1
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Murugesan P, Begum H, Tangutur AD. Inhibitor of DNA binding/differentiation proteins as IDs for pancreatic cancer: Role in pancreatic cancer initiation, development and prognosis. Gene 2023; 853:147092. [PMID: 36464175 DOI: 10.1016/j.gene.2022.147092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 11/11/2022] [Accepted: 11/28/2022] [Indexed: 12/03/2022]
Abstract
A family of inhibitors of cell differentiation or DNA-binding proteins, known as ID proteins (ID1-4), function as mighty transcription factors in various cellular processes, such as inhibiting differentiation, promoting cell-cycle progression, senescence, angiogenesis, tumorigenesis, and metastasis in cancer. Pancreatic cancer represents the deadliest cancer with the lowest survival rate of 10% due to the diagnosis at an advanced fatal stage and therapeutic resistance. Modestly, the only curative option for this lethal cancer is surgery but is done in less than 15-20% of patients because of the locally aggressive and early metastatic nature. Finding the earliest biomarkers and targeting the various hallmarks of pancreatic cancer can improve the treatment and survival of pancreatic cancer patients. Therefore, herein in this review, we explore in depth the potential roles of ID proteins function in hallmarks of pancreatic cancer, signaling pathways, and its oncogenic and tumor-suppressive effects. Hence, understanding the roles of dysregulated ID proteins would provide new insights into its function in pancreatic cancer tumorigenesis.
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Affiliation(s)
- Periyasamy Murugesan
- Department of Applied Biology, CSIR-Indian Institute of Chemical Technology, Hyderabad 500007, India; Academy of Scientific and Innovative Research, Ghaziabad, Uttar Pradesh 201002, India
| | - Habeebunnisa Begum
- Department of Applied Biology, CSIR-Indian Institute of Chemical Technology, Hyderabad 500007, India; Academy of Scientific and Innovative Research, Ghaziabad, Uttar Pradesh 201002, India
| | - Anjana Devi Tangutur
- Department of Applied Biology, CSIR-Indian Institute of Chemical Technology, Hyderabad 500007, India; Academy of Scientific and Innovative Research, Ghaziabad, Uttar Pradesh 201002, India.
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Homodimeric and Heterodimeric Interactions among Vertebrate Basic Helix-Loop-Helix Transcription Factors. Int J Mol Sci 2021; 22:ijms222312855. [PMID: 34884664 PMCID: PMC8657788 DOI: 10.3390/ijms222312855] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 11/11/2021] [Accepted: 11/17/2021] [Indexed: 01/01/2023] Open
Abstract
The basic helix–loop–helix transcription factor (bHLH TF) family is involved in tissue development, cell differentiation, and disease. These factors have transcriptionally positive, negative, and inactive functions by combining dimeric interactions among family members. The best known bHLH TFs are the E-protein homodimers and heterodimers with the tissue-specific TFs or ID proteins. These cooperative and dynamic interactions result in a complex transcriptional network that helps define the cell’s fate. Here, the reported dimeric interactions of 67 vertebrate bHLH TFs with other family members are summarized in tables, including specifications of the experimental techniques that defined the dimers. The compilation of these extensive data underscores homodimers of tissue-specific bHLH TFs as a central part of the bHLH regulatory network, with relevant positive and negative transcriptional regulatory roles. Furthermore, some sequence-specific TFs can also form transcriptionally inactive heterodimers with each other. The function, classification, and developmental role for all vertebrate bHLH TFs in four major classes are detailed.
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Yokura-Yamada Y, Araki M, Maeda M. Ectopic expression of Id1 or Id3 inhibits transcription of the GATA-4 gene in P19CL6 cells under differentiation condition. Drug Discov Ther 2021; 15:189-196. [PMID: 34421098 DOI: 10.5582/ddt.2021.01069] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Inhibitor of DNA binding (Id) is a dominant negative form of the E-box binding basic-helix-loop-helix (bHLH) transcription factor since it is devoid of the basic region required for DNA binding and forms an inactive hetero dimer with bHLH proteins. The E-box sequence located in the promoter region of the GATA-binding protein 4 (GATA-4) gene is essential for transcriptional activation in P19CL6 cells. These cells differentiate into cardiomyocytes and start to express GATA-4, which further triggers cardiac-specific gene expression. In this study, expression plasmids for Ids tagged with human influenza hemagglutinin (HA)-FLAG were constructed and introduced into P19CL6 cells. The stable clones expressing the recombinant Id proteins (Id1 or Id3) were isolated. The GATA-4 gene expression in these clones under differentiation condition in the presence of 1% dimethyl sulfoxide (DMSO) was repressed, with concomitant abolishment of the transcription of α-myosin heavy chain (α-MHC), which is a component of cardiac myofibrils. Thus, the increased expression of Id protein could affect GATA-4 gene expression and negatively regulate the differentiation of P19CL6 cells.
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Affiliation(s)
- Yumei Yokura-Yamada
- Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka, Japan
| | | | - Masatomo Maeda
- Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka, Japan
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Roschger C, Cabrele C. The Id-protein family in developmental and cancer-associated pathways. Cell Commun Signal 2017; 15:7. [PMID: 28122577 PMCID: PMC5267474 DOI: 10.1186/s12964-016-0161-y] [Citation(s) in RCA: 122] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Accepted: 12/29/2016] [Indexed: 01/15/2023] Open
Abstract
Inhibitors of DNA binding and cell differentiation (Id) proteins are members of the large family of the helix-loop-helix (HLH) transcription factors, but they lack any DNA-binding motif. During development, the Id proteins play a key role in the regulation of cell-cycle progression and cell differentiation by modulating different cell-cycle regulators both by direct and indirect mechanisms. Several Id-protein interacting partners have been identified thus far, which belong to structurally and functionally unrelated families, including, among others, the class I and II bHLH transcription factors, the retinoblastoma protein and related pocket proteins, the paired-box transcription factors, and the S5a subunit of the 26 S proteasome. Although the HLH domain of the Id proteins is involved in most of their protein-protein interaction events, additional motifs located in their N-terminal and C-terminal regions are required for the recognition of diverse protein partners. The ability of the Id proteins to interact with structurally different proteins is likely to arise from their conformational flexibility: indeed, these proteins contain intrinsically disordered regions that, in the case of the HLH region, undergo folding upon self- or heteroassociation. Besides their crucial role for cell-fate determination and cell-cycle progression during development, other important cellular events have been related to the Id-protein expression in a number of pathologies. Dysregulated Id-protein expression has been associated with tumor growth, vascularization, invasiveness, metastasis, chemoresistance and stemness, as well as with various developmental defects and diseases. Herein we provide an overview on the structural properties, mode of action, biological function and therapeutic potential of these regulatory proteins.
