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Sluchanko NN, Gusev NB. 14-3-3 proteins and regulation of cytoskeleton. BIOCHEMISTRY (MOSCOW) 2011; 75:1528-46. [PMID: 21417993 DOI: 10.1134/s0006297910130031] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The proteins of the 14-3-3 family are universal adapters participating in multiple processes running in the cell. We describe the structure, isoform composition, and distribution of 14-3-3 proteins in different tissues. Different elements of 14-3-3 structure important for dimer formation and recognition of protein targets are analyzed in detail. Special attention is paid to analysis of posttranslational modifications playing important roles in regulation of 14-3-3 function. The data of the literature concerning participation of 14-3-3 in regulation of intercellular contacts and different elements of cytoskeleton formed by microfilaments are analyzed. We also describe participation of 14-3-3 in regulation of small G-proteins and protein kinases important for proper functioning of cytoskeleton. The data on the interaction of 14-3-3 with different components of microtubules are presented, and the probable role of 14-3-3 in developing of certain neurodegenerative diseases is discussed. The data of the literature concerning the role of 14-3-3 in formation and normal functioning of intermediate filaments are also reviewed. It is concluded that due to its adapter properties 14-3-3 plays an important role in cytoskeleton regulation. The cytoskeletal proteins that are abundant in the cell might compete with the other protein targets of 14-3-3 and therefore can indirectly regulate many intracellular processes that are dependent on 14-3-3.
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Affiliation(s)
- N N Sluchanko
- Department of Biochemistry, Faculty of Biology, Lomonosov Moscow State University, Russia
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52
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Nagata M, Sakurai-Yageta M, Yamada D, Goto A, Ito A, Fukuhara H, Kume H, Morikawa T, Fukayama M, Homma Y, Murakami Y. Aberrations of a cell adhesion molecule CADM4 in renal clear cell carcinoma. Int J Cancer 2011; 130:1329-37. [DOI: 10.1002/ijc.26160] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2010] [Accepted: 01/27/2011] [Indexed: 11/07/2022]
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53
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Chen L, Hughes RA, Baines AJ, Conboy J, Mohandas N, An X. Protein 4.1R regulates cell adhesion, spreading, migration and motility of mouse keratinocytes by modulating surface expression of beta1 integrin. J Cell Sci 2011; 124:2478-87. [PMID: 21693581 DOI: 10.1242/jcs.078170] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Protein 4.1R is a membrane-cytoskeleton adaptor protein that has diverse roles in controlling the cell surface expression and/or function of transmembrane proteins, and in organizing F-actin. 4.1R is expressed in keratinocytes, but its role in these cells has not been explored. Here, we have investigated the role of 4.1R in skin using 4.1R(-/-) mice. Cell adhesion, spreading, migration and motility were significantly impaired in 4.1R(-/-) keratinocytes, and 4.1R(-/-) mice exhibited defective epidermal wound healing. Cultured 4.1R(-/-) keratinocytes on fibronectin failed to form actin stress fibres and focal adhesions. Furthermore, in the absence of 4.1R, the surface expression, and consequently the activity of β1 integrin were reduced. These data enabled the identification of a functional role for protein 4.1R in keratinocytes by modulating the surface expression of β1 integrin, possibly through a direct association between 4.1R and β1 integrin.
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Affiliation(s)
- Lixiang Chen
- Red Cell Physiology Laboratory, New York Blood Center, New York, NY 10065, USA
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54
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Theos A, Boyd KP, Korf BR. The Neurofibromatoses. HARPER'S TEXTBOOK OF PEDIATRIC DERMATOLOGY 2011. [DOI: 10.1002/9781444345384.ch128] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2025]
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55
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Buttermore ED, Dupree JL, Cheng J, An X, Tessarollo L, Bhat MA. The cytoskeletal adaptor protein band 4.1B is required for the maintenance of paranodal axoglial septate junctions in myelinated axons. J Neurosci 2011; 31:8013-24. [PMID: 21632923 PMCID: PMC3121702 DOI: 10.1523/jneurosci.1015-11.2011] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2011] [Revised: 04/06/2011] [Accepted: 04/11/2011] [Indexed: 02/06/2023] Open
Abstract
Precise targeting and maintenance of axonal domains in myelinated axons is essential for saltatory conduction. Caspr and Caspr2, which localize at paranodal and juxtaparanodal domains, contain binding sites for the cytoskeletal adaptor protein 4.1B. The exact role of 4.1B in the organization and maintenance of axonal domains is still not clear. Here, we report the generation and characterization of 4.1B-null mice. We show that loss of 4.1B in the PNS results in mislocalization of Caspr at paranodes and destabilization of paranodal axoglial septate junctions (AGSJs) as early as postnatal day 30. In the CNS, Caspr localization is progressively disrupted and ultrastructural analysis showed paranodal regions that were completely devoid of AGSJs, with axolemma separated from the myelin loops, and loops coming off the axolemma. Most importantly, our phenotypic analysis of previously generated 4.1B mutants, used in the study by Horresh et al. (2010), showed that Caspr localization was not affected in the PNS, even after 1 year; and 4.1R was neither expressed, nor enriched at the paranodes. Furthermore, ultrastructural analysis of these 4.1B mutants showed destabilization of CNS AGSJs at ∼ 1 year. We also discovered that the 4.1B locus is differentially expressed in the PNS and CNS, and generates multiple splice isoforms in the PNS, suggesting 4.1B may function differently in the PNS versus CNS. Together, our studies provide direct evidence that 4.1B plays a pivotal role in interactions between the paranodal AGSJs and axonal cytoskeleton, and that 4.1B is critically required for long-term maintenance of axonal domains in myelinated axons.
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Affiliation(s)
- Elizabeth D. Buttermore
- Curriculum in Neurobiology
- Department of Cell and Molecular Physiology
- University of North Carolina Neuroscience Center, and
| | - Jeffrey L. Dupree
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, Virginia 23298-0709
| | - JrGang Cheng
- University of North Carolina Neuroscience Center, and
| | - Xiuli An
- Red Cell Physiology Laboratory, New York Blood Center, New York City, New York 10065, and
| | - Lino Tessarollo
- Neural Development Group, Mouse Cancer Genetics Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702
| | - Manzoor A. Bhat
- Curriculum in Neurobiology
- Department of Cell and Molecular Physiology
- University of North Carolina Neuroscience Center, and
- Carolina Center for Developmental Disabilities, University of North Carolina School of Medicine, Chapel Hill, North Carolina 27599
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Lack of protein 4.1G causes altered expression and localization of the cell adhesion molecule nectin-like 4 in testis and can cause male infertility. Mol Cell Biol 2011; 31:2276-86. [PMID: 21482674 DOI: 10.1128/mcb.01105-10] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Protein 4.1G is a member of the protein 4.1 family, which in general serves as adaptors linking transmembrane proteins to the cytoskeleton. 4.1G is thought to be widely expressed in many cells and tissues, but its function remains largely unknown. To explore the function of 4.1G in vivo, we generated 4.1G(-/-) mice and bred the mice in two backgrounds: C57BL/6 (B6) and 129/Sv (129) hybrids (B6-129) and inbred B6. Although the B6 4.1G(-/-) mice showed no obvious abnormalities, deficiency of 4.1G in B6-129 hybrids was associated with male infertility. Histological examinations of these 4.1G(-/-) mice revealed atrophy, impaired cell-cell contact and sloughing off of spermatogenic cells in seminiferous epithelium, and lack of mature spermatids in the epididymis. Ultrastructural examination revealed enlarged intercellular spaces between spermatogenic and Sertoli cells as well as the spermatid deformities. At the molecular level, 4.1G is associated with the nectin-like 4 (NECL4) adhesion molecule. Importantly, the expression of NECL4 was decreased, and the localization of NECL4 was altered in 4.1G(-/-) testis. Thus, our findings imply that 4.1G plays a role in spermatogenesis by mediating cell-cell adhesion between spermatogenic and Sertoli cells through its interaction with NECL4 on Sertoli cells. Additionally, the finding that infertility is present in B6-129 but not on the B6 background suggests the presence of a major modifier gene(s) that influences 4.1G function and is associated with male infertility.
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Zhan Y, Modi N, Stewart AM, Hieronimus RI, Liu J, Gutmann DH, Chadee DN. Regulation of mixed lineage kinase 3 is required for Neurofibromatosis-2-mediated growth suppression in human cancer. Oncogene 2011; 30:781-9. [PMID: 20890305 PMCID: PMC3017676 DOI: 10.1038/onc.2010.453] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2010] [Revised: 08/04/2010] [Accepted: 08/25/2010] [Indexed: 12/25/2022]
Abstract
The Neurofibromatosis-2 (NF2) tumor suppressor merlin negatively regulates cell proliferation in numerous cell types. We have previously shown that the NF2 protein (merlin/schwannomin) associates with mixed lineage kinase 3 (MLK3), a mitogen-activated protein kinase (MAPK) kinase kinase that is required for the proliferation of normal and neoplastic cells. In this study, we show that merlin inhibits MLK3 activity, as well as the activation of its downstream effectors, B-Raf, extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK). The ability of merlin to regulate MLK3 activity requires a direct association between MLK3 and residues in the C-terminal region of merlin. Merlin integrates Rho GTPase family signaling with MAPK activity by inhibiting the binding between MLK3 and its upstream activator, Cdc42. Furthermore, we demonstrate that MLK3 is required for merlin-mediated suppression of cell proliferation and invasion. Collectively, these results establish merlin as a potent inhibitor of MLK3, ERK and JNK activation in cancer, and provide a mechanistic link between deregulated MAPK and Rho GTPase signaling in NF2 growth control.
