1
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Mary L, Leclerc D, Gilot D, Belaud-Rotureau MA, Jaillard S. The TALE never ends: A comprehensive overview of the role of PBX1, a TALE transcription factor, in human developmental defects. Hum Mutat 2022; 43:1125-1148. [PMID: 35451537 DOI: 10.1002/humu.24388] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 03/25/2022] [Accepted: 04/20/2022] [Indexed: 11/07/2022]
Abstract
PBX1 is a highly conserved atypical homeodomain transcription factor (TF) belonging to the TALE (three amino acid loop extension) family. Dimerized with other TALE proteins, it can interact with numerous partners and reach dozens of regulating sequences, suggesting its role as a pioneer factor. PBX1 is expressed throughout the embryonic stages (as early as the blastula stage) in vertebrates. In human, PBX1 germline variations are linked to syndromic renal anomalies (CAKUTHED). In this review, we summarized available data on PBX1 functions, PBX1-deficient animal models, and PBX1 germline variations in humans. Two types of genetic alterations were identified in PBX1 gene. PBX1 missense variations generate a severe phenotype including lung hypoplasia, cardiac malformations, and sexual development defects (DSDs). Conversely, truncating variants generate milder phenotypes (mainly cryptorchidism and deafness). We suggest that defects in PBX1 interactions with various partners, including proteins from the HOX (HOXA7, HOXA10, etc.), WNT (WNT9B, WNT3), and Polycomb (BMI1, EED) families are responsible for abnormal proliferation and differentiation of the embryonic mesenchyme. These alterations could explain most of the defects observed in humans. However, some phenotype variability (especially DSDs) remains poorly understood. Further studies are needed to explore the TALE family in greater depth.
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Affiliation(s)
- Laura Mary
- Service de Cytogénétique et Biologie Cellulaire, CHU Rennes, Rennes, France
- INSERM, EHESP, IRSET (Institut de recherche en santé, environnement et travail)- UMR_S 1085, Université Rennes 1, Rennes, France
| | - Delphine Leclerc
- Inserm U1242, Centre de lutte contre le cancer Eugène Marquis, Université de Rennes, Rennes, France
| | - David Gilot
- Service de Cytogénétique et Biologie Cellulaire, CHU Rennes, Rennes, France
- Inserm U1242, Centre de lutte contre le cancer Eugène Marquis, Université de Rennes, Rennes, France
| | - Marc-Antoine Belaud-Rotureau
- Service de Cytogénétique et Biologie Cellulaire, CHU Rennes, Rennes, France
- INSERM, EHESP, IRSET (Institut de recherche en santé, environnement et travail)- UMR_S 1085, Université Rennes 1, Rennes, France
| | - Sylvie Jaillard
- Service de Cytogénétique et Biologie Cellulaire, CHU Rennes, Rennes, France
- INSERM, EHESP, IRSET (Institut de recherche en santé, environnement et travail)- UMR_S 1085, Université Rennes 1, Rennes, France
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2
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Parker HJ, De Kumar B, Pushel I, Bronner ME, Krumlauf R. Analysis of lamprey meis genes reveals that conserved inputs from Hox, Meis and Pbx proteins control their expression in the hindbrain and neural tube. Dev Biol 2021; 479:61-76. [PMID: 34310923 DOI: 10.1016/j.ydbio.2021.07.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 06/10/2021] [Accepted: 07/22/2021] [Indexed: 11/23/2022]
Abstract
Meis genes are known to play important roles in the hindbrain and neural crest cells of jawed vertebrates. To explore the roles of Meis genes in head development during evolution of vertebrates, we have identified four meis genes in the sea lamprey genome and characterized their patterns of expression and regulation, with a focus on the hindbrain and pharynx. Each of the lamprey meis genes displays temporally and spatially dynamic patterns of expression, some of which are coupled to rhombomeric domains in the developing hindbrain and select pharyngeal arches. Studies of Meis loci in mouse and zebrafish have identified enhancers that are bound by Hox and TALE (Meis and Pbx) proteins, implicating these factors in the direct regulation of Meis expression. We examined the lamprey meis loci and identified a series of cis-elements conserved between lamprey and jawed vertebrate meis genes. In transgenic reporter assays we demonstrated that these elements act as neural enhancers in lamprey embryos, directing reporter expression in appropriate domains when compared to expression of their associated endogenous meis gene. Sequence alignments reveal that these conserved elements are in similar relative positions of the meis loci and contain a series of consensus binding motifs for Hox and TALE proteins. This suggests that ancient Hox and TALE-responsive enhancers regulated expression of ancestral vertebrate meis genes in segmental domains in the hindbrain and have been retained in the meis loci during vertebrate evolution. The presence of conserved Meis, Pbx and Hox binding sites in these lamprey enhancers links Hox and TALE factors to regulation of lamprey meis genes in the developing hindbrain, indicating a deep ancestry for these regulatory interactions prior to the divergence of jawed and jawless vertebrates.
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Affiliation(s)
- Hugo J Parker
- Stowers Institute for Medical Research, Kansas City, MO, 64110, USA
| | - Bony De Kumar
- Stowers Institute for Medical Research, Kansas City, MO, 64110, USA
| | - Irina Pushel
- Stowers Institute for Medical Research, Kansas City, MO, 64110, USA
| | - Marianne E Bronner
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Robb Krumlauf
- Stowers Institute for Medical Research, Kansas City, MO, 64110, USA; Department of Anatomy and Cell Biology, Kansas University Medical Center, Kansas City, KS, 66160, USA.
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3
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Chang LW, Tseng IC, Wang LH, Sun YH. Isoform-specific functions of an evolutionarily conserved 3 bp micro-exon alternatively spliced from another exon in Drosophila homothorax gene. Sci Rep 2020; 10:12783. [PMID: 32732884 PMCID: PMC7392893 DOI: 10.1038/s41598-020-69644-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Accepted: 07/14/2020] [Indexed: 12/03/2022] Open
Abstract
Micro-exons are exons of very small size (usually 3–30 nts). Some micro-exons are alternatively spliced. Their functions, regulation and evolution are largely unknown. Here, we present an example of an alternatively spliced 3 bp micro-exon (micro-Ex8) in the homothorax (hth) gene in Drosophila. Hth is involved in many developmental processes. It contains a MH domain and a TALE-class homeodomain (HD). It binds to another homeodomain Exd via its MH domain to promote the nuclear import of the Hth-Exd complex and serve as a cofactor for Hox proteins. The MH and HD domains in Hth as well as the HTh-Exd interaction are highly conserved in evolution. The alternatively spliced micro-exon lies between the exons encoding the MH and HD domains. We provide clear proof that the micro-Ex8 is produced by alternative splicing from a 48 bp full-length exon 8 (FL-Ex8) and the micro-Ex8 is the first three nt is FL-Ex8. We found that the micro-Ex8 is the ancient form and the 3 + 48 organization of alternatively spliced overlapping exons only emerged in the Schizophora group of Diptera and is absolutely conserved in this group. We then used several strategies to test the in vivo function of the two types of isoforms and found that the micro-Ex8 and FL-Ex8 isoforms have largely overlapping functions but also have non-redundant functions that are tissue-specific, which supports their strong evolutionary conservation. Since the different combinations of protein interaction of Hth with Exd and/or Hox can have different DNA target specificity, our finding of alternatively spliced isoforms adds to the spectrum of structural and functional diversity under developmental regulation.
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Affiliation(s)
- Ling-Wen Chang
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, ROC
| | - I-Chieh Tseng
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, ROC.,Institute of Genomic Sciences, National Yang-Ming University, Taipei, Taiwan, ROC.,Department of Life Science, Chinese Culture University, Taipei, Taiwan, ROC
| | - Lan-Hsin Wang
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan.
| | - Y Henry Sun
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, ROC. .,Institute of Genomic Sciences, National Yang-Ming University, Taipei, Taiwan, ROC.
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4
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Singh A, Gogia N, Chang CY, Sun YH. Proximal fate marker homothorax marks the lateral extension of stalk-eyed fly Cyrtodopsis whitei. Genesis 2019; 57:e23309. [PMID: 31162816 DOI: 10.1002/dvg.23309] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 05/21/2019] [Accepted: 05/21/2019] [Indexed: 11/08/2022]
Abstract
The placement of eyes on insect head is an important evolutionary trait. The stalk-eyed fly, Cyrtodopsis whitei, exhibits a hypercephaly phenotype where compound eyes are located on lateral extension from the head while the antennal segments are placed inwardly on this stalk. This stalk-eyed phenotype is characteristic of the family Diopsidae in the Diptera order and dramatically deviates from other dipterans, such as Drosophila. Like other insects, the adult eye and antenna of stalk-eyed fly develop from a complex eye-antennal imaginal disc. We analyzed the markers involved in proximo-distal (PD) axis of the developing eye imaginal disc of the stalk-eyed flies. We used homothorax (hth) and distalless (dll), two highly conserved genes as the marker for proximal and distal fate, respectively. We found that lateral extensions between eye and antennal field of the stalk-eyed fly's eye-antennal imaginal disc exhibit robust Hth expression. Hth marks the head specific fate in the eye- and proximal fate in the antenna-disc. Thus, the proximal fate marker Hth expression evolves in the stalk-eyed flies to generate lateral extensions for the placement of the eye on the head. Moreover, during pupal eye metamorphosis, the lateral extension folds back on itself to place the antenna inside and the adult compound eye on the distal tip. Interestingly, the compound eye in other insects does not have a prominent PD axis as observed in the stalk-eyed fly.
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Affiliation(s)
- Amit Singh
- Department of Biology, University of Dayton, Dayton, Ohio.,Premedical Program, University of Dayton, Dayton, Ohio.,Center for Tissue Regeneration and Engineering at Dayton (TREND), University of Dayton, Dayton, Ohio.,The Integrative Science and Engineering Center, University of Dayton, Dayton, Ohio.,Center for Genomic Advocacy (TCGA), Indiana State University, Terre Haute, Indiana.,Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Neha Gogia
- Department of Biology, University of Dayton, Dayton, Ohio
| | - Chia-Yu Chang
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Yi Henry Sun
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
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5
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Oriente F, Perruolo G, Cimmino I, Cabaro S, Liotti A, Longo M, Miele C, Formisano P, Beguinot F. Prep1, A Homeodomain Transcription Factor Involved in Glucose and Lipid Metabolism. Front Endocrinol (Lausanne) 2018; 9:346. [PMID: 30002646 PMCID: PMC6032887 DOI: 10.3389/fendo.2018.00346] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 06/11/2018] [Indexed: 12/28/2022] Open
Abstract
The three-amino acid loop extension (TALE) homeodomain proteins are a family of transcription factor including the mammalian Pbx, MEIS and Prep proteins. TALE proteins can bind other transcription factors such as Pdx-1 and play an important role in the regulation of glucose metabolism. Experiments performed in mutant mice have shown that while the single Pbx1 or Pdx-1 knockout mice feature pancreatic islet malformations, impaired glucose tolerance and hypoinsulinemia, the trans-heterozygous Pbx1+/-Pdx1+/- mice develop age-dependent overt diabetes mellitus. In contrast, Prep1 plays a different role with respect to these proteins. Indeed, Prep1 hypomorphic mice, expressing low levels of protein, feature pancreatic islet hypoplasia accompanied by hypoinsulinemia similar to Pbx1 or Pdx1. Nevertheless, these animals show increased insulin sensitivity in skeletal muscle, liver and adipose tissue accompanied by protection from streptozotocin-induced diabetes. In addition, Prep1 hypomorphic mice feature reduced triglyceride synthesis and do not develop steatohepatitis after a methionine and coline deficient diet. In this review we have underlined how important metabolic functions are controlled by TALE proteins, in particular by Prep1, leading to hypothesis that its suppression might represent beneficial effect in the care of metabolic diseases.
