in cancer, especially ovarian cancer. These large cytoskeletal proteins have primary roles in the maintenance of cytoskeletal integrity but are also associated with scaffolds of intermediate filaments and hemidesmosomal adhesion complexes mediating signalling pathways that regulate cellular growth, migration, invasion and differentiation as well as stress response. Abnormalities of plakins, and the closely related spectraplakins, result in diseases of the skin, striated muscle and nervous tissue. Their prevalence in epithelial cells suggests that plakins may play a role in epithelial ovarian cancer progression and recurrence. In this review article, we explore the roles of plakins, particularly plectin, periplakin and envoplakin in disease-states and cancers with emphasis on ovarian cancer. We discuss the potential role the plakin family of proteins play in regulating cancer cell growth, survival, migration, invasion and drug resistance. We highlight potential relationships between plakins, epithelial-mesenchymal transition (EMT) and cancer stem cells (CSCs) and discuss how interaction of these processes may affect ovarian cancer progression, chemoresistance and ultimately recurrence. We propose that molecular changes in the expression of plakins leads to the transition of benign ovarian tumours to carcinomas, as well as floating cellular aggregates (commonly known as spheroids) in the ascites microenvironment, which may contribute to the sustenance and progression of the disease. In this review, attempts have been made to understand the crucial changes in plakin expression in relation to progression and recurrence of ovarian cancer. Video Abstract
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Affiliation(s)
- Tamsin Wesley
- Fiona Elsey Cancer Research Institute, Ballarat Technology Central Park, Suites 23-26, 106-110 Lydiard Street South, Ballarat, VIC, 3353, Australia.,School of Science, Psychology and Sport, Federation University Australia, Ballarat, VIC, 3010, Australia
| | - Stuart Berzins
- Fiona Elsey Cancer Research Institute, Ballarat Technology Central Park, Suites 23-26, 106-110 Lydiard Street South, Ballarat, VIC, 3353, Australia.,School of Science, Psychology and Sport, Federation University Australia, Ballarat, VIC, 3010, Australia
| | - George Kannourakis
- Fiona Elsey Cancer Research Institute, Ballarat Technology Central Park, Suites 23-26, 106-110 Lydiard Street South, Ballarat, VIC, 3353, Australia.,School of Science, Psychology and Sport, Federation University Australia, Ballarat, VIC, 3010, Australia
| | - Nuzhat Ahmed
- Fiona Elsey Cancer Research Institute, Ballarat Technology Central Park, Suites 23-26, 106-110 Lydiard Street South, Ballarat, VIC, 3353, Australia. .,School of Science, Psychology and Sport, Federation University Australia, Ballarat, VIC, 3010, Australia. .,Department of Obstetrics and Gynaecology, University of Melbourne, Melbourne, VIC, 3052, Australia. .,Centre for Reproductive Health, The Hudson Institute of Medical Research and Department of Translational Medicine, Monash University, Melbourne, VIC, 3168, Australia.
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9
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Ma D, Pan Z, Chang Q, Zhang JJ, Liu X, Hua N, Li GH. KLF5-mediated Eppk1 expression promotes cell proliferation in cervical cancer via the p38 signaling pathway. BMC Cancer 2021; 21:377. [PMID: 33827480 PMCID: PMC8028205 DOI: 10.1186/s12885-021-08040-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 03/15/2021] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Epiplakin1 (Eppk1) is part of epidermal growth factor (EGF) signal and takes part in reorganization of cytoskeleton and cell proliferation. However, the role of Eppk1 in cervical cancer (CC) remains unknown. METHODS To express Eppk1 and KLF5 and their correlation, we used RNA-sequence, RT-qPCR, TCGA database and immunofluorescence staining in vitro and in different pathological cervical tissues. In CC cell lines, we tested adenovirus-mediated over expression or knockdown of KLF5 and siRNA-mediated knockdown of Eppk1 and a suiting assessment of cell proliferation and cell signaling by western blot and CCK8 tests. We studied the mechanism by which KLF5 regulates Eppk1 expression by reporter gene test and chromatin immunoprecipitation test. RESULTS Eppk1 expression promoted in CC tissues and cell lines compared with increased KLF5 expression. The results of immunofluorescence staining further showed the increased co-expression of Eppk1 and KLF5 correlated substantially with tumorigenesis in cervical tissues. Overexpression of KLF5 significantly increased Eppk1 expression at transcription and translation levels. Conversely, the knockdown of KLF5 by siRNA against KLF5 decreased Eppk1 expression. Mechanically, KLF5 activated Eppk1 transcription by direct binding to the Eppk1 promoter. Gain- and loss-of-function experiments reported that KLF5 promoted cell proliferation in Hela partly dependent on Eppk1 upregulation. Besides, KLF5-mediated activation of p38 signaling significantly decreased after Eppk1 knockdown compared with decline of proliferation, suggesting that Eppk1 lies upstream of p38 signaling affecting cell proliferation. Finally, Eppk1 expression is positively correlated with tumor size in clinicopathological features of CC. CONCLUSIONS Eppk1 may be an effective therapeutic target for affecting p38 signaling pathway and cell proliferation in cervical cancer.
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Affiliation(s)
- Dong Ma
- School of Public Health, North China University of Science and Technology, 21 Bohai Avenue, Caofeidian New City, Tangshan, 063210, China
| | - Zhe Pan
- School of Public Health, North China University of Science and Technology, 21 Bohai Avenue, Caofeidian New City, Tangshan, 063210, China
| | - Quan Chang
- School of Public Health, North China University of Science and Technology, 21 Bohai Avenue, Caofeidian New City, Tangshan, 063210, China
| | - Jin-Jin Zhang
- School of Public Health, North China University of Science and Technology, 21 Bohai Avenue, Caofeidian New City, Tangshan, 063210, China
| | - Xiao Liu
- Department of Infection Control, the Fourth Hospital of Hebei Medical University, No.12 Jian Kang Rd., Shi Jiazhuang, 050011, China.
| | - Na Hua
- Tangshan Customs, People's Republic of China, Tangshan, 063200, China
| | - Guo-Hua Li
- Department of Oncology, the Second Hospital of Tangshan, Tangshan, 063000, China
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10
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Laan M, Salumets A, Klein A, Reintamm K, Bichele R, Peterson H, Peterson P. Post-Aire Medullary Thymic Epithelial Cells and Hassall's Corpuscles as Inducers of Tonic Pro-Inflammatory Microenvironment. Front Immunol 2021; 12:635569. [PMID: 33868260 PMCID: PMC8050345 DOI: 10.3389/fimmu.2021.635569] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 03/05/2021] [Indexed: 11/13/2022] Open
Abstract
While there is convincing evidence on the role of Aire-positive medullary thymic epithelial cells (mTEC) in the induction of central tolerance, the nature and function of post-Aire mTECs and Hassall's corpuscles have remained enigmatic. Here we summarize the existing data on these late stages of mTEC differentiation with special focus on their potential to contribute to central tolerance induction by triggering the unique pro-inflammatory microenvironment in the thymus. In order to complement the existing evidence that has been obtained from mouse models, we performed proteomic analysis on microdissected samples from human thymic medullary areas at different differentiation stages. The analysis confirms that at the post-Aire stages, the mTECs lose their nuclei but maintain machinery required for translation and exocytosis and also upregulate proteins specific to keratinocyte differentiation and cornification. In addition, at the late stages of differentiation, the human mTECs display a distinct pro-inflammatory signature, including upregulation of the potent endogenous TLR4 agonist S100A8/S100A9. Collectively, the study suggests a novel mechanism by which the post-Aire mTECs and Hassall's corpuscles contribute to the thymic microenvironment with potential cues on the induction of central tolerance.