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Affiliation(s)
- Y Zhan
- Department of Biological Sciences, University of Toledo, Toledo, OH, USA
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58
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Bartholow TL, Chandran UR, Becich MJ, Parwani AV. Immunohistochemical staining of radixin and moesin in prostatic adenocarcinoma. BMC Clin Pathol 2011; 11:1. [PMID: 21235778 PMCID: PMC3029218 DOI: 10.1186/1472-6890-11-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2010] [Accepted: 01/14/2011] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Some members of the Protein 4.1 superfamily are believed to be involved in cell proliferation and growth, or in the regulation of these processes. While the expression levels of two members of this family, radixin and moesin, have been studied in many tumor types, to our knowledge they have not been investigated in prostate cancer. METHODS Tissue microarrays were immunohistochemically stained for either radixin or moesin, with the staining intensities subsequently quantified and statistically analyzed using One-Way ANOVA or nonparametric equivalent with subsequent Student-Newman-Keuls tests for multiple comparisons. There were 11 cases of normal donor prostates (NDP), 14 cases of benign prostatic hyperplasia (BPH), 23 cases of high-grade prostatic intraepithelial neoplasia (HGPIN), 88 cases of prostatic adenocarcinoma (PCa), and 25 cases of normal tissue adjacent to adenocarcinoma (NAC) analyzed in the microarrays. RESULTS NDP, BPH, and HGPIN had higher absolute staining scores for radixin than PCa and NAC, but with a significant difference observed between only HGPIN and PCa (p = < 0.001) and HGPIN and NAC (p = 0.001). In the moesin-stained specimens, PCa, NAC, HGPIN, and BPH all received absolute higher staining scores than NDP, but the differences were not significant. Stage 4 moesin-stained PCa had a significantly reduced staining intensity compared to Stage 2 (p = 0.003). CONCLUSIONS To our knowledge, these studies represent the first reports on the expression profiles of radixin and moesin in prostatic adenocarcinoma. The current study has shown that there were statistically significant differences observed between HGPIN and PCa and HGPIN and NAC in terms of radixin expression. The differences in the moesin profiles by tissue type were not statistically significant. Additional larger studies with these markers may further elucidate their potential roles in prostatic neoplasia progression.
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Affiliation(s)
| | - Uma R Chandran
- Department of Biomedical Informatics, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Michael J Becich
- Department of Biomedical Informatics, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Anil V Parwani
- Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
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59
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Ellender M, Harrison JD, Meijne E, Huiskamp R, Kozlowski RE, Haines JW, Edwards AA, Ainsbury EA, Moody JC, Bouffler SD, Cox R. Intestinal tumours induced in Apc(Min/+) mice by X-rays and neutrons. Int J Radiat Biol 2011; 87:385-99. [PMID: 21219111 DOI: 10.3109/09553002.2011.542542] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE To compare the development of intestinal adenomas following neutron and X-ray exposure of Apc(Min/+) mice (Apc - adenomatous polyposis coli; Min - multiple intestinal neoplasia). MATERIALS AND METHODS Adult mice were exposed to acute doses of X-rays or fission neutrons. Tumour counting was undertaken 200 days later and samples were taken for Loss of Heterozygosity (LOH) analysis. RESULTS Tumour numbers (adenomas and microadenomas) increased by 1.4-fold, 1.7-fold, 2.7-fold and 9-fold, after 0.5, 1, 2 and 5 Gy X-rays, respectively, and by 2.4-fold and 5.7-fold, after 0.5 and 1 Gy fission neutrons, respectively. LOH analysis of tumours from neutron-exposed mice showed that 63% had lost Apc and 90% (cf. 53% in controls) had lost D18mit84, a marker for Epb4.1l4a/NBL4 (erythrocyte protein band 4.1-like 4a/novel band 4.1-like 4), known to be involved in the Wnt (wingless-related mouse mammary tumour virus integration site) pathway. Some tumours from neutron-exposed mice appeared to have homozygous loss of some chromosomal markers. CONCLUSIONS X-ray or fission neutron irradiation results in strongly enhanced tumour multiplicities. Comparison of tumour yields indicated a low Relative Biological Effectiveness of around 2-8 for fission neutrons compared with X-rays. LOH in intestinal tumours from neutron-exposed mice appeared to be more complex than previously reported for tumours from X-irradiated mice.
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Affiliation(s)
- Michele Ellender
- Health Protection Agency, Centre for Radiation, Chemical and Environmental Hazards, Chilton, Didcot, Oxfordshire, UK.
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60
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Schulz WA, Ingenwerth M, Djuidje CE, Hader C, Rahnenführer J, Engers R. Changes in cortical cytoskeletal and extracellular matrix gene expression in prostate cancer are related to oncogenic ERG deregulation. BMC Cancer 2010; 10:505. [PMID: 20860828 PMCID: PMC2955608 DOI: 10.1186/1471-2407-10-505] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2010] [Accepted: 09/22/2010] [Indexed: 12/30/2022] Open
Abstract
Background The cortical cytoskeleton network connects the actin cytoskeleton to various membrane proteins, influencing cell adhesion, polarity, migration and response to extracellular signals. Previous studies have suggested changes in the expression of specific components in prostate cancer, especially of 4.1 proteins (encoded by EPB41 genes) which form nodes in this network. Methods Expression of EPB41L1, EPB41L2, EPB41L3 (protein: 4.1B), EPB41L4B (EHM2), EPB41L5, EPB49 (dematin), VIL2 (ezrin), and DLG1 (summarized as „cortical cytoskeleton" genes) as well as ERG was measured by quantitative RT-PCR in a well-characterized set of 45 M0 prostate adenocarcinoma and 13 benign tissues. Hypermethylation of EPB41L3 and GSTP1 was compared in 93 cancer tissues by methylation-specific PCR. Expression of 4.1B was further studied by immunohistochemistry. Results EPB41L1 and EPB41L3 were significantly downregulated and EPB41L4B was upregulated in cancer tissues. Low EPB41L1 or high EPB41L4B expression were associated with earlier biochemical recurrence. None of the other cortical cytoskeleton genes displayed expression changes, in particular EPB49 and VIL2, despite hints from previous studies. EPB41L3 downregulation was significantly associated with hypermethylation of its promoter and strongly correlated with GSTP1 hypermethylation. Protein 4.1B was detected most strongly in the basal cells of normal prostate epithelia. Its expression in carcinoma cells was similar to the weaker one in normal luminal cells. EPB41L3 downregulation and EPB41L4B upregulation were essentially restricted to the 22 cases with ERG overexpression. Expression changes in EPB41L3 and EPB41L4B closely paralleled those previously observed for the extracellular matrix genes FBLN1 and SPOCK1, respectively. Conclusions Specific changes in the cortical cytoskeleton were observed during prostate cancer progression. They parallel changes in the expression of extracellular matrix components and all together appear to be associated with oncogenic ERG overexpression. We hypothesize that these alterations may contribute to the increased invasivity conferred to prostate cancer cells by ERG deregulation.
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Affiliation(s)
- Wolfgang A Schulz
- Department of Urology, Heinrich Heine University, Moorenstr. 5, 40225 Düsseldorf, Germany.
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61
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Identification of SNP markers on 1p36 and association analysis of EPB41 with mandibular prognathism in a Chinese population. Arch Oral Biol 2010; 55:867-72. [PMID: 20797695 DOI: 10.1016/j.archoralbio.2010.07.018] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2010] [Revised: 07/02/2010] [Accepted: 07/27/2010] [Indexed: 11/21/2022]
Abstract
OBJECTIVE The results of a genome-wide scan suggested that chromosome locus 1p36 might be linked to the etiology of mandibular prognathism (MP) amongst Asian ethnicities. In this study, we performed a two-stage case-control association study to determine whether one or more genes that confer susceptibility to MP are located within this genomic region. DESIGN In the first stage of the study, we examined 103 single nucleotide polymorphisms (SNPs) on 1p36 across an 8.6Mb critical region and within four candidate genes in 158 cases and 147 controls to identify genes associated with MP. In the second stage of the study, we examined an additional 23 SNPs within the erythrocyte membrane protein band 4.1 (EPB41) gene in 211 cases and 224 controls. RESULTS Four SNPs located in the EPB41 gene showed possible allelic and genotypic associations with MP (P<0.03 and P<0.05, respectively) in the first stage. In the analysis of single SNPs in the second stage, the allele of rs4654388 showed the strongest significant association with MP (P=0.008) and the rs4654388 G-allele was associated with a significantly increased risk of MP (OR: 1.78, 95% CI: 1.16-2.74). Haplotype analysis revealed that MP was associated significantly with haplotype GTTCAGGT (P(corrected)=0.031), which included the rs4654388 G-allele. CONCLUSIONS An association between genetic polymorphisms in the EPB41 gene and MP has been observed. Although the polymorphisms which may contribute to MP have not been determined, the results of our study suggest that the EPB41 gene could confer susceptibility to MP.
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Moulding the shape of a metastatic cell. Leuk Res 2010; 34:843-7. [PMID: 20189645 DOI: 10.1016/j.leukres.2010.02.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2010] [Revised: 02/06/2010] [Accepted: 02/07/2010] [Indexed: 11/23/2022]
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63
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Dutertre M, Lacroix-Triki M, Driouch K, de la Grange P, Gratadou L, Beck S, Millevoi S, Tazi J, Lidereau R, Vagner S, Auboeuf D. Exon-based clustering of murine breast tumor transcriptomes reveals alternative exons whose expression is associated with metastasis. Cancer Res 2010; 70:896-905. [PMID: 20103641 DOI: 10.1158/0008-5472.can-09-2703] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In the field of bioinformatics, exon profiling is a developing area of disease-associated transcriptome analysis. In this study, we performed a microarray-based transcriptome analysis at the single exon level in mouse 4T1 primary mammary tumors with different metastatic capabilities. A novel bioinformatics platform was developed that identified 679 genes with differentially expressed exons in 4T1 tumors, many of which were involved in cell morphology and movement. Of 152 alternative exons tested by reverse transcription-PCR, 97 were validated as differentially expressed in primary tumors with different metastatic capability. This analysis revealed candidate progression genes, hinting at variations in protein functions by alternate exon usage. In a parallel effort, we developed a novel exon-based clustering analysis and identified alternative exons in tumor transcriptomes that were associated with dissemination of primary tumor cells to sites of pulmonary metastasis. This analysis also revealed that the splicing events identified by comparing primary tumors were not aberrant events. Lastly, we found that a subset of differentially spliced variant transcripts identified in the murine model was associated with poor prognosis in a large clinical cohort of patients with breast cancer. Our findings illustrate the utility of exon profiling to define novel theranostic markers for study in cancer progression and metastasis.