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Affiliation(s)
- Francesco Oriente
- Department of Translational Medicine, Federico II University of Naples, Naples, Italy
- URT Genomic of Diabetes, Institute of Experimental Endocrinology and Oncology, National Research Council, Naples, Italy
| | - Giuseppe Perruolo
- Department of Translational Medicine, Federico II University of Naples, Naples, Italy
- URT Genomic of Diabetes, Institute of Experimental Endocrinology and Oncology, National Research Council, Naples, Italy
| | - Ilaria Cimmino
- Department of Translational Medicine, Federico II University of Naples, Naples, Italy
- URT Genomic of Diabetes, Institute of Experimental Endocrinology and Oncology, National Research Council, Naples, Italy
| | - Serena Cabaro
- Department of Translational Medicine, Federico II University of Naples, Naples, Italy
- URT Genomic of Diabetes, Institute of Experimental Endocrinology and Oncology, National Research Council, Naples, Italy
| | - Antonietta Liotti
- Department of Translational Medicine, Federico II University of Naples, Naples, Italy
- URT Genomic of Diabetes, Institute of Experimental Endocrinology and Oncology, National Research Council, Naples, Italy
| | - Michele Longo
- Department of Translational Medicine, Federico II University of Naples, Naples, Italy
- URT Genomic of Diabetes, Institute of Experimental Endocrinology and Oncology, National Research Council, Naples, Italy
| | - Claudia Miele
- Department of Translational Medicine, Federico II University of Naples, Naples, Italy
- URT Genomic of Diabetes, Institute of Experimental Endocrinology and Oncology, National Research Council, Naples, Italy
| | - Pietro Formisano
- Department of Translational Medicine, Federico II University of Naples, Naples, Italy
- URT Genomic of Diabetes, Institute of Experimental Endocrinology and Oncology, National Research Council, Naples, Italy
- *Correspondence: Pietro Formisano
| | - Francesco Beguinot
- Department of Translational Medicine, Federico II University of Naples, Naples, Italy
- URT Genomic of Diabetes, Institute of Experimental Endocrinology and Oncology, National Research Council, Naples, Italy
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6
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Mathiasen L, Valentini E, Boivin S, Cattaneo A, Blasi F, Svergun DI, Bruckmann C. The flexibility of a homeodomain transcription factor heterodimer and its allosteric regulation by DNA binding. FEBS J 2016; 283:3134-54. [PMID: 27390177 DOI: 10.1111/febs.13801] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Revised: 05/20/2016] [Accepted: 07/06/2016] [Indexed: 12/27/2022]
Abstract
UNLABELLED Transcription factors are known to modify the DNA that they bind. However, DNA can also serve as an allosteric ligand whose binding modifies the conformation of transcriptional regulators. Here, we describe how heterodimer PBX1:PREP1, formed by proteins playing major roles in embryonic development and tumorigenesis, undergoes an allosteric transition upon DNA binding. We demonstrate through a number of biochemical and biophysical methods that PBX1:PREP1 exhibits a structural change upon DNA binding. Small-angle X-ray scattering (SAXS), circular dichroism (CD), isothermal titration calorimetry (ITC), and limited proteolysis demonstrate a different shape, α-helical content, thermodynamic behavior, and solution environment of the holo-complex (with DNA) compared to the apo-complex (without DNA). Given that PBX1 as such does not have a defined DNA selectivity, structural changes upon DNA binding become major factors in the function of the PBX1:PREP1 complex. The observed changes are mapped at both the amino- and carboxy-terminal regions of the two proteins thereby providing important insights to determine how PBX1:PREP1 dimer functions. DATABASE Small-angle scattering data are available in SASBDB under accession numbers SASDAP7, SASDAQ7, and SASDAR7.
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Affiliation(s)
- Lisa Mathiasen
- FIRC (Foundation for Italian Cancer Research) Institute of Molecular Oncology (IFOM), Milan, Italy
| | | | | | - Angela Cattaneo
- FIRC (Foundation for Italian Cancer Research) Institute of Molecular Oncology (IFOM), Milan, Italy
| | - Francesco Blasi
- FIRC (Foundation for Italian Cancer Research) Institute of Molecular Oncology (IFOM), Milan, Italy
| | | | - Chiara Bruckmann
- FIRC (Foundation for Italian Cancer Research) Institute of Molecular Oncology (IFOM), Milan, Italy
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7
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Abstract
Metazoans encode clusters of paralogous Hox genes that are critical for proper development of the body plan. However, there are a number of unresolved issues regarding how paralogous Hox factors achieve specificity to control distinct cell fates. First, how do Hox paralogs, which have very similar DNA binding preferences in vitro, drive different transcriptional programs in vivo? Second, the number of potential Hox binding sites within the genome is vast compared to the number of sites bound. Hence, what determines where in the genome Hox factors bind? Third, what determines whether a Hox factor will activate or repress a specific target gene? Here, we review the current evidence that is beginning to shed light onto these questions. In particular, we highlight how cooperative interactions with other transcription factors (especially PBC and HMP proteins) and the sequences of cis-regulatory modules provide a basis for the mechanisms of Hox specificity. We conclude by integrating a number of the concepts described throughout the review in a case study of a highly interrogated Drosophila cis-regulatory module named “The Distal-less Conserved Regulatory Element” (DCRE).
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Affiliation(s)
- Arya Zandvakili
- Molecular and Developmental Biology Graduate Program, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229, USA
- Medical-Scientist Training Program, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA;
| | - Brian Gebelein
- Division of Developmental Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229, USA
- Correspondence: ; Tel.: +1-513-636-3366
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8
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Grimmel J, Dorresteijn AWC, Fröbius AC. Formation of body appendages during caudal regeneration in Platynereis dumerilii: adaptation of conserved molecular toolsets. EvoDevo 2016; 7:10. [PMID: 27076904 PMCID: PMC4830062 DOI: 10.1186/s13227-016-0046-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2016] [Accepted: 03/30/2016] [Indexed: 01/13/2023] Open
Abstract
Background Platynereis and other polychaete annelids with homonomous segmentation are regarded to closely resemble ancestral forms of bilateria. The head region comprises the prostomium, the peristomium, a variable number of cephalized body segments and several appendages, like cirri, antennae and palps. The trunk of such polychaetes shows numerous, nearly identical segments. Each segment bears a parapodium with species-specific morphology on either side. The posterior end of the trunk features a segment proliferation zone and a terminal pygidium with the anus and anal cirri. The removal of a substantial part of the posterior trunk is by no means lethal. Cells at the site of injury dedifferentiate and proliferate forming a blastema to regenerate both the pygidium and the proliferation zone. The pygidium forms new anal cirri, and the proliferation zone generates new segments at a rapid pace. The formation of body appendages like the cirri and the segmental parapodia can thus be studied in the caudal regenerate of Platynereis within only a few days. Results The development of body appendages in Platynereis is regulated by a network of genes common to polychaetes but also shared by distant taxa. We isolated DNA sequences from P. dumerilii of five genes known to be involved in appendage formation within other groups: Meis/homothorax, Pbx1/extradenticle, Dlx/Distal-less, decapentaplegic and specificprotein1/buttonhead. Analyses of expression patterns during caudal regeneration by in situ hybridization reveal striking similarities related to expression in arthropods and vertebrates. All genes exhibit transient expression during differentiation and growth of segments. As was shown previously in other phyla Pdu-Meis/hth and Pdu-Pbx1/exd are co-expressed, although the expression is not limited to the proximal part of the parapodia. Pdu-Dll is prominent in parapodia but upregulated in the anal cirri. No direct dependence concerning Pdu-Dll and Pdu-sp/btd expression is observed in Platynereis. Pdu-dpp shows an expression pattern not comparable to its expression in other taxa. Conclusions The expression patterns observed suggest conserved roles of these genes during appendage formation across different clades, but the underlying mechanisms utilizing this toolset might not be identical. Some genes show broad expression along the proximodistal axis indicating a possible role in proximodistal patterning of body appendages. Other genes exhibit expression patterns limited to specific parts and tissues of the growing parapodia, thus presumably being involved in formation of taxon-specific morphological differences. Electronic supplementary material The online version of this article (doi:10.1186/s13227-016-0046-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jan Grimmel
- Institut für Allgemeine und Spezielle Zoologie, Abteilung Entwicklungsbiologie, Justus-Liebig-Universität Gießen, Stephanstraße 24, 35390 Gießen, Germany
| | - Adriaan W C Dorresteijn
- Institut für Allgemeine und Spezielle Zoologie, Abteilung Entwicklungsbiologie, Justus-Liebig-Universität Gießen, Stephanstraße 24, 35390 Gießen, Germany
| | - Andreas C Fröbius
- Institut für Allgemeine und Spezielle Zoologie, Abteilung Entwicklungsbiologie, Justus-Liebig-Universität Gießen, Stephanstraße 24, 35390 Gießen, Germany
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9
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Wernet MF, Desplan C. Homothorax and Extradenticle alter the transcription factor network in Drosophila ommatidia at the dorsal rim of the retina. Development 2014; 141:918-28. [PMID: 24496628 DOI: 10.1242/dev.103127] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
A narrow band of ommatidia in the dorsal periphery of the Drosophila retina called the dorsal rim area (DRA) act as detectors for polarized light. The transcription factor Homothorax (Hth) is expressed in DRA inner photoreceptors R7 and R8 and is both necessary and sufficient to induce the DRA fate, including specialized morphology and unique Rhodopsin expression. Hth expression is the result of Wingless (Wg) pathway activity at the eye margins and restriction to the dorsal eye by the selector genes of the Iroquois complex (Iro-C). However, how the DRA is limited to exactly one or two ommatidial rows is not known. Although several factors regulating the Drosophila retinal mosaic are expressed in DRA ommatidia, the role of Hth in this transcriptional network is uncharacterized. Here we show that Hth functions together with its co-factor Extradenticle (Exd) to repress the R8-specific factor Senseless (Sens) in DRA R8 cells, allowing expression of an ultraviolet-sensitive R7 Rhodopsin (Rh3). Furthermore, Hth/Exd act in concert with the transcriptional activators Orthodenticle (Otd) and Spalt (Sal), to activate expression of Rh3 in the DRA. The resulting monochromatic coupling of Rh3 between R7 and R8 in DRA ommatidia is important for comparing celestial e-vector orientation rather than wavelengths. Finally, we show that Hth expression expands to many ommatidial rows in regulatory mutants of optomotorblind (omb), a transcription factor transducing Wg signaling at the dorsal and ventral eye poles. Therefore, locally restricted recruitment of the DRA-specific factor Hth alters the transcriptional network that regulates Rhodopsin expression across ommatidia.