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Affiliation(s)
- Martti Laan
- Molecular Pathology Research Group, Institute of Biomedicine and Translational Medicine, University of Tartu, Tartu, Estonia
| | - Ahto Salumets
- Molecular Pathology Research Group, Institute of Biomedicine and Translational Medicine, University of Tartu, Tartu, Estonia
- Institute of Computer Science, Faculty of Science and Technology, University of Tartu, Tartu, Estonia
| | - Annabel Klein
- Molecular Pathology Research Group, Institute of Biomedicine and Translational Medicine, University of Tartu, Tartu, Estonia
| | - Kerli Reintamm
- Molecular Pathology Research Group, Institute of Biomedicine and Translational Medicine, University of Tartu, Tartu, Estonia
| | - Rudolf Bichele
- Molecular Pathology Research Group, Institute of Biomedicine and Translational Medicine, University of Tartu, Tartu, Estonia
| | - Hedi Peterson
- Institute of Computer Science, Faculty of Science and Technology, University of Tartu, Tartu, Estonia
| | - Pärt Peterson
- Molecular Pathology Research Group, Institute of Biomedicine and Translational Medicine, University of Tartu, Tartu, Estonia
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Ishikawa K, Furuhashi M, Sasaki T, Kudoh J, Tsuchisaka A, Hashimoto T, Sasaki T, Yoshioka H, Eshima N, Matsuda-Hirose H, Sakai T, Hatano Y, Fujiwara S. Intragenic copy number variation within human epiplakin 1 (EPPK1) generates variation of molecular size of epiplakin. J Dermatol Sci 2018; 91:S0923-1811(18)30234-2. [PMID: 29866520 DOI: 10.1016/j.jdermsci.2018.05.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 04/25/2018] [Accepted: 05/21/2018] [Indexed: 11/21/2022]
Affiliation(s)
- Kazushi Ishikawa
- Department of Dermatology, Faculty of Medicine, Oita University, 1-1 Idaigaoka, Hasama-machi, Yufu 879-5593, Japan
| | - Mie Furuhashi
- Laboratory of Gene Medicine, Keio University School of Medicine, Tokyo, Japan
| | - Takashi Sasaki
- Center for Supercentenarian Medical Research, Keio University School of Medicine, Tokyo, Japan
| | - Jun Kudoh
- Laboratory of Gene Medicine, Keio University School of Medicine, Tokyo, Japan
| | - Atsunari Tsuchisaka
- Kurume University Institute of Cutaneous Cell Biology, 67 Asahimachi, Kurume, Fukuoka 830-0011, Japan
| | - Takashi Hashimoto
- Kurume University Institute of Cutaneous Cell Biology, 67 Asahimachi, Kurume, Fukuoka 830-0011, Japan
| | - Takako Sasaki
- Department of Matrix Biology, Faculty of Medicine, Oita University, 1-1 Idaigaoka, Hasama-machi, Yufu 879-5593, Japan
| | - Hidekatsu Yoshioka
- Department of Matrix Biology, Faculty of Medicine, Oita University, 1-1 Idaigaoka, Hasama-machi, Yufu 879-5593, Japan
| | - Nobuoki Eshima
- Department of Biostatistics, Faculty of Medicine, Oita University, 1-1 Idaigaoka, Hasama-machi, Yufu 879-5593, Japan
| | - Haruna Matsuda-Hirose
- Department of Dermatology, Faculty of Medicine, Oita University, 1-1 Idaigaoka, Hasama-machi, Yufu 879-5593, Japan
| | - Takashi Sakai
- Department of Dermatology, Faculty of Medicine, Oita University, 1-1 Idaigaoka, Hasama-machi, Yufu 879-5593, Japan
| | - Yutaka Hatano
- Department of Dermatology, Faculty of Medicine, Oita University, 1-1 Idaigaoka, Hasama-machi, Yufu 879-5593, Japan
| | - Sakuhei Fujiwara
- Department of Dermatology, Faculty of Medicine, Oita University, 1-1 Idaigaoka, Hasama-machi, Yufu 879-5593, Japan.
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Hu L, Huang Z, Wu Z, Ali A, Qian A. Mammalian Plakins, Giant Cytolinkers: Versatile Biological Functions and Roles in Cancer. Int J Mol Sci 2018; 19:ijms19040974. [PMID: 29587367 PMCID: PMC5979291 DOI: 10.3390/ijms19040974] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Revised: 03/18/2018] [Accepted: 03/20/2018] [Indexed: 01/07/2023] Open
Abstract
Cancer is a highly lethal disease that is characterized by aberrant cell proliferation, migration, and adhesion, which are closely related to the dynamic changes of cytoskeletons and cytoskeletal-adhesion. These will further result in cell invasion and metastasis. Plakins are a family of giant cytolinkers that connect cytoskeletal elements with each other and to junctional complexes. With various isoforms composed of different domain structures, mammalian plakins are broadly expressed in numerous tissues. They play critical roles in many cellular processes, including cell proliferation, migration, adhesion, and signaling transduction. As these cellular processes are key steps in cancer development, mammalian plakins have in recent years attracted more and more attention for their potential roles in cancer. Current evidence shows the importance of mammalian plakins in various human cancers and demonstrates mammalian plakins as potential biomarkers for cancer. Here, we introduce the basic characteristics of mammalian plakins, review the recent advances in understanding their biological functions, and highlight their roles in human cancers, based on studies performed by us and others. This will provide researchers with a comprehensive understanding of mammalian plakins, new insights into the development of cancer, and novel targets for cancer diagnosis and therapy.
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Affiliation(s)
- Lifang Hu
- Laboratory for Bone Metabolism, Key Laboratory for Space Biosciences and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, China.
- Research Center for Special Medicine and Health Systems Engineering, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, China.
- NPU-UAB Joint Laboratory for Bone Metabolism, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, China.
| | - Zizhan Huang
- Laboratory for Bone Metabolism, Key Laboratory for Space Biosciences and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, China.
- Research Center for Special Medicine and Health Systems Engineering, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, China.
- NPU-UAB Joint Laboratory for Bone Metabolism, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, China.
| | - Zixiang Wu
- Laboratory for Bone Metabolism, Key Laboratory for Space Biosciences and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, China.
- Research Center for Special Medicine and Health Systems Engineering, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, China.
- NPU-UAB Joint Laboratory for Bone Metabolism, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, China.
| | - Arshad Ali
- Laboratory for Bone Metabolism, Key Laboratory for Space Biosciences and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, China.
- Research Center for Special Medicine and Health Systems Engineering, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, China.
- NPU-UAB Joint Laboratory for Bone Metabolism, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, China.
| | - Airong Qian
- Laboratory for Bone Metabolism, Key Laboratory for Space Biosciences and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, China.
- Research Center for Special Medicine and Health Systems Engineering, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, China.
- NPU-UAB Joint Laboratory for Bone Metabolism, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, China.
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Kokado M, Okada Y, Miyamoto T, Yamanaka O, Saika S. Effects of epiplakin-knockdown in cultured corneal epithelial cells. BMC Res Notes 2016; 9:278. [PMID: 27206504 PMCID: PMC4873999 DOI: 10.1186/s13104-016-2082-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 05/10/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND To investigate effects of knockdown of epiplakin gene expression on the homeostasis of cultured corneal epithelial cell line. We previously reported acceleration of corneal epithelial wound healing in an epiplakin-null mouse. METHODS Gene expression of epiplakin was knockdowned by employing siRNA transfection in SV40-immortalized human corneal epithelial cell line. Protein expression of E-cadherin, keratin 6 and vimentin was examined by western blotting. Cell migration and proliferation were examined by using scratch assay and Alamar blue assay, respectively. RESULTS Scratch assay and Alamar blue assay showed migration and proliferation of the cells was accelerated by epiplakin knockdown. siRNA-knockdown of epiplakin suppressed protein expression of E-cadherin, keratin 6 and vimentin. CONCLUSIONS Decreased expression of E-cadherin, keratin 6 and vimentin might be included in the mechanisms of cell migration acceleration in the absence of epiplakin. The mechanism of cell proliferation stimulation by epiplakin knockdown is to be investigated.
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Affiliation(s)
- Masahide Kokado
- Department of Ophthalmology, Wakayama Medical University School of Medicine, 811-1 Kimiidera, Wakayama, 641-0012, Japan.
| | - Yuka Okada
- Department of Ophthalmology, Wakayama Medical University School of Medicine, 811-1 Kimiidera, Wakayama, 641-0012, Japan
| | - Takeshi Miyamoto
- Department of Ophthalmology, Wakayama Medical University School of Medicine, 811-1 Kimiidera, Wakayama, 641-0012, Japan
| | - Osamu Yamanaka
- Department of Ophthalmology, Wakayama Medical University School of Medicine, 811-1 Kimiidera, Wakayama, 641-0012, Japan
| | - Shizuya Saika
- Department of Ophthalmology, Wakayama Medical University School of Medicine, 811-1 Kimiidera, Wakayama, 641-0012, Japan
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14
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Epiplakin Is a Paraneoplastic Pemphigus Autoantigen and Related to Bronchiolitis Obliterans in Japanese Patients. J Invest Dermatol 2016; 136:399-408. [DOI: 10.1038/jid.2015.408] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 09/23/2015] [Accepted: 09/26/2015] [Indexed: 11/09/2022]
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15
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Szabo S, Wögenstein KL, Fuchs P. Functional and Genetic Analysis of Epiplakin in Epithelial Cells. Methods Enzymol 2015; 569:261-85. [PMID: 26778563 DOI: 10.1016/bs.mie.2015.06.018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Epiplakin is a large member (>700 kDa) of the plakin protein family and exclusively expressed in epithelial cell types. Compared to other plakin proteins epiplakin exhibits an unusual structure as it consists entirely of a variable number of consecutive plakin repeat domains (13 in humans, 16 in mice). The only binding partners of epiplakin identified so far are keratins of simple as well as of stratified epithelia. Epiplakin-deficient mice show no obvious spontaneous phenotype. However, ex vivo studies using epiplakin-deficient primary cells indicated protective functions of epiplakin in response to stress. Recent studies using stress models for organs of the gastrointestinal tract revealed that epiplakin-deficient mice develop more pronounced pancreas and liver injuries than their wild-type littermates. In addition, impaired stress-induced keratin network reorganization was observed in the affected organs, and primary epiplakin-deficient hepatocytes showed reduced tolerance for forced keratin overexpression which could be rescued by a chemical chaperone. These findings indicate protective functions of epiplakin in chaperoning disease-induced keratin reorganization. In this review, we describe some of the methods we used to analyze epiplakin's function with the focus on biochemical and ex vivo techniques.