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Okumura K, Mochizuki E, Yokohama M, Yamakawa H, Shitara H, Mburu P, Yonekawa H, Brown SD, Kikkawa Y. Protein 4.1 expression in the developing hair cells of the mouse inner ear. Brain Res 2010; 1307:53-62. [DOI: 10.1016/j.brainres.2009.10.039] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2009] [Revised: 10/14/2009] [Accepted: 10/14/2009] [Indexed: 01/11/2023]
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65
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Betts-Henderson J, Bartesaghi S, Crosier M, Lindsay S, Chen HL, Salomoni P, Gottlob I, Nicotera P. The nystagmus-associated FRMD7 gene regulates neuronal outgrowth and development. Hum Mol Genet 2009; 19:342-51. [PMID: 19892780 DOI: 10.1093/hmg/ddp500] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Mutations in the gene encoding FERM domain-containing 7 protein (FRMD7) are recognized as an important cause of X-linked idiopathic infantile nystagmus (IIN). However, the precise role of FRMD7 and its involvement in the pathogenesis of IIN are not understood. In the present study, we have explored the role of FRMD7 in neuronal development. Using in situ hybridization and immunohistochemistry, we reveal that FRMD7 expression is spatially and temporally regulated in both the human and mouse brain during embryonic and fetal development. Furthermore, we show that FRMD7 expression is up-regulated upon retinoic acid (RA)-induced differentiation of mouse neuroblastoma NEURO2A cells, suggesting FRMD7 may play a role in this process. Indeed, we demonstrate, for the first time, that knockdown of FRMD7 during neuronal differentiation results in altered neurite development. Taken together, our data suggest that FRMD7 is involved in multiple aspects of neuronal development, and have direct importance to further understanding the pathogenesis of IIN.
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Sakurai-Yageta M, Masuda M, Tsuboi Y, Ito A, Murakami Y. Tumor suppressor CADM1 is involved in epithelial cell structure. Biochem Biophys Res Commun 2009; 390:977-82. [PMID: 19854157 DOI: 10.1016/j.bbrc.2009.10.088] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2009] [Accepted: 10/18/2009] [Indexed: 01/02/2023]
Abstract
The tumor suppressor, CADM1, is involved in cell adhesion and preferentially inactivated in invasive cancer. We have previously reported that CADM1 associates with an actin-binding protein, 4.1B/DAL-1, and a scaffold protein, membrane protein palmitoylated 3 (MPP3)/DLG3. However, underlying mechanism of tumor suppression by CADM1 is not clarified yet. Here, we demonstrate that MPP1/p55 and MPP2/DLG2, as well as MPP3, interact with both CADM1 and 4.1B, forming a tripartite complex. We then examined cell biological roles of CADM1 and its complex in epithelia using HEK293 cells. Among MPP1-3, MPP2 is recruited to the CADM1-4.1B complex in the early process of adhesion in HEK293 cells. By suppression of CADM1 expression using siRNA, HEK293 lose epithelia-like structure and show flat morphology with immature cell adhesion. 4.1B and MPP2, as well as E-cadherin and ZO-1, are mislocalized from the membrane by depletion of CADM1 in HEK293. Mislocalization of MPP2 is also observed in several cancer cells lacking CADM1 expression with the transformed morphology. These findings suggest that CADM1 is involved in the formation of epithelia-like cell structure with 4.1B and MPP2, while loss of its function could cause morphological transformation of cancer cells.
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Affiliation(s)
- Mika Sakurai-Yageta
- Division of Molecular Pathology, Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan
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Hoy JL, Constable JR, Vicini S, Fu Z, Washbourne P. SynCAM1 recruits NMDA receptors via protein 4.1B. Mol Cell Neurosci 2009; 42:466-83. [PMID: 19796685 DOI: 10.1016/j.mcn.2009.09.010] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2009] [Revised: 09/12/2009] [Accepted: 09/21/2009] [Indexed: 11/27/2022] Open
Abstract
Cell adhesion molecules have been implicated as key organizers of synaptic structures, but there is still a need to determine how these molecules facilitate neurotransmitter receptor recruitment to developing synapses. Here, we identify erythrocyte protein band 4.1-like 3 (protein 4.1B) as an intracellular effector molecule of Synaptic Cell Adhesion Molecule 1 (SynCAM1) that is sufficient to recruit NMDA-type receptors (NMDARs) to SynCAM1 adhesion sites in COS7 cells. Protein 4.1B in conjunction with SynCAM1 also increased the frequency of NMDAR-mediated mEPSCs and area of presynaptic contact in an HEK293 cell/ neuron co-culture assay. Studies in cultured hippocampal neurons reveal that manipulation of protein 4.1B expression levels specifically affects NMDAR-mediated activity and localization. Finally, further experimentation in COS7 cells show that SynCAM1 may also interact with protein 4.1N to specifically effect AMPA type receptor (AMPAR) recruitment. Thus, SynCAM1 may recruit both AMPARs and NMDARs by independent mechanisms during synapse formation.
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Affiliation(s)
- Jennifer L Hoy
- Institute of Neuroscience, University of Oregon, Eugene, OR 97403, USA
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Federici C, Brambilla D, Lozupone F, Matarrese P, de Milito A, Lugini L, Iessi E, Cecchetti S, Marino M, Perdicchio M, Logozzi M, Spada M, Malorni W, Fais S. Pleiotropic function of ezrin in human metastatic melanomas. Int J Cancer 2009; 124:2804-12. [PMID: 19235924 DOI: 10.1002/ijc.24255] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The membrane cytoskeleton cross-linker, ezrin, has recently been depicted as a key regulator in the progression and metastasis of several pediatric tumors. Less defined appears the role of ezrin in human adult tumors, especially melanoma. We therefore addressed ezrin involvement in the metastatic phenotype of human adult metastatic melanoma cells. Our results show that cells resected from melanoma metastatic lesions of patients, display marked metastatic spreading capacity in SCID mice organs. Stable transfection of human melanoma cells with an ezrin deletion mutant comprising only 146 N-terminal aminoacids led to the abolishment of metastatic dissemination. In vitro experiments revealed ezrin direct molecular interactions with molecules related to metastatic functions such as CD44, merlin and Lamp-1, consistent with its participation to the formation of phagocitic vacuoles, vesicular sorting and migration capacities of melanoma cells. Moreover, the ezrin fragment capable of binding to CD44 was shorter than that previously reported, and transfection with the ezrin deletion mutant abrogated plasma membrane Lamp-1 recruitment. This study highlights key involvement of ezrin in a complex machinery, which allows metastatic cancer cells to migrate, invade and survive in very unfavorable conditions. Our in vivo and in vitro data reveal that ezrin is the hub of the metastatic behavior also in human adult tumors.
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Affiliation(s)
- Cristina Federici
- Department of Therapeutic Research and Medicines Evaluation, Istituto Superiore di Sanità, Rome, Italy
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69
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Rolly protein (ROLP)-Epb4.1/3: a potential protein-protein interaction relevant for the maintenance of cell adhesion. Int J Mol Sci 2009; 10:2054-2065. [PMID: 19564939 PMCID: PMC2695267 DOI: 10.3390/ijms10052054] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2009] [Accepted: 05/11/2009] [Indexed: 11/17/2022] Open
Abstract
We recently described Rolly Protein (ROLP), a small protein synthesized by substrate-adherent cells in a broad range of tissues. In a first set of experiments performed taking advantage of bone forming tibial cartilage as an experimental model we showed that ROLP transcription is associated to cells in an active proliferation state, whereas its downregulation is observed when cell proliferation decreases. Taking advantage of siRNA technology we also documented the expression modulation of some apoptosis-related genes in ROLP-silenced cells. In this work we search for the possible molecular interactors of ROLP by using both the antibody array approach as well as the co-immunoprecipitation approach. Results suggest the occurrence of an interaction of ROLP with Erythrocyte membrane Protein Band 4.1/3 (Epb4.1/3), an oncosuppressor downregulated in tumor development and in metastatic tissues; in addition we report experimental results that keep in line also with a potential interaction of ROLP with other PDZ-containing proteins. We also present experimental evidences supporting a role played by ROLP in cell adhesion thus supporting the existence of a biologically relevant link between ROLP and Epb4.1/3. We here suggest that ROLP might exert its biological role cooperating with Epb4.1/3, a protein that is involved in biological pathways that are often inhibited in tumor metastasis. Given the role of Epb4.1/3 in contrasting cancerogenesis we think that its cooperation with ROLP might be relevant in cancer studies and deserves further investigation.
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70
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Abstract
Cellular function and adaptive behavior is often driven by signals generated in response to the local tissue microenvironment. Cell surface receptors that detect changes in extracellular matrix composition and modifications to extracellular matrix components, are ideally positioned to provide highly responsive sensors of changes in the microenvironment and mediate changes in cellular function required to maintain tissue integrity. Receptors can act as "on/off" switches, but ligand/receptor complexes that provide "rheostatic" control may be more sensitive, provide a more rapid mechanism of control and allow for fine-tuning of cellular responses to the microenvironment. Herein, we review evidence that transitions in the physiochemical properties of the extracellular glycosaminoglycan hyaluronan and in the function of its major receptor, CD44, differentially regulate ERK and Rac signal transduction pathways to provide critical rheostatic control of mesenchymal cell proliferation.
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Affiliation(s)
- Ellen Puré
- Wistar Institute and Department of Pharmacology, University of Pennsylvania, School of Medicine, Philadelphia, PA 19104, USA
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71
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Abstract
PURPOSE OF REVIEW Central nervous system (CNS) neurovascular units are multicellular complexes consisting of neurons and astrocytes, vascular endothelial cells and pericytes, as well as an assortment of growth factors and extracellular matrix (ECM) proteins. Here, I will discuss the current knowledge of signaling networks essential for the development and physiology of CNS neurovascular units, particularly in the brain. RECENT FINDINGS Molecular genetic studies have identified various signaling proteins that regulate the formation and function of CNS neurovascular units. These include members of the integrin family of ECM adhesion receptors, ECM proteins such as Wnts and latent transforming growth factor betas, and various transcriptional regulators, including beta-catenin and the inhibitors of DNA binding (Ids). SUMMARY Neurovascular units are the cellular and molecular interfaces between the circulatory system and the CNS. Recent molecular genetic analyses in mice and other model organisms have revealed the first mechanisms underlying bidirectional communication between neural and vascular components. In particular, ECM-mediated adhesion and signaling pathways have been identified as essential for neurovascular development and physiology. Understanding how these various gene products normally control neurovascular unit formation and function will lend new insights into the causes and possible treatments of debilitating neurovascular-related diseases such as birth defects, stroke, and age-related dementia.
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Affiliation(s)
- Joseph H McCarty
- Department of Cancer Biology, University of Texas M.D. Anderson Cancer Center, Houston, Texas, USA.
