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Yu T, Matsuda M. Epb41l5 interacts with Iqcb1 and regulates ciliary function in zebrafish embryos. J Cell Sci 2020; 133:jcs240648. [PMID: 32501287 PMCID: PMC7338265 DOI: 10.1242/jcs.240648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Accepted: 05/13/2020] [Indexed: 11/20/2022] Open
Abstract
Erythrocyte protein band 4.1 like 5 (EPB41L5) is an adaptor protein beneath the plasma membrane that functions to control epithelial morphogenesis. Here we report a previously uncharacterized role of EPB41L5 in controlling ciliary function. We found that EPB41L5 forms a complex with IQCB1 (previously known as NPHP5), a ciliopathy protein. Overexpression of EPB41L5 reduced IQCB1 localization at the ciliary base in cultured mammalian epithelial cells. Conversely, epb41l5 knockdown increased IQCB1 localization at the ciliary base. epb41l5-deficient zebrafish embryos or embryos expressing C-terminally modified forms of Epb41l5 developed cilia with reduced motility and exhibited left-right patterning defects, an outcome of abnormal ciliary function. We observed genetic synergy between epb41l5 and iqcb1. Moreover, EPB41L5 decreased IQCB1 interaction with CEP290, another ciliopathy protein and a component of the ciliary base and centrosome. Together, these observations suggest that EPB41L5 regulates the composition of the ciliary base and centrosome through IQCB1 and CEP290.
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Affiliation(s)
- Tiffany Yu
- Department of Cell Biology and Molecular Medicine, Rutgers New Jersey Medical School, Newark, NJ 07302, USA
| | - Miho Matsuda
- Department of Cell Biology and Molecular Medicine, Rutgers New Jersey Medical School, Newark, NJ 07302, USA
- Department of Cell, Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
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Retinogenesis of the Human Fetal Retina: An Apical Polarity Perspective. Genes (Basel) 2019; 10:genes10120987. [PMID: 31795518 PMCID: PMC6947654 DOI: 10.3390/genes10120987] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 11/25/2019] [Accepted: 11/26/2019] [Indexed: 12/20/2022] Open
Abstract
The Crumbs complex has prominent roles in the control of apical cell polarity, in the coupling of cell density sensing to downstream cell signaling pathways, and in regulating junctional structures and cell adhesion. The Crumbs complex acts as a conductor orchestrating multiple downstream signaling pathways in epithelial and neuronal tissue development. These pathways lead to the regulation of cell size, cell fate, cell self-renewal, proliferation, differentiation, migration, mitosis, and apoptosis. In retinogenesis, these are all pivotal processes with important roles for the Crumbs complex to maintain proper spatiotemporal cell processes. Loss of Crumbs function in the retina results in loss of the stratified appearance resulting in retinal degeneration and loss of visual function. In this review, we begin by discussing the physiology of vision. We continue by outlining the processes of retinogenesis and how well this is recapitulated between the human fetal retina and human embryonic stem cell (ESC) or induced pluripotent stem cell (iPSC)-derived retinal organoids. Additionally, we discuss the functionality of in utero and preterm human fetal retina and the current level of functionality as detected in human stem cell-derived organoids. We discuss the roles of apical-basal cell polarity in retinogenesis with a focus on Leber congenital amaurosis which leads to blindness shortly after birth. Finally, we discuss Crumbs homolog (CRB)-based gene augmentation.