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Affiliation(s)
- Mathias F Wernet
- Center for Developmental Genetics, Department of Biology, New York University, 100 Washington Place, New York, NY 10003, USA
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10
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Longobardi E, Penkov D, Mateos D, De Florian G, Torres M, Blasi F. Biochemistry of the tale transcription factors PREP, MEIS, and PBX in vertebrates. Dev Dyn 2014; 243:59-75. [PMID: 23873833 PMCID: PMC4232920 DOI: 10.1002/dvdy.24016] [Citation(s) in RCA: 107] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Revised: 06/19/2013] [Accepted: 07/05/2013] [Indexed: 12/22/2022] Open
Abstract
TALE (three amino acids loop extension) homeodomain transcription factors are required in various steps of embryo development, in many adult physiological functions, and are involved in important pathologies. This review focuses on the PREP, MEIS, and PBX sub-families of TALE factors and aims at giving information on their biochemical properties, i.e., structure, interactors, and interaction surfaces. Members of the three sets of protein form dimers in which the common partner is PBX but they can also directly interact with other proteins forming higher-order complexes, in particular HOX. Finally, recent advances in determining the genome-wide DNA-binding sites of PREP1, MEIS1, and PBX1, and their partial correspondence with the binding sites of some HOX proteins, are reviewed. These studies have generated a few general rules that can be applied to all members of the three gene families. PREP and MEIS recognize slightly different consensus sequences: PREP prefers to bind to promoters and to have PBX as a DNA-binding partner; MEIS prefers HOX as partner, and both PREP and MEIS drive PBX to their own binding sites. This outlines the clear individuality of the PREP and MEIS proteins, the former mostly devoted to basic cellular functions, the latter more to developmental functions.
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Affiliation(s)
- E Longobardi
- Fondazione Istituto FIRC di Oncologia Molecolare (IFOM), Milano, Italy
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11
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Cerdá-Esteban N, Spagnoli FM. Glimpse into Hox and tale regulation of cell differentiation and reprogramming. Dev Dyn 2013; 243:76-87. [PMID: 24123411 DOI: 10.1002/dvdy.24075] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2013] [Revised: 09/15/2013] [Accepted: 10/04/2013] [Indexed: 12/20/2022] Open
Abstract
During embryonic development, cells become gradually restricted in their developmental potential and start elaborating lineage-specific transcriptional networks to ultimately acquire a unique differentiated state. Hox genes play a central role in specifying regional identities, thereby providing the cell with critical information on positional value along its differentiation path. The exquisite DNA-binding specificity of the Hox proteins is frequently dependent upon their interaction with members of the TALE family of homeodomain proteins. In addition to their function as Hox-cofactors, TALE homeoproteins control multiple crucial developmental processes through Hox-independent mechanisms. Here, we will review recent findings on the function of both Hox and TALE proteins in cell differentiation, referring mostly to vertebrate species. In addition, we will discuss the direct implications of this knowledge on cell plasticity and cell reprogramming.
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Affiliation(s)
- Nuria Cerdá-Esteban
- Laboratory of Molecular and Cellular Basis of Embryonic Development, Max Delbrück Center for Molecular Medicine, Berlin, Germany
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12
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Moran MT, Tare M, Kango-Singh M, Singh A. Homeotic Gene teashirt (tsh) has a neuroprotective function in amyloid-beta 42 mediated neurodegeneration. PLoS One 2013; 8:e80829. [PMID: 24282556 PMCID: PMC3840013 DOI: 10.1371/journal.pone.0080829] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Accepted: 10/07/2013] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Alzheimer's disease (AD) is a debilitating age related progressive neurodegenerative disorder characterized by the loss of cognition, and eventual death of the affected individual. One of the major causes of AD is the accumulation of Amyloid-beta 42 (Aβ42) polypeptides formed by the improper cleavage of amyloid precursor protein (APP) in the brain. These plaques disrupt normal cellular processes through oxidative stress and aberrant signaling resulting in the loss of synaptic activity and death of the neurons. However, the detailed genetic mechanism(s) responsible for this neurodegeneration still remain elusive. METHODOLOGY/ PRINCIPLE FINDINGS We have generated a transgenic Drosophila eye model where high levels of human Aβ42 is misexpressed in the differentiating photoreceptor neurons of the developing eye, which phenocopy Alzheimer's like neuropathology in the neural retina. We have utilized this model for a gain of function screen using members of various signaling pathways involved in the development of the fly eye to identify downstream targets or modifiers of Aβ42 mediated neurodegeneration. We have identified the homeotic gene teashirt (tsh) as a suppressor of the Aβ42 mediated neurodegenerative phenotype. Targeted misexpression of tsh with Aβ42 in the differentiating retina can significantly rescue neurodegeneration by blocking cell death. We found that Tsh protein is absent/ downregulated in the neural retina at this stage. The structure function analysis revealed that the PLDLS domain of Tsh acts as an inhibitor of the neuroprotective function of tsh in the Drosophila eye model. Lastly, we found that the tsh paralog, tiptop (tio) can also rescue Aβ42 mediated neurodegeneration. CONCLUSIONS/SIGNIFICANCE We have identified tsh and tio as new genetic modifiers of Aβ42 mediated neurodegeneration. Our studies demonstrate a novel neuroprotective function of tsh and its paralog tio in Aβ42 mediated neurodegeneration. The neuroprotective function of tsh is independent of its role in retinal determination.
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Affiliation(s)
- Michael T. Moran
- Department of Biology, University of Dayton, Dayton, Ohio, United States of America
| | - Meghana Tare
- Department of Biology, University of Dayton, Dayton, Ohio, United States of America
| | - Madhuri Kango-Singh
- Department of Biology, University of Dayton, Dayton, Ohio, United States of America
- Premedical Program, University of Dayton, Dayton, Ohio, United States of America
- Center for Tissue Regeneration and Engineering at Dayton (TREND), University of Dayton, Dayton, Ohio, United States of America
| | - Amit Singh
- Department of Biology, University of Dayton, Dayton, Ohio, United States of America
- Premedical Program, University of Dayton, Dayton, Ohio, United States of America
- Center for Tissue Regeneration and Engineering at Dayton (TREND), University of Dayton, Dayton, Ohio, United States of America
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13
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Barnett AA, Thomas RH. The expression of limb gap genes in the mite Archegozetes longisetosus reveals differential patterning mechanisms in chelicerates. Evol Dev 2013; 15:280-92. [PMID: 23809702 DOI: 10.1111/ede.12038] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The modular organization of arthropod limbs has lead to the evolution of a diversity of appendages within this phylum. A conserved trait within the arthropods is the utilization of a conserved set of regulatory genes that specify the appendage podomeres along the proximo-distal axis, termed the limb gap genes. These include extradenticle, homothorax, dachshund, and Distal-less. The deployment of these genes in the most basally branching arthropod group, the chelicerates, has only been studied in detail in two chelicerate groups, the harvestmen and spiders. Given the broad range of appendage diversity within the chelicerates, comparative studies of gap gene deployment in other chelicerates groups is needed. We therefore followed limb gap gene expression in a member of the largest chelicerate group, Acari, the oribatid mite Archegozetes longisetosus. We show that in contrast to many arthropod species, A. longisetosus expresses homothorax and extradenticle exclusively in the proximal portion of the appendages, which refutes the hypothesis of a sister-group relationship between chelicerates and myriapods. We also provide evidence that mites posses the ancestral chelicerate condition of possessing three-segmented chelicerae, which also express the gene dachshund. This adds support to the hypothesis that a cheliceral dachshund domain is ancestral to arachnids. Lastly, we provide evidence that the suppression of the fourth pair of walking legs, a putative synapomorphy for Acari, is accomplished by repressing the development of the medial and distal regions of the limb.
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Affiliation(s)
- Austen A Barnett
- Department of Zoology, Southern Illinois University, Carbondale, IL 62901, USA
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14
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Ladam F, Sagerström CG. Hox regulation of transcription: more complex(es). Dev Dyn 2013; 243:4-15. [PMID: 23765878 DOI: 10.1002/dvdy.23997] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Revised: 05/31/2013] [Accepted: 06/03/2013] [Indexed: 11/10/2022] Open
Abstract
Hox genes encode transcription factors with important roles during embryogenesis and tissue differentiation. Genetic analyses initially demonstrated that interfering with Hox genes has profound effects on the specification of cell identity, suggesting that Hox proteins regulate very specific sets of target genes. However, subsequent biochemical analyses revealed that Hox proteins bind DNA with relatively low affinity and specificity. Furthermore, it became clear that a given Hox protein could activate or repress transcription, depending on the context. A resolution to these paradoxes presented itself with the discovery that Hox proteins do not function in isolation, but interact with other factors in complexes. The first such "cofactors" were members of the Extradenticle/Pbx and Homothorax/Meis/Prep families. However, the list of Hox-interacting proteins has continued to grow, suggesting that Hox complexes contain many more components than initially thought. Additionally, the activities of the various components and the exact mechanisms whereby they modulate the activity of the complex remain puzzling. Here, we review the various proteins known to participate in Hox complexes and discuss their likely functions. We also consider that Hox complexes of different compositions may have different activities and discuss mechanisms whereby Hox complexes may be switched between active and inactive states.
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Affiliation(s)
- Franck Ladam
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts
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15
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Appendage patterning in the primitively wingless hexapods Thermobia domestica (Zygentoma: Lepismatidae) and Folsomia candida (Collembola: Isotomidae). Dev Genes Evol 2013; 223:341-50. [DOI: 10.1007/s00427-013-0449-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Accepted: 07/01/2013] [Indexed: 12/21/2022]
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16
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Bischof J, Björklund M, Furger E, Schertel C, Taipale J, Basler K. A versatile platform for creating a comprehensive UAS-ORFeome library in Drosophila. Development 2013; 140:2434-42. [PMID: 23637332 DOI: 10.1242/dev.088757] [Citation(s) in RCA: 219] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Overexpression screens are used to explore gene functions in Drosophila, but this strategy suffers from the lack of comprehensive and systematic fly strain collections and efficient methods for generating such collections. Here, we present a strategy that could be used efficiently to generate large numbers of transgenic Drosophila strains, and a collection of 1149 UAS-ORF fly lines that were created with the site-specific ΦC31 integrase method. For this collection, we used a set of 655 genes that were cloned as two variants, either as an open reading frame (ORF) with a native stop codon or with a C-terminal 3xHA tag. To streamline the procedure for transgenic fly generation, we demonstrate the utility of injecting pools of plasmids into embryos, each plasmid containing a randomised sequence (barcode) that serves as a unique identifier for plasmids and, subsequently, fly strains. We also developed a swapping technique that facilitates the rapid exchange of promoters and epitope tags in vivo, expanding the versatility of the ORF collection. The work described here serves as the basis of a systematic library of Gal4/UAS-regulated transgenes.
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Affiliation(s)
- Johannes Bischof
- Institute of Molecular Life Sciences, University of Zurich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
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17
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Lafontaine CA, Grainger S, Hess BL, Béland M, Lohnes D. Cdx1 interacts physically with a subset of Hox proteins. Biochemistry 2012; 51:9698-705. [PMID: 23121490 DOI: 10.1021/bi301241q] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Cdx and Hox gene families encode homeodomain-containing transcription factors involved in anterior-posterior vertebral patterning. Although Cdx proteins are direct transcriptional regulators of Hox gene expression, both Hox and Cdx proteins are known to interact with other homeodomain transcription factors, leading us to speculate that Cdx and Hox proteins may also interact physically. In testing this, we found that that Cdx1 is indeed capable of associating with a subset of Hox proteins. This interaction is localized to the homeodomain region of both classes of proteins, is reliant on specific arginine residues in helix I of the Hox homeodomain, and is further modulated by N-terminal Hox sequences. More promiscuous interactions were seen with Hox proteins expressed in vivo, suggestive of bridging factors or post-translational modifications. Finally, we demonstrate that this interaction modulates Cdx-Hox transcriptional activity on a Hox-responsive element. This study is the first example of Cdx-Hox protein interactions and suggests that such complexes may modulate Hox and/or Cdx function.