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72
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Niv MY, Iida K, Zheng R, Horiguchi A, Shen R, Nanus DM. Rational redesign of neutral endopeptidase binding to merlin and moesin proteins. Protein Sci 2009; 18:1042-50. [PMID: 19388049 DOI: 10.1002/pro.114] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Neutral endopeptidase (NEP) is a 90- to 110-kDa cell-surface peptidase that is normally expressed by numerous tissues but whose expression is lost or reduced in a variety of malignancies. The anti-tumorigenic function of NEP is mediated not only by its catalytic activity but also through direct protein-protein interactions of its cytosolic region with several binding partners, including Lyn kinase, PTEN, and ezrin/radixin/moesin (ERM) proteins. We have previously shown that mutation of the K(19)K(20)K(21) basic cluster in NEPs' cytosolic region to residues QNI disrupts binding to the ERM proteins. Here we show that the ERM-related protein merlin (NF2) does not bind NEP or its cytosolic region. Using experimental data, threading, and sequence analysis, we predicted the involvement of moesin residues E(159)Q(160) in binding to the NEP cytosolic domain. Mutation of these residues to NL (to mimic the corresponding N(159)L(160) residues in the nonbinder merlin) disrupted moesin binding to NEP. Mutation of residues N(159)L(160)Y(161)K(162)M(163) in merlin to the corresponding moesin residues resulted in NEP binding to merlin. This engineered NEP peptide-merlin interaction was diminished by the QNI mutation in NEP, supporting the role of the NEP basic cluster in binding. We thus identified the region of interaction between NEP and moesin, and engineered merlin into a NEP-binding protein. These data form the basis for further exploration of the details of NEP-ERM binding and function.
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Affiliation(s)
- Masha Y Niv
- Institute of Biochemistry, Food Science and Nutrition, Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, P.O. Box 12, Rehovot 76100, Israel
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73
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Kang Q, Wang T, Zhang H, Mohandas N, An X. A Golgi-associated protein 4.1B variant is required for assimilation of proteins in the membrane. J Cell Sci 2009; 122:1091-9. [PMID: 19299464 DOI: 10.1242/jcs.039644] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The archetypal membrane skeleton is that of the erythrocyte, consisting predominantly of spectrin, actin, ankyrin R and protein 4.1R. The presence in the Golgi of a membrane skeleton with a similar structure has been inferred, based on the identification of Golgi-associated spectrin and ankyrin. It has long been assumed that a Golgi-specific protein 4.1 must also exist, but it has not previously been found. We demonstrate here that a hitherto unknown form of protein 4.1, a 200 kDa 4.1B, is associated with the Golgi of Madin-Darby canine kidney (MDCK) and human bronchial epithelial (HBE) cells. This 4.1B variant behaves like a Golgi marker after treatment with Brefeldin A and during mitosis. Depletion of the protein in HBE cells by siRNA resulted in disruption of the Golgi structure and failure of Na(+)/K(+)-ATPase, ZO-1 and ZO-2 to migrate to the membrane. Thus, this newly identified Golgi-specific protein 4.1 appears to have an essential role in maintaining the structure of the Golgi and in assembly of a subset of membrane proteins.
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Affiliation(s)
- Qiaozhen Kang
- Red Cell Physiology Laboratory, New York Blood Center, New York, NY 10065, USA
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74
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Yang Y, Baboolal TG, Siththanandan V, Chen M, Walker ML, Knight PJ, Peckham M, Sellers JR. A FERM domain autoregulates Drosophila myosin 7a activity. Proc Natl Acad Sci U S A 2009; 106:4189-94. [PMID: 19255446 PMCID: PMC2649957 DOI: 10.1073/pnas.0808682106] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2008] [Indexed: 12/22/2022] Open
Abstract
Full-length Drosophila myosin 7a (myosin 7a-FL) has a complex tail containing a short predicted coiled coil followed by a MyTH4-FERM domain, an SH3 domain, and a C-terminal MyTH4-FERM domain. Myosin 7a-FL expressed in Sf9 cells is monomeric despite the predicted coiled coil. We showed previously that Subfragment-1 (S1) from this myosin has MgATPase of V(max) approximately 1 s(-1) and K(ATPase) approximately 1 microM actin. We find that myosin 7a-FL has V(max) similar to S1 but K(ATPase) approximately 30 microM. Thus, at low actin concentrations (5 microM), the MgATPase of S1 is fully activated, whereas that of myosin 7a-FL is low, suggesting that the tail regulates activity. Electron microscopy of myosin 7a-FL with ATP shows the tail is tightly bent back against the motor domain. Myosin 7a-FL extends at either high ionic strength or without ATP, revealing the motor domain, lever, and tail. A series of C-terminal truncations show that deletion of 99 aa (the MyTH7 subdomain of the C-terminal FERM domain) is sufficient to abolish bending, and the K(ATPase) is then similar to S1. This region is highly conserved in myosin 7a. We found that a double mutation in it, R2140A-K2143A, abolishes bending and reduces K(ATPase) to S1 levels. In addition, the expressed C-terminal FERM domain binds actin with K(d) approximately 30 microM regardless of ATP, similar to the K(ATPase) value for myosin 7a-FL. We propose that at low cellular actin concentrations, myosin 7a-FL is bent and inactive, but at high actin concentrations, it is unfolded and active because the C-terminal FERM domain binds to actin.
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Affiliation(s)
- Yi Yang
- Laboratory of Molecular Physiology, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892
| | - Thomas G. Baboolal
- Astbury Centre for Structural Molecular Biology and Institute of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom; and
| | - Verl Siththanandan
- Laboratory of Molecular Physiology, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892
| | - Michael Chen
- Laboratory of Molecular Physiology, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892
| | - Matthew L. Walker
- MLW Consulting, 11 Race Hill, Launceston, Cornwall PL15 9BB, United Kingdom
| | - Peter J. Knight
- Astbury Centre for Structural Molecular Biology and Institute of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom; and
| | - Michelle Peckham
- Astbury Centre for Structural Molecular Biology and Institute of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom; and
| | - James R. Sellers
- Laboratory of Molecular Physiology, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892
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75
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Transition dependency: a gene-gene interaction measure for times series microarray data. EURASIP JOURNAL ON BIOINFORMATICS & SYSTEMS BIOLOGY 2009:535869. [PMID: 19223963 DOI: 10.1155/2009/535869] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2008] [Revised: 07/31/2008] [Accepted: 11/06/2008] [Indexed: 11/17/2022]
Abstract
Gene-Gene dependency plays a very important role in system biology as it pertains to the crucial understanding of different biological mechanisms. Time-course microarray data provides a new platform useful to reveal the dynamic mechanism of gene-gene dependencies. Existing interaction measures are mostly based on association measures, such as Pearson or Spearman correlations. However, it is well known that such interaction measures can only capture linear or monotonic dependency relationships but not for nonlinear combinatorial dependency relationships. With the invocation of hidden Markov models, we propose a new measure of pairwise dependency based on transition probabilities. The new dynamic interaction measure checks whether or not the joint transition kernel of the bivariate state variables is the product of two marginal transition kernels. This new measure enables us not only to evaluate the strength, but also to infer the details of gene dependencies. It reveals nonlinear combinatorial dependency structure in two aspects: between two genes and across adjacent time points. We conduct a bootstrap-based chi(2) test for presence/absence of the dependency between every pair of genes. Simulation studies and real biological data analysis demonstrate the application of the proposed method. The software package is available under request.
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76
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Cytoskeletal protein 4.1R negatively regulates T-cell activation by inhibiting the phosphorylation of LAT. Blood 2009; 113:6128-37. [PMID: 19190245 DOI: 10.1182/blood-2008-10-182329] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Protein 4.1R (4.1R) was first identified in red cells where it plays an important role in maintaining mechanical stability of red cell membrane. 4.1R has also been shown to be expressed in T cells, but its function has been unclear. In the present study, we use 4.1R-deficient mice to explore the role of 4.1R in T cells. We show that 4.1R is recruited to the immunologic synapse after T cell-antigen receptor (TCR) stimulation. We show further that CD4+ T cells of 4.1R-/- mice are hyperactivated and that they displayed hyperproliferation and increased production of interleukin-2 (IL-2) and interferon gamma (IFNgamma). The hyperactivation results from enhanced phosphorylation of LAT and its downstream signaling molecule ERK. The 4.1R exerts its effect by binding directly to LAT, and thereby inhibiting its phosphorylation by ZAP-70. Moreover, mice deficient in 4.1R display an elevated humoral response to immunization with T cell-dependent antigen. Thus, we have defined a hitherto unrecognized role for 4.1R in negatively regulating T-cell activation by modulating intracellular signal transduction.
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77
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Ohno N, Terada N, Komada M, Saitoh S, Costantini F, Pace V, Germann PG, Weber K, Yamakawa H, Ohara O, Ohno S. Dispensable role of protein 4.1B/DAL-1 in rodent adrenal medulla regarding generation of pheochromocytoma and plasmalemmal localization of TSLC1. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2009; 1793:506-15. [PMID: 19321127 DOI: 10.1016/j.bbamcr.2009.01.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2008] [Revised: 12/06/2008] [Accepted: 01/06/2009] [Indexed: 02/07/2023]
Abstract
Protein 4.1B is a membrane skeletal protein expressed in various organs, and is associated with tumor suppressor in lung cancer-1 (TSLC1) in vitro. Although involvement of 4.1B in the intercellular junctions and tumor-suppression was suggested, some controversial results posed questions to the general tumor-suppressive function of 4.1B and its relation to TSLC1 in vivo. In this study, the expression of 4.1B and its interaction with TSLC1 were examined in rodent adrenal gland, and the involvement of 4.1B in tumorigenesis and the effect of 4.1B deficiency on TSLC1 distribution were also investigated using rodent pheochromocytoma and 4.1B-knockout mice. Although plasmalemmal immunolocalization of 4.1B was shown in chromaffin cells of rodent adrenal medulla, expression of 4.1B was maintained in developed pheochromocytoma, and morphological abnormality or pheochromocytoma generation could not be found in 4.1B-deficient mice. Furthermore, molecular interaction and colocalization of 4.1B and TSLC1 were observed in mouse adrenal gland, but the immunolocalization of TSLC1 along chromaffin cell membranes was not affected in the 4.1B-deficient mice. These results suggest that the function of 4.1B as tumor suppressor might significantly differ among organs and species, and that plasmalemmal retention of TSLC1 would be maintained by molecules other than 4.1B interacting in rodent chromaffin cells.