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Jeong MH, Park SY, Lee SH, Seo J, Yoo JY, Park SH, Kim MJ, Lee S, Jang S, Choi HK, Lee JE, Shin SJ, Choi KC, Cheong JH, Yoon HG. EPB41L5 Mediates TGFβ-Induced Metastasis of Gastric Cancer. Clin Cancer Res 2019; 25:3617-3629. [PMID: 30814110 DOI: 10.1158/1078-0432.ccr-18-2959] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 11/27/2018] [Accepted: 02/21/2019] [Indexed: 11/16/2022]
Abstract
PURPOSE Because of disease heterogeneity, limited studies on effective chemotherapies and therapeutic agents for advanced gastric cancer are available. Erythrocyte membrane protein band 4.1-like 5 (EPB41L5) has critical roles in renal and breast cancer metastasis. However, its role in metastatic gastric cancer remains unknown. EXPERIMENTAL DESIGN The specimens of 78 gastric cancer patients were analyzed by oligonucleotide microarray and survival analysis. In vitro experiments and metastatic mice models were used to assess the effects of EPB41L5 on gastric cancer metastasis. RESULTS Gastric cancer patients with high EPB41L5 levels had poor prognosis and low survival rate. Further, TGFβ1-induced EPB41L5 expression promoted gastric cancer cell migration and invasion by Smad-dependent TGFβ signaling. Phospho-Smad3 recruitment to the EPB41L5 promoter was significantly inhibited by a TGFβ inhibitor. EPB41L5 overexpression increased lung metastasis of gastric cancer cells in nude mice, which was completely reversed by anti-EPB41L5 monoclonal antibody treatment. Importantly, p120-catenin knockdown abolished EPB41L5-enhanced gastric cancer cell metastasis. Anti-EPB41L5 monoclonal antibody treatment blocked the association of EPB41L5 with p120-catenin. CONCLUSIONS TGFβ/EPB41L5/p120-catenin axis regulates gastric cancer cell metastasis, and EPB41L5 is a promising therapeutic target for advanced gastric cancer.
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Affiliation(s)
- Mi-Hyeon Jeong
- Department of Biochemistry and Molecular Biology, Brain Korea 21 PLUS Project for Medical Sciences, Yonsei University College of Medicine, Seoul, Korea
| | - Soo-Yeon Park
- Department of Biochemistry and Molecular Biology, Brain Korea 21 PLUS Project for Medical Sciences, Yonsei University College of Medicine, Seoul, Korea
| | - Seung-Hyun Lee
- Department of Biochemistry and Molecular Biology, Brain Korea 21 PLUS Project for Medical Sciences, Yonsei University College of Medicine, Seoul, Korea
| | - JaeSung Seo
- Department of Biochemistry and Molecular Biology, Brain Korea 21 PLUS Project for Medical Sciences, Yonsei University College of Medicine, Seoul, Korea
| | - Jung-Yoon Yoo
- Department of Biochemistry and Molecular Biology, Brain Korea 21 PLUS Project for Medical Sciences, Yonsei University College of Medicine, Seoul, Korea
| | - Seung-Ho Park
- Department of Biomedical Sciences, Asan Medical Center, AMIST, University of Ulsan College of Medicine, Seoul, Korea
| | - Mi Jeong Kim
- Department of Biochemistry and Molecular Biology, Brain Korea 21 PLUS Project for Medical Sciences, Yonsei University College of Medicine, Seoul, Korea
| | - SooYeon Lee
- Department of Biochemistry and Molecular Biology, Brain Korea 21 PLUS Project for Medical Sciences, Yonsei University College of Medicine, Seoul, Korea
| | - Subhin Jang
- Department of Biochemistry and Molecular Biology, Brain Korea 21 PLUS Project for Medical Sciences, Yonsei University College of Medicine, Seoul, Korea
| | - Hyo-Kyoung Choi
- Division of Nutrition and Metabolism Research Group, Korea Food Research Institute, Gyeonggi-do, Korea
| | - Jae Eun Lee
- Department of Surgery, Yonsei University College of Medicine, Seoul, Korea
| | - Su-Jin Shin
- Department of Pathology, Hanyang University College of Medicine, Seoul, Korea
| | - Kyung-Chul Choi
- Department of Biomedical Sciences, Asan Medical Center, AMIST, University of Ulsan College of Medicine, Seoul, Korea.
| | - Jae-Ho Cheong
- Department of Biochemistry and Molecular Biology, Brain Korea 21 PLUS Project for Medical Sciences, Yonsei University College of Medicine, Seoul, Korea. .,Department of Surgery, Yonsei University College of Medicine, Seoul, Korea
| | - Ho-Geun Yoon
- Department of Biochemistry and Molecular Biology, Brain Korea 21 PLUS Project for Medical Sciences, Yonsei University College of Medicine, Seoul, Korea.