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Affiliation(s)
- Cornelia Roschger
- Department of Molecular Biology, University of Salzburg, Billrothstrasse 11, Salzburg, 5020, Austria
| | - Chiara Cabrele
- Department of Molecular Biology, University of Salzburg, Billrothstrasse 11, Salzburg, 5020, Austria.
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Manrique I, Nguewa P, Bleau AM, Nistal-Villan E, Lopez I, Villalba M, Gil-Bazo I, Calvo A. The inhibitor of differentiation isoform Id1b, generated by alternative splicing, maintains cell quiescence and confers self-renewal and cancer stem cell-like properties. Cancer Lett 2014; 356:899-909. [PMID: 25449776 DOI: 10.1016/j.canlet.2014.10.035] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Revised: 10/29/2014] [Accepted: 10/30/2014] [Indexed: 12/14/2022]
Abstract
Id1 has been shown to play a critical role in tumorigenesis and angiogenesis. Moreover, recent reports have involved Id1 in the maintenance of cancer stem cell features in some tumor types. The Id1 gene generates two isoforms through alternative splicing: Id1a and Id1b. We have investigated the role of each isoform in cancer development. Using lentiviral systems we modified the endogenous expression of each of these isoforms in cancer cells and analyzed their biological effect both in vitro and in vivo. Overexpression of Id1b in murine CT26 and 3LL cells caused a G0/G1 cell cycle arrest and reduced proliferation, clonogenicity and phospho-ERK1/2 levels, while increasing p27 levels. High levels of Id1a had an opposite effect and the proportion of cells in the S phase increased significantly. In vivo models confirmed the inhibitory role of Id1b in primary tumor growth and metastasis. Through microarray analysis we found that the cancer stem cell (CSC) markers ALDH1A1 and Notch-1 were up-regulated specifically in Id1b-overexpressing cells. By using qPCR we also found overexpression of Sca-1, Tert, Sox-2 and Oct-4 in these cells. Increased levels of Id1b promoted self-renewal and CSC-like properties, as shown by their high capacity for developing secondary tumorspheres and retaining the PKH26 dye. The acquisition of CSC phenotype was confirmed in human PC-3 cells that overexpressed Id1b. Our results show that Id1b maintains cells in a quiescent state and promotes self-renewal and CSC-like features. On the contrary, Id1a promotes cell proliferation.
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Affiliation(s)
- Irene Manrique
- Program in Solid Tumors and Biomarkers, Center for Applied Medical Research (CIMA), University of Navarra, Pamplona, Spain
| | - Paul Nguewa
- Program in Solid Tumors and Biomarkers, Center for Applied Medical Research (CIMA), University of Navarra, Pamplona, Spain; Instituto de Salud Tropical and Department of Microbiology and Parasitology, University of Navarra, Pamplona, Spain
| | - Anne-Marie Bleau
- Program in Solid Tumors and Biomarkers, Center for Applied Medical Research (CIMA), University of Navarra, Pamplona, Spain
| | - Estanislao Nistal-Villan
- Gene Therapy and Regulation of Gene Expression Program, Center for Applied Medical Research (CIMA), University of Navarra, Pamplona, Spain
| | - Ines Lopez
- Program in Solid Tumors and Biomarkers, Center for Applied Medical Research (CIMA), University of Navarra, Pamplona, Spain
| | - Maria Villalba
- Program in Solid Tumors and Biomarkers, Center for Applied Medical Research (CIMA), University of Navarra, Pamplona, Spain; Department of Histology and Pathology, University of Navarra, Pamplona, Spain
| | - Ignacio Gil-Bazo
- Program in Solid Tumors and Biomarkers, Center for Applied Medical Research (CIMA), University of Navarra, Pamplona, Spain; Department of Oncology, Clinica Universidad de Navarra, Pamplona, Spain
| | - Alfonso Calvo
- Program in Solid Tumors and Biomarkers, Center for Applied Medical Research (CIMA), University of Navarra, Pamplona, Spain; Department of Histology and Pathology, University of Navarra, Pamplona, Spain.
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Yang J, Li X, Morrell NW. Id proteins in the vasculature: from molecular biology to cardiopulmonary medicine. Cardiovasc Res 2014; 104:388-98. [PMID: 25274246 DOI: 10.1093/cvr/cvu215] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The inhibitors of differentiation (Id) proteins belong to the helix-loop-helix group of transcription factors and regulate cell differentiation and proliferation. Recent studies have reported that Id proteins play important roles in cardiogenesis and formation of the vasculature. We have also demonstrated that heritable pulmonary arterial hypertension (HPAH) patients have dysregulated Id gene expression in pulmonary artery smooth muscle cells. The interaction between bone morphogenetic proteins and other growth factors or cytokines regulates Id gene expression, which impacts on pulmonary vascular cell differentiation and proliferation. Exploration of the roles of Id proteins in vascular remodelling that occurs in PAH and atherosclerosis might provide new insights into the molecular basis of these diseases. In addition, current progress in identification of the interactors of Id proteins will further the understanding of the function of Ids in vascular cells and enable the identification of novel targets for therapy in PAH and other cardiovascular diseases.