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Affiliation(s)
- Nobuhiko Ohno
- Department of Anatomy and Molecular Histology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Chuo, Yamanashi 409-3898, Japan
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78
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Abstract
During evolution, as organisms increased in complexity and function, the need for the ensheathment and insulation of axons by glia became vital for faster conductance of action potentials in nerves. Myelination, as the process is termed, facilitates the formation of discrete domains within the axolemma that are enriched in ion channels, and macromolecular complexes consisting of cell adhesion molecules and cytoskeletal regulators. While it is known that glia play a substantial role in the coordination and organization of these domains, the mechanisms involved and signals transduced between the axon and glia, as well as the proteins regulating axo-glial junction formation remain elusive. Emerging evidence has shed light on the processes regulating myelination and domain differentiation, and key molecules have been identified that are required for their assembly and maintenance. This review highlights these recent findings, and relates their significance to domain disorganization as seen in several demyelinating disorders and other neuropathies.
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Affiliation(s)
- Courtney Thaxton
- Department of Cell and Molecular Physiology, Curriculum in Neurobiology, UNC-Neuroscience Center and Neurodevelopmental Disorders Research Center, University of North Carolina School of Medicine, Chapel Hill, NC 27599-7545, USA
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The neurofibromatosis 2 protein, merlin, regulates glial cell growth in an ErbB2- and Src-dependent manner. Mol Cell Biol 2008; 29:1472-86. [PMID: 19103750 DOI: 10.1128/mcb.01392-08] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Individuals with the inherited cancer predisposition syndrome neurofibromatosis 2 (NF2) develop several central nervous system (CNS) malignancies, including glial cell neoplasms (ependymomas). Recent studies have suggested that the NF2 protein, merlin (or schwannomin), may regulate receptor tyrosine kinase signaling, intracellular mitogenic growth control pathways, or adherens junction organization in non-nervous-system cell types. For this report, we used glial fibrillary acidic protein conditional knockout mice and derivative glia to determine how merlin regulates CNS glial cell proliferation. We show that the loss of merlin in glial cells results in increased proliferation in vitro and in vivo. Merlin regulation of glial cell growth reflects deregulated Src activity, such that pharmacologic or genetic inhibition of Src activation reduces Nf2(-/-) glial cell growth to wild-type levels. We further show that Src regulates Nf2(-/-) glial cell growth by sequentially regulating FAK and paxillin phosphorylation/activity. Next, we demonstrate that Src activation results from merlin regulation of ErbB2 activation and that genetic or pharmacologic ErbB2 inhibition reduces Nf2(-/-) glial cell Src/Src effector activation and proliferation to wild-type levels. Lastly, we show that merlin competes with Src for direct binding to ErbB2 and present a novel molecular mechanism for merlin regulation of ErbB2-dependent Src signaling and growth control.
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80
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Yoon KJ, Phelps DA, Bush RA, Remack JS, Billups CA, Khoury JD. ICAM-2 expression mediates a membrane-actin link, confers a nonmetastatic phenotype and reflects favorable tumor stage or histology in neuroblastoma. PLoS One 2008; 3:e3629. [PMID: 18978946 PMCID: PMC2575377 DOI: 10.1371/journal.pone.0003629] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2008] [Accepted: 10/13/2008] [Indexed: 11/18/2022] Open
Abstract
The actin cytoskeleton is a primary determinant of tumor cell motility and metastatic potential. Motility and metastasis are thought to be regulated, in large part, by the interaction of membrane proteins with cytoplasmic linker proteins and of these linker proteins, in turn, with actin. However, complete membrane-to-actin linkages have been difficult to identify. We used co-immunoprecipitation and competitive peptide assays to show that intercellular adhesion molecule-2 (ICAM-2)/alpha-actinin/actin may comprise such a linkage in neuroblastoma cells. ICAM-2 expression limited the motility of these cells and redistributed actin fibers in vitro, and suppressed development of disseminated tumors in an in vivo model of metastatic neuroblastoma. Consistent with these observations, immunohistochemical analysis demonstrated ICAM-2 expression in primary neuroblastoma tumors exhibiting features that are associated with limited metastatic disease and more favorable clinical outcome. In neuroblastoma cell lines, ICAM-2 expression did not affect AKT activation, tumorigenic potential or chemosensitivity, as has been reported for some types of transfected cells. The observed ICAM-2-mediated suppression of metastatic phenotype is a novel function for this protein, and the interaction of ICAM-2/alpha-actinin/actin represents the first complete membrane-linker protein-actin linkage to impact tumor cell motility in vitro and metastatic potential in an in vivo model. Current work focuses on identifying specific protein domains critical to the regulation of neuroblastoma cell motility and metastasis and on determining if these domains represent exploitable therapeutic targets.
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Affiliation(s)
- Karina Jin Yoon
- Department of Molecular Pharmacology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA.
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81
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Galvan A, Falvella FS, Spinola M, Frullanti E, Leoni VP, Noci S, Alonso MR, Zolin A, Spada E, Milani S, Pastorino U, Incarbone M, Santambrogio L, Gonzalez Neira A, Dragani TA. A polygenic model with common variants may predict lung adenocarcinoma risk in humans. Int J Cancer 2008; 123:2327-30. [PMID: 18729187 DOI: 10.1002/ijc.23789] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Genome-wide screening for genetic loci associated with risk of lung adenocarcinoma (ADCA) was carried out in pooled DNA using the Illumina 300K single-nucleotide polymorphism (SNP) array, in a joint analysis of 2 Italian case-control series matched by age, gender and smoking habit. The rare allele carrier status of 8 SNPs was associated with a decreased lung ADCA risk [odds ratios (OR): 0.6-0.8]. In a polygenic model characterized by additive and interchangeable effects, individuals carrying 2 to 6 rare alleles at these 8 SNPs showed a significant trend toward a decreased risk of lung ADCA (up to OR of 0.3). These results suggest the relevance of a polygenic model in the modulation of individual risk of lung ADCA in the general population.
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82
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Hirano M, Hashimoto S, Yonemura S, Sabe H, Aizawa S. EPB41L5 functions to post-transcriptionally regulate cadherin and integrin during epithelial-mesenchymal transition. ACTA ACUST UNITED AC 2008; 182:1217-30. [PMID: 18794329 PMCID: PMC2542480 DOI: 10.1083/jcb.200712086] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
EPB41L5 belongs to the band 4.1 superfamily. We investigate here the involvement of EPB41L5 in epithelial-mesenchymal transition (EMT) during mouse gastrulation. EPB41L5 expression is induced during TGFbeta-stimulated EMT, whereas silencing of EPB41L5 by siRNA inhibits this transition. In EPB41L5 mutants, cell-cell adhesion is enhanced, and EMT is greatly impaired during gastrulation. Moreover, cell attachment, spreading, and mobility are greatly reduced by EPB41L5 deficiency. Gene transcription regulation during EMT occurs normally at the mRNA level; EPB41L5 siRNA does not affect either the decrease in E-cadherin or the increase in integrin expression. However, at the protein level, the decrease in E-cadherin and increase in integrin are inhibited in both EPB41L5 siRNA-treated NMuMG cells and mutant mesoderm. We find that EPB41L5 binds p120ctn through its N-terminal FERM domain, inhibiting p120ctn-E-cadherin binding. EPB41L5 overexpression causes E-cadherin relocalization into Rab5-positive vesicles in epithelial cells. At the same time, EPB41L5 binds to paxillin through its C terminus, enhancing integrin/paxillin association, thereby stimulating focal adhesion formation.
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Affiliation(s)
- Mariko Hirano
- Laboratory for Vertebrate Body Plan, Center for Developmental Biology, RIKEN Kobe, Chuo-ku, Kobe 650-0047, Japan
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83
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Bernkopf DB, Williams ED. Potential role of EPB41L3 (protein 4.1B/Dal-1) as a target for treatment of advanced prostate cancer. Expert Opin Ther Targets 2008; 12:845-53. [PMID: 18554153 DOI: 10.1517/14728222.12.7.845] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
BACKGROUND Loss of erythrocyte membrane protein band 4.1-like 3 (EPB41L3; aliases: protein 4.1B, differentially expressed in adenocarcinoma of the lung-1 (Dal-1)) expression has been implicated in tumor progression. OBJECTIVE To evaluate literature describing the role of EPB41L3 in tumorigenesis and metastasis, and to consider whether targeting this gene would be useful in the treatment of prostate cancer. METHODS A literature review of studies describing EPB41L3 and its aliases was conducted. Online databases (NCBI, SwissProt) were also interrogated to collect further data. RESULTS/CONCLUSION A growing body of evidence supports a role for loss of EPB41L3 in tumor progression, including in prostate cancer. Therapeutic strategies that could be harnessed to upregulate EPB41L3 gene expression in prostate cancer cells are currently being developed.
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Affiliation(s)
- Dominic B Bernkopf
- Monash University, Centre for Cancer Research, Monash Institute of Medical Research, Monash Medical Centre, 246 Clayton Road, Clayton, Victoria, 3168, Australia
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84
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Yokoyama T, Osada H, Murakami H, Tatematsu Y, Taniguchi T, Kondo Y, Yatabe Y, Hasegawa Y, Shimokata K, Horio Y, Hida T, Sekido Y. YAP1 is involved in mesothelioma development and negatively regulated by Merlin through phosphorylation. Carcinogenesis 2008; 29:2139-46. [PMID: 18725387 DOI: 10.1093/carcin/bgn200] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
We previously reported the results of bacterial artificial chromosome array comprehensive genomic hybridization of malignant pleural mesotheliomas (MPMs), including two cases with high-level amplification in the 11q22 locus. In this study, we found that the YAP1 gene encoding a transcriptional coactivator was localized in this amplified region and overexpressed in both cases, suggesting it as a candidate oncogene in this region. We analyzed the involvement of YAP1 in MPM proliferation, as well as its functional and physical interaction with Merlin encoded by the neurofibromatosis type 2 (NF2) tumor suppressor gene, which is frequently mutated in MPMs. YAP1-RNA interference suppressed growth of a mesothelioma cell line NCI-H290 with NF2 homozygous deletion, probably through cell-cycle arrest and apoptosis induction, whereas YAP1 transfection promoted the growth of MeT-5A, an immortalized mesothelial cell line. We also found that the introduction of NF2 into NCI-H290 induced phosphorylation at serine 127 of YAP1, which was accompanied by reduction of nuclear localization of YAP1, whereas nuclear localization of a YAP1 S 127A mutant was not affected. Furthermore, results of immunoprecipitation and in vitro pull-down assays indicated a physical interaction between Merlin and YAP1. These results suggest that YAP1 is involved in mesothelial cell growth and that the transcriptional coactivator activity of YAP1 is functionally inhibited by Merlin through the induction of phosphorylation and cytoplasmic retention of YAP1. This is the first report of negative regulatory signaling from Merlin to YAP1 in mammalian cells. Future studies of transcriptional targets of YAP1 in MPMs may shed light on the molecular mechanisms of MPM development and lead to new therapeutic strategies.