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Affiliation(s)
- Sandra Szabo
- Department of Biochemistry and Cell Biology, Max F. Perutz Laboratories, University of Vienna, Vienna Biocenter (VBC), Vienna, Austria
| | - Karl L Wögenstein
- Department of Biochemistry and Cell Biology, Max F. Perutz Laboratories, University of Vienna, Vienna Biocenter (VBC), Vienna, Austria
| | - Peter Fuchs
- Department of Biochemistry and Cell Biology, Max F. Perutz Laboratories, University of Vienna, Vienna Biocenter (VBC), Vienna, Austria.
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16
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Development of a Novel Green Fluorescent Protein-Based Binding Assay to Study the Association of Plakins with Intermediate Filament Proteins. Methods Enzymol 2015; 569:117-37. [PMID: 26778556 DOI: 10.1016/bs.mie.2015.06.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Protein-protein interactions are fundamental for most biological processes, such as the formation of cellular structures and enzymatic complexes or in signaling pathways. The identification and characterization of protein-protein interactions are therefore essential for understanding the mechanisms and regulation of biological systems. The organization and dynamics of the cytoskeleton, as well as its anchorage to specific sites in the plasma membrane and organelles, are regulated by the plakins. These structurally related proteins anchor different cytoskeletal networks to each other and/or to other cellular structures. The association of several plakins with intermediate filaments (IFs) is critical for maintenance of the cytoarchitecture. Pathogenic mutations in the genes encoding different plakins can lead to dramatic manifestations, occurring principally in the skin, striated muscle, and/or nervous system, due to cytoskeletal disorganization resulting in abnormal cell fragility. Nevertheless, it is still unclear how plakins bind to IFs, although some general rules are slowly emerging. We here describe in detail a recently developed protein-protein fluorescence binding assay, based on the production of recombinant proteins tagged with green fluorescent protein (GFP) and their use as fluid-phase fluorescent ligands on immobilized IF proteins. Using this method, we have been able to assess the ability of C-terminal regions of GFP-tagged plakin proteins to bind to distinct IF proteins and IF domains. This simple and sensitive technique, which is expected to facilitate further studies in this area, can also be potentially employed for any kind of protein-protein interaction studies.
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Szabo S, Wögenstein KL, Österreicher CH, Guldiken N, Chen Y, Doler C, Wiche G, Boor P, Haybaeck J, Strnad P, Fuchs P. Epiplakin attenuates experimental mouse liver injury by chaperoning keratin reorganization. J Hepatol 2015; 62:1357-66. [PMID: 25617501 PMCID: PMC4451473 DOI: 10.1016/j.jhep.2015.01.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Revised: 12/08/2014] [Accepted: 01/05/2015] [Indexed: 12/04/2022]
Abstract
BACKGROUND & AIMS Epiplakin is a member of the plakin protein family and exclusively expressed in epithelial tissues where it binds to keratins. Epiplakin-deficient (Eppk1(-/-)) mice displayed no obvious spontaneous phenotype, but their keratinocytes showed a faster keratin network breakdown in response to stress. The role of epiplakin in the stressed liver remained to be elucidated. METHODS Wild-type (WT) and Eppk1(-/-) mice were subjected to common bile duct ligation (CBDL) or fed with a 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC)-containing diet. The importance of epiplakin during keratin reorganization was assessed in primary hepatocytes. RESULTS Our experiments revealed that epiplakin is expressed in hepatocytes and cholangiocytes, and binds to keratin 8 (K8) and K18 via multiple domains. In several liver stress models epiplakin and K8 genes displayed identical expression patterns and transgenic K8 overexpression resulted in elevated hepatic epiplakin levels. After CBDL and DDC treatment, Eppk1(-/-) mice developed a more pronounced liver injury and their livers contained larger amounts of hepatocellular keratin granules, indicating impaired disease-induced keratin network reorganization. In line with these findings, primary Eppk1(-/-) hepatocytes showed increased formation of keratin aggregates after treatment with the phosphatase inhibitor okadaic acid, a phenotype which was rescued by the chemical chaperone trimethylamine N-oxide (TMAO). Finally, transfection experiments revealed that Eppk1(-/-) primary hepatocytes were less able to tolerate forced K8 overexpression and that TMAO treatment rescued this phenotype. CONCLUSION Our data indicate that epiplakin plays a protective role during experimental liver injuries by chaperoning disease-induced keratin reorganization.
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Affiliation(s)
- Sandra Szabo
- Department of Biochemistry and Cell Biology, Max F. Perutz Laboratories, University of Vienna, Vienna, Austria
| | - Karl L Wögenstein
- Department of Biochemistry and Cell Biology, Max F. Perutz Laboratories, University of Vienna, Vienna, Austria
| | - Christoph H Österreicher
- Institute of Pharmacology, Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Nurdan Guldiken
- Department of Internal Medicine III and IZKF, University Hospital Aachen, Aachen, Germany
| | - Yu Chen
- Department of Internal Medicine III and IZKF, University Hospital Aachen, Aachen, Germany
| | - Carina Doler
- Institute of Pathology, Medical University of Graz, Graz, Austria
| | - Gerhard Wiche
- Department of Biochemistry and Cell Biology, Max F. Perutz Laboratories, University of Vienna, Vienna, Austria
| | - Peter Boor
- Division of Nephrology and Institute of Pathology, RWTH University of Aachen, Aachen, Germany
| | | | - Pavel Strnad
- Department of Internal Medicine III and IZKF, University Hospital Aachen, Aachen, Germany
| | - Peter Fuchs
- Department of Biochemistry and Cell Biology, Max F. Perutz Laboratories, University of Vienna, Vienna, Austria.
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Kumar G, Gotesman M, El-Matbouli M. Interaction of Tetracapsuloides bryosalmonae, the causative agent of proliferative kidney disease, with host proteins in the kidney of Salmo trutta. Parasitol Res 2015; 114:1721-7. [PMID: 25663070 PMCID: PMC4412511 DOI: 10.1007/s00436-015-4357-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Accepted: 01/22/2015] [Indexed: 12/23/2022]
Abstract
Tetracapsuloides bryosalmonae (Myxozoa) is the causative agent of proliferative kidney disease in various species of salmonids which are found in Europe and North America. Less information about the interactions of T. bryosalmonae proteins with salmonid proteins during parasite development is known. In this study, anti-T. bryosalmonae monoclonal antibody-linked to N-hydroxysuccinimide-activated spin columns were used to purify parasite and host proteins from the kidneys of infected and non-infected brown trout (Salmo trutta) Linnaeus, 1758. The samples were next analyzed by electrospray ionization coupled to mass spectrometry to identify proteins that may be involved in the infection and proliferation of T. bryosalmonae within the brown trout host. A total of 6 parasite proteins and 40 different host proteins were identified in this analysis. The identified host proteins function in various processes, which include host defense, enzymatic, and structural components. In conjunction with modern molecular based tools, such siRNA, gene replacement, or gene disruption, this data can ultimately be used to develop novel control methods for T. bryosalmonae, based on the proteins or pathways identified in this study.
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Affiliation(s)
- Gokhlesh Kumar
- Clinical Division of Fish Medicine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria
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Plectin-related skin diseases. J Dermatol Sci 2014; 77:139-45. [PMID: 25530118 DOI: 10.1016/j.jdermsci.2014.11.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Revised: 11/05/2014] [Accepted: 11/12/2014] [Indexed: 12/20/2022]
Abstract
Plectin has been characterized as a linker protein that is expressed in many cell types and is distinctive in various isoforms in the N-terminus and around the rod domain due to complicated alternative splicing of PLEC, the gene encoding plectin. Plectin deficiency causes autosomal recessive epidermolysis bullosa simplex (EBS) with involvement of the skin and other organs, such as muscle and gastrointestinal tract, depending on the expression pattern of the defective protein. In addition, a point mutation in the rod domain of plectin leads to autosomal dominant EBS, called as EBS-Ogna. Plectin can be targeted by circulating autoantibodies in subepidermal autoimmune blistering diseases. This review summarizes plectin-related skin diseases, from congenital to autoimmune disorders.