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Affiliation(s)
- Jun Yang
- Department of Cell Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & Peking Union Medical College, 5 DongdanSantiao, Beijing 100005, China
| | - Xiaohui Li
- Department of Pharmacology, School of Pharmaceutical Science, Central South University, Changsha, China
| | - Nicholas W Morrell
- Department of Medicine, University of Cambridge School of Clinical Medicine, Level 5, Addenbrooke's Hospital, Hills Road, Cambridge CB2 0QQ, UK
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Differential Tumor Expression of Inhibitor of Differentiation-1 in Prostate Cancer Patients With Extreme Clinical Phenotypes and Prognostic Implications. Clin Genitourin Cancer 2014; 12:87-93. [DOI: 10.1016/j.clgc.2013.08.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Revised: 08/09/2013] [Accepted: 08/27/2013] [Indexed: 11/19/2022]
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Ghinassi B, Verrucci M, Jelicic K, Di Noia A, Migliaccio G, Migliaccio AR. Interleukin-3 and erythropoietin cooperate in the regulation of the expression of erythroid-specific transcription factors during erythroid differentiation. Exp Hematol 2007; 35:735-47. [PMID: 17577923 DOI: 10.1016/j.exphem.2007.02.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
OBJECTIVE To characterize how interleukin-3 and erythropoietin regulate cell fate by modulating the expression of lineage-specific transcription factors. METHODS This study analyzed mRNA and protein levels, gene transcription rates, and mRNA and protein stabilities of erythroid-specific transcription factors in lineage-restricted cells derived from the 32D cell line cultured either in interleukin-3 or erythropoietin. RESULTS Erythroid 32D subclones expressed levels of Idl, Gata-2, and Scl comparable and levels of Eklf and Gata-1 higher than those expressed by myeloid subclones. While maintained in interleukin-3, erythroid cells remained immature despite their high expression of Gata-1, Gata-2, Scl, Eklf, and Idl. Switching the erythroid cells to erythropoietin induced cell maturation (within 48 hours) and reduced expression of Gata-2 and Idl (in 24 hours) but did not alter the expression of Gata-1. The effects of interleukin-3 were mostly mediated by increases in transcription rates (Scl and Gata-2), and that of erythropoietin was apparently due to increased mRNA and protein (Gata-1, Scl, and Eklf) stability. In particular, erythropoietin increased the stability of the processed and transcriptionally more active form of GATA-1 protein. CONCLUSIONS These results suggest that interleukin-3 and erythropoietin cooperate to establish the lineage-specific transcription factor milieu of erythroid cells: interleukin-3 regulates mainly gene transcription and erythropoietin consistently increases mRNA and protein stability.
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Affiliation(s)
- Barbara Ghinassi
- Department of Hematology, Oncology and Molecular Medicine, Istituto Superiore Sanità, Rome, Italy
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9
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Kiewitz SD, Cabrele C. Synthesis and conformational properties of protein fragments based on the Id family of DNA-binding and cell-differentiation inhibitors. Biopolymers 2006; 80:762-74. [PMID: 15880794 DOI: 10.1002/bip.20287] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Id proteins are dominant negative regulators of the helix-loop-helix (HLH) transcription factors and are important during development, especially by preventing cell differentiation while inducing cell proliferation. In contrast, they are poorly expressed in healthy adults but are found in several tumor types. The Id HLH motif is responsible for the inhibitory activity, whereas not much is known about the role of the N- and C-termini. In the presented work, synthetic peptides reproducing the HLH, the N-terminal region, and the C-terminal region of the Id proteins were characterized by CD. The four HLH sequences built highly stable helical conformations, whereas the N- and C-termini were unstructured, with the exception of an alanine-rich fragment preceding the Id4 HLH motif. Deletion of the loop connecting the two helices led to helix destabilization for all four Id HLH peptides. In addition, modifications of the amino acid composition within the hydrophobic face of the helices of the Id1 HLH peptide induced conformational changes, mostly associated with loss of helix content. Moreover, a fragment containing the helix-2 and the C-terminus of the Id1 protein did not show any helical character. Therefore, both the helix propensity and stability of the HLH domain were shown to be strongly dependent on favorable interhelical contacts. In contrast, it is suggested that the regions beyond this domain could rather play a destabilizing role, for example, by increasing the flexibility of the folded protein.
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Affiliation(s)
- Sebastian D Kiewitz
- Fakultät für Chemie und Pharmazie, Universität Regensburg, Universitätsstr. 31, 93053 Regensburg, Germany
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Qi J, Su Y, Sun R, Zhang F, Luo X, Yang Z, Luo X. CASK inhibits ECV304 cell growth and interacts with Id1. Biochem Biophys Res Commun 2005; 328:517-21. [PMID: 15694377 DOI: 10.1016/j.bbrc.2005.01.014] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2004] [Indexed: 12/28/2022]
Abstract
Calcium/calmodulin-dependent serine protein kinase (CASK) is generally known as a scaffold protein. Here we show that overexpression of CASK resulted in a reduced rate of cell growth, while inhibition of expression of endogenous CASK via RNA-mediated interference resulted in an increased rate of cell growth in ECV304 cells. To explore the molecular mechanism, we identified a novel CASK-interacting protein, inhibitor of differentiation 1 (Id1) with a yeast two-hybrid screening. Furthermore, endogenous CASK and Id1 proteins were co-precipitated from the lysates of ECV304 cells by immunoprecipitation. Mammalian two-hybrid protein-protein interaction assays indicated that CASK possessed a different binding activity for Id1 and its alternative splicing variant. It is known that Id proteins play important roles in regulation of cell proliferation and differentiation. Thus, we speculate that the regulation of cell growth mediated by CASK may be involved in Id1. Our findings indicate a novel function of CASK, the mechanism that remains to be further investigated.
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Affiliation(s)
- Jie Qi
- Burn Research Institute, Southwest Hospital, Third Military Medical University, State Key Laboratory of Trauma, Burn and Combined Injury, Chongqing 400038, PR China
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Forrest S, McNamara C. Id family of transcription factors and vascular lesion formation. Arterioscler Thromb Vasc Biol 2004; 24:2014-20. [PMID: 15345510 DOI: 10.1161/01.atv.0000143932.03151.ad] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Vascular smooth muscle cell (VSMC) modulation to a de-differentiated phenotype and proliferation are key components of vascular lesion formation. Understanding how these processes are regulated is essential to understanding the progression of vascular diseases such as atherosclerosis and in-stent restenosis. The Id family of helix-loop-helix (HLH) transcription factors has emerged as important regulators of cellular growth and differentiation. Recent published findings have implicated the Id proteins as important regulators of growth and phenotypic modulation in VSMC and in the vascular response to injury. In this review, we summarize what is known regarding how the Id proteins function to control cellular growth and differentiation and their role in vascular lesion formation.
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Affiliation(s)
- Scott Forrest
- Cardiovascular Division, Department of Internal Medicine and the Cardiovascular Research Center, University of Virginia, Charlottesville, VA 22901, USA
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12
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Abstract
Id proteins are important parts of signaling pathways involved in development, cell cycle and tumorigenesis. They were first shown to act as dominant negative antagonists of the basic helix-loop-helix family of transcription factors, which positively regulate differentiation in many cell lineages. The Id proteins do this by associating with the ubiquitous E proteins and preventing them from binding DNA or other transcription factors. Id proteins also associate with Ets transcription factors and the Rb family of tumor suppressor proteins, and are downstream targets of transforming growth factor beta and bone morphogenic protein signaling. Thus, the Id proteins have become important molecules for understanding basic biological processes as well as targets for potential therapeutic intervention in human disease.