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Quinn PM, Pellissier LP, Wijnholds J. The CRB1 Complex: Following the Trail of Crumbs to a Feasible Gene Therapy Strategy. Front Neurosci 2017; 11:175. [PMID: 28424578 PMCID: PMC5380682 DOI: 10.3389/fnins.2017.00175] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 03/16/2017] [Indexed: 12/24/2022] Open
Abstract
Once considered science fiction, gene therapy is rapidly becoming scientific reality, targeting a growing number of the approximately 250 genes linked to hereditary retinal disorders such as retinitis pigmentosa and Leber's congenital amaurosis. Powerful new technologies have emerged, leading to the development of humanized models for testing and screening these therapies, bringing us closer to the goal of personalized medicine. These tools include the ability to differentiate human induced pluripotent stem cells (iPSCs) to create a “retina-in-a-dish” model and the self-formed ectodermal autonomous multi-zone, which can mimic whole eye development. In addition, highly specific gene-editing tools are now available, including the CRISPR/Cas9 system and the recently developed homology-independent targeted integration approach, which allows gene editing in non-dividing cells. Variants in the CRB1 gene have long been associated with retinopathies, and more recently the CRB2 gene has also been shown to have possible clinical relevance with respect to retinopathies. In this review, we discuss the role of the CRB protein complex in patients with retinopathy. In addition, we discuss new opportunities provided by stem cells and gene-editing tools, and we provide insight into how the retinal therapeutic pipeline can be improved. Finally, we discuss the current state of adeno-associated virus-mediated gene therapy and how it can be applied to treat retinopathies associated with mutations in CRB1.
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Affiliation(s)
- Peter M Quinn
- Department of Ophthalmology, Leiden University Medical CenterLeiden, Netherlands
| | - Lucie P Pellissier
- Unité Physiologie de la Reproduction et des Comportements, INRA UMR85, Centre National de la Recherche Scientifique UMR-7247, Institut Français du Cheval et de l'Équitation, Université François RabelaisNouzilly, France
| | - Jan Wijnholds
- Department of Ophthalmology, Leiden University Medical CenterLeiden, Netherlands.,Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and SciencesAmsterdam, Netherlands
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Chu CW, Gerstenzang E, Ossipova O, Sokol SY. Lulu regulates Shroom-induced apical constriction during neural tube closure. PLoS One 2013; 8:e81854. [PMID: 24282618 PMCID: PMC3839891 DOI: 10.1371/journal.pone.0081854] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2013] [Accepted: 10/19/2013] [Indexed: 02/06/2023] Open
Abstract
Apical constriction is an essential cell behavior during neural tube closure, but its underlying mechanisms are not fully understood. Lulu, or EPB4.1l5, is a FERM domain protein that has been implicated in apical constriction and actomyosin contractility in mouse embryos and cultured cells. Interference with the function of Lulu in Xenopus embryos by a specific antisense morpholino oligonucleotide or a carboxy-terminal fragment of Lulu impaired apical constriction during neural plate hinge formation. This effect was likely due to lack of actomyosin contractility in superficial neuroectodermal cells. By contrast, overexpression of Lulu RNA in embryonic ectoderm cells triggered ectopic apico-basal elongation and apical constriction, accompanied by the apical recruitment of F-actin. Depletion of endogenous Lulu disrupted the localization and activity of Shroom3, a PDZ-containing actin-binding protein that has also been implicated in apical constriction. Furthermore, Lulu and Shroom3 RNAs cooperated in triggering ectopic apical constriction in embryonic ectoderm. Our findings reveal that Lulu is essential for Shroom3-dependent apical constriction during vertebrate neural tube closure.