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Affiliation(s)
- Toshihiko Yokoyama
- Division of Molecular Oncology, Aichi Cancer Center Research Institute, 1-1 Kanokoden, Chikusa-ku, Nagoya 464-8681, Japan
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85
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Yamauchi J, Miyamoto Y, Kusakawa S, Torii T, Mizutani R, Sanbe A, Nakajima H, Kiyokawa N, Tanoue A. Neurofibromatosis 2 tumor suppressor, the gene induced by valproic acid, mediates neurite outgrowth through interaction with paxillin. Exp Cell Res 2008; 314:2279-88. [PMID: 18486129 DOI: 10.1016/j.yexcr.2008.03.019] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2008] [Revised: 03/26/2008] [Accepted: 03/29/2008] [Indexed: 01/10/2023]
Abstract
Valproic acid (VPA), the drug for bipolar disorder and epilepsy, has a potent ability to induce neuronal differentiation, yet comparatively little is presently known about the underlying mechanism. We previously demonstrated that c-Jun N-terminal kinase (JNK) phosphorylation of the focal adhesion protein paxillin mediates differentiation in N1E-115 neuroblastoma cells. Here, we show that VPA up-regulates the neurofibromatosis type 2 (NF2) tumor suppressor, merlin, to regulate neurite outgrowth through the interaction with paxillin. The inhibition of merlin function by its knockdown or expression of merlin harboring the Gln-538-to-Pro mutation, a naturally occurring NF2 missense mutation deficient in linking merlin to the actin cytoskeleton, decreases VPA-induced neurite outgrowth. Importantly, the expression of merlin by itself is not sufficient to induce neurite outgrowth, which requires co-expression with paxillin, the binding partner of merlin. In fact, the missense mutation Trp-60-to-Cys or Phe-62-to-Ser, that is deficient in binding to paxillin, reduces neurite outgrowth induced by VPA. In addition, co-expression of a paxillin construct harboring the mutation at the JNK phosphorylation site with merlin results in blunted induction of the outgrowth. We also find that the first LIM domain of paxillin is a major binding region with merlin and that expression of the isolated first LIM domain blocks the effects of VPA. Furthermore, similar findings that merlin regulates neurite outgrowth through the interaction with paxillin have been observed in several kinds of neuronal cells. These results suggest that merlin is an as yet unknown regulator of neurite outgrowth through the interaction with paxillin, providing a possibly common mechanism regulating neurite formation.
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Affiliation(s)
- Junji Yamauchi
- Department of Pharmacology, National Research Institute for Child Health and Development, 2-10-1 Okura, Setagaya, Tokyo 157-8535, Japan.
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86
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Zander L, Bemark M. Identification of genes deregulated during serum-free medium adaptation of a Burkitt's lymphoma cell line. Cell Prolif 2008; 41:136-55. [PMID: 18211290 DOI: 10.1111/j.1365-2184.2007.00500.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
OBJECTIVE Serum is usually added to growth media when mammalian cells are cultured in vitro to supply the cells with growth factors, hormones, nutrients and trace elements. Defined proteins and metal ions, such as insulin, growth factors, transferrin and sodium selenite, are sometimes also included and can in some cases substitute serum components. How adaptation to serum free media influences cells has not been studied in detail. MATERIALS AND METHODS We have adapted the Burkitt's lymphoma line Ramos to a serum-free medium that supports long-term survival and studied gene expression changes that occurred during the adaptation process. RESULTS AND CONCLUSIONS The adaptation process was characterized by initial cell population growth arrest, and after that extensive cell death, followed by proliferation and long-term survival of clonal cultures. Proliferation and cell cycle progression of the serum-free cultures closely mimicked that of serum-dependent cells. Affymetrix micro-array technology was used to identify gene expression alterations that had occurred during the adaptation. Most changes were subtle, but frequently the genes with altered expression were involved in basal cellular functions such as cell division, cell cycle regulation, apoptosis and cell signalling. Some alterations were restored when the cells were transferred back to serum-containing medium, indicating that expression of these genes was controlled by components in serum. Others were not, and may represent changes that were selected during the adaptation process. Among these were, for example, several genes within the Wnt signalling pathway.
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Affiliation(s)
- L Zander
- Department of Microbiology and Immunology, Gothenburg University, Göteborg, Sweden
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87
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Houshmandi SS, Gutmann DH. All in the family: using inherited cancer syndromes to understand de-regulated cell signaling in brain tumors. J Cell Biochem 2008; 102:811-9. [PMID: 17721931 DOI: 10.1002/jcb.21506] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The cell signaling pathways that are tightly regulated during development are often co-opted by cancer cells to allow them to escape from the constraints that normally limit cell growth and cell movement. In this regard, de-regulated signaling in cancer cells confers a number of key tumor-associated properties, including increased cell proliferation, decreased cell death, and increased cell motility. The identification of some of these critical signaling pathways in the nervous system has come from studies of inherited cancer syndromes in which affected individuals develop brain tumors. The study of brain tumors arising in patients with neurofibromatosis 1 (NF1), neurofibromatosis 2 (NF2), and tuberous sclerosis complex (TSC) has already uncovered several key intracellular signaling pathways important for modulating brain tumor growth. An in-depth analysis of these intracellular signaling pathways will not only lead to an improved understanding of the process of brain tumorigenesis, but may also provide important molecular targets for future therapeutic drug design.
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Affiliation(s)
- S Sean Houshmandi
- Department of Neurology, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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88
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James MF, Lelke JM, Maccollin M, Plotkin SR, Stemmer-Rachamimov AO, Ramesh V, Gusella JF. Modeling NF2 with human arachnoidal and meningioma cell culture systems: NF2 silencing reflects the benign character of tumor growth. Neurobiol Dis 2008; 29:278-92. [PMID: 17962031 PMCID: PMC2266821 DOI: 10.1016/j.nbd.2007.09.002] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2007] [Revised: 08/28/2007] [Accepted: 09/03/2007] [Indexed: 11/28/2022] Open
Abstract
Meningiomas, common tumors arising from arachnoidal cells of the meninges, may occur sporadically, or in association with the inherited disorder, neurofibromatosis 2 (NF2). Most sporadic meningiomas result from NF2 inactivation, resulting in loss of tumor suppressor merlin, implicated in regulating membrane-cytoskeletal organization. To investigate merlin function in an authentic target cell type for NF2 tumor formation, we established primary cultures from genetically-matched meningioma and normal arachnoidal tissues. Our studies revealed novel and distinct cell biological and biochemical properties unique to merlin-deficient meningioma cells compared to merlin-expressing arachnoidal and meningioma cells, and other NF2-deficient cell types. Merlin-deficient meningioma cells displayed cytoskeletal and cell contact defects, altered cell morphology and growth properties, most notably cell senescence, implicating the activation of senescence pathways in limiting benign meningioma growth. Merlin suppression by RNAi in arachnoidal cells replicated merlin-deficient meningioma features, thus establishing these cell systems as disease-relevant models for studying NF2 tumorigenesis.
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Affiliation(s)
- Marianne F James
- Molecular Neurogenetics Unit, Center for Human Genetic Research, Massachusetts General Hospital, Richard B. Simches Research Building, 185 Cambridge Street, Boston, MA 02114, USA
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89
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Wong SY, Haack H, Kissil JL, Barry M, Bronson RT, Shen SS, Whittaker CA, Crowley D, Hynes RO. Protein 4.1B suppresses prostate cancer progression and metastasis. Proc Natl Acad Sci U S A 2007; 104:12784-9. [PMID: 17640904 PMCID: PMC1924789 DOI: 10.1073/pnas.0705499104] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2007] [Indexed: 11/18/2022] Open
Abstract
Protein 4.1B is a 4.1/ezrin/radixin/moesin domain-containing protein whose expression is frequently lost in a variety of human tumors, including meningiomas, non-small-cell lung cancers, and breast carcinomas. However, its potential tumor-suppressive function under in vivo conditions remains to be validated. In a screen for genes involved with prostate cancer metastasis, we found that 4.1B expression is reduced in highly metastatic tumors. Down-regulation of 4.1B increased the metastatic propensity of poorly metastatic cells in an orthotopic model of prostate cancer. Furthermore, 4.1B-deficient mice displayed increased susceptibility for developing aggressive, spontaneous prostate carcinomas. In both cases, enhanced tumor malignancy was associated with reduced apoptosis. Because expression of Protein 4.1B is frequently down-regulated in human clinical prostate cancer, as well as in a spectrum of other tumor types, these results suggest a more general role for Protein 4.1B as a negative regulator of cancer progression to metastatic disease.