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Affiliation(s)
- Marianna B Ruzinova
- Department of Cell Biology, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue Box 241, New York, NY 10021, USA
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13
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Tang J, Gordon GM, Müller MG, Dahiya M, Foreman KE. Kaposi's sarcoma-associated herpesvirus latency-associated nuclear antigen induces expression of the helix-loop-helix protein Id-1 in human endothelial cells. J Virol 2003; 77:5975-84. [PMID: 12719589 PMCID: PMC154010 DOI: 10.1128/jvi.77.10.5975-5984.2003] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2002] [Accepted: 02/20/2003] [Indexed: 11/20/2022] Open
Abstract
Kaposi's sarcoma (KS)-associated herpesvirus (KSHV) (also known as human herpesvirus 8) is a gamma-2 herpesvirus believed to be the etiologic agent responsible for KS. The pathogenesis of this potentially life-threatening neoplasm is complex and unclear, and it is currently unknown how KSHV causes KS. Id (named for inhibitor of DNA binding or inhibitor of differentiation) proteins were identified in 1990 and found to be naturally occurring dominant-negative inhibitors of basic helix-loop-helix transcription factors. Id-1, the most well-studied member of this family, has since been shown to play a key role in several biological systems including cellular differentiation, cell cycle regulation, and tumorigenesis. In this report, we demonstrate that Id-1 is expressed at high levels in KS tumor cells both in vitro and in vivo but is expressed at relatively modest levels in endothelial cells (ECs), the likely precursor of the KS tumor cell. Infection of precursor cells with KSHV may be responsible for this enhanced expression, as KSHV infection induced Id-1 27-fold in ECs under our experimental conditions. Furthermore, we demonstrate that the KSHV-encoded latency-associated nuclear antigen (LANA) protein appears to be involved. Expression of LANA in ECs resulted in Id-1 induction that was almost identical to the induction seen with KSHV-infected ECs. These results demonstrate the expression of Id-1 in KS tumor cells and indicate the KSHV LANA protein may be, at least in part, responsible. This may be an important mechanism by which KSHV allows KS tumor cells to escape normal cell cycle regulation and enhances their proliferation.
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Affiliation(s)
- Jun Tang
- Department of Pathology and Skin Cancer Research Program, Cardinal Bernardin Cancer Center, Loyola University Medical Center, Maywood, Illinois 60153, USA
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14
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Vallée M, Guay F, Beaudry D, Matte J, Blouin R, Laforest JP, Lessard M, Palin MF. Effects of Breed, Parity, and Folic Acid Supplement on the Expression of Folate Metabolism Genes in Endometrial and Embryonic Tissues from Sows in Early Pregnancy1. Biol Reprod 2002; 67:1259-67. [PMID: 12297544 DOI: 10.1095/biolreprod67.4.1259] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Folic acid and glycine are factors of great importance in early gestation. In sows, folic acid supplement can increase litter size through a decrease in embryonic mortality, while glycine, the most abundant amino acid in the sow oviduct, uterine, and allantoic fluids, is reported to act as an organic osmoregulator. In this study, we report the characterization of cytoplasmic serine hydroxymethyltransferase (cSHMT), T-protein, and vT-protein (variant T-protein) mRNA expression levels in endometrial and embryonic tissues in gestating sows on Day 25 of gestation according to the breed, parity, and folic acid + glycine supplementation. Expression levels of cSHMT, T-protein, and vT-protein mRNA in endometrial and embryonic tissues were performed using semiquantitative reverse transcription-polymerase chain reaction. We also report, for the first time, an alternative splicing event in the porcine T-protein gene. Results showed that a T-protein splice variant, vT-protein, is present in all the tested sow populations. Further characterizations revealed that this T-protein splice variant contains a coding intron that can adopt a secondary structure. Results demonstrated that cSHMT mRNA expression levels were significantly higher in sows receiving the folic acid + glycine supplementation, independently of the breed or parity and in both endometrial and embryonic tissues. Upon receiving the same treatment, the vT-protein and T-protein mRNA expression levels were significantly reduced in the endometrial tissue of Yorkshire-Landrace sows only. These results indicate that modulation of specific gene expression levels in endometrial and embryonic tissues of sows in early gestation could be one of the mechanism involved with the role of folic acid on improving swine reproduction traits.
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Affiliation(s)
- Maud Vallée
- Département de Biologie, Université de Sherbrooke, Québec, Canada J1K 2R1
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15
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Wittwer M, Flück M, Hoppeler H, Müller S, Desplanches D, Billeter R. Prolonged unloading of rat soleus muscle causes distinct adaptations of the gene profile. FASEB J 2002; 16:884-6. [PMID: 11967225 DOI: 10.1096/fj.01-0792fje] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Using commercially available microarray technology, we investigated a series of transcriptional adaptations caused by atrophy of rat m. soleus due to 35 days of hindlimb suspension. We detected 395 out of 1,200 tested transcripts, which reflected 1%-5% of totally expressed genes. From various cellular functional pathways, we detected multiple genes that spanned a 200-fold range of gene expression levels. Statistical analysis combining L1 regression with the sign test based on the conservative Bonferroni correction identified 105 genes that underwent transcriptional adaptations with atrophy. Generally, expressional changes were discrete (<50%) and pointed in the same direction for genes belonging to the same cellular functional units. In particular, a distinct expressional adaptation of genes involved in fiber transformation; that is, metabolism, protein turnover, and cell regulation were noted and matched to corresponding transcriptional changes in nutrient trafficking. Expressional changes of extracellular proteases, and of genes involved in nerve-muscle interaction and excitation-contraction coupling identify previously not recognized adaptations that occur in atrophic m. soleus. Considerations related to technical and statistical aspects of the array approach for profiling the skeletal muscle genome and the impact of observed novel adaptations of the m. soleus transcriptome are put into perspective of the physiological adaptations occurring with muscular atrophy.
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Abstract
We present the sequence and expression pattern of chick Id4 and compare its distribution to that of other vertebrate Id genes. At early stages, Id4 expression is discrete, with transcript transiently expressed in subsets of migrating neural crest cells, the dorsal myocardium, the segmental plate mesoderm, and the tail bud. Later, expression is also observed in the telencephalic vesicles and corneal epithelium. Of all the Id genes, Id4 exhibits the most restricted pattern in the developing nervous system, with little expression in the presumptive neural crest or placodes. Id4 appears in the neural tube much later than other Id genes. However, all four Id genes display overlapping patterns in the branchial arches and tail bud.