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20
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Wögenstein KL, Szabo S, Lunova M, Wiche G, Haybaeck J, Strnad P, Boor P, Wagner M, Fuchs P. Epiplakin deficiency aggravates murine caerulein-induced acute pancreatitis and favors the formation of acinar keratin granules. PLoS One 2014; 9:e108323. [PMID: 25232867 PMCID: PMC4169488 DOI: 10.1371/journal.pone.0108323] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2014] [Accepted: 08/19/2014] [Indexed: 11/23/2022] Open
Abstract
Epiplakin, a member of the plakin protein family, is exclusively expressed in epithelial tissues and was shown to bind to keratins. Epiplakin-deficient (EPPK−/−) mice showed no obvious spontaneous phenotype, however, EPPK−/− keratinocytes displayed faster keratin network breakdown in response to stress. The role of epiplakin in pancreas, a tissue with abundant keratin expression, was not yet known. We analyzed epiplakin’s expression in healthy and inflamed pancreatic tissue and compared wild-type and EPPK−/− mice during caerulein-induced acute pancreatitis. We found that epiplakin was expressed primarily in ductal cells of the pancreas and colocalized with apicolateral keratin bundles in murine pancreatic acinar cells. Epiplakin’s diffuse subcellular localization in keratin filament-free acini of K8-deficient mice indicated that its filament-associated localization in acinar cells completely depends on its binding partner keratin. During acute pancreatitis, epiplakin was upregulated in acinar cells and its redistribution closely paralleled keratin reorganization. EPPK−/− mice suffered from aggravated pancreatitis but showed no obvious regeneration phenotype. At the most severe stage of the disease, EPPK−/− acinar cells displayed more keratin aggregates than those of wild-type mice. Our data propose epiplakin to be a protective protein during acute pancreatitis, and that its loss causes impaired disease-associated keratin reorganization.
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Affiliation(s)
- Karl L. Wögenstein
- Department of Biochemistry and Cell Biology, Max F. Perutz Laboratories, University of Vienna, Vienna, Austria
| | - Sandra Szabo
- Department of Biochemistry and Cell Biology, Max F. Perutz Laboratories, University of Vienna, Vienna, Austria
| | - Mariia Lunova
- Department of Internal Medicine III and IZKF, University Hospital Aachen, Aachen, Germany
| | - Gerhard Wiche
- Department of Biochemistry and Cell Biology, Max F. Perutz Laboratories, University of Vienna, Vienna, Austria
| | | | - Pavel Strnad
- Department of Internal Medicine III and IZKF, University Hospital Aachen, Aachen, Germany
| | - Peter Boor
- Division of Nephrology and Institute of Pathology, RWTH University of Aachen, Aachen, Germany
| | - Martin Wagner
- Department of Internal Medicine I, University Medical Center Ulm, Ulm, Germany
| | - Peter Fuchs
- Department of Biochemistry and Cell Biology, Max F. Perutz Laboratories, University of Vienna, Vienna, Austria
- * E-mail:
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Wu G, Clerens S, Farouk MM. LC MS/MS identification of large structural proteins from bull muscle and their degradation products during post mortem storage. Food Chem 2014; 150:137-44. [DOI: 10.1016/j.foodchem.2013.10.158] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2013] [Revised: 10/17/2013] [Accepted: 10/26/2013] [Indexed: 11/25/2022]
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22
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Bouameur JE, Favre B, Borradori L. Plakins, a versatile family of cytolinkers: roles in skin integrity and in human diseases. J Invest Dermatol 2013; 134:885-894. [PMID: 24352042 DOI: 10.1038/jid.2013.498] [Citation(s) in RCA: 90] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Revised: 10/16/2013] [Accepted: 10/25/2013] [Indexed: 11/09/2022]
Abstract
The plakin family consists of giant proteins involved in the cross-linking and organization of the cytoskeleton and adhesion complexes. They further modulate several fundamental biological processes, such as cell adhesion, migration, and polarization or signaling pathways. Inherited and acquired defects of plakins in humans and in animal models potentially lead to dramatic manifestations in the skin, striated muscles, and/or nervous system. These observations unequivocally demonstrate the key role of plakins in the maintenance of tissue integrity. Here we review the characteristics of the mammalian plakin members BPAG1 (bullous pemphigoid antigen 1), desmoplakin, plectin, envoplakin, epiplakin, MACF1 (microtubule-actin cross-linking factor 1), and periplakin, highlighting their role in skin homeostasis and diseases.
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Affiliation(s)
- Jamal-Eddine Bouameur
- Departments of Dermatology and Clinical Research, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland; Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Bertrand Favre
- Departments of Dermatology and Clinical Research, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland.
| | - Luca Borradori
- Departments of Dermatology and Clinical Research, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland
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23
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Parry DAD. Fifty years of fibrous protein research: a personal retrospective. J Struct Biol 2013; 186:320-34. [PMID: 24148884 DOI: 10.1016/j.jsb.2013.10.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Revised: 10/09/2013] [Accepted: 10/11/2013] [Indexed: 02/02/2023]
Abstract
As a result of X-ray fiber diffraction studies on fibrous proteins and crystallographic data on fragments derived from them, new experimental techniques across the biophysical and biochemical spectra, sophisticated computer modeling and refinement procedures, widespread use of bioinformatics and improved specimen preparative procedures the structures of many fibrous proteins have now been determined to at least low resolution. In so doing these structures have yielded insight into the relationship that exists between sequence and conformation and this, in turn, has led to improved methodologies for predicting structure from sequence data alone. In this personal retrospective a selection of progress made during the past 50years is discussed in terms of events to which the author has made some contribution.
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Affiliation(s)
- David A D Parry
- Institute of Fundamental Sciences, Massey University, Private Bag 11-222, Palmerston North 4442, New Zealand.
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Shimada H, Nambu-Niibori A, Wilson-Morifuji M, Mizuguchi S, Araki N, Sumiyoshi H, Sato M, Mezaki Y, Senoo H, Ishikawa K, Hatano Y, Okamoto O, Fujiwara S. Epiplakin modifies the motility of the HeLa cells and accumulates at the outer surfaces of 3-D cell clusters. J Dermatol 2013; 40:249-58. [PMID: 23398049 DOI: 10.1111/1346-8138.12076] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2012] [Accepted: 11/21/2012] [Indexed: 11/27/2022]
Abstract
Elimination of epiplakin (EPPK) by gene targeting in mice results in acceleration of keratinocyte migration during wound healing, suggesting that epithelial cellular EPPK may be important for the regulation of cellular motility. To study the function of EPPK, we developed EPPK knock-down (KD) and EPPK-overexpressing HeLa cells and analyzed cellular phenotypes and motility by fluorescence/differential interference contrast time-lapse microscopy and immunolocalization of actin and vimentin. Cellular motility of EPPK-KD cells was significantly elevated, but that of EPPK-overexpressing cells was obviously depressed. Many spike-like projections were observed on EPPK-KD cells, with fewer such structures on overexpressing cells. By contrast, in EPPK-KD cells, expression of E-cadherin was unchanged but vimentin fibers were thinner and sparser than in controls, and they were more concentrated at the peri-nucleus, as observed in migrating keratinocytes at wound edges in EPPK(-/-) mice. In Matrigel 3-D cultures, EPPK co-localized on the outer surface of cell clusters with zonula occludens-1 (ZO-1), a marker of tight junctions. Our results suggest that EPPK is associated with the machinery for cellular motility and contributes to tissue architecture via the rearrangement of intermediate filaments.
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Affiliation(s)
- Hiromitsu Shimada
- Department of Tumor Genetics and Biology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan
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Suozzi KC, Wu X, Fuchs E. Spectraplakins: master orchestrators of cytoskeletal dynamics. J Cell Biol 2012; 197:465-75. [PMID: 22584905 PMCID: PMC3352950 DOI: 10.1083/jcb.201112034] [Citation(s) in RCA: 138] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2011] [Accepted: 04/23/2012] [Indexed: 01/26/2023] Open
Abstract
The dynamics of different cytoskeletal networks are coordinated to bring about many fundamental cellular processes, from neuronal pathfinding to cell division. Increasing evidence points to the importance of spectraplakins in integrating cytoskeletal networks. Spectraplakins are evolutionarily conserved giant cytoskeletal cross-linkers, which belong to the spectrin superfamily. Their genes consist of multiple promoters and many exons, yielding a vast array of differential splice forms with distinct functions. Spectraplakins are also unique in their ability to associate with all three elements of the cytoskeleton: F-actin, microtubules, and intermediate filaments. Recent studies have begun to unveil their role in a wide range of processes, from cell migration to tissue integrity.