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Affiliation(s)
- Chih-Wen Chu
- Department of Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Emma Gerstenzang
- Department of Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Olga Ossipova
- Department of Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Sergei Y. Sokol
- Department of Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- * E-mail:
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Abstract
First identified in Drosophila, the Crumbs (Crb) proteins are important in epithelial polarity, apical membrane formation, and tight junction (TJ) assembly. The conserved Crb intracellular region includes a FERM (band 4.1/ezrin/radixin/moesin) binding domain (FBD) whose mammalian binding partners are not well understood and a PDZ binding motif that interacts with mammalian Pals1 (protein associated with lin seven) (also known as MPP5). Pals1 binds Patj (Pals1-associated tight-junction protein), a multi-PDZ-domain protein that associates with many tight junction proteins. The Crb complex also binds the conserved Par3/Par6/atypical protein kinase C (aPKC) polarity cassette that restricts migration of basolateral proteins through phosphorylation. Here, we describe a Crb3 knockout mouse that demonstrates extensive defects in epithelial morphogenesis. The mice die shortly after birth, with cystic kidneys and proteinaceous debris throughout the lungs. The intestines display villus fusion, apical membrane blebs, and disrupted microvilli. These intestinal defects phenocopy those of Ezrin knockout mice, and we demonstrate an interaction between Crumbs3 and ezrin. Taken together, our data indicate that Crumbs3 is crucial for epithelial morphogenesis and plays a role in linking the apical membrane to the underlying ezrin-containing cytoskeleton.
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Hoffmann A, Huang Y, Suetsugu-Maki R, Ringelberg CS, Tomlinson CR, Del Rio-Tsonis K, Tsonis PA. Implication of the miR-184 and miR-204 competitive RNA network in control of mouse secondary cataract. Mol Med 2012; 18:528-38. [PMID: 22270329 DOI: 10.2119/molmed.2011.00463] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Accepted: 01/17/2012] [Indexed: 11/06/2022] Open
Abstract
The high recurrence rate of secondary cataract (SC) is caused by the intrinsic differentiation activity of residual lens epithelial cells after extra-capsular lens removal. The objective of this study was to identify changes in the microRNA (miRNA) expression profile during mouse SC formation and to selectively manipulate miRNA expression for potential therapeutic intervention. To model SC, mouse cataract surgery was performed and temporal changes in the miRNA expression pattern were determined by microarray analysis. To study the potential SC counterregulative effect of miRNAs, a lens capsular bag in vitro model was used. Within the first 3 wks after cataract surgery, microarray analysis demonstrated SC-associated expression pattern changes of 55 miRNAs. Of the identified miRNAs, miR-184 and miR-204 were chosen for further investigations. Manipulation of miRNA expression by the miR-184 inhibitor (anti-miR-184) and the precursor miRNA for miR-204 (pre-miR-204) attenuated SC-associated expansion and migration of lens epithelial cells and signs of epithelial to mesenchymal transition such as α-smooth muscle actin expression. In addition, pre-miR-204 attenuated SC-associated expression of the transcription factor Meis homeobox 2 (MEIS2). Examination of miRNA target binding sites for miR-184 and miR-204 revealed an extensive range of predicted target mRNA sequences that were also a target to a complex network of other SC-associated miRNAs with possible opposing functions. The identification of the SC-specific miRNA expression pattern together with the observed in vitro attenuation of SC by anti-miR-184 and pre-miR-204 suggest that miR-184 and miR-204 play a significant role in the control of SC formation in mice that is most likely regulated by a complex competitive RNA network.