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Affiliation(s)
- Y Kee
- Division of Biology, 139-74 California Institute of Technology, Pasadena, CA 91125, USA
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17
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Affiliation(s)
- M L Hammarskjöld
- Myles H. Thaler Center for AIDS and Human Retrovirus Research, Department of Microbiology, University of Virginia, Charlottesville, VA 22908, USA
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18
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Schaefer BM, Koch J, Wirzbach A, Kramer MD. Expression of the helix-loop-helix protein ID1 in keratinocytes is upregulated by loss of cell-matrix contact. Exp Cell Res 2001; 266:250-9. [PMID: 11399053 DOI: 10.1006/excr.2001.5215] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
To analyze the inhibitor of DNA-binding type 1 (ID1) in the human epidermis and in cultured keratinocytes we generated and characterized ID1-specific monoclonal antibodies. Immunohistological studies on human skin biopsies revealed that ID1 is not detectable in normal human epidermis but in lesional epidermis of bullous pemphigoid. In the latter case we found ID1 in the cytoplasm of basal and proximal suprabasal keratinocytes. Cultured normal human epidermal keratinocytes displayed ID1 in the cytoplasm; upon differentiation into a multilayered keratinocyte sheet, ID1 was no longer detectable. It was reexpressed after dispase-mediated detachment of the keratinocyte cultures from the growth substratum. In this case ID1 was localized to the cytoplasm and the nucleus. Our data indicate that after epidermal injury-in our case loss of cell-matrix contact-ID1 is upregulated in affected keratinocytes. In view of the ID1 function in other cell types, we speculate that ID1 facilitates the transition from the resting to the migrating and proliferating keratinocyte required for efficient repair of epidermal lesions by reepithelialization. Taken together we suggest that ID1 is an important player in epidermal (patho-)physiology.
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Affiliation(s)
- B M Schaefer
- Institute for Immunology, Im Neuenheimer Feld 305, Heidelberg, D-69120, Germany.
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19
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Liu J, Beqaj S, Yang Y, Honoré B, Schuger L. Heterogeneous nuclear ribonucleoprotein-H plays a suppressive role in visceral myogenesis. Mech Dev 2001; 104:79-87. [PMID: 11404082 DOI: 10.1016/s0925-4773(01)00377-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Mouse embryonic mesenchymal cells undergo spontaneous smooth muscle (SM) differentiation upon spreading/elongation in culture (Relan et al., J. Cell Biol. 147 (1999) 1341; Yang et al., Development 125 (1998) 2621; Yang et al., Development 126 (1999) 3027). Using these cells we generated a subtracted cDNA library to identify potential suppressors of SM myogenesis. One of the differentially expressed genes was heterogeneous nuclear ribonucleoprotein-H (hnRNP-H), which is involved in pre-mRNA alternative splicing. hnRNP-H was highly expressed in mesenchymal cells prior to the onset of SM differentiation, but its expression rapidly decreased in mesenchymal cells undergoing SM myogenesis. In vivo, the drop in hnRNP-H expression was restricted to visceral SM cells. Antisense oligodeoxynucleotide and antisense RNA were used to inhibit hnRNP-H synthesis in SM-differentiating mesenchymal cells and in embryonic lung explants. A decrease in hnRNP-H levels resulted in upregulation of SM-specific gene expression and increased bronchial SM development in lung explants. hnRNP-H overexpression in cell cultures had the opposite effect. These studies, therefore, indicate a novel role for hnRNP-H in the control of visceral myogenesis.
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Affiliation(s)
- J Liu
- Department of Pathology, Wayne State University School of Medicine, Detroit, MI 48201, USA
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20
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Christy BA. A role for an alternatively spliced Id3 isoform in vascular lesions? Arterioscler Thromb Vasc Biol 2001; 21:727-8. [PMID: 11348865 DOI: 10.1161/01.atv.21.5.727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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21
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Matsumura ME, Li F, Berthoux L, Wei B, Lobe DR, Jeon C, Hammarskjöld ML, McNamara CA. Vascular Injury Induces Posttranscriptional Regulation of the Id3 Gene. Arterioscler Thromb Vasc Biol 2001; 21:752-8. [PMID: 11348870 DOI: 10.1161/01.atv.21.5.752] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
—The molecular mechanisms that regulate the proliferation of smooth muscle cells (SMCs) of the vasculature in response to injury are poorly understood. Members of the inhibitor of DNA binding (Id) class of helix-loop-helix transcription factors are known to regulate the growth of a variety of cell types; however, the expression of the various Id genes in SMCs and in vascular lesions has not been examined. In the present study, the yeast 2-hybrid system was used to clone Id genes from a cultured rat aortic SMC library. By use of ubiquitous E proteins as bait, Id3 and a novel isoform of Id3 (Id3a) were cloned. Id3a is the product of alternative splicing of the Id3 gene, resulting in inclusion of a 115-bp “coding intron,” which encodes a unique 29–amino acid carboxyl terminus for the Id3a protein. Unlike Id3, Id3a mRNA was not detected in the normal rat carotid artery. However, after balloon injury, Id3a was abundantly expressed throughout the neointimal layer. In addition, mRNA of the human homologue of Id3a (Id3L) was detected in human carotid atherosclerotic plaques. Adenovirus-mediated overexpression of these Id3 isoforms in cultured rat aortic SMCs revealed that infection of SMCs with an adenovirus overexpressing Id3a (in contrast to Id3) resulted in a significant decrease in cell number versus AdLacZ-infected cells. DNA fragmentation analysis suggested that this decrease in SMC viability was due to increased apoptotic activity in cells infected with adenovirus overexpressing Id3a. These results provide evidence that alternative splicing of the Id3 gene may represent an important mechanism by which neointimal SMC growth is attenuated during vascular lesion formation.
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Affiliation(s)
- M E Matsumura
- Cardiovascular Division, Department of Internal Medicine, University of Virginia Health Sciences Center, Charlottesville 22908, USA
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22
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Abstract
Overexpression of the helix-loop-helix motif-containing transcription inhibitor Id3 has been shown to repress muscle-specific gene expression. Consistent with its putative negative regulatory role in the myogenic process, Id3 is highly expressed in proliferating myoblasts but down regulated when myoblasts are induced to differentiate. To investigate how Id3 expression may be transcriptionally regulated, we isolated a mouse Id3 genomic DNA fragment and characterized its organization and promoter activity. Comparison of the Id3 gene from human and mouse demonstrated a conserved exon-intron organization in which the first intron interrupts the C-terminal protein coding region and the second intron interrupts the 3' untranslated region at analogous positions in the two species. Sequence analysis of the 5'-flanking region revealed an unexpected mouse strain-specific genetic polymorphism due to a single base substitution. Deletion analysis revealed that as little as 180 base pairs of the mouse Id3 promoter upstream of the transcription start site is sufficient for a high level of gene expression in proliferating C2C12 myoblasts. In particular, the region between the nucleotide position -180 and -34 appeared to be crucial for maximal reporter gene activity and interacted specifically with C2C12 nuclear proteins. Finally, we showed that, despite the creation of a putative transcription factor-binding site, the genetic polymorphism observed did not affect Id3 promoter activity in proliferating C2C12 cells.