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Affiliation(s)
- Kathleen C. Suozzi
- The Howard Hughes Medical Institute and Laboratory of Mammalian Cell Biology and Development, The Rockefeller University, New York, NY 10065
| | - Xiaoyang Wu
- The Howard Hughes Medical Institute and Laboratory of Mammalian Cell Biology and Development, The Rockefeller University, New York, NY 10065
| | - Elaine Fuchs
- The Howard Hughes Medical Institute and Laboratory of Mammalian Cell Biology and Development, The Rockefeller University, New York, NY 10065
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Matsuo A, Yoshida T, Yasukawa T, Miki R, Kume K, Kume S. Epiplakin1 is expressed in the cholangiocyte lineage cells in normal liver and adult progenitor cells in injured liver. Gene Expr Patterns 2011; 11:255-62. [PMID: 21216305 DOI: 10.1016/j.gep.2011.01.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2010] [Accepted: 01/03/2011] [Indexed: 12/16/2022]
Abstract
We have previously identified Epiplakin1 (Eppk1) as a gene expressed in pancreatic progenitor cells. Here we studied the expression of Eppk1 in developing and regenerating livers in mice. Eppk1 is initially expressed in the early bipotential hepatoblasts and is later confined to the cholangiocytes. After birth, Eppk1 is expressed in the bile duct. In the livers of mice fed with a choline-deficient ethionine-supplemented (CDE) diet, Eppk1-positive cells dramatically increase in number. The Eppk1-positive cells express A6, thereby indicating that they are hepatic progenitor cells. Other cholangiocyte markers, such as Cytokeratins, E-cadherin, osteopontin and Sox9, are also co-expressed in the hepatic progenitor cells. Some of the Eppk1-positive cells express PCNA, a proliferation marker, thereby suggesting their identities as transient amplifying cells. In conclusion, we have shown that Eppk1 serves as a useful marker for detecting the hepatic progenitor population in the developing and adult liver. The use of Eppk1 as a marker will facilitate studies of mouse hepatic progenitor cells.
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Affiliation(s)
- Akira Matsuo
- Department of Stem Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, Honjo 2-2-1, Kumamoto 860-0811, Japan
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Ishikawa K, Sumiyoshi H, Matsuo N, Takeo N, Goto M, Okamoto O, Tatsukawa S, Kitamura H, Fujikura Y, Yoshioka H, Fujiwara S. Epiplakin accelerates the lateral organization of keratin filaments during wound healing. J Dermatol Sci 2010; 60:95-104. [PMID: 20926261 DOI: 10.1016/j.jdermsci.2010.08.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2010] [Revised: 08/03/2010] [Accepted: 08/25/2010] [Indexed: 11/16/2022]
Abstract
BACKGROUND Epiplakin (EPPK) belongs to the plakin family of cytolinker proteins and, resembling other members of the plakin family such as BPAG1 (an autoantigen of bullous pemphigoid) and plectin, EPPK has plakin repeat domains (PRDs) that bind to intermediate filaments. Elimination of EPPK by gene targeting in mice resulted in the acceleration of keratinocyte migration during wound healing. EPPK is expressed in proliferating keratinocytes at wound edges and, in view of its putative function in binding to keratin, we postulated that the keratin network in EPPK-null (EPPK(-/-)) mice might be disrupted during wound healing. OBJECTIVE To examine this hypothesis and to determine the precise localization of EPPK in relation to keratin filaments, we compared the non-wounded and wounded epidermis of wild-type and EPPK(-/-) mice. METHODS Non-wounded epidermis and wounded epidermis from wild-type and EPPK(-/-) mice were examined by immunofluorescence staining and electron microscopy before and after double immunostaining. RESULTS EPPK was colocalized with keratin 17 (K17) more extensively than with other keratins examined in wounded epidermis. The expression of K5, K10, K6, and K17 was the same in EPPK(-/-) mice after wounding as in normal mice, but diameters of keratin filaments were reduced in EPPK(-/-) keratinocytes. Electron microscopy after immunostaining revealed that EPPK colocalized with K5, K10 and K6 after wounding in wild-type mice. CONCLUSION Our data indicate that EPPK accelerates keratin bundling in proliferating keratinocytes during wound healing and suggest that EPPK might contribute to reinforcement of keratin networks under mechanical stress.
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Affiliation(s)
- Kazushi Ishikawa
- Department of Dermatology, Faculty of Medicine, Oita University, Hasama-machi, Oita, Japan
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Rezniczek GA, Walko G, Wiche G. Plectin gene defects lead to various forms of epidermolysis bullosa simplex. Dermatol Clin 2010; 28:33-41. [PMID: 19945614 DOI: 10.1016/j.det.2009.10.004] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Plectin is an important organizer of the keratin filament cytoskeleton in basal keratinocytes. It is essential for anchoring these filaments to the extracellular matrix via hemidesmosomal integrins. Loss of plectin or incorrect function of the protein due to mutations in its gene can lead to various forms of the skin blistering disease, epidermolysis bullosa simplex. Severity and subtype of the disease is dependent on the specific mutation and can be associated with (late-onset) muscular dystrophy or pyloric atresia. Mouse models mimicking the human phenotypes allow detailed study of plectin function.
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Affiliation(s)
- Günther A Rezniczek
- Department of Biochemistry and Cell Biology, Max F. Perutz Laboratories, University of Vienna, Dr.-Bohr-Gasse 9, 1030 Vienna, Austria
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Yoshida T, Guo X, Namekata K, Mitamura Y, Kume S, Harada T. Expression of Epiplakin1 in the developing and adult mouse retina. Jpn J Ophthalmol 2010; 54:85-8. [DOI: 10.1007/s10384-009-0751-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2009] [Accepted: 08/31/2009] [Indexed: 11/30/2022]
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Exclusion of EGFR, HRAS, DSP, JUP, CTNNB1, PLEC1, and EPPK1 as functional candidate genes in 7 families with syndromic diarrhoea. J Pediatr Gastroenterol Nutr 2009; 48:501-3. [PMID: 19322062 DOI: 10.1097/mpg.0b013e3181846aab] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
Syndromic diarrhoea (SD) is a rare disease associating intractable diarrhoea and hair abnormalities. In an attempt to identify the gene causative for SD, we studied several functional candidate genes, based on their implication in overlapping phenotypes in mice (EGFR) or in humans (HRAS, JUP, DSP EPPK1, PLEC1, and CTNNB1) in 8 patients affected by SD. Except for EGFR and HRAS, all selected genes encode for cell adhesion proteins. Using direct sequencing or linkage analysis, we excluded all of the candidate genes as the disease-causing gene in our group of patients; however, the hypothesis of intercellular junctions defect in SD remains seductive.
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Yoshida T, Shiraki N, Baba H, Goto M, Fujiwara S, Kume K, Kume S. Expression patterns of epiplakin1 in pancreas, pancreatic cancer and regenerating pancreas. Genes Cells 2008; 13:667-78. [PMID: 18498355 DOI: 10.1111/j.1365-2443.2008.01196.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Epiplakin1 (Eppk1) is a plakin family gene with its function remains largely unknown, although the plakin genes are known to function in interconnecting cytoskeletal filaments and anchoring them at plasma membrane-associated adhesive junction. Here we analyzed the expression patterns of Eppk1 in the developing and adult pancreas in the mice. In the embryonic pancreas, Eppk1+/Pdx1+ and Eppk1+/Sox9+ pancreatic progenitor cells were observed in early pancreatic epithelium. Since Pdx1 expression overlapped with that of Sox9 at this stage, these multipotent progenitor cells are Eppk1+/Pdx1+/Sox9+ cells. Then Eppk1 expression becomes confined to Ngn3+ or Sox9+ endocrine progenitor cells, and p48+ exocrine progenitor cells, and then restricted to the duct cells and a cells at birth. In the adult pancreas, Eppk1 is expressed in centroacinar cells (CACs) and in duct cells. Eppk1 is observed in pancreatic intraepithelial neoplasia (PanIN), previously identified as pancreatic ductal adenocarcinoma (PDAC) precursor lesions. In addition, the expansion of Eppk1-positive cells occurs in a caerulein-induced acute pancreatitis, an acinar cell regeneration model. Furthermore, in the partial pancreatectomy (Px) regeneration model using mice, Eppk1 is expressed in "ducts in foci", a tubular structure transiently induced. These results suggest that Eppk1 serves as a useful marker for detecting pancreatic progenitor cells in developing and regenerating pancreas.
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Affiliation(s)
- Tetsu Yoshida
- Division of Stem Cell Biology, Department of Regeneration Medicine, Institute of Molecular Embryology and Genetics, Japan
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32
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Spazierer D, Raberger J, Gross K, Fuchs P, Wiche G. Stress-induced recruitment of epiplakin to keratin networks increases their resistance to hyperphosphorylation-induced disruption. J Cell Sci 2008; 121:825-33. [PMID: 18285451 DOI: 10.1242/jcs.013755] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Epiplakin is a large (>725 kDa) cytoskeletal protein exclusively expressed in epithelial tissues. It has a unique structure, consisting entirely of plakin repeat domains (PRDs), one of the hallmarks of spectraplakin protein family members. Previous studies, including the phenotypic analyses of knockout mice, failed to reveal the biological function of epiplakin. Using in vitro binding assays, we show here that all but one of the 16 PRDs of mouse epiplakin bind to keratins of basal keratinocytes. Nevertheless, in primary keratinocyte cell cultures, epiplakin only partially colocalized with keratin intermediate filament networks. However, upon application of cellular stress in the form of keratin hyperphosphorylation, osmotic shock or UV irradiation, the entire cytoplasmic epiplakin pool became associated with keratin. In response to such types of stress, epiplakin initially translocated to the still-intact keratin filament network and remained associated with keratin after its disruption and transformation into granular aggregates. Time-course experiments revealed that serine/threonine (okadaic acid) and tyrosine (orthovanadate) phosphatase inhibitor-induced filament disruption in differentiated keratinocytes proceeded faster in epiplakin-deficient cells compared with wild-type cells. Our data suggest that epiplakin plays a role in keratin filament reorganization in response to stress, probably by protecting keratin filaments against disruption in a chaperone-like fashion.