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Affiliation(s)
- Andrea Hoffmann
- Department of Biology and Center for Tissue Regeneration and Engineering, University of Dayton, Dayton, Ohio 45469-2320, USA
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Warzecha CC, Carstens RP. Complex changes in alternative pre-mRNA splicing play a central role in the epithelial-to-mesenchymal transition (EMT). Semin Cancer Biol 2012; 22:417-27. [PMID: 22548723 DOI: 10.1016/j.semcancer.2012.04.003] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2011] [Accepted: 04/16/2012] [Indexed: 12/18/2022]
Abstract
The epithelial-to-mesenchymal transition (EMT) is an important developmental process that is also implicated in disease pathophysiology, such as cancer progression and metastasis. A wealth of literature in recent years has identified important transcriptional regulators and large-scale changes in gene expression programs that drive the phenotypic changes that occur during the EMT. However, in the past couple of years it has become apparent that extensive changes in alternative splicing also play a profound role in shaping the changes in cell behavior that characterize the EMT. While long known splicing switches in FGFR2 and p120-catenin provided hints of a larger program of EMT-associated alternative splicing, the recent identification of the epithelial splicing regulatory proteins 1 and 2 (ESRP1 and ESRP2) began to reveal this genome-wide post-transcriptional network. Several studies have now demonstrated the truly vast extent of this alternative splicing program. The global switches in splicing associated with the EMT add an important additional layer of post-transcriptional control that works in harmony with transcriptional and epigenetic regulation to effect complex changes in cell shape, polarity, and behavior that mediate transitions between epithelial and mesenchymal cell states. Future challenges include the need to investigate the functional consequences of these splicing switches at both the individual gene as well as systems level.
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Affiliation(s)
- Claude C Warzecha
- Department of Medicine, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA 19104, United States
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Murata K, Nunomura W, Takakuwa Y, Cherr GN. Two different unique cardiac isoforms of protein 4.1R in zebrafish, Danio rerio, and insights into their cardiac functions as related to their unique structures. Dev Growth Differ 2011; 52:591-602. [PMID: 20887560 DOI: 10.1111/j.1440-169x.2010.01195.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Protein 4.1R (4.1R) has been identified as the major component of the human erythrocyte membrane skeleton. The members of the protein 4.1 gene family are expressed in a tissue-specific alternative splicing manner that increases their functions in each tissue; however, the exact roles of cardiac 4.1R in the developing myocardium are poorly understood. In zebrafish (ZF), we identified two heart-specific 4.1R isoforms, ZF4.1RH2 and ZF4.1RH3, encoding N-terminal 30 kDa (FERM) domain and spectrin-actin binding domain (SABD) and C-terminal domain (CTD), separately. Applying immunohistochemistry using specific antibodies for 30 kDa domain and CTD separately, the gene product of ZF4.1RH2 and ZF4.1RH3 appeared only in the ventricle and in the atrium, respectively, in mature hearts. During embryogenesis, both gene expressions are expressed starting 24 h post-fertilization (hpf). Following whole-mount in situ hybridization, ZF4.1RH3 gene expression was detected in the atrium of 37 hpf embryos. These results indicate that the gene product of ZF4.1RH3 is essential for normal morphological shape of the developing heart and to support the repetitive cycles of its muscle contraction and relaxation.
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Affiliation(s)
- Kenji Murata
- Department of Animal Science, University of California, Davis, CA, USA.