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Affiliation(s)
- Christine A Lafontaine
- Department of Cellular and Molecular Medicine, University of Ottawa, 451 Smyth Road, Ottawa, Ontario, Canada
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18
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Wang CW, Sun YH. Segregation of eye and antenna fates maintained by mutual antagonism in Drosophila. Development 2012; 139:3413-21. [DOI: 10.1242/dev.078857] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
A general question in development is how do adjacent primordia adopt different developmental fates and stably maintain their distinct fates? In Drosophila melanogaster, the adult eye and antenna originate from the embryonic eye-antenna primordium. These cells proliferate in the larval stage to form the eye-antenna disc. The eye or antenna differs at mid second instar with the restricted expression of Cut (Ct), a homeodomain transcriptional repressor, in the antenna disc and Eyeless (Ey), a Pax6 transcriptional activator, in the eye disc. In this study, we show that ey transcription in the antenna disc is repressed by two homeodomain proteins, Ct and Homothorax (Hth). Loss of Ct and Hth in the antenna disc resulted in ectopic eye development in the antenna. Conversely, the Ct and Hth expression in the eye disc was suppressed by the homeodomain transcription factor Sine oculis (So), a direct target of Ey. Loss of So in the eye disc caused ectopic antenna development in the eye. Therefore, the segregation of eye and antenna fates is stably maintained by mutual repression of the other pathway.
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Affiliation(s)
- Cheng-Wei Wang
- Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei, Taiwan, Republic of China
- Institute of Molecular Biology, Academia Sinica, Nankang, Taipei, Taiwan, Republic of China
| | - Y. Henry Sun
- Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei, Taiwan, Republic of China
- Institute of Molecular Biology, Academia Sinica, Nankang, Taipei, Taiwan, Republic of China
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19
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Sgadò P, Ferretti E, Grbec D, Bozzi Y, Simon HH. The atypical homeoprotein Pbx1a participates in the axonal pathfinding of mesencephalic dopaminergic neurons. Neural Dev 2012; 7:24. [PMID: 22748019 PMCID: PMC3407702 DOI: 10.1186/1749-8104-7-24] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2012] [Accepted: 07/02/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The pre B-cell leukemia transcription factor 1 (Pbx1) genes belong to the three amino acid loop extension family of homeodomain proteins that form hetero-oligomeric complexes with other homeodomain transcription factors, thereby modulating target specificity, DNA binding affinity and transcriptional activity of their molecular associates. RESULTS Here, we provide evidence that Pbx1 is expressed in mesencephalic dopaminergic neurons from embryonic day 11 into adulthood and determines some of the cellular properties of this neuronal population. In Pbx1-deficient mice, the mesencephalic dopaminergic axons stall during mid-gestation at the border between di- and telencephalon before entering the ganglionic eminence, leading to a loose organization of the axonal bundle and partial misrouting. In Pbx1-deficient dopaminergic neurons, the high affinity netrin-1 receptor, deleted in colon cancer (DCC), is down-regulated. Interestingly, we found several conserved Pbx1 binding sites in the first intron of DCC, suggesting a direct regulation of DCC transcription by Pbx1. CONCLUSIONS The expression of Pbx1 in dopaminergic neurons and its regulation of DCC expression make it an important player in defining the axonal guidance of the midbrain dopaminergic neurons, with possible implications for the normal physiology of the nigro-striatal system as well as processes related to the degeneration of neurons during the course of Parkinson's disease.
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Affiliation(s)
- Paola Sgadò
- Laboratory of Molecular Neuropathology, Centre for Integrative Biology, University of Trento, Trento, Italy.
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20
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Singh A, Tare M, Puli OR, Kango-Singh M. A glimpse into dorso-ventral patterning of the Drosophila eye. Dev Dyn 2011; 241:69-84. [PMID: 22034010 DOI: 10.1002/dvdy.22764] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/06/2011] [Indexed: 12/15/2022] Open
Abstract
During organogenesis in all multi-cellular organisms, axial patterning is required to transform a single layer organ primordium into a three-dimensional organ. The Drosophila eye model serves as an excellent model to study axial patterning. Dorso-ventral (DV) axis determination is the first lineage restriction event during axial patterning of the Drosophila eye. The early Drosophila eye primordium has a default ventral fate, and the dorsal eye fate is established by onset of dorsal selector gene pannier (pnr) expression in a group of cells on the dorsal eye margin. The boundary between dorsal and ventral compartments called the equator is the site for Notch (N) activation, which triggers cell proliferation and differentiation. This review will focus on (1) chronology of events during DV axis determination; (2) how early division of eye into dorsal and ventral compartments contributes towards the growth and patterning of the fly retina, and (3) functions of DV patterning genes.
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Affiliation(s)
- Amit Singh
- Department of Biology, University of Dayton, Dayton, Ohio 45469, USA.
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21
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Singh A, Tare M, Kango-Singh M, Son WS, Cho KO, Choi KW. Opposing interactions between homothorax and Lobe define the ventral eye margin of Drosophila eye. Dev Biol 2011; 359:199-208. [PMID: 21920354 DOI: 10.1016/j.ydbio.2011.08.017] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2011] [Revised: 08/22/2011] [Accepted: 08/28/2011] [Indexed: 11/19/2022]
Abstract
Patterning in multi-cellular organisms involves progressive restriction of cell fates by generation of boundaries to divide an organ primordium into smaller fields. We have employed the Drosophila eye model to understand the genetic circuitry responsible for defining the boundary between the eye and the head cuticle on the ventral margin. The default state of the early eye is ventral and depends on the function of Lobe (L) and the Notch ligand Serrate (Ser). We identified homothorax (hth) as a strong enhancer of the L mutant phenotype of loss of ventral eye. Hth is a MEIS class gene with a highly conserved Meis-Hth (MH) domain and a homeodomain (HD). Hth is known to bind Extradenticle (Exd) via its MH domain for its nuclear translocation. Loss-of-function of hth, a negative regulator of eye, results in ectopic ventral eye enlargements. This phenotype is complementary to the L mutant phenotype of loss-of-ventral eye. However, if L and hth interact during ventral eye development remains unknown. Here we show that (i) L acts antagonistically to hth, (ii) Hth is upregulated in the L mutant background, and (iii) MH domain of Hth is required for its genetic interaction with L, while its homeodomain is not, (iv) in L mutant background ventral eye suppression function of Hth involves novel MH domain-dependent factor(s), and (v) nuclear localization of Exd is not sufficient to mediate the Hth function in the L mutant background. Further, Exd is not a critical rate-limiting factor for the Hth function. Thus, optimum levels of L and Hth are required to define the boundary between the developing eye and head cuticle on the ventral margin.
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Affiliation(s)
- Amit Singh
- Department of Biology, University of Dayton, OH 45469, USA.
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22
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In der Rieden PMJ, Jansen HJ, Durston AJ. XMeis3 is necessary for mesodermal Hox gene expression and function. PLoS One 2011; 6:e18010. [PMID: 21464931 PMCID: PMC3065463 DOI: 10.1371/journal.pone.0018010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2010] [Accepted: 02/21/2011] [Indexed: 12/13/2022] Open
Abstract
Hox transcription factors provide positional information during patterning of the anteroposterior axis. Hox transcription factors can co-operatively bind with PBC-class co-factors, enhancing specificity and affinity for their appropriate binding sites. The nuclear localisation of these co-factors is regulated by the Meis-class of homeodomain proteins. During development of the zebrafish hindbrain, Meis3 has previously been shown to synergise with Hoxb1 in the autoregulation of Hoxb1. In Xenopus XMeis3 posteriorises the embryo upon ectopic expression. Recently, an early temporally collinear expression sequence of Hox genes was detected in Xenopus gastrula mesoderm (see intro. P3). There is evidence that this sequence sets up the embryo's later axial Hox expression pattern by time-space translation. We investigated whether XMeis3 is involved in regulation of this early mesodermal Hox gene expression. Here, we present evidence that XMeis3 is necessary for expression of Hoxd1, Hoxb4 and Hoxc6 in mesoderm during gastrulation. In addition, we show that XMeis3 function is necessary for the progression of gastrulation. Finally, we present evidence for synergy between XMeis3 and Hoxd1 in Hoxd1 autoregulation in mesoderm during gastrulation.
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23
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Capellini TD, Zappavigna V, Selleri L. Pbx homeodomain proteins: TALEnted regulators of limb patterning and outgrowth. Dev Dyn 2011; 240:1063-86. [PMID: 21416555 DOI: 10.1002/dvdy.22605] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/13/2011] [Indexed: 12/14/2022] Open
Abstract
Limb development has long provided an excellent model for understanding the genetic principles driving embryogenesis. Studies utilizing chick and mouse have led to new insights into limb patterning and morphogenesis. Recent research has centered on the regulatory networks underlying limb development. Here, we discuss the hierarchical, overlapping, and iterative roles of Pbx family members in appendicular development that have emerged from genetic analyses in the mouse. Pbx genes are essential in determining limb bud positioning, early bud formation, limb axes establishment and coordination, and patterning and morphogenesis of most elements of the limb and girdle. Pbx proteins directly regulate critical effectors of limb and girdle development, including morphogen-encoding genes like Shh in limb posterior mesoderm, and transcription factor-encoding genes like Alx1 in pre-scapular domains. Interestingly, at least in limb buds, Pbx appear to act not only as Hox cofactors, but also in the upstream control of 5' HoxA/D gene expression.
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Affiliation(s)
- Terence D Capellini
- Department of Cell and Developmental Biology, Weill Medical College of Cornell University, New York, New York, USA
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24
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Sánchez-Guardado LÓ, Ferran JL, Rodríguez-Gallardo L, Puelles L, Hidalgo-Sánchez M. Meis gene expression patterns in the developing chicken inner ear. J Comp Neurol 2011; 519:125-47. [PMID: 21120931 DOI: 10.1002/cne.22508] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
We are interested in stable gene network activities operating sequentially during inner ear specification. The implementation of this patterning process is a key event in the generation of functional subdivisions of the otic vesicle during early embryonic development. The vertebrate inner ear is a complex sensory structure that is a good model system for characterization of developmental mechanisms controlling patterning and specification. Meis genes, belonging to the TALE family, encode homodomain-containing transcription factors remarkably conserved during evolution, which play a role in normal and neoplastic development. To gain understanding of the possible role of homeobox Meis genes in the developing chick inner ear, we comprehensively analyzed their spatiotemporal expression patterns from early otic specification stages onwards. In the invaginating otic placode, Meis1/2 transcripts were observed in the borders of the otic cup, being absent in the portion of otic epithelium closest to the hindbrain. As development proceeds, Meis1 and Meis2 expressions became restricted to the dorsomedial otic epithelium. Both genes were strongly expressed in the entire presumptive domain of the semicircular canals, and more weakly in all associated cristae. The endolymphatic apparatus was labeled in part by Meis1/2. Meis1 was also expressed in the lateral wall of the growing cochlear duct, while Meis2 expression was detected in a few cells of the developing acoustic-vestibular ganglion. Our results suggest a possible role of Meis assigning regional identity in the morphogenesis, patterning, and specification of the developing inner ear.