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Affiliation(s)
- K Yeh
- Department of Pharmacology, University of Missouri-Columbia, Columbia, MO 65212, USA
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23
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Locatelli F, Bracale M, Magaraggia F, Faoro F, Manzocchi LA, Coraggio I. The product of the rice myb7 unspliced mRNA dimerizes with the maize leucine zipper Opaque2 and stimulates its activity in a transient expression assay. J Biol Chem 2000; 275:17619-25. [PMID: 10747941 DOI: 10.1074/jbc.m000647200] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
myb7 mRNA is present in rice in spliced and unspliced forms, splicing being enhanced by anoxia. The protein (Mybleu) encoded by the unspliced mRNA is composed of an incomplete Myb domain followed by a leucine zipper; however, it lacks canonical sequences for DNA binding, transcriptional activation, and nuclear localization. We show here that in transiently transformed tobacco protoplasts, Mybleu is able to enhance the transcriptional activity of the maize leucine zipper Opaque2 on its target b32 promoter. The Mybleu transactivation effect is strictly dependent on the presence of Opaque2 and is driven by Mybleu-Opaque2 heterodimers. Mybleu is located in the nucleus, both in rice and in transformed tobacco protoplasts. In rice, the protein is expressed in regions corresponding to undifferentiated cells of roots and coleoptiles. Therefore, myb7 mRNA encodes, depending on its splicing, two transcription factors belonging to separate classes. One of them, Mybleu, has novel structural characteristics, suggesting the existence of new mechanisms acting in the activation of transcription.
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Affiliation(s)
- F Locatelli
- Istituto Biosintesi Vegetali, Consiglio Nazionale delle Ricerche, via Bassini 15, 20133 Milano, Italy
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24
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van Crüchten I, Cinato E, Fox M, King ER, Newton JS, Riechmann V, Sablitzky F. Structure, chromosomal localisation and expression of the murine dominant negative helix-loop-helix Id4 gene. BIOCHIMICA ET BIOPHYSICA ACTA 1998; 1443:55-64. [PMID: 9838043 DOI: 10.1016/s0167-4781(98)00196-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Id proteins antagonise the functional properties of DNA-binding, basic helix-loop-helix transcription factors. Id proteins inhibited cell differentiation in various model systems, both in vitro and in vivo. They are transcriptionally and post-transcriptionally regulated during cell cycle progression and promote cell proliferation. In order to establish the molecular and functional properties of Id4, we analysed structure, chromosomal localisation and expression of the murine Id4 gene. Sequence analysis indicated that the Id4 gene consists of three exons. Multiple transcription start sites map about 300 bp upstream of the ATG translational start codon within a 30-bp region of the Id4 promoter, which lacks a classic TATA box. Expression of the Id4 gene results in four major transcripts, most likely generated by differential use of polyadenylation sites. Abundance of the four transcripts varies across tissues, suggesting tissue-specific regulation of polyadenylation and/or post-transcriptional regulation of Id4 expression. However, the Id4 gene seems to be expressed as a single protein. Id4 expression is switched on during embryogenesis between day 7.5 and 9.5 of gestation and is most abundant in adult brain, kidney and testis. Id4 maps to chromosome 13 of the mouse.
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Affiliation(s)
- I van Crüchten
- University College London, Department of Medicine, The Windeyer Institute of Medical Sciences, 46 Cleveland Street, London W1P 6DB, UK
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25
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Asp J, Thornemo M, Inerot S, Lindahl A. The helix-loop-helix transcription factors Id1 and Id3 have a functional role in control of cell division in human normal and neoplastic chondrocytes. FEBS Lett 1998; 438:85-90. [PMID: 9821964 DOI: 10.1016/s0014-5793(98)01268-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The expression and localization of the helix-loop-helix transcription factors Id1 and Id3, as well as localization of the E12-protein, were studied in cells isolated from human articular cartilage and chondrosarcoma. Serum withdrawal down-regulated Id1 and Id3 expression in chondrocytes but not the Id1 expression in chondrosarcoma cells. Antisense oligonucleotides directed against Id1 and Id3 decreased BrdU labeling in both cell types. E12 was localized to the nucleus in chondrocytes and non-confluent tumor cells and in confluent tumor cells, E12 had a cytoplasmic localization. This study suggests a functional role for Id1 and Id3 in the control of proliferation and differentiation of cartilage.
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Affiliation(s)
- J Asp
- Research Center for Endocrinology and Metabolism, Department of Clinical Chemistry and Transfusion Medicine, Sahlgrenska University Hospital, Göteborg, Sweden
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26
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Tamura Y, Sugimoto M, Ohnishi K, Sakai T, Hara E. Differential activity of a variant form of the human Id-1 protein generated by alternative splicing. FEBS Lett 1998; 436:169-73. [PMID: 9781672 DOI: 10.1016/s0014-5793(98)01117-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Members of the Id family of helix-loop-helix proteins are ubiquitously expressed and dimerize with members of the class A and class B basic helix-loop-helix proteins. Due to the absence of a basic region, Id proteins act as dominant-negative antagonists of basic helix-loop-helix transcription factors, which regulate cell growth and differentiation in diverse cell types. Recent findings suggest that the functions of Id proteins are well regulated at both the transcriptional level and the post-transcriptional level. We show here that the alternative splicing variant of human Id-1 protein possesses a different binding specificity for basic helix-loop-helix transcription factors and is expressed in a cell cycle-dependent manner. Therefore, alternative splicing of Id-1 could provide a post-transcriptional mechanism to regulate Id-1 function.