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Affiliation(s)
- Daniel Spazierer
- Department of Molecular Cell Biology, Max F. Perutz Laboratories, University of Vienna, A-1030 Vienna, Austria
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Lien HC, Hsiao YH, Lin YS, Yao YT, Juan HF, Kuo WH, Hung MC, Chang KJ, Hsieh FJ. Molecular signatures of metaplastic carcinoma of the breast by large-scale transcriptional profiling: identification of genes potentially related to epithelial-mesenchymal transition. Oncogene 2007; 26:7859-71. [PMID: 17603561 DOI: 10.1038/sj.onc.1210593] [Citation(s) in RCA: 155] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Metaplastic carcinoma of the breast (MCB) is a poorly understood subtype of breast cancer. It is generally characterized by the coexistence of ductal carcinomatous and transdifferentiated sarcomatous components, but the underlying molecular alterations, possibly related to epithelial-mesenchymal transition (EMT), remain elusive. We performed transcriptional profiling using half-a-genome oligonucleotide microarrays to elucidate genetic profiles of MCBs and their differences to those of ductal carcinoma of breasts (DCBs) using discarded specimens of four MCBs and 34 DCBs. Unsupervised clustering disclosed distinctive expression profiles between MCBs and DCBs. Supervised analysis identified gene signatures discriminating MCBs from DCBs and between MCB subclasses. Notably, many of the discriminator genes were associated with downregulation of epithelial phenotypes and with synthesis, remodeling and adhesion of extracellular matrix, with some of them have known or inferred roles related to EMT. Importantly, several of the discriminator genes were upregulated in a mutant Snail-transfected MCF7 cell known to exhibit features of EMT, thereby indicating a crucial role for EMT in the pathogenesis of MCBs. Finally, the identification of SPARC and vimentin as poor prognostic factors reinforced the role of EMT in cancer progression. These data advance our understanding of MCB and offer clues to the molecular alterations underlying EMT.
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Affiliation(s)
- H C Lien
- Department of Pathology, College of Medicine, National Taiwan University, Taipei, Taiwan
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Sonnenberg A, Liem RKH. Plakins in development and disease. Exp Cell Res 2007; 313:2189-203. [PMID: 17499243 DOI: 10.1016/j.yexcr.2007.03.039] [Citation(s) in RCA: 228] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2007] [Revised: 03/01/2007] [Accepted: 03/06/2007] [Indexed: 11/22/2022]
Abstract
Plakins are large multi-domain molecules that have various functions to link cytoskeletal elements together and to connect them to junctional complexes. Plakins were first identified in epithelial cells where they were found to connect the intermediate filaments to desmosomes and hemidesmosomes [Ruhrberg, C., and Watt, F.M. (1997). The plakin family: versatile organizers of cytoskeletal architecture. Curr Opin Genet Dev 7, 392-397.]. They were subsequently found to be important for the integrity of muscle cells. Most recently, they have been found in the nervous system, where their functions appear to be more complex, including cross-linking of microtubules (MTs) and actin filaments [Leung, C.L., Zheng, M., Prater, S.M., and Liem, R.K. (2001). The BPAG1 locus: Alternative splicing produces multiple isoforms with distinct cytoskeletal linker domains, including predominant isoforms in neurons and muscles. J Cell Biol 154, 691-697., Leung, C.L., Sun, D., Zheng, M., Knowles, D.R., and Liem, R.K. (1999). Microtubule actin cross-linking factor (MACF): a hybrid of dystonin and dystrophin that can interact with the actin and microtubule cytoskeletons. J Cell Biol 147, 1275-1286.]. These plakins have also indicated their relationship to the spectrin superfamily of proteins and the plakins appear to be evolutionarily related to the spectrins, but have diverged to perform different specialized functions. In invertebrates, a single plakin is present in both Drosophila melanogaster and Caenorhabditis elegans, which resemble the more complex plakins found in mammals [Roper, K., Gregory, S.L., and Brown, N.H. (2002). The 'spectraplakins': cytoskeletal giants with characteristics of both spectrin and plakin families. J Cell Sci 115, 4215-4225.]. In contrast, there are seven plakins found in mammals and most of them have alternatively spliced forms leading to a very complex group of proteins with potential tissue specific functions [Jefferson, J.J., Leung, C.L., and Liem, R.K. (2004). Plakins: goliaths that link cell junctions and the cytoskeleton. Nat Rev Mol Cell Biol 5, 542-553.]. In this review, we will first describe the plakins, desmoplakin, plectin, envoplakin and periplakin and then describe two other mammalian plakins, Bullous pemphigoid antigen 1 (BPAG1) and microtubule actin cross-linking factor 1 (MACF1), that are expressed in multiple isoforms in different tissues. We will also describe the relationship of these two proteins to the invertebrate plakins, shortstop (shot) in Drosophila and VAB-10 in C. elegans. Finally, we will describe an unusual mammalian plakin, called epiplakin.
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Affiliation(s)
- Arnoud Sonnenberg
- Division of Cell Biology, The Netherlands Cancer Inst., Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands.
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Mendoza G, Pemberton TJ. A new locus for autosomal dominant amelogenesis imperfecta on chromosome 8q24.3. Hum Genet 2007; 120:653-62. [PMID: 17024372 PMCID: PMC6174526 DOI: 10.1007/s00439-006-0246-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2006] [Accepted: 08/14/2006] [Indexed: 10/24/2022]
Abstract
Amelogenesis imperfecta (AI) is a collective term used to describe phenotypically diverse forms of defective tooth enamel development. AI has been reported to exhibit a variety of inheritance patterns, and several loci have been identified that are associated with AI. We have performed a genome-wide scan in a large Brazilian family segregating an autosomal dominant form of AI and mapped a novel locus to 8q24.3. A maximum multipoint LOD score of 7.5 was obtained at marker D8S2334 (146,101,309 bp). The disease locus lies in a 1.9 cM (2.1 Mb) region according to the Rutgers Combined Linkage-Physical map, between a VNTR marker (at 143,988,705 bp) and the telomere (146,274,826 bp). Ten candidate genes were identified based on gene ontology and microarray-facilitated gene selection using the expression of murine orthologues in dental tissue, and examined for the presence of a mutation. However, no causative mutation was identified.
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Affiliation(s)
- Gustavo Mendoza
- Institute for Genetic Medicine, University of Southern California, 2250 Alcazar Street, CSC-240, Los Angeles, CA 90033, USA
| | - Trevor J. Pemberton
- Institute for Genetic Medicine, University of Southern California, 2250 Alcazar Street, CSC-240, Los Angeles, CA 90033, USA
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Abstract
Epiplakin, a cytoskeletal linker protein, was originally identified as an autoantigen in a serum specimen obtained from a patient with subepidermal blistering disease. To examine the binding ability of epiplakin with intermediate filaments (IF), we performed slot-blot assays using fusion proteins that included various domains and subdomains of epiplakin. At least two of the 4.6 copies in the B domains of epiplakin were necessary for the binding of fusion proteins to keratin. The repeated structures of linker domains also played an important role in the binding of epiplakin to keratin in these assays while also increasing the repeated structure in the linker domain of epiplakin which is involved in the increased binding to IF. A similar but weaker binding to vimentin and desmin was also detected. These observations indicated that the highly repeated structures of epiplakin in both the B and the linker domains, which is the unique feature of this molecule in the plakin family, play an essential role in the functioning of this molecule.