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Abstract
The road to producing an eye begins with the decision to commit a population of cells to adopting an eye tissue fate, the process of retinal determination. Over the past decade and a half, a network of transcription factors has been found to mediate this process in all seeing animals. This retinal determination network is known to regulate not only tissue fate but also cell proliferation, pattern formation, compartment boundary establishment, and even retinal cell specification. The compound eye of the fruit fly, Drosophila melanogaster, has proven to be an excellent experimental system to study the mechanisms by which this network regulates organogenesis and tissue patterning. In fact the founding members of most of the gene families that make up this network were first isolated in Drosophila based on loss-of-function phenotypes that affect the eye. This chapter will highlight the history of discovery of the retinal determination network and will draw attention to the molecular and biochemical mechanisms that underlie our understanding of how the fate of the retina is determined.
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Affiliation(s)
- Justin P Kumar
- Department of Biology, Indiana University, Bloomington, Indiana, USA
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26
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Oriente F, Iovino S, Cabaro S, Cassese A, Longobardi E, Miele C, Ungaro P, Formisano P, Blasi F, Beguinot F. Prep1 controls insulin glucoregulatory function in liver by transcriptional targeting of SHP1 tyrosine phosphatase. Diabetes 2011; 60:138-47. [PMID: 20864515 PMCID: PMC3012165 DOI: 10.2337/db10-0860] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
OBJECTIVE We investigated the function of the Prep1 gene in insulin-dependent glucose homeostasis in liver. RESEARCH DESIGN AND METHODS Prep1 action on insulin glucoregulatory function has been analyzed in liver of Prep1-hypomorphic mice (Prep1(i/i)), which express 2-3% of Prep1 mRNA. RESULTS Based on euglycemic hyperinsulinemic clamp studies and measurement of glycogen content, livers from Prep1(i/i) mice feature increased sensitivity to insulin. Tyrosine phosphorylation of both insulin receptor (IR) and insulin receptor substrate (IRS)1/2 was significantly enhanced in Prep1(i/i) livers accompanied by a specific downregulation of the SYP and SHP1 tyrosine phosphatases. Prep1 overexpression in HepG2 liver cells upregulated SYP and SHP1 and inhibited insulin-induced IR and IRS1/2 phosphorylation and was accompanied by reduced glycogen content. Consistently, overexpression of the Prep1 partner Pbx1, but not of p160MBP, mimicked Prep1 effects on tyrosine phosphorylations, glycogen content, and on SYP and SHP1 expression. In Prep1 overexpressing cells, antisense silencing of SHP1, but not that of SYP, rescued insulin-dependent IR phosphorylation and glycogen accumulation. Both Prep1 and Pbx1 bind SHP1 promoter at a site located between nucleotides -2,113 and -1,778. This fragment features enhancer activity and induces luciferase function by 7-, 6-, and 30-fold, respectively, in response to Prep1, Pbx1, or both. CONCLUSIONS SHP1, a known silencer of insulin signal, is a transcriptional target of Prep1. In liver, transcriptional activation of SHP1 gene by Prep1 attenuates insulin signal transduction and reduces glucose storage.
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Affiliation(s)
- Francesco Oriente
- Dipartimento di Biologia e Patologia Cellulare e Molecolare and Istituto di Endocrinologia ed Oncologia Sperimentale del Consiglio Nazionale delle Ricerche, Università degli Studi di Napoli Federico II, Naples, Italy
| | - Salvatore Iovino
- Dipartimento di Biologia e Patologia Cellulare e Molecolare and Istituto di Endocrinologia ed Oncologia Sperimentale del Consiglio Nazionale delle Ricerche, Università degli Studi di Napoli Federico II, Naples, Italy
| | - Serena Cabaro
- Dipartimento di Biologia e Patologia Cellulare e Molecolare and Istituto di Endocrinologia ed Oncologia Sperimentale del Consiglio Nazionale delle Ricerche, Università degli Studi di Napoli Federico II, Naples, Italy
| | - Angela Cassese
- Dipartimento di Biologia e Patologia Cellulare e Molecolare and Istituto di Endocrinologia ed Oncologia Sperimentale del Consiglio Nazionale delle Ricerche, Università degli Studi di Napoli Federico II, Naples, Italy
| | - Elena Longobardi
- Istituto FIRC di Oncologia Molecolare (Fondazione Italiana per la Ricerca sul Cancro Institute of Molecular Oncology), Milano, Italy
- Università Vita Salute San Raffaele, Milano, Italy
| | - Claudia Miele
- Dipartimento di Biologia e Patologia Cellulare e Molecolare and Istituto di Endocrinologia ed Oncologia Sperimentale del Consiglio Nazionale delle Ricerche, Università degli Studi di Napoli Federico II, Naples, Italy
| | - Paola Ungaro
- Dipartimento di Biologia e Patologia Cellulare e Molecolare and Istituto di Endocrinologia ed Oncologia Sperimentale del Consiglio Nazionale delle Ricerche, Università degli Studi di Napoli Federico II, Naples, Italy
| | - Pietro Formisano
- Dipartimento di Biologia e Patologia Cellulare e Molecolare and Istituto di Endocrinologia ed Oncologia Sperimentale del Consiglio Nazionale delle Ricerche, Università degli Studi di Napoli Federico II, Naples, Italy
| | - Francesco Blasi
- Istituto FIRC di Oncologia Molecolare (Fondazione Italiana per la Ricerca sul Cancro Institute of Molecular Oncology), Milano, Italy
- Università Vita Salute San Raffaele, Milano, Italy
| | - Francesco Beguinot
- Dipartimento di Biologia e Patologia Cellulare e Molecolare and Istituto di Endocrinologia ed Oncologia Sperimentale del Consiglio Nazionale delle Ricerche, Università degli Studi di Napoli Federico II, Naples, Italy
- Corresponding author: Francesco Beguinot,
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27
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Three-amino-acid-loop-extension homeodomain factor Meis3 regulates cell survival via PDK1. Proc Natl Acad Sci U S A 2010; 107:20494-9. [PMID: 21059917 DOI: 10.1073/pnas.1007001107] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Three-amino-acid-loop-extension (TALE) homeodomain proteins including Meis and Pbx families are generally recognized for their roles in growth and differentiation during vertebrate embryogenesis and tumorigenesis. Whereas genetic studies indicate that Pbx1 regulates the development and function of insulin-producing pancreatic β-cells, the role of Meis family members in β-cells is still unknown. Here we show that Meis3 is abundantly expressed in pancreatic islets and β-cells and that it regulates β-cell survival. We further identify the 3-phosphoinositide-dependent protein kinase 1 (PDK1), a well-known kinase involved in the PI3K-Akt signaling pathway, as a direct Meis3 target, which mediates its role in β-cell survival. This regulatory module appears to function broadly as we also identify Meis3 regulation of cell survival and PDK1 expression in ovarian carcinoma cells, suggesting a unique function for Meis3 beyond the traditional roles for TALE homeodomain factors during embryogenesis.
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Oros SM, Tare M, Kango-Singh M, Singh A. Dorsal eye selector pannier (pnr) suppresses the eye fate to define dorsal margin of the Drosophila eye. Dev Biol 2010; 346:258-71. [PMID: 20691679 PMCID: PMC2945442 DOI: 10.1016/j.ydbio.2010.07.030] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2010] [Revised: 07/26/2010] [Accepted: 07/27/2010] [Indexed: 12/28/2022]
Abstract
Axial patterning is crucial for organogenesis. During Drosophila eye development, dorso-ventral (DV) axis determination is the first lineage restriction event. The eye primordium begins with a default ventral fate, on which the dorsal eye fate is established by expression of the GATA-1 transcription factor pannier (pnr). Earlier, it was suggested that loss of pnr function induces enlargement in the dorsal eye due to ectopic equator formation. Interestingly, we found that in addition to regulating DV patterning, pnr suppresses the eye fate by downregulating the core retinal determination genes eyes absent (eya), sine oculis (so) and dacshund (dac) to define the dorsal eye margin. We found that pnr acts downstream of Ey and affects the retinal determination pathway by suppressing eya. Further analysis of the "eye suppression" function of pnr revealed that this function is likely mediated through suppression of the homeotic gene teashirt (tsh) and is independent of homothorax (hth), a negative regulator of eye. Pnr expression is restricted to the peripodial membrane on the dorsal eye margin, which gives rise to head structures around the eye, and pnr is not expressed in the eye disc proper that forms the retina. Thus, pnr has dual function, during early developmental stages pnr is involved in axial patterning whereas later it promotes the head specific fate. These studies will help in understanding the developmental regulation of boundary formation of the eye field on the dorsal eye margin.
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Affiliation(s)
- Sarah M. Oros
- Premedical Programs, University of Dayton, Dayton, OH 45469
- Department of Biology, University of Dayton, Dayton, OH 45469
| | - Meghana Tare
- Department of Biology, University of Dayton, Dayton, OH 45469
| | - Madhuri Kango-Singh
- Premedical Programs, University of Dayton, Dayton, OH 45469
- Department of Biology, University of Dayton, Dayton, OH 45469
- Center for Tissue Regeneration and Engineering at Dayton (TREND), University of Dayton, Dayton, OH 45469
| | - Amit Singh
- Premedical Programs, University of Dayton, Dayton, OH 45469
- Department of Biology, University of Dayton, Dayton, OH 45469
- Center for Tissue Regeneration and Engineering at Dayton (TREND), University of Dayton, Dayton, OH 45469
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29
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Pillay LM, Forrester AM, Erickson T, Berman JN, Waskiewicz AJ. The Hox cofactors Meis1 and Pbx act upstream of gata1 to regulate primitive hematopoiesis. Dev Biol 2010; 340:306-17. [PMID: 20123093 DOI: 10.1016/j.ydbio.2010.01.033] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2009] [Revised: 01/26/2010] [Accepted: 01/26/2010] [Indexed: 01/29/2023]
Abstract
During vertebrate development, the initial wave of hematopoiesis produces cells that help to shape the developing circulatory system and oxygenate the early embryo. The differentiation of primitive erythroid and myeloid cells occurs within a short transitory period, and is subject to precise molecular regulation by a hierarchical cascade of transcription factors. The TALE-class homeodomain transcription factors Meis and Pbx function to regulate embryonic hematopoiesis, but it is not known where Meis and Pbx proteins participate in the hematopoietic transcription factor cascade. To address these questions, we have ablated Meis1 and Pbx proteins in zebrafish, and characterized their molecular effects on known markers of primitive hematopoiesis. Embryos lacking Meis1 and Pbx exhibit a severe reduction in the expression of gata1, the earliest marker of erythroid cell fate, and fail to produce visible circulating blood cells. Concomitant with a loss of gata1, Meis1- and Pbx-depleted embryos exhibit downregulated embryonic hemoglobin (hbae3) expression, and possess increased numbers of pu.1-positive myeloid cells. gata1-overexpression rescues hbae3 expression in Pbx-depleted; meis1-morphant embryos, placing Pbx and Meis1 upstream of gata1 in the erythropoietic transcription factor hierarchy. Our study conclusively demonstrates that Meis1 and Pbx act to specify the erythropoietic cell lineage and inhibit myelopoiesis.