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Affiliation(s)
- Sunny Y. Wong
- *Howard Hughes Medical Institute, Massachusetts Institute of Technology Center for Cancer Research, Cambridge, MA 02139
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Herbert Haack
- *Howard Hughes Medical Institute, Massachusetts Institute of Technology Center for Cancer Research, Cambridge, MA 02139
| | - Joseph L. Kissil
- Molecular and Cellular Oncogenesis Program, The Wistar Institute, Philadelphia, PA 19104; and
| | - Marc Barry
- *Howard Hughes Medical Institute, Massachusetts Institute of Technology Center for Cancer Research, Cambridge, MA 02139
| | - Roderick T. Bronson
- **Department of Biomedical Sciences, Tufts School of Veterinary Medicine, North Grafton, MA 01536
| | - Steven S. Shen
- *Howard Hughes Medical Institute, Massachusetts Institute of Technology Center for Cancer Research, Cambridge, MA 02139
| | - Charles A. Whittaker
- *Howard Hughes Medical Institute, Massachusetts Institute of Technology Center for Cancer Research, Cambridge, MA 02139
| | - Denise Crowley
- *Howard Hughes Medical Institute, Massachusetts Institute of Technology Center for Cancer Research, Cambridge, MA 02139
| | - Richard O. Hynes
- *Howard Hughes Medical Institute, Massachusetts Institute of Technology Center for Cancer Research, Cambridge, MA 02139
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139
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90
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Hsu EC, Lin YC, Hung CS, Huang CJ, Lee MY, Yang SC, Ting LP. Suppression of hepatitis B viral gene expression by protein-tyrosine phosphatase PTPN3. J Biomed Sci 2007; 14:731-44. [PMID: 17588219 DOI: 10.1007/s11373-007-9187-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2007] [Accepted: 06/03/2007] [Indexed: 10/23/2022] Open
Abstract
Protein-tyrosine phosphatase PTPN3 is a membrane-associated non-receptor protein-tyrosine phosphatase. PTPN3 contains a N-terminal FERM domain, a middle PDZ domain, and a C-terminal phosphatase domain. Upon co-expression of PTPN3, the level of human hepatitis B viral (HBV) RNAs, 3.5 kb, 2.4/2.1 kb, and 0.7 kb transcribed from a replicating HBV expression plasmid is significantly reduced in human hepatoma HuH-7 cells. When the expression of endogenous PTPN3 protein is diminished by specific small interfering RNA, the expression of HBV genes is enhanced, indicating that the endogenous PTPN3 indeed plays a suppressive role on HBV gene expression. PTPN3 can interact with HBV core protein. The interaction is mediated via the PDZ domain of PTPN3 and the carboxyl-terminal last four amino acids of core. Either deletion of PDZ domain of PTPN3 or substitution of PDZ ligand in core has no effect on PTPN3-mediated suppression. These results clearly show that the interaction of PTPN3 with core is not required for PTPN3 suppressive effect. Mutation of (359)serine and (835)serine of 14-3-3beta binding sites to alanine, which slightly reduces the interaction with 14-3-3beta, does not influence the PTPN3 effect. In contrast, mutation of the invariant (842)cysteine residue in phosphatase domain to serine, which makes the phosphatase activity inactive, does not change its subcellular localization and interaction with core or 14-3-3beta, but completely abolishes PTPN3-mediated suppression. Furthermore, deletion of FERM domain does not affect the phosphatase activity or interaction with 14-3-3beta, but changes the subcellular localization from cytoskeleton-membrane interface to cytoplasm and nucleus, abolishes binding to core, and diminishes the PTPN3 effect on HBV gene expression. Taken together, these results demonstrate that the phosphatase activity and FERM domain of PTPN3 are essential for its suppression of HBV gene expression.
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MESH Headings
- Carcinoma, Hepatocellular/metabolism
- Cells, Cultured
- Fluorescent Antibody Technique
- Gene Expression Regulation, Viral
- Gene Silencing
- Genes, Viral
- Hepatitis B virus/genetics
- Hepatitis B virus/metabolism
- Humans
- Liver Neoplasms/metabolism
- Protein Structure, Tertiary
- Protein Tyrosine Phosphatase, Non-Receptor Type 3/analysis
- Protein Tyrosine Phosphatase, Non-Receptor Type 3/genetics
- Protein Tyrosine Phosphatase, Non-Receptor Type 3/metabolism
- Suppression, Genetic
- Transfection
- Tumor Cells, Cultured
- Viral Core Proteins/genetics
- Viral Core Proteins/metabolism
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Affiliation(s)
- En-Chi Hsu
- Institute of Microbiology and Immunology, School of Life Science, National Yang-Ming University, Pei-Tou, Taipei 11221, Taiwan, ROC
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91
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Terawaki SI, Kitano K, Hakoshima T. Structural basis for type II membrane protein binding by ERM proteins revealed by the radixin-neutral endopeptidase 24.11 (NEP) complex. J Biol Chem 2007; 282:19854-62. [PMID: 17459884 DOI: 10.1074/jbc.m609232200] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
ERM (Ezrin/Radixin/Moesin) proteins mediate formation of membrane-associated cytoskeletons by simultaneously binding actin filaments and the C-terminal cytoplasmic tails of adhesion molecules (type I membrane proteins). ERM proteins also bind neutral endopeptidase 24.11 (NEP), a type II membrane protein, even though the N-terminal cytoplasmic tail of NEP possesses the opposite peptide polarity to that of type I membrane proteins. Here, we determined the crystal structure of the radixin FERM (Four point one and ERM) domain complexed with the N-terminal NEP cytoplasmic peptide. In the FERM-NEP complex, the amphipathic region of the peptide forms a beta strand followed by a hairpin that bind to a shallow groove of FERM subdomain C. NEP binding is stabilized by beta-beta interactions and docking of the NEP hairpin into the hydrophobic pocket of subdomain C. Whereas the binding site of NEP on the FERM domain overlaps with the binding site of intercellular adhesion molecule (ICAM)-2, NEP lacks the Motif-1 sequence conserved in ICAM-2 and related adhesion molecules. The NEP hairpin, although lacking the typical inter-chain hydrogen bond but is stabilized by hydrogen bonds with the main chain and side chains of subdomain C, directs the C-terminal basic region of the NEP peptide away from the groove and toward the membrane. The overlap of the binding sites on subdomain C for NEP and Motif-1 adhesion molecules such as CD44 provides the structural basis for the suppression of cell adhesion through interaction between NEP and ERM proteins.
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Affiliation(s)
- Shin-ichi Terawaki
- Structural Biology Laboratory, Nara Institute of Science and Technology, and CREST, Japan Science and Technology Agency, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan
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92
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Haase D, Meister M, Muley T, Hess J, Teurich S, Schnabel P, Hartenstein B, Angel P. FRMD3, a novel putative tumour suppressor in NSCLC. Oncogene 2007; 26:4464-8. [PMID: 17260017 DOI: 10.1038/sj.onc.1210225] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Lung cancer including non-small cell lung carcinoma (NSCLC) represents a leading cause of cancer death in Western countries. Yet, understanding its pathobiology to improve early diagnosis and therapeutic strategies is still a major challenge of today's biomedical research. We analyzed a set of differentially regulated genes that were identified in skin cancer by a comprehensive microarray study, for their expression in NSCLC. We found that ferm domain containing protein 3 (FRMD3), a member of the protein 4.1 superfamily, is expressed in normal lung tissue but silenced in 54 out of 58 independent primary NSCLC tumours compared to patient-matched normal lung tissue. FRMD3 overexpression in different epithelial cell lines resulted in a decreased clonogenicity as measured by colony formation assay. Although cell attachment capabilities and cell proliferation rate remained unchanged, this phenotype was most likely owing to induced apoptosis. Our data identify FRMD3 as a novel putative tumour suppressor gene suggesting an important role in the origin and progression of lung cancer.
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Affiliation(s)
- D Haase
- Deutsches Krebsforschungszentrum Heidelberg, Division of Signal Transduction and Growth Control, Heidelberg, Germany
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93
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Pérez-Ferreiro CM, Lospitao E, Correas I. Protein 4.1R self-association: identification of the binding domain. Biochem J 2006; 400:457-65. [PMID: 16881872 PMCID: PMC1698608 DOI: 10.1042/bj20060644] [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: 11/17/2022]
Abstract
Erythroid protein 4.1 (4.1R) stabilizes the spectrin-actin network and anchors it to the plasma membrane. To contribute to the characterization of non-erythroid protein 4.1R, we used sedimentation, pull-down and co-immunoprecipitation assays to investigate the ability of protein 4.1R to establish inter-/intra-molecular associations. We demonstrated that the small 4.1R isoforms of 60 kDa (4.1R60), but not the larger isoforms of 80 and 135 kDa (4.1R80 and 4.1R135), were self-associated, and that a domain contained in all 4.1R isoforms, the core region, was responsible for 4.1R self-association. Results from denaturing-renaturing experiments, in which an initially non-self-associated 4.1R80 isoform became self-associated, suggested that an initially hidden core region was subsequently exposed. This hypothesis was supported by results from pull-down assays, which showed that the core region interacted with the N-terminal end of the FERM (4.1, ezrin, radixin, moesin) domain that is present in 4.1R80 and 4.1R135 isoforms but absent from 4.1R60 isoforms. Consistently, 4.1R80 isoforms bound neither to each other nor to 4.1R60 isoforms. We propose that 4.1R60 isoforms are constitutively self-associated, whereas 4.1R80 and 4.1R135 self-association is prevented by intramolecular interactions.
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Affiliation(s)
- Carmen M Pérez-Ferreiro
- Departamento de Biología Molecular, CBMSO (Centro de Biología Molecular Severo Ochoa), UAM/CSIC, Cantoblanco, E-28049 Madrid, Spain.
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94
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Baser ME. The distribution of constitutional and somatic mutations in the neurofibromatosis 2 gene. Hum Mutat 2006; 27:297-306. [PMID: 16521120 DOI: 10.1002/humu.20317] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Constitutional heterozygous inactivating mutations in the neurofibromatosis 2 (NF2) tumor suppressor gene cause the autosomal dominant disease NF2, and biallelic inactivating somatic NF2 mutations are found in a high proportion of unilateral sporadic vestibular schwannoma (USVS) and sporadic meningioma. We surveyed the distributions of constitutional NF2 mutations in 823 NF2 families, 278 somatic NF2 mutations in USVS, and 208 somatic NF2 mutations in sporadic meningioma. Based on the available NF2 mutation data, the most dominant influence on the spectra of mutations in exons 1-15 are C>T transitions that change arginine codons (CGA) to stop codons (TGA) due to spontaneous deamination of methylcytosine to thymine in CpG dinucleotides. The paucity of reported mutations in exon 9 and the absence of reported mutations in exons 16 and 17 may be related to structure-function relationships in the NF2 protein.