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Affiliation(s)
- Y Tamura
- Department of Preventive Medicine, Kyoto Prefectural University of Medicine, Japan
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27
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Norton JD, Deed RW, Craggs G, Sablitzky F. Id helix—loop—helix proteins in cell growth and differentiation. Trends Cell Biol 1998. [DOI: 10.1016/s0962-8924(98)80013-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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28
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Langlands K, Yin X, Anand G, Prochownik EV. Differential interactions of Id proteins with basic-helix-loop-helix transcription factors. J Biol Chem 1997; 272:19785-93. [PMID: 9242638 DOI: 10.1074/jbc.272.32.19785] [Citation(s) in RCA: 181] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Dimerization of three Id proteins (Id1, Id2, and Id3) with the four class A E proteins (E12, E47, E2-2, and HEB) and two groups of class B proteins, the myogenic regulatory factors (MRFs: MyoD, myogenin, Myf-5 and MRF4/Myf-6), and the hematopoietic factors (Scl/Tal-1, Tal-2, and Lyl-1) were tested in a quantitative yeast 2-hybrid assay. All three Ids bound with high affinity to E proteins, but a much broader range of interactions was observed between Ids and the class B factors. Id1 and Id2 interacted strongly with MyoD and Myf-5 and weakly with myogenin and MRF4/Myf-6, whereas Id3 interacted weakly with all four MRFs. Similar specificities were observed in co-immunoprecipitation and mammalian 2-hybrid analyses. No interactions were found between the Ids and any of the hematopoietic factors. Each Id was able to disrupt the ability of E protein-MyoD complexes to transactivate from a muscle creatine kinase reporter construct in vivo. Finally, mutagenesis experiments showed that the differences between Id1 and Id3 binding map to three amino acids in the first helix and to a small cluster of upstream residues. The Id proteins thus display a signature range of interactions with all of their potential dimerization partners and may play a role in myogenesis which is distinct from that in hematopoiesis.
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Affiliation(s)
- K Langlands
- Section of Hematology/Oncology, Children's Hospital of Pittsburgh, The, Pittsburgh, Pennsylvania 15213, USA
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29
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Nehlin JO, Hara E, Kuo WL, Collins C, Campisi J. Genomic organization, sequence, and chromosomal localization of the human helix-loop-helix Id1 gene. Biochem Biophys Res Commun 1997; 231:628-34. [PMID: 9070860 DOI: 10.1006/bbrc.1997.6152] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The helix-loop-helix protein Id-1 regulates growth and differentiation in many mammalian cells. In human fibroblasts, Id1 and Id1', a putative splicing variant, are cell cycle regulated, essential for proliferation, repressed by senescence, and overexpressed by some tumor cells. To better understand Id1, we determined the complete sequence, transcriptional start, and localization of the human Id1 gene. Human Id1 has two exons (426 bp and 42 bp), separated by an intron (239 bp). Id1' results from failure to splice the intron, which encodes 7 amino acids prior to a stop codon. Thus, Id1 and Id1' proteins differ only at the extreme C-terminus. Id1 transcription initiated 96 bp upstream of the initiation AUG; 2 kb of upstream sequence stimulated transcription of a reporter gene. Human Id1 maps to chromosome 20 at q11, very close to the centromere but outside the amplicons frequently found in human cancers.
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Affiliation(s)
- J O Nehlin
- Department of Cancer Biology and Molecular Cytogenetics Resource, Berkeley National Laboratory, University of California 94720, USA
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30
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Duncan MK, Bordas L, Dicicco-Bloom E, Chada KK. Expression of the helix-loop-helix genes Id-1 and NSCL-1 during cerebellar development. Dev Dyn 1997; 208:107-14. [PMID: 8989525 DOI: 10.1002/(sici)1097-0177(199701)208:1<107::aid-aja10>3.0.co;2-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Neurons throughout the central nervous system (CNS) undergo proliferation, migration, and differentiation during their histogenesis. Although numerous regulatory molecules are expressed in developing neurons, it is unknown whether most of these molecules have the same function throughout the CNS or play different roles in different neuronal populations. Previous studies have shown that Id-1 and NSCL-1 are expressed at high levels in the ventricular and subependymal zones, respectively, of the embryonic brain. In the present study, the expression of Id-1 and NSCL-1 was further investigated during postnatal development of the cerebellum. By Northern blot hybridization analysis, the expression levels of Id-1 and NSCL-1 mRNA were developmentally regulated in the cerebellum, with the highest mRNA levels coinciding with the time of maximal granule cell histogenesis. By in situ hybridization, NSCL-1 mRNA was found in the premigratory zone of the external granule layer (EGL), a structure developmentally analogous to the subependymal zone of the embryonic brain. In normal mice, Id-1 mRNA was found to be transiently expressed in the upper internal granule layer (IGL), a population of cells that recently completed their migration from the EGL. In the mouse mutant weaver, Id mRNA was only seen in granule cells that have reached their normal positions in the IGL. No Id-1 hybridization signal was observed in the large numbers of granule cells remaining in the EGL of weaver mice, indicating that Id-1 expression is controlled by spatial cues. The lack of Id-1 expression in ectopic weaver granule cells is compatible with previous suggestions of arrested differentiation. These results support the idea that transcriptional regulators of the helix-loop-helix gene family play important roles in neuronal development, exhibiting region-specific expression and function.
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Affiliation(s)
- M K Duncan
- Department of Biochemistry, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, Piscataway 08854, USA
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31
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Deed RW, Jasiok M, Norton JD. Attenuated function of a variant form of the helix-loop-helix protein, Id-3, generated by an alternative splicing mechanism. FEBS Lett 1996; 393:113-6. [PMID: 8804437 DOI: 10.1016/0014-5793(96)00868-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The Id family of helix-loop-helix proteins function as negative regulators of DNA binding, basic helix-loop-helix proteins in the regulation of cell growth and differentiation. We report here on the identification of a 17 kDa variant of the 14 kDa Id-3 protein termed Id-3L (long version) which possesses a unique 60 amino acid carboxy-terminus generated by read through of a 'coding intron' and alternative splicing. Northern analysis revealed expression of a minor 1.1 kb Id-3L transcript together with the predominant 0.95 kb Id-3 transcript in the majority of adult human tissues analysed. The variant Id-3L protein is functionally distinguishable from conventional Id-3 since in in vitro DNA mobility shift assays, it was greatly impaired in its ability to abrogate binding of the basic helix-loop-helix protein, E47, to an E box recognition sequence.
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Affiliation(s)
- R W Deed
- CRC Department of Gene Regulation, Paterson Institute for Cancer Research, Christie Hospital NHS Trust, UK.