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Affiliation(s)
- Laura M Pillay
- Department of Biological Sciences, University of Alberta, Edmonton, Canada
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30
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Jiang Y, Shi H, Liu J. Two Hox cofactors, the Meis/Hth homolog UNC-62 and the Pbx/Exd homolog CEH-20, function together during C. elegans postembryonic mesodermal development. Dev Biol 2009; 334:535-46. [PMID: 19643105 DOI: 10.1016/j.ydbio.2009.07.034] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2009] [Revised: 07/14/2009] [Accepted: 07/20/2009] [Indexed: 01/12/2023]
Abstract
The TALE homeodomain-containing PBC and MEIS proteins play multiple roles during metazoan development. Mutations in these proteins can cause various disorders, including cancer. In this study, we examined the roles of MEIS proteins in mesoderm development in C. elegans using the postembryonic mesodermal M lineage as a model system. We found that the MEIS protein UNC-62 plays essential roles in regulating cell fate specification and differentiation in the M lineage. Furthermore, UNC-62 appears to function together with the PBC protein CEH-20 in regulating these processes. Both unc-62 and ceh-20 have overlapping expression patterns within and outside of the M lineage, and they share physical and regulatory interactions. In particular, we found that ceh-20 is genetically required for the promoter activity of unc-62, providing evidence for another layer of regulatory interactions between MEIS and PBC proteins.
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Affiliation(s)
- Yuan Jiang
- Department of Molecular Biology and Genetics, Cornell University, 439 Biotechnology Building, Ithaca, NY 14853, USA
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31
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Rutjens B, Bao D, van Eck-Stouten E, Brand M, Smeekens S, Proveniers M. Shoot apical meristem function in Arabidopsis requires the combined activities of three BEL1-like homeodomain proteins. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2009; 58:641-54. [PMID: 19175771 DOI: 10.1111/j.1365-313x.2009.03809.x] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
In plants, most of the above-ground body is formed post-embryonically by the continuous organogenic potential of the shoot apical meristem (SAM). Proper function of the SAM requires maintenance of a delicate balance between the depletion of stem cell daughters into developing primordia and proliferation of the central stem cell population. Here we show that initiation and maintenance of the Arabidopsis SAM, including that of floral meristems, requires the combinatorial action of three members of the BELL-family of TALE homeodomain proteins, ARABIDOPSIS THALIANA HOMEOBOX 1 (ATH1), PENNYWISE (PNY) and POUND-FOOLISH (PNF). All three proteins interact with the KNOX TALE homeodomain protein STM, and combined lesions in ATH1, PNY and PNF result in a phenocopy of stm mutations. Therefore, we propose that ath1 pny pnf meristem defects result from loss of combinatorial BELL-STM control. Further, we demonstrate that heterodimerization-controlled cellular localization of BELL and KNOX proteins involves a CRM1/exportin-1-mediated nuclear exclusion mechanism that is probably generic to control the activity of BELL and KNOX combinations. We conclude that in animals and plants corresponding mechanisms regulate the activity of TALE homeodomain proteins through controlled nuclear-cytosolic distribution of these proteins.
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Affiliation(s)
- Bas Rutjens
- Department of Biology, Utrecht University, The Netherlands
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32
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Prep1 deficiency induces protection from diabetes and increased insulin sensitivity through a p160-mediated mechanism. Mol Cell Biol 2008; 28:5634-45. [PMID: 18644868 DOI: 10.1128/mcb.00117-08] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
We have examined glucose homeostasis in mice hypomorphic for the homeotic transcription factor gene Prep1. Prep1-hypomorphic (Prep1(i/i)) mice exhibit an absolute reduction in circulating insulin levels but normal glucose tolerance. In addition, these mice exhibit protection from streptozotocin-induced diabetes and enhanced insulin sensitivity with improved glucose uptake and insulin-dependent glucose disposal by skeletal muscle. This muscle phenotype does not depend on reduced expression of the known Prep1 transcription partner, Pbx1. Instead, in Prep1(i/i) muscle, we find normal Pbx1 but reduced levels of the recently identified novel Prep1 interactor p160. Consistent with this reduction, we find a muscle-selective increase in mRNA and protein levels of PGC-1alpha, accompanied by enhanced expression of the GLUT4 transporter, responsible for insulin-stimulated glucose uptake in muscle. Indeed, using L6 skeletal muscle cells, we induced the opposite effects by overexpressing Prep1 or p160, but not Pbx1. In vivo skeletal muscle delivery of p160 cDNA in Prep1(i/i) mice also reverses the molecular phenotype. Finally, we show that Prep1 controls the stability of the p160 protein. We conclude that Prep1 controls insulin sensitivity through the p160-GLUT4 pathway.
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33
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Prpic NM, Telford MJ. Expression of homothorax and extradenticle mRNA in the legs of the crustacean Parhyale hawaiensis: evidence for a reversal of gene expression regulation in the pancrustacean lineage. Dev Genes Evol 2008; 218:333-9. [PMID: 18504609 PMCID: PMC2668558 DOI: 10.1007/s00427-008-0221-4] [Citation(s) in RCA: 20] [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: 02/08/2008] [Accepted: 04/14/2008] [Indexed: 12/04/2022]
Abstract
In Drosophila leg development, the extradenticle (exd) gene is expressed ubiquitously and its co-factor homothorax (hth) is restricted to the proximal leg portion. This condition is conserved in other insect species but is reversed in chelicerates and myriapods. As the region of co-expression does not differ in the two groups and transcripts from both are necessary for function, this difference in expression is likely to be functionally neutral. Here, we report the expression patterns of exd and hth in a crustacean, the amphipod shrimp Parhyale hawaiensis. The patterns in P. hawaiensis are similar to the insect patterns, supporting the close relationship between crustaceans and insects in the taxon Tetraconata. However, mRNA expression of exd in P. hawaiensis is weak in the distal leg parts, thus being intermediate between the complete lack of distal exd expression in chelicerates and myriapods and the strong distal exd expression in insects. Our data suggest that the reversal of the gene expression regulation of hth and exd occurred in the pancrustacean lineage.
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Affiliation(s)
- Nikola-Michael Prpic
- Department of Developmental Biology, GZMB New Building, Georg-August-University Goettingen, Johann-Friedrich-Blumenbach Institute for Zoology and Anthropology, Justus-von-Liebig-Weg 11, 37077 Goettingen, Germany
| | - Maximilian J. Telford
- Department of Biology, Darwin Building, University College London, Gower Street, London, WC1E 6BT UK
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34
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Chromosomal binding sites of the homeotic cofactor Homothorax. Mol Genet Genomics 2008; 280:73-81. [PMID: 18481089 DOI: 10.1007/s00438-008-0347-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2007] [Accepted: 04/24/2008] [Indexed: 02/05/2023]
Abstract
The Meis family oncoproteins play a crucial role in leukemogenesis and are highly expressed in other types of cancer as well. The transforming potential of Meis proteins depends on their ability to activate gene expression and therefore, revealing the identity of their target genes is very important. The genome of the fruit fly Drosophila melanogaster contains a single Meis gene, homothorax (hth), which plays multiple roles in embryonic and adult development. Mutations in hth affect the development of numerous embryonic and adult tissues, suggesting that Hth regulates the transcription of a large number of genes. However, it is not known how many genes are regulated directly by Hth and what is the nature of these genes. To address this question, we examined the distribution of the in vivo binding sites of Hth on polytene chromosomes. We found that in the salivary glands (SG) of third instar larvae, Hth binds to approximately 150 chromosomal sites in a very reproducible pattern. More than hundred of these sites were mapped cytologically. Interestingly, Hth accumulates at high levels in some of the most prominent hormone-induced chromosomal puffs, pointing to a possible role of Hth in activation of ecdysone-induced targets. Interfering with the normal transcriptional activity of Hth in larval SGs leads to dramatic reduction in cell size and DNA content implicating Hth in the regulation of cell growth and endoreplication in larval SGs.
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35
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Prince F, Katsuyama T, Oshima Y, Plaza S, Resendez-Perez D, Berry M, Kurata S, Gehring WJ. The YPWM motif links Antennapedia to the basal transcriptional machinery. Development 2008; 135:1669-79. [DOI: 10.1242/dev.018028] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
HOX genes specify segment identity along the anteroposterior axis of the embryo. They code for transcription factors harbouring the highly conserved homeodomain and a YPWM motif, situated amino terminally to it. Despite their highly diverse functions in vivo, HOX proteins display similar biochemical properties in vitro, raising the question of how this specificity is achieved. In our study, we investigated the importance of the Antennapedia(Antp) YPWM motif for homeotic transformations in adult Drosophila. By ectopic overexpression, the head structures of the fly can be transformed into structures of the second thoracic segment, such as antenna into second leg, head capsule into thorax (notum) and eye into wing. We found that the YPWM motif is absolutely required for the eye-to-wing transformation. Using the yeast two-hybrid system, we were able to identify a novel ANTP-interacting protein, Bric-à-brac interacting protein 2(BIP2), that specifically interacts with the YPWM motif of ANTP in vitro, as well as in vivo, transforming eye to wing tissue. BIP2 is a TATA-binding protein associated factor (also known as dTAFII3) that links ANTP to the basal transcriptional machinery.
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Affiliation(s)
- Frédéric Prince
- Biozentrum, University of Basel, Klingelberstrasse 70, CH-4056 Basel,Switzerland
| | | | - Yoshiteru Oshima
- ETH Zurich, Department of Biosystems, CH-4058 Basel, Switzerland
| | - Serge Plaza
- CNS-Centre de Biologie du Developpement, 118 route de NARBONNE, Bat 4R3, 31062 Toulouse, France
| | | | - Meera Berry
- Micromet AG, Am Klopferspitz 19, 82152 Martinsried/Munich, Germany
| | - Shoichiro Kurata
- ETH Zurich, Department of Biosystems, CH-4058 Basel, Switzerland
| | - Walter J. Gehring
- Biozentrum, University of Basel, Klingelberstrasse 70, CH-4056 Basel,Switzerland
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36
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Divergent and conserved roles of extradenticle in body segmentation and appendage formation, respectively, in the cricket Gryllus bimaculatus. Dev Biol 2008; 313:67-79. [DOI: 10.1016/j.ydbio.2007.09.060] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2007] [Revised: 09/19/2007] [Accepted: 09/26/2007] [Indexed: 11/19/2022]
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37
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Dworkin I, Lee W, McCloskey F, Larsen E. Complex genetic interactions govern the temporal effects of Antennapedia on antenna-to-leg transformations in Drosophila melanogaster. J Genet 2007; 86:111-23. [PMID: 17968139 DOI: 10.1007/s12041-007-0016-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
The putative regulatory relationships between Antennapedia (Antp), spalt major (salm) and homothorax (hth) are tested with regard to the sensitive period of antenna-to-leg transformations. Although Antp expression repressed hth as predicted, contrary to expectations, hth did not show increased repression at higher Antp doses, whereas salm, a gene downstream of hth, did show such a dose response. Loss of hth allowed antenna-to-leg transformations but the relative timing of proximal-distal transformations was reversed, relative to transformations induced by ectopic Antp. Finally, overexpression of Hth was only partially able to rescue transformations induced by ectopic Antp. These results indicate that there may be additional molecules involved in antenna/leg identity and that spatial, temporal and dosage relationships are more subtle than suspected and must be part of a robust understanding of molecular network behaviour involved in determining appendage identity in Drosophila melanogaster.