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Affiliation(s)
- Wenqing Wang
- Department of Anatomy, Biology and Medicine (Dermatology), Faculty of Medicine, Oita University, Hasama-machi, Yufu, Japan
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37
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Spazierer D, Fuchs P, Reipert S, Fischer I, Schmuth M, Lassmann H, Wiche G. Epiplakin is dispensable for skin barrier function and for integrity of keratin network cytoarchitecture in simple and stratified epithelia. Mol Cell Biol 2006; 26:559-68. [PMID: 16382147 PMCID: PMC1346901 DOI: 10.1128/mcb.26.2.559-568.2006] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Epiplakin, a giant epithelial protein of >700 kDa, belongs to the plakin family of cytolinker proteins. It represents an atypical family member, however, as it consists entirely of plakin repeat domains but lacks any of the other domains commonly shared by plakins. Hence, its putative function as a cytolinker protein remains to be shown. To investigate epiplakin's biological role, we generated epiplakin-deficient mice by gene targeting in embryonic stem cells. Epiplakin-deficient mice were viable and fertile, without developing any discernible phenotype. Ultrastructurally, their epidermis revealed no differences compared to wild-type littermates, and cornified envelopes isolated from skin showed no alterations in shape or stability. Furthermore, neither embryonal formation nor later function of the epithelial barrier was affected. In primary cultures of epiplakin-deficient keratinocytes, the organization of actin filaments, microtubules, and keratin networks was found to be normal. Similarly, no alterations in keratin network organization were observed in simple epithelia of small intestine and liver or in primary hepatocytes. We conclude that, despite epiplakin's abundant and highly specific expression in stratified and simple epithelia, its absence in mice does not lead to severe skin dysfunctions, nor has it detectable consequences for keratin filament organization and cytoarchitecture of cells.
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Affiliation(s)
- Daniel Spazierer
- Department of Molecular Cell Biology, Max F. Perutz Laboratories, University of Vienna, Dr. Bohrgasse 9, A-1030 Vienna, Austria
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Goto M, Sumiyoshi H, Sakai T, Fässler R, Ohashi S, Adachi E, Yoshioka H, Fujiwara S. Elimination of epiplakin by gene targeting results in acceleration of keratinocyte migration in mice. Mol Cell Biol 2006; 26:548-58. [PMID: 16382146 PMCID: PMC1346887 DOI: 10.1128/mcb.26.2.548-558.2006] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Epiplakin (EPPK) was originally identified as a human epidermal autoantigen. To identify the function of epiplakin, we generated epiplakin "knockout" mice. These mice developed normally, with apparently normal epidermis and hair. Electron microscopy after immunostaining revealed the presence of EPPK adjacent to keratin filaments in wild-type mice, suggesting that epiplakin might associate with keratin. The appearance and localization of keratin bundles in intact epidermal keratinocytes of EPPK-/- mice were similar to those in wild-type mice. Wounds on the backs of EPPK-/- mice closed more rapidly than those on the backs of wild-type and heterozygous mice. The outgrowth of keratinocytes from skin explants from knockout mice was enhanced compared to outgrowth from explants from wild-type mice, even in the presence of mitomycin C, suggesting that the difference in keratinocyte outgrowth might be due to a difference in the speed of migration of keratinocytes. At wound edges in wild-type mice, EPPK was expressed in proliferating keratinocytes in conjunction with keratin 6. In EPPK-/- mice, no similar proliferating keratinocytes were observed, but migrating keratinocytes weakly expressed keratin 6. EPPK was coexpressed with keratin 6 in some keratinocytes in explant cultures from wild mice. We propose that EPPK might be linked functionally with keratin 6.
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Affiliation(s)
- Mizuki Goto
- Department of Anatomy, Biology and Medicine (Dermatology and Biochemistry), Faculty of Medicine, Oita University, Idaigaoka 1-1, Hasama-machi, Yufu 879-5593, Japan
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Lin CM, Chen HJ, Leung CL, Parry DAD, Liem RKH. Microtubule actin crosslinking factor 1b: a novel plakin that localizes to the Golgi complex. J Cell Sci 2005; 118:3727-38. [PMID: 16076900 DOI: 10.1242/jcs.02510] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
MACF1 (microtubule actin crosslinking factor), also called ACF7 (actin crosslinking family 7) is a cytoskeletal linker protein that can associate with both actin filaments and microtubules. We have identified a novel alternatively spliced isoform of MACF1. We named this isoform MACF1b and renamed the original isoform MACF1a. MACF1b is identical to MACF1a, except that it has a region containing plakin (or plectin) repeats in the middle of the molecule. MACF1b is ubiquitously expressed in adult tissues with especially high levels in the lung. We studied the subcellular localization of MACF1b proteins in mammalian cell lines. In two lung cell lines, MACF1b was chiefly localized to the Golgi complex. Upon treatments that disrupt the Golgi complex, MACF1b redistributed into the cytosol, but remained co-localized with the dispersed Golgi ministacks. MACF1b proteins can be detected in the enriched Golgi fraction by western blotting. The domain of MACF1b that targets it to the Golgi was found at the N-terminal part of the region that contains the plakin repeats. Reducing the level of MACF1 proteins by small-interfering RNA resulted in the dispersal of the Golgi complex.
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Affiliation(s)
- Chung-Ming Lin
- Department of Pathology, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA
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Jang SI, Kalinin A, Takahashi K, Marekov LN, Steinert PM. Characterization of human epiplakin: RNAi-mediated epiplakin depletion leads to the disruption of keratin and vimentin IF networks. J Cell Sci 2005; 118:781-93. [PMID: 15671067 DOI: 10.1242/jcs.01647] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Epiplakin is a member of the plakin family with multiple copies of the plakin repeat domain (PRD). We studied the subcellular distribution and interactions of human epiplakin by immunostaining, overlay assays and RNAi knockdown. Epiplakin decorated the keratin intermediate filaments (IF) network and partially that of vimentin. In the binding assays, the repeat unit (PRD plus linker) showed strong binding and preferentially associated with assembled IF over keratin monomers. Epiplakin knockdown revealed disruption of IF networks in simple epithelial but not in epidermal cells. In rescue experiments, the repeat unit was necessary to prevent the collapse of IF networks in transient knockdown; however, it could only partially restore the keratin but not the vimentin IF network in stably knocked down HeLa cells. We suggest that epiplakin is a cytolinker involved in maintaining the integrity of IF networks in simple epithelial cells. Furthermore, we observed an increase of epiplakin expression in keratinocytes after the calcium switch, suggesting the involvement of epiplakin in the process of keratinocyte differentiation.
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Affiliation(s)
- Shyh-Ing Jang
- Laboratory of Skin Biology, NIAMS, National Institutes of Health, Bethesda, MD 20892-8023, USA
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Green KJ, Böhringer M, Gocken T, Jones JCR. Intermediate filament associated proteins. ADVANCES IN PROTEIN CHEMISTRY 2005; 70:143-202. [PMID: 15837516 DOI: 10.1016/s0065-3233(05)70006-1] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Intermediate filament associated proteins (IFAPs) coordinate interactions between intermediate filaments (IFs) and other cytoskeletal elements and organelles, including membrane-associated junctions such as desmosomes and hemidesmosomes in epithelial cells, costameres in striated muscle, and intercalated discs in cardiac muscle. IFAPs thus serve as critical connecting links in the IF scaffolding that organizes the cytoplasm and confers mechanical stability to cells and tissues. However, in recent years it has become apparent that IFAPs are not limited to structural crosslinkers and bundlers but also include chaperones, enzymes, adapters, and receptors. IF networks can therefore be considered scaffolding upon which associated proteins are organized and regulated to control metabolic activities and maintain cell homeostasis.
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Affiliation(s)
- Kathleen J Green
- Departments of Pathology and Dermatology and R.H. Lurie Cancer Center, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA
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Parry DAD. Structural and functional implications of sequence repeats in fibrous proteins. ADVANCES IN PROTEIN CHEMISTRY 2005; 70:11-35. [PMID: 15837512 DOI: 10.1016/s0065-3233(05)70002-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The amino acid sequences of increasingly large proteins have been determined in recent years, and it has become more and more apparent that within these sequences nature has employed only a finite number of structural?functional motifs. These may be strung along the sequence in tandem and, in some cases, several hundred times. In other instances, the positions of the motifs show little obvious order as regards to their relative linear arrangement within the sequence. The observed sequence repeats have been shown to vary in size over at least two orders of magnitude. It is shown here that the repeats can readily be classified on the basis of character, and five distinct groups have been identified. The first of these (Type A) represents those motifs that are fixed in length and conserved absolutely in sequence (>99%); the second (Type B) includes motifs that are also fixed in length, but where absolute sequence conservation occurs only in some positions of the repeat. The third category (Type C) contains fixed length motifs, but the character of only some of the positions in the motif is maintained. The fourth group (Type D) includes motifs that have nonintegral lengths. The fifth class (Type E) contains motifs, often displaying some variations in their lengths even within a single species, which maintain a discrete structural form related directly to their function. Examples are presented for each category of repeat, and these are drawn almost exclusively from the fibrous proteins and those proteins that are normally associated with them in vivo.