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Hsu YC, Jensen AM. Multiple domains in the Crumbs Homolog 2a (Crb2a) protein are required for regulating rod photoreceptor size. BMC Cell Biol 2010; 11:60. [PMID: 20670434 PMCID: PMC2927502 DOI: 10.1186/1471-2121-11-60] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2009] [Accepted: 07/29/2010] [Indexed: 12/26/2022] Open
Abstract
Background Vertebrate retinal photoreceptors are morphologically complex cells that have two apical regions, the inner segment and the outer segment. The outer segment is a modified cilium and is continuously regenerated throughout life. The molecular and cellular mechanisms that underlie vertebrate photoreceptor morphogenesis and the maintenance of the outer segment are largely unknown. The Crumbs (Crb) complex is a key regulator of apical membrane identity and size in epithelia and in Drosophila photoreceptors. Mutations in the human gene CRUMBS HOMOLOG 1 (CRB1) are associated with early and severe vision loss. Drosophila Crumbs and vertebrate Crb1 and Crumbs homolog 2 (Crb2) proteins are structurally similar, all are single pass transmembrane proteins with a large extracellular domain containing multiple laminin- and EGF-like repeats and a small intracellular domain containing a FERM-binding domain and a PDZ-binding domain. In order to begin to understand the role of the Crb family of proteins in vertebrate photoreceptors we generated stable transgenic zebrafish in which rod photoreceptors overexpress full-length Crb2a protein and several other Crb2a constructs engineered to lack specific domains. Results We examined the localization of Crb2a constructs and their effects on rod morphology. We found that only the full-length Crb2a protein approximated the normal localization of Crb2a protein apical to adherens junctions in the photoreceptor inner segment. Several Crb2a construct proteins localized abnormally to the outer segment and one construct localized abnormally to the cell body. Overexpression of full-length Crb2a greatly increased inner segment size while expression of several other constructs increased outer segment size. Conclusions Our observations suggest that particular domains in Crb2a regulate its localization and thus may regulate its regionalized function. Our results also suggest that the PDZ-binding domain in Crb2a might bring a protein(s) into the Crb complex that alters the function of the FERM-binding domain.
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Affiliation(s)
- Ya-Chu Hsu
- Department of Biology, University of Massachusetts, Amherst, MA 01003, USA
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Nakajima H, Tanoue T. Epithelial cell shape is regulated by Lulu proteins via myosin-II. J Cell Sci 2010; 123:555-66. [PMID: 20103536 DOI: 10.1242/jcs.057752] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Cell-shape change in epithelial structures is fundamental to animal morphogenesis. Recent studies identified myosin-II as the major generator of driving forces for cell-shape changes during morphogenesis. Lulu (Epb41l5) is a major regulator of morphogenesis, although the downstream molecular and cellular mechanisms remain obscure in mammals. In Drosophila and zebrafish, Lulu proteins were reported to negatively regulate Crumbs, an apical domain regulator, thus regulating morphogenesis. In this study, we show that mammalian Lulu activates myosin-II, thus regulating epithelial cell shape. In our experiments, Lulu expression in epithelial cells resulted in apical constriction and lateral elongation in the cells, accompanied by upregulation of myosin-II. The inhibition of myosin-II activity almost completely blocked this Lulu-driven cell-shape change. We further found that Rock participates in the myosin-II activation. Additionally, RNAi-mediated depletion of Lulu in epithelial cells resulted in disorganization of myosin-II and a concomitant loss of proper lateral domain organization in the cells. From these results, we propose that Lulu regulates epithelial cell shape by controlling myosin-II activity.
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Affiliation(s)
- Hiroyuki Nakajima
- Global COE Program for Integrative Membrane Biology, Graduate School of Medicine, Kobe University, Chuo-ku, Kobe 650-0017, Japan
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12
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Warzecha CC, Shen S, Xing Y, Carstens RP. The epithelial splicing factors ESRP1 and ESRP2 positively and negatively regulate diverse types of alternative splicing events. RNA Biol 2009; 6:546-62. [PMID: 19829082 DOI: 10.4161/rna.6.5.9606] [Citation(s) in RCA: 163] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Cell-type and tissue-specific alternative splicing events are regulated by combinatorial control involving both abundant RNA binding proteins as well as those with more discrete expression and specialized functions. Epithelial Splicing Regulatory Proteins 1 and 2 (ESRP1 and ESRP2) are recently discovered epithelial-specific RNA binding proteins that promote splicing of the epithelial variant of the FGFR2, ENAH, CD44 and CTNND1 transcripts. To catalogue a larger set of splicing events under the regulation of the ESRPs we profiled splicing changes induced by RNA interference-mediated knockdown of ES RP1 and ES RP2 expression in a human epithelial cell line using the splicing sensitive Affymetrix Exon ST1.0 Arrays. Analysis of the microarray data resulted in the identification of over a hundred candidate ESRP regulated splicing events. We were able to independently validate 38 of these targets by RT-PCR. The ESRP regulated events encompass all known types of alternative splicing events, most prominent being alternative cassette exons and splicing events leading to alternative 3' terminal exons. Importantly, a number of these regulated splicing events occur in gene transcripts that encode proteins with well-described roles in the regulation of actin cytoskeleton organization, cell-cell adhesion, cell polarity and cell migration. In sum, this work reveals a novel list of transcripts differentially spliced in epithelial and mesenchymal cells, implying that coordinated alternative splicing plays a critical role in determination of cell type identity. These results further establish ESRP1 and ESRP2 as global regulators of an epithelial splicing regulatory network.