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Affiliation(s)
- Ian Dworkin
- Department of Zoology, University of Toronto, 25 Herbord St., Toronto, Ontario M5S 3G5, Canada.
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38
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Stevens KE, Mann RS. A balance between two nuclear localization sequences and a nuclear export sequence governs extradenticle subcellular localization. Genetics 2007; 175:1625-36. [PMID: 17277370 PMCID: PMC1855138 DOI: 10.1534/genetics.106.066449] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
During animal development, transcription factor activities are modulated by several means, including subcellular localization. The Hox cofactor Extradenticle (Exd) has a dynamic subcellular localization, such that Exd is cytoplasmic by default, but is nuclear when complexed with another homeodomain protein, Homothorax (Hth). These observations raise the question of whether dimerization with Hth simply induces Exd's nuclear localization or, alternatively, if Hth is also necessary for Exd activity. To address this question, we analyzed the nuclear transport signals in Exd, including a divergent nuclear export signal (NES) and two nuclear localization signals (NLSs). We show that, although these signals are weak compared to canonical signals, they balance each other in Exd. We also provide evidence that Exd contains an NLS mask that contributes to its cytoplasmic localization. With these signals characterized, we generated forms of Exd that are nuclear localized in the absence of Hth. Surprisingly, although these Exd forms are functional, they do not phenocopy Hth overexpression. These findings suggest that Hth is required for Exd activity, not simply for inducing its nuclear localization.
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Affiliation(s)
- Katherine E Stevens
- Department of Genetics and Development, Columbia University, New York, New York 10032, USA
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39
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Moens CB, Selleri L. Hox cofactors in vertebrate development. Dev Biol 2006; 291:193-206. [PMID: 16515781 DOI: 10.1016/j.ydbio.2005.10.032] [Citation(s) in RCA: 379] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2005] [Revised: 10/17/2005] [Accepted: 10/24/2005] [Indexed: 11/18/2022]
Abstract
Hox genes encode homeodomain-containing transcription factors that pattern the body axes of animal embryos. It is well established that the exquisite DNA-binding specificity that allows different Hox proteins to specify distinct structures along the body axis is frequently dependent on interactions with other DNA-binding proteins which act as Hox cofactors. These include the PBC and MEIS classes of TALE (Three Amino acid Loop Extension) homeodomain proteins. The PBC class comprises fly Extradenticle (Exd) and vertebrate Pbx homeoproteins, whereas the MEIS class includes fly Homothorax (Hth) and vertebrate Meis and Prep homeoproteins. Exd was first implicated as a Hox cofactor based on mutant phenotypes in the fly. In vertebrates, PBC and MEIS homeobox proteins play important roles in development and disease. In this review, we describe the evidence that these functions reflect a requirement for Pbx and Meis/Prep proteins as Hox cofactors. However, there is mounting evidence that, like in the fly, Pbx and Meis/Prep proteins function more broadly, and we also discuss how "Hox cofactors" function as partners for other, non-Hox transcription factors during development. Conversely, we review the evidence that Hox proteins have functions that are independent of Pbx and Meis/Prep cofactors and discuss the possibility that other proteins may participate in the DNA-bound Hox complex, contributing to DNA-binding specificity in the absence of, or in addition to, Pbx and Meis/Prep.
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Affiliation(s)
- Cecilia B Moens
- Division of Basic Science and HHMI, Fred Hutchinson Cancer Research Center, Seattle, WA 98115, USA.
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40
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Cole M, Nolte C, Werr W. Nuclear import of the transcription factor SHOOT MERISTEMLESS depends on heterodimerization with BLH proteins expressed in discrete sub-domains of the shoot apical meristem of Arabidopsis thaliana. Nucleic Acids Res 2006; 34:1281-92. [PMID: 16513846 PMCID: PMC1388269 DOI: 10.1093/nar/gkl016] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The gene SHOOT MERISTEMLESS (STM) is required for the initiation and the maintenance of the shoot apical meristem (SAM) in Arabidopsis and encodes a MEINOX/three amino acid loop extension (TALE)-HD-type transcription factor. Translational fusions with the green fluorescent protein showed that STM is not nuclear by default. In a yeast two-hybrid screen performed with a meristem-enriched cDNA library, three interacting BLH (Bel1-like homeodomain) transcription factors were identified. According to bimolecular fluorescence complementation, STM is targeted into the nuclear compartment through heterodimerization with BLH partner proteins, which are expressed in distinct SAM domains from the center to the periphery. On a functional level, overexpression experiments in transgenic Arabidopsis plants suggest that individual heterodimers provide distinct contributions. These results contribute to our understanding of the STM transcription factor function in the SAM and also shed new light on the evolution of the TALE-HD super gene family in animal and plant lineages.
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Affiliation(s)
| | | | - Wolfgang Werr
- To whom correspondence should be addressed. Tel: +49 221 470 2619; Fax: +49 221 470 5164;
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41
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Stultz BG, Jackson DG, Mortin MA, Yang X, Beachy PA, Hursh DA. Transcriptional activation by extradenticle in the Drosophila visceral mesoderm. Dev Biol 2006; 290:482-94. [PMID: 16403493 DOI: 10.1016/j.ydbio.2005.11.041] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2005] [Revised: 11/22/2005] [Accepted: 11/22/2005] [Indexed: 11/16/2022]
Abstract
decapentaplegic (dpp) is a direct target of Ultrabithorax (Ubx) in parasegment 7 (PS7) of the embryonic visceral mesoderm. We demonstrate that extradenticle (exd) and homothorax (hth) are also required for dpp expression in this location, as well as in PS3, at the site of the developing gastric caecae. A 420 bp element from dpp contains EXD binding sites necessary for expressing a reporter gene in both these locations. Using a specificity swap, we demonstrate that EXD directly activates this element in vivo. Activation does not require Ubx, demonstrating that EXD can activate transcription independently of homeotic proteins. Restoration is restricted to the domains of endogenous dpp expression, despite ubiquitous expression of altered specificity EXD. We demonstrate that nuclear EXD is more extensively phosphorylated than the cytoplasmic form, suggesting that EXD is a target of signal transduction by protein kinases.
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MESH Headings
- Amino Acid Sequence
- Animals
- Animals, Genetically Modified
- Binding Sites
- Blotting, Western
- Body Patterning
- Cell Nucleus/metabolism
- Crosses, Genetic
- Cytoplasm/metabolism
- Drosophila Proteins/genetics
- Drosophila Proteins/metabolism
- Drosophila Proteins/physiology
- Electrophoresis, Gel, Two-Dimensional
- Embryo, Nonmammalian/metabolism
- Enhancer Elements, Genetic
- Gene Expression Regulation, Developmental
- Genes, Reporter
- Homeodomain Proteins/genetics
- Homeodomain Proteins/metabolism
- Homeodomain Proteins/physiology
- Immunoblotting
- Immunohistochemistry
- Mesoderm/metabolism
- Molecular Sequence Data
- Phosphorylation
- Protein Binding
- Protein Structure, Tertiary
- Signal Transduction
- Transcription Factors/genetics
- Transcription Factors/metabolism
- Transcription Factors/physiology
- Transcriptional Activation
- Transgenes
- beta-Galactosidase/metabolism
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Affiliation(s)
- Brian G Stultz
- Cellular and Tissue Therapy Branch, Center for Biologics Evaluation and Research, Food and Drug Administration, HFM-730, Bldg. 29B, Rm. 1E16, 8800 Rockville Pike, Bethesda, MD 20892, USA
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42
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Truernit E, Siemering KR, Hodge S, Grbic V, Haseloff J. A map of KNAT gene expression in the Arabidopsis root. PLANT MOLECULAR BIOLOGY 2006; 60:1-20. [PMID: 16463096 DOI: 10.1007/s11103-005-1673-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2004] [Accepted: 08/01/2005] [Indexed: 05/06/2023]
Abstract
Homeodomain proteins are key regulators of patterning during the development of animal and plant body plans. Knotted1-like TALE homeodomain proteins have been found to play important roles in the development of the Arabidopsis shoot apical meristem and are part of a complex regulatory network of protein interactions. We have investigated the possible role of the knotted1-like genes KNAT1, KNAT3, KNAT4, and KNAT5 in Arabidopsis root development. Root growth is indeterminate, and the organ shows distinct zones of cell proliferation, elongation and differentiation along its longitudinal axis. Here we show that KNAT1, KNAT3, KNAT4 and KNAT5 show cell type specific expression patterns in the Arabidopsis root. Moreover, they are expressed in different spatially restricted patterns along the longitudinal root axis and in lateral root primordia. Hormones play an important role in maintenance of root growth, and we have studied their effect on KNAT gene expression. We show that KNAT3 expression is repressed by moderate levels of cytokinin. In addition, we show that the subcellular localization of KNAT3 and KNAT4 is regulated, indicating post-translational control of the activities of these transcription factors. The regulated expression of KNAT1, KNAT3, KNAT4 and KNAT5 within the Arabidopsis root suggests a role for these genes in root development. Our data provide the first systematic survey of KNAT gene expression in the Arabidopsis root.
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Affiliation(s)
- Elisabeth Truernit
- Department of Plant Sciences, University of Cambridge, CB2 3EA, Downing Site, Cambridge, UK
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43
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Zhu BK, Pruitt SC. Determination of transcription factors and their possible roles in the regulation of Pax3 gene expression in the mouse B16 F1 melanoma cell line. Melanoma Res 2005; 15:363-73. [PMID: 16179863 DOI: 10.1097/00008390-200510000-00004] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The objective of this study was to determine which transcription factors regulate the expression of the Pax3 gene in the mouse B16 F1 melanoma cell line. The results showed that the -14 kilobase pair (kbp) Pax3 promoter, but not the -1.6 kbp Pax3 promoter, promoted Pax3 gene expression in B16 cells. Comparison of the sequence of the -14 kbp human Pax3 promoter with mouse Pax3 promoters indicated that homology sequences were located between -6.9 and -5.8 kbp, and also that the 1.1 kbp fragment (between -6.9 and -5.8 kbp), linked -1.6 kbp proximal to the Pax3 promoter [plasmid PGPax3PIV (N6.9/5.8) delta SST Lacz], could mimic the functions of plasmid PGPax3 -14(N-1.6) Lacz. Mutations of the core binding elements of either Pax3 site I or II or both sites I and II reduced significantly the beta-galactosidase (beta-gal) activity in the cells. However, mutations of the core binding sequences of site A or B increased significantly the beta-gal activity in the cells. Biochemistry analysis demonstrated that POU transcription factors (Oct-1 and Brn-2) bind to the specific binding elements of both sites I and II to stimulate Pax3 gene expression, whereas the TALE homeodomain-containing proteins (Pbx and Prep1) bind with the core binding sequences of sites A and B to repress the expression of the Pax3 gene in B16 cells.
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Affiliation(s)
- Bi-ke Zhu
- Faculty of Veterinary Science, University of Sydney, Camden, New South Wales, Australia.