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Affiliation(s)
- Michael E Baser
- Academic Unit of Medical Genetics, St. Mary's Hospital, Manchester, United Kingdom
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95
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Pellock BJ, Buff E, White K, Hariharan IK. The Drosophila tumor suppressors Expanded and Merlin differentially regulate cell cycle exit, apoptosis, and Wingless signaling. Dev Biol 2006; 304:102-15. [PMID: 17258190 PMCID: PMC1924969 DOI: 10.1016/j.ydbio.2006.12.021] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2006] [Revised: 12/05/2006] [Accepted: 12/10/2006] [Indexed: 12/19/2022]
Abstract
Mutations that inactivate either merlin (mer) or expanded (ex) result in increased cell growth and proliferation in Drosophila. Both Mer and Ex are members of the Band 4.1 protein superfamily, and, based on analyses of mer ex double mutants, they are proposed to function together in at least a partially redundant manner upstream of the Hippo (Hpo) and Warts (Wts) proteins to regulate cell growth and division. By individually analyzing ex and mer mutant phenotypes, we have found important qualitative and quantitative differences in the ways Mer and Ex function to regulate cell proliferation and cell survival. Though both mer and ex restrict cell and tissue growth, ex clones exhibit delayed cell cycle exit in the developing eye, while mer clones do not. Conversely, loss of mer substantially compromises normal developmental apoptosis in the pupal retina, while loss of ex has only mild effects. Finally, ex has a role in regulating Wingless protein levels in the eye that is not obviously shared by either mer or hpo. Taken together, our data suggest that Mer and Ex differentially regulate multiple downstream pathways.
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Affiliation(s)
- Brett J. Pellock
- Massachusetts General Hospital Cutaneous Biology Research Center
- Massachusetts General Hospital Cancer Center
| | - Eugene Buff
- Massachusetts General Hospital Cancer Center
| | - Kristin White
- Massachusetts General Hospital Cutaneous Biology Research Center
| | - Iswar K. Hariharan
- Massachusetts General Hospital Cancer Center
- University of California, Berkeley Department of Molecular and Cell Biology
- *Corresponding author: Iswar K. Hariharan, University of California, Berkeley, Department of Molecular and Cell Biology, 361 LSA, Berkeley, CA 94720, , phone: 510 643 7438, fax: 510 643 7448
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96
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Ohno N, Terada N, Yamakawa H, Komada M, Ohara O, Trapp BD, Ohno S. Expression of protein 4.1G in Schwann cells of the peripheral nervous system. J Neurosci Res 2006; 84:568-77. [PMID: 16752423 DOI: 10.1002/jnr.20949] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The membrane-associated cytoskeletal proteins, including protein 4.1 family, play important roles in membrane integrity, protein targeting, and signal transduction. Although protein 4.1G (4.1G) is expressed ubiquitously in mammalian tissues, it can have very discrete distributions within cells. The present study investigated the expression and distributions of 4.1G in rodent sciatic nerve. Northern and Western blot analysis detected abundant 4.1G mRNA and protein in rat sciatic nerve extracts. Immunohistochemical staining with a 4.1G-specific antibody and double immunolabeling with E-cadherin, betaIV spectrin, and connexin 32 detected 4.1G in paranodal loops, Schmidt-Lanterman incisures, and periaxonal, mesaxonal, and abaxonal membranes of rodent sciatic nerve. Immunoelectron microscopy confirmed the immunodistribution of 4.1G in Schwann cells. In developing mouse sciatic nerves, 4.1G was diffusely distributed in immature Schwann cells and gradually localized at paranodes, incisures, and periaxonal and mesaxonal membranes during their maturation. These data support the concept that 4.1G plays an important role in the membrane expansion and specialization that occurs during formation and maintenance of myelin internodes in the peripheral nervous system.
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Affiliation(s)
- Nobuhiko Ohno
- Department of Anatomy, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Chuo-City, Yamanashi, Japan
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97
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Terawaki SI, Maesaki R, Hakoshima T. Structural basis for NHERF recognition by ERM proteins. Structure 2006; 14:777-89. [PMID: 16615918 DOI: 10.1016/j.str.2006.01.015] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2005] [Revised: 12/27/2005] [Accepted: 01/20/2006] [Indexed: 11/28/2022]
Abstract
The Na+/H+ exchanger regulatory factor (NHERF) is a key adaptor protein involved in the anchoring of ion channels and receptors to the actin cytoskeleton through binding to ERM (ezrin/radixin/moesin) proteins. NHERF binds the FERM domain of ERM proteins, although NHERF has no signature Motif-1 sequence for FERM binding found in adhesion molecules. The crystal structures of the radixin FERM domain complexed with the NHERF-1 and NHERF-2 C-terminal peptides revealed a peptide binding site of the FERM domain specific for the 13 residue motif MDWxxxxx(L/I)Fxx(L/F) (Motif-2), which is distinct from Motif-1. This Motif-2 forms an amphipathic alpha helix for hydrophobic docking to subdomain C of the FERM domain. This docking causes induced-fit conformational changes in subdomain C and affects binding to adhesion molecule peptides, while the two binding sites are not overlapped. Our studies provide structural paradigms for versatile ERM linkages between membrane proteins and the cytoskeleton.
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Affiliation(s)
- Shin-ichi Terawaki
- Structural Biology Laboratory, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan
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98
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Gerber MA, Bahr SM, Gutmann DH. Protein 4.1B/differentially expressed in adenocarcinoma of the lung-1 functions as a growth suppressor in meningioma cells by activating Rac1-dependent c-Jun-NH(2)-kinase signaling. Cancer Res 2006; 66:5295-303. [PMID: 16707455 DOI: 10.1158/0008-5472.can-05-1628] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Meningiomas are the second most common brain tumor in adults, yet comparatively little is presently known about the dysregulated growth control pathways involved in their formation and progression. One of the most frequently observed genetic changes in benign meningioma involves loss of protein 4.1B expression. Previous studies from our laboratory have shown that protein 4.1B growth suppression in meningioma is associated with the activation of the c-Jun-NH(2)-kinase (JNK) pathway and requires localization of a small unique region (U2 domain) of protein 4.1B to the plasma membrane. To define the relationship between protein 4.1B expression and JNK activation, as well as to determine the mechanism of JNK activation by protein 4.1B, we used a combination of genetic and pharmacologic approaches. In this report, we show that protein 4.1B/differentially expressed in adenocarcinoma of the lung-1 (DAL-1) expression in meningioma cells in vitro results in JNK activation, which requires the sequential activation of Src, Rac1, and JNK. In addition, inhibition of Rac1 or JNK activation abrogates protein 4.1B/DAL-1 growth suppression and cyclin A regulation. Last, protein 4.1B/DAL-1 regulation of this critical growth control pathway in meningioma cells requires the presence of the U2 domain. Collectively, these observations provide the first mechanistic insights into the function of protein 4.1B as a growth regulator in meningioma cells.
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Affiliation(s)
- Mark A Gerber
- Department of Neurology, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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99
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Baines AJ. A FERM-adjacent (FA) region defines a subset of the 4.1 superfamily and is a potential regulator of FERM domain function. BMC Genomics 2006; 7:85. [PMID: 16626485 PMCID: PMC1459144 DOI: 10.1186/1471-2164-7-85] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2005] [Accepted: 04/20/2006] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Proteins containing FERM domains comprise a diverse group of eukaryotic proteins that bind membrane proteins and lipids. In doing so, they organise membrane microstructure, and coordinate the disposition of signalling and cell adhesion complexes. In protein 4.1R, phosphorylation adjacent to the FERM domain regulates its activity, and membrane mechanical properties. RESULTS A novel sequence domain has been detected in a subset of proteins that contain FERM domains. This subset includes the true 4.1 proteins, some tyrosine phosphatases, rho-GEF proteins and type II transmembrane proteins, as well as some uncharacterised FERM proteins. This FERM-adjacent region is always closely proximate to the C-terminal of the FERM domain. This sequence is likely to be folded with elements of alpha and beta structure. The FERM-adjacent region of 4.1R contains serine residues phosphorylated by PKC and PKA; these appear conserved in about half of all other FERM-adjacent regions. Phylogenetic analyses indicate that all proteins containing a FERM-adjacent region arose from a single ancestor after FERM domains had started to proliferate in genomes of animals, plants and mycetozoa. CONCLUSION The FERM-adjacent region defines a subset of the FERM proteins in animals. The conservation of motifs in this region that are potential substrates for kinases together with the known regulatory phosphorylation of 4.1R in this region raises the possibility that the FERM-adjacent region is a regulatory adaptation in this subset of the FERM proteins.
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Affiliation(s)
- Anthony J Baines
- Department of Biosciences, University of Kent, Canterbury, CT2 7NJ, UK.
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Kramer-Zucker AG, Wiessner S, Jensen AM, Drummond IA. Organization of the pronephric filtration apparatus in zebrafish requires Nephrin, Podocin and the FERM domain protein Mosaic eyes. Dev Biol 2006; 285:316-29. [PMID: 16102746 PMCID: PMC2836015 DOI: 10.1016/j.ydbio.2005.06.038] [Citation(s) in RCA: 184] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2005] [Revised: 05/24/2005] [Accepted: 06/17/2005] [Indexed: 02/07/2023]
Abstract
Podocytes are specialized cells of the kidney that form the blood filtration barrier in the kidney glomerulus. The barrier function of podocytes depends upon the development of specialized cell-cell adhesion complexes called slit-diaphragms that form between podocyte foot processes surrounding glomerular blood vessels. Failure of the slit-diaphragm to form results in leakage of high molecular weight proteins into the blood filtrate and urine, a condition called proteinuria. In this work, we test whether the zebrafish pronephros can be used as an assay system for the development of glomerular function with the goal of identifying novel components of the slit-diaphragm. We first characterized the function of the zebrafish homolog of Nephrin, the disease gene associated with the congenital nephritic syndrome of the Finnish type, and Podocin, the gene mutated in autosomal recessive steroid-resistant nephrotic syndrome. Zebrafish nephrin and podocin were specifically expressed in pronephric podocytes and required for the development of pronephric podocyte cell structure. Ultrastructurally, disruption of nephrin or podocin expression resulted in a loss of slit-diaphragms at 72 and 96 h post-fertilization and failure to form normal podocyte foot processes. We also find that expression of the band 4.1/FERM domain gene mosaic eyes in podocytes is required for proper formation of slit-diaphragm cell-cell junctions. A functional assay of glomerular filtration barrier revealed that absence of normal nephrin, podocin or mosaic eyes expression results in loss of glomerular filtration discrimination and aberrant passage of high molecular weight substances into the glomerular filtrate.
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Affiliation(s)
| | - Stephanie Wiessner
- Renal Unit, Massachusetts General Hospital 149-8000, 149 13th Street, Charlestown, MA 02129, USA
| | - Abbie M. Jensen
- Biology Department, 221 Morrill South, University of Massachusetts, Amherst, MA 01003, USA
| | - Iain A. Drummond
- Renal Unit, Massachusetts General Hospital 149-8000, 149 13th Street, Charlestown, MA 02129, USA
- Corresponding author. Fax: +1 617 726 5669. (I.A. Drummond)
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