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32
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Hernandez MC, Andres-Barquin PJ, Israel MA. Molecular cloning of the cDNA encoding a helix-loop-helix protein, mouse ID1B: tissue-specific expression of ID1A and ID1B genes. BIOCHIMICA ET BIOPHYSICA ACTA 1996; 1308:28-30. [PMID: 8765747 DOI: 10.1016/0167-4781(96)00092-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
A cDNA encoding a 168 amino acid mouse ID1B helix-loop-helix protein, the longest among the ID family of proteins so far identified, was cloned and its nucleotide sequence determined. Mouse ID1B mRNA is distinguishable from the mRNA encoding ID1A at its 3' end, and the relative level of expression of these two different mRNAs is similar in most tissues, with exception of skeletal muscle and kidney. Comparison of the most carboxyl terminal predicted amino acid sequences of ID1 proteins reveals 100% identity for ID1A, but the predicted Id1B proteins of several species are different.
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Affiliation(s)
- M C Hernandez
- Department of Neurological Surgery, School of Medicine, University of California, San Francisco 94143-0520, USA
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33
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Loveys DA, Streiff MB, Kato GJ. E2A basic-helix-loop-helix transcription factors are negatively regulated by serum growth factors and by the Id3 protein. Nucleic Acids Res 1996; 24:2813-20. [PMID: 8759016 PMCID: PMC145994 DOI: 10.1093/nar/24.14.2813] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Id3, a member of the Id multigene family of dominant negative helix-loop-helix transcription factors, is induced sharply in murine fibroblasts by serum growth factors. To identify relevant targets of Id3 activity, the yeast two-hybrid system was used to identify proteins that dimerize with Id3. Four murine cDNAs were identified in the screen, all of which encode helix-loop-helix proteins: E12, E47, ALF1 and Id4. Co-immunoprecipitation assays confirm that Id3 interacts with E12, E47 and two alternative splice products of ALF1 in vitro. Id3 disrupts DNA binding by these proteins in vitro and blocks transcriptional activation by these factors in cultured murine cells. Additionally, Id3 shows evidence of interacting with the related proteins E2-2 and MyoD, but not c-Myc. These results suggest that Id3 can function as a general negative regulator of the basic-helix-loop-helix family of transcription factors exemplified by the 'E' proteins and MyoD. Although it was previously suspected that E2A is constitutively expressed, our data indicate that E2A is induced in quiescent fibroblasts, by growth factor withdrawal but not by contact inhibition of cell proliferation. These observations extend the role of Id3 in the functional antagonism of E2A-class transcription factors, and suggest that E2A proteins may mediate growth inhibition.
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Affiliation(s)
- D A Loveys
- Division of Pediatric Hematology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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34
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Cioce V, Csaky KG, Chan AM, Bottaro DP, Taylor WG, Jensen R, Aaronson SA, Rubin JS. Hepatocyte growth factor (HGF)/NK1 is a naturally occurring HGF/scatter factor variant with partial agonist/antagonist activity. J Biol Chem 1996; 271:13110-5. [PMID: 8662798 DOI: 10.1074/jbc.271.22.13110] [Citation(s) in RCA: 103] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Hepatocyte growth factor/scatter factor (HGF/SF) stimulates cell proliferation, motility, and morphogenesis by activation of its receptor, the c-Met tyrosine kinase. HGF/SF is structurally related to plasminogen, including an amino-terminal hairpin loop, four kringle domains, and a serine protease-like region. A truncated HGF/SF isoform, designated HGF/NK2, which extends through the second kringle domain and behaves as a competitive HGF/SF antagonist, was previously shown to be encoded by an alternative HGF/SF transcript. In this study, we describe a second naturally occurring HGF/SF variant, HGF/NK1, consisting of the HGF/SF amino-terminal sequence and first kringle domain. This product is encoded by a 2-kilobase alternative transcript containing intronic sequence that was contiguous with exon K1b. Analysis of baculovirus-expressed HGF/NK1 revealed that this isoform possesses the heparin binding properties of HGF/SF and modest mitogenic and scattering activity relative to HGF/SF. However, at a 40-fold molar excess, HGF/NK1 inhibited HGF/SF-dependent DNA synthesis. HGF/NK1 stimulated tyrosine phosphorylation of Met, and covalent affinity cross-linking demonstrated a direct HGF/NK1-receptor interaction. These findings establish that the HGF/SF gene encodes multiple alternative products, which include not only a mitogenic agonist (HGF/SF) and a pure antagonist (HGF/NK2) but also a molecule with partial agonist/antagonist properties.
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Affiliation(s)
- V Cioce
- Laboratory of Cellular and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
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35
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Wibley J, Deed R, Jasiok M, Douglas K, Norton J. A homology model of the Id-3 helix-loop-helix domain as a basis for structure-function predictions. BIOCHIMICA ET BIOPHYSICA ACTA 1996; 1294:138-46. [PMID: 8645731 DOI: 10.1016/0167-4838(96)00008-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The function of the dominant negative Id (inhibitor of differentiation) helix-loop-helix (HLH) proteins is to dimerize with, and prevent the DNA binding of basic HLH (bHLH) transcription factors. A three-dimensional homology model was constructed for the HLH domain of human Id3 based on the X-ray crystal structures of the E47, MyoD, and Max bHLH proteins. The model showed that, in contrast to bHLH proteins, Id proteins appear able to dimerize without DNA stabilization because of better packing of the hydrophobic core, and the absence of destabilizing polar loop residues and of repulsive positive charges in the monomer interface at the base of the four alpha-helix bundle. This prediction was tested by in vitro protein-binding experiments, which showed that Id3 did indeed self-associate. It also showed that the inability of Id proteins to bind DNA arises from the non-basic, poorly defined, random coil structure of the region corresponding to that responsible for bHLH DNA-binding. A model of the Id1 protein was constructed and revealed a potential site of charge-charge repulsion in the hypothetical homodimer interface that may explain its observed inability to form homodimers.
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Affiliation(s)
- J Wibley
- Department of Pharmacy, University of Manchester, UK
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36
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Abstract
We have identified a divergent member of the Xenopus Id family, XIdx, which disrupts binding of myogenic factor/E-protein complexes to DNA in vitro and inhibits transactivation of the E-box regulated cardiac actin gene by MyoD in embryonic tissue. XIdx transcripts accumulate from the early neurula stage in discrete domains of the anterior neural plate and subsequently identify regions of the developing nervous system, including the eye rudiments and the rhombencephalon. These results suggest that bHLH proteins and their Id protein regulators may participate in patterning of embryonic neural tissue. Phylogenetic analysis indicates that XIdx is the product of a novel Id gene and is distinct from XId2, which is expressed primarily in the developing pronephros.
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Affiliation(s)
- R Wilson
- Laboratory of Developmental Biochemistry, National Institute for Medical Research, London, UK
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