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Affiliation(s)
- David A D Parry
- Institute of Fundamental Sciences, Massey University, Palmerston North 5301, New Zealand
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43
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Takeo N, Wang W, Matsuo N, Sumiyoshi H, Yoshioka H, Fujiwara S. Structure and heterogeneity of the human gene for epiplakin (EPPK1). J Invest Dermatol 2004; 121:1224-6. [PMID: 14708632 DOI: 10.1046/j.1523-1747.2003.12550_5.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Koster J, Borradori L, Sonnenberg A. Hemidesmosomes: molecular organization and their importance for cell adhesion and disease. Handb Exp Pharmacol 2004:243-280. [PMID: 20455096 DOI: 10.1007/978-3-540-68170-0_9] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
In the skin, basal epithelial cells constantly divide to renew the epidermis. The newly formed epithelial cells then differentiate in a process called keratinization, ultimately leading to the death of these cells and a pile-up of cell material containing vast amounts of keratins. The basal keratinocytes in skin are attached to their underlying basement membrane via specialized adhesion complexes termed hemidesmosomes (HDs). These complexes ascertain stable adhesion of the epidermis to the dermis, and mutations in components of these complexes often result in tissue fragility and blistering of the skin. In this review, we will describe the various hemidesmosomal proteins in detail as well as, briefly, the protein families to which they belong. Specifically, we will report the protein-protein interactions involved in the assembly of hemidesmosomes and their molecular organization. Some signaling pathways involving primarily the alpha6beta4 integrin will be discussed, since they appear to profoundly modulate the assembly and function of hemidesmosomes. Furthermore, the importance of these hemidesmosomal components for the maintenance of tissue homeostasis and their involvement in various clinical disorders will be emphasized. Finally, we will present a model for the assembly of HDs, based on our present knowledge.
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Affiliation(s)
- J Koster
- Division of Cell Biology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands
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Steinert PM, Parry DAD, Marekov LN. Trichohyalin mechanically strengthens the hair follicle: multiple cross-bridging roles in the inner root shealth. J Biol Chem 2003; 278:41409-19. [PMID: 12853460 DOI: 10.1074/jbc.m302037200] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Trichohyalin is expressed in specialized epithelia that are unusually mechanically strong, such as the inner root sheath cells of the hair follicle. We have previously shown that trichohyalin is sequentially subjected to post-synthetic modifications by peptidylarginine deaminases, which convert many of its arginines to citrullines, and by transglutaminases, which introduce intra- and interprotein chain cross-links. Here we have characterized in detail the proteins to which it becomes cross-linked in vivo in the inner root sheath of the mouse hair follicle. We suggest that it has three principal roles. First, it serves as an interfilamentous matrix protein by becoming cross-linked both to itself and to the head and tail end domains of the inner root sheath keratin intermediate filament chains. A new antibody reveals that arginines of the tail domains of the keratins are modified to citrullines before cross-linking, which clarifies previous studies. Second, trichohyalin serves as a cross-bridging reinforcement protein of the cornified cell envelope of the inner root sheath cells by becoming cross-linked to several known or novel barrier proteins, including involucrin, small proline-rich proteins, repetin, and epiplakin. Third, it coordinates linkage between the keratin filaments and cell envelope to form a seamless continuum. Together, our new data document that trichohyalin is a multi-functional cross-bridging protein that functions in the inner root sheath and perhaps in other specialized epithelial tissues by conferring to and coordinating mechanical strength between their peripheral cell envelope barrier structures and their cytoplasmic keratin filament networks.
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Affiliation(s)
- Peter M Steinert
- Laboratory of Skin Biology, NIAMS, National Institutes of Health, Bethesda, Maryland 20892-8023, USA
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Herrmann H, Hesse M, Reichenzeller M, Aebi U, Magin TM. Functional complexity of intermediate filament cytoskeletons: from structure to assembly to gene ablation. INTERNATIONAL REVIEW OF CYTOLOGY 2003; 223:83-175. [PMID: 12641211 DOI: 10.1016/s0074-7696(05)23003-6] [Citation(s) in RCA: 150] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The cell biology of intermediate filament (IF) proteins and their filaments is complicated by the fact that the members of the gene family, which in humans amount to at least 65, are differentially expressed in very complex patterns during embryonic development. Thus, different tissues and cells express entirely different sets and amounts of IF proteins, the only exception being the nuclear B-type lamins, which are found in every cell. Moreover, in the course of evolution the individual members of this family have, within one species, diverged so much from each other with regard to sequence and thus molecular properties that it is hard to envision a unifying kind of function for them. The known epidermolytic diseases, caused by single point mutations in keratins, have been used as an argument for a role of IFs in mechanical "stress resistance," something one would not have easily ascribed to the beaded chain filaments, a special type of IF in the eye lens, or to nuclear lamins. Therefore, the power of plastic dish cell biology may be limited in revealing functional clues for these structural elements, and it may therefore be of interest to go to the extreme ends of the life sciences, i.e., from the molecular properties of individual molecules including their structure at the atomic level to targeted inactivation of their genes in living animals, mouse, and worm to define their role more precisely in metazoan cell physiology.
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Affiliation(s)
- Harald Herrmann
- Division of Cell Biology, German Cancer Research Center, D-69120 Heidelberg, Germany
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Spazierer D, Fuchs P, Pröll V, Janda L, Oehler S, Fischer I, Hauptmann R, Wiche G. Epiplakin gene analysis in mouse reveals a single exon encoding a 725-kDa protein with expression restricted to epithelial tissues. J Biol Chem 2003; 278:31657-66. [PMID: 12791695 DOI: 10.1074/jbc.m303055200] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Based on cDNA cloning and sequencing, human epiplakin has been classified as a member of the plakin protein family of cytolinkers. We report here the characterization of the mouse epiplakin gene locus and the isolation of full-length mouse epiplakin cDNA using BAC vectors. We found that the protein is encoded by a single remarkably large exon (>20 kb) that consists of a series of 0.8-1.5-kb-long DNA repeats, eight of which are virtually identical. Consequently, mouse epiplakin contains 16 plakin repeat domains, three more than reported for the human protein and eight more than predicted for the mouse protein based on the contig characterized by the Mouse Genome Sequencing Consortium. Using antibodies raised to a highly conserved repeating epiplakin sequence domain, we show that the protein in cells is expressed in its full length (725 kDa), and we provide evidence that the size of human epiplakin previously may have been underestimated. In addition we show on transcript and protein levels that epiplakin is restricted to epithelial tissues and that its gene maps to mouse chromosome 15 (human chromosome 8). This study lays the groundwork for future genetic approaches aimed at defining the biological role of this unique protein.
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Affiliation(s)
- Daniel Spazierer
- Vienna Biocenter, Institute of Biochemistry and Molecular Cell Biology, University of Vienna, A-1030 Vienna, Austria
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Fujii T, Kunimatsu M. Interaction of protein-bound polysaccharide (PSK) with smooth muscle myosin regulatory light chain. Biol Pharm Bull 2003; 26:771-4. [PMID: 12808284 DOI: 10.1248/bpb.26.771] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The interaction of a protein-bound polysaccharide (PSK) isolated from Basidiomycetes with smooth muscle myosin components was evaluated by limited digestion, urea/glycerol gel electrophoresis, affinity chromatography and overlay assay using a peptide array. PSK was bound to the regulatory light chain (RLC) of myosin, but not to the essential light chain. The binding to PSK was definitely observed for unphosphorylated RLC, compared to phosphorylated one. From the amino acid sequence of the RLC, 490 peptides were synthesized on a cellulose membrane. Overlay assays showed that the PSK-binding on the molecule of RLC were localized in the N- and C-terminal basic regions and these sites were conserved in RLC from the human smooth muscle and nonmuscle cells.
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Affiliation(s)
- Toshihiro Fujii
- Department of Kansei Engineering, Faculty of Textile Science and Technology, Shinshu University, Ueda, Nagano 386-8567, Japan.
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Karashima T, Watt FM. Interaction of periplakin and envoplakin with intermediate filaments. J Cell Sci 2002; 115:5027-37. [PMID: 12432088 DOI: 10.1242/jcs.00191] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Periplakin is a component of desmosomes and the epidermal cornified envelope. Its N-terminal domain interacts with the plasma membrane; it heterodimerises with envoplakin via its rod domain; and its C-terminus interacts with intermediate filaments. Periplakin has the shortest C-terminus of the plakin family, comprising only the linker domain found in all conventional plakins. By transient transfection of COS7 cells and primary human epidermal keratinocytes with deletion mutants of the periplakin C-terminus we mapped sequences required for intermediate filament interaction to two regions of the linker motif that are most highly conserved amongst the plakins. The results were confirmed by overlay assays of the binding of in vitro translated periplakin constructs to keratins and vimentin. We found that envoplakin and periplakin could still associate with each other when parts of their rod domains were deleted and, surprisingly, that removal of the entire rod domain did not completely inhibit their interaction. Co-transfection of constructs containing the C-termini of envoplakin and periplakin suggested that the periplakin C-terminus may stabilise the interaction of the envoplakin C-terminus with intermediate filaments. We conclude that the periplakin C-terminus plays an important role in linking periplakin and envoplakin to intermediate filaments.
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Affiliation(s)
- Tadashi Karashima
- Keratinocyte Laboratory, Cancer Research UK, 44 Lincoln's Inn Fields, London WC2A 3PX, UK
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