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Affiliation(s)
- Claude C Warzecha
- Renal Division, Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA, USA
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13
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FERM proteins in animal morphogenesis. Curr Opin Genet Dev 2009; 19:357-67. [PMID: 19596566 DOI: 10.1016/j.gde.2009.05.006] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2009] [Accepted: 05/29/2009] [Indexed: 01/19/2023]
Abstract
Proteins containing a FERM domain are ubiquitous components of the cytocortex of animal cells where they are engaged in structural, transport, and signaling functions. Recent years have seen a wealth of genetic studies in model organisms that explore FERM protein function in development and tissue organization. In addition, mutations in several FERM protein-encoding genes have been associated with human diseases. This review will provide a brief overview of the FERM domain structure and the FERM protein superfamily and then discuss recent advances in our understanding of the mechanism of function and developmental requirement of several FERM proteins including Moesin, Myosin-VIIA, Myosin-XV, Coracle/Band4.1 as well as Yurt and its vertebrate homologs Mosaic Eyes and EPB41L5/YMO1/Limulus.
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Munson C, Huisken J, Bit-Avragim N, Kuo T, Dong PD, Ober EA, Verkade H, Abdelilah-Seyfried S, Stainier DYR. Regulation of neurocoel morphogenesis by Pard6 gamma b. Dev Biol 2008; 324:41-54. [PMID: 18817769 DOI: 10.1016/j.ydbio.2008.08.033] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2008] [Revised: 08/16/2008] [Accepted: 08/23/2008] [Indexed: 12/21/2022]
Abstract
The Par3/Par6/aPKC protein complex plays a key role in the establishment and maintenance of apicobasal polarity, a cellular characteristic essential for tissue and organ morphogenesis, differentiation and homeostasis. During a forward genetic screen for liver and pancreas mutants, we identified a pard6gammab mutant, representing the first known pard6 mutant in a vertebrate organism. pard6gammab mutants exhibit defects in epithelial tissue development as well as multiple lumens in the neural tube. Analyses of the cells lining the neural tube cavity, or neurocoel, in wildtype and pard6gammab mutant embryos show that lack of Pard6gammab function leads to defects in mitotic spindle orientation during neurulation. We also found that the PB1 (aPKC-binding) and CRIB (Cdc-42-binding) domains and the KPLG amino acid sequence within the PDZ domain (Pals1-and Crumbs binding) are not required for Pard6gammab localization but are essential for its function in neurocoel morphogenesis. Apical membranes are reduced, but not completely absent, in mutants lacking the zygotic, or both the maternal and zygotic, function of pard6gammab, leading us to examine the localization and function of the three additional zebrafish Pard6 proteins. We found that Pard6alpha, but not Pard6beta or Pard6gammaa, could partially rescue the pard6gammab(s441) mutant phenotypes. Altogether, these data indicate a previously unappreciated functional diversity and complexity within the vertebrate pard6 gene family.
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Affiliation(s)
- Chantilly Munson
- Department of Biochemistry and Biophysics, Genetics and Human Genetics, University of California, San Francisco, CA 94158, USA
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