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Akin ZN, Nazarali AJ. Hox genes and their candidate downstream targets in the developing central nervous system. Cell Mol Neurobiol 2005; 25:697-741. [PMID: 16075387 DOI: 10.1007/s10571-005-3971-9] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2003] [Accepted: 04/14/2004] [Indexed: 12/14/2022]
Abstract
1. Homeobox (Hox) genes were originally discovered in the fruit fly Drosophila, where they function through a conserved homeodomain as transcriptional regulators to control embryonic morphogenesis. Since then over 1000 homeodomain proteins have been identified in several species. In vertebrates, 39 Hox genes have been identified as homologs of the original Drosophila complex, and like their Drosophila counterparts they are organized within chromosomal clusters. Vertebrate Hox genes have also been shown to play a critical role in embryonic development as transcriptional regulators. 2. Both the Drosophila and vertebrate Hox genes have been shown to interact with various cofactors, such as the TALE homeodomain proteins, in recognition of consensus sequences within regulatory elements of their target genes. These protein-protein interactions are believed to contribute to enhancing the specificity of target gene recognition in a cell-type or tissue- dependent manner. The regulatory activity of a particular Hox protein on a specific regulatory element is highly variable and dependent on its interacting partners within the transcriptional complex. 3. In vertebrates, Hox genes display spatially restricted patterns of expression within the developing CNS, both along the anterioposterior and dorsoventral axis of the embryo. Their restricted gene expression is suggestive of a regulatory role in patterning of the CNS, as well as in cell specification. Determining the precise function of individual Hox genes in CNS morphogenesis through classical mutational analyses is complicated due to functional redundancy between Hox genes. 4. Understanding the precise mechanisms through which Hox genes mediate embryonic morphogenesis requires the identification of their downstream target genes. Although Hox genes have been implicated in the regulation of several pathways, few target genes have been shown to be under their direct regulatory control. Development of methodologies used for the isolation of target genes and for the analysis of putative targets will be beneficial in establishing the genetic pathways controlled by Hox factors. 5. Within the developing CNS various cell adhesion molecules and signaling molecules have been identified as candidate downstream target genes of Hox proteins. These targets play a role in processes such as cell migration and differentiation, and are implicated in contributing to neuronal processes such as plasticity and/or specification. Hence, Hox genes not only play a role in patterning of the CNS during early development, but may also contribute to cell specification and identity.
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Affiliation(s)
- Z N Akin
- Laboratory of Molecular Biology, College of Pharmacy and Nutrition, University of Saskatchewan, 116 Thorvaldson Building, 110 Science Place, Saskatoon, Saskatchewan, S7N 5C9, Canada
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Dong Y, Friedrich M. Comparative analysis of Wingless patterning in the embryonic grasshopper eye. Dev Genes Evol 2005; 215:177-97. [PMID: 15747130 DOI: 10.1007/s00427-004-0465-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2004] [Accepted: 12/13/2004] [Indexed: 10/25/2022]
Abstract
The signaling factor Wingless regulates multiple steps during the postembryonic development of the Drosophila eye. To obtain insight into the molecular regulation of embryonic eye development in primitive insects, we studied the expression of wg and genes projected to interact with wg in the grasshopper Schistocerca americana. We find that the dynamic and complex expression of wg in the early grasshopper procephalon results in three paired expression domains with relevance to eye primordium development. By comparison with Drosophila, these domains are compatible with a conserved function of wg during anteroposterior and dorsoventral axis formation by repression of retinal differentiation and stimulation of tissue proliferation. This is further supported by the expression of grasshopper orthologs of the retina determination genes sine oculis and eyes absent, and by inhibition of retina differentiation in grasshopper eye primordia cultured with LiCl. Surprisingly, the expression of wg and the grasshopper orthologs of pannier, fringe, Delta, and Iroquois complex is inconsistent with induction of midline centered Notch signaling activity, which is essential for Drosophila retina development. Similarly substantial evolutionary divergence is found concerning the control of retina versus head epidermis specification. The transcription factor Extradenticle (Exd), which cooperates with wg in specifying the Drosophila head epidermis, is not detected outside the labral and antennal primordia in the embryonic grasshopper head. Our results, which provide the first insight into the molecular control of eye primordium formation in primitive insects, suggest substantial modification of this process during the evolution of the Drosophila mode of postembryonic eye development.
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Affiliation(s)
- Ying Dong
- Department of Biological Sciences, Wayne State University, 5047 Gullen Mall, Detroit, MI 48202, USA
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46
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Dorsoventral boundary for organizing growth and planar polarity in the Drosophila eye. ACTA ACUST UNITED AC 2005. [DOI: 10.1016/s1574-3349(05)14004-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Bhatt AM, Etchells JP, Canales C, Lagodienko A, Dickinson H. VAAMANA--a BEL1-like homeodomain protein, interacts with KNOX proteins BP and STM and regulates inflorescence stem growth in Arabidopsis. Gene 2004; 328:103-11. [PMID: 15019989 DOI: 10.1016/j.gene.2003.12.033] [Citation(s) in RCA: 120] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2003] [Revised: 11/14/2003] [Accepted: 12/02/2003] [Indexed: 11/26/2022]
Abstract
Plant shoot growth depends on the activity of the shoot apical meristem (SAM), where organ primordia are initiated. In turn, the function of the SAM depends on the activities of homeodomain (HD) proteins of the knotted1-like homeobox (KNOX) class [Long et al., Nature 379 (1996) 66; Vollbrecht et al., Development 127 (2000) 3161]. In plants, KNOX proteins have been shown to interact specifically with the BEL1-like (BELL) class of homeodomain proteins [Bellaoui et al., Plant Cell 13 (2001) 2455; Muller et al., Plant 27 (2001) 13; Smith et al., Proc. Natl. Acad. Sci. USA 99 (2002) 9579], through a domain conserved between plants and animals. We have isolated a mutation in a BELL homeobox gene VAAMANA (VAN) that causes a dwarf phenotype. In addition, van inflorescence stems have clusters of cauline leaves; typically three are produced at each node. VAN interacts specifically with the class I KNOX proteins SHOOTMERISTEMLESS (STM), BREVIPEDICELLUS (BP), and KNAT6 (K6), and nuclear localisation of a VAN-GFP fusion depends on co-expression of STM or BP in tobacco leaves. This suggests that localisation of VAN, like that of the animal PBC homeodomain protein [Rieckhof et al., Cell 91 (1997) 171; Berthelsen et al., Genes Dev. 13 (1999) 946], is also regulated by interaction with a partner homeodomain protein.
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MESH Headings
- Amino Acid Sequence
- Arabidopsis/genetics
- Arabidopsis/growth & development
- Arabidopsis Proteins/genetics
- Arabidopsis Proteins/metabolism
- Base Sequence
- Blotting, Northern
- Cell Nucleus/metabolism
- Cloning, Molecular
- DNA, Complementary/chemistry
- DNA, Complementary/genetics
- Flowers/genetics
- Flowers/growth & development
- Gene Expression Regulation, Developmental
- Gene Expression Regulation, Plant
- Green Fluorescent Proteins
- Homeodomain Proteins/genetics
- Homeodomain Proteins/metabolism
- Luminescent Proteins/genetics
- Luminescent Proteins/metabolism
- Microscopy, Confocal
- Molecular Sequence Data
- Mutation
- Phenotype
- Phylogeny
- Plant Proteins/genetics
- Plant Proteins/metabolism
- Protein Binding
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Recombinant Fusion Proteins/genetics
- Recombinant Fusion Proteins/metabolism
- Saccharomyces cerevisiae/genetics
- Sequence Alignment
- Sequence Analysis, DNA
- Sequence Homology, Amino Acid
- Two-Hybrid System Techniques
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Affiliation(s)
- Anuj M Bhatt
- Department of Plant Sciences, University of Oxford, South Parks Road, Oxford OX1 3RB, UK.
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Sprecher SG, Müller M, Kammermeier L, Miller DFB, Kaufman TC, Reichert H, Hirth F. Hox gene cross-regulatory interactions in the embryonic brain of Drosophila. Mech Dev 2004; 121:527-36. [PMID: 15172684 DOI: 10.1016/j.mod.2004.04.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2004] [Revised: 04/08/2004] [Accepted: 04/09/2004] [Indexed: 11/27/2022]
Abstract
During embryonic development of the Drosophila brain, the Hox gene labial is required for the regionalized specification of the tritocerebral neuromere. In order to gain further insight into the mechanisms of Hox gene action in the CNS, we have studied the molecular and genetic basis of cross-regulatory interactions between labial and other more posterior Hox genes using the GAL4/UAS system for targeted misexpression. Misexpression of posterior Hox genes in the embryonic neuroectoderm results in a labial loss-of function phenotype and a corresponding lack of Labial protein expression in the tritocerebrum. This is due to repression of labial gene transcription in the embryonic brain. Enhancer analysis suggests that this transcriptional repression operates on a 3.65 kb brain-specific labial-enhancer element. A functional analysis of Antennapedia and Ultrabithorax protein domains shows that the transcriptional repression of labial requires homeodomain-DNA interactions but is not dependent on a functional hexapeptide. The repressive activity of a Hox protein on labial expression in the tritocerebrum can, however, be abolished by concomitant misexpression of a Hox protein and the cofactors Homothorax and nuclear-targeted Extradenticle. Taken together, these results provide novel and detailed insight into the cross-regulatory interactions of Hox genes in embryonic brain development and suggest that specification of tritocerebral neuronal identity requires equilibrated levels of a Hox protein and Hth and n-Exd cofactors.
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Affiliation(s)
- Simon G Sprecher
- Institute of Zoology, Biocenter/Pharmacenter University of Basel, Klingelbergstr.50, CH-4056 Basel, Switzerland
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Villaescusa JC, Verrotti AC, Ferretti E, Farookhi R, Blasi F. Expression of Hox cofactor genes during mouse ovarian follicular development and oocyte maturation. Gene 2004; 330:1-7. [PMID: 15087118 DOI: 10.1016/j.gene.2004.01.024] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2003] [Revised: 01/15/2004] [Accepted: 01/26/2004] [Indexed: 11/21/2022]
Abstract
Very little is known about the expression and function of the HOX and HOX-cofactors genes in mammalian oogenesis. The aim of the present study was to determine the expression of PBX and PREP-1 gene products in the mouse ovary and their localization to particular ovarian compartment, specifically the oocyte-containing ovarian follicle. Immunocytochemical analysis demonstrated that PREP-1 was present in both granulosa cells and oocytes. PREP-1 was found in the nucleus in primary oocytes, but in the cytoplasm of fully-grown oocytes; in granulosa cells, however, PREP-1 was always localized to the nuclei. No PREP-1 immunoreactivity was found in corpus luteum, theca or stroma. PBX-1 was found in the cytosol of the oocyte, while PBX-2 expression was mostly restricted to the nuclei of granulosa cells. In addition, PBX-2 was also found in the nucleus of primary oocytes. Since PREP-PBX complexes act in vivo in conjunction with HOX transcription factors, we have used RT-PCR to identify HOX genes expressed in the ovary. This analysis identified transcripts for six HOX genes (A5, A9, B6, B7, C6 and C8) and two more TALE cofactors (PREP2 and Meis2). Thus, a number of HOX and HOX cofactor genes are expressed in the mammalian ovary. The restricted expression pattern for PBX-1 and PBX-2 and the changes in expression and localization of PREP-1 in the oocyte and granulosa cells suggest a previously unsuspected involvement of these transcription factors in oocyte maturation and development, as well as in granulosa cell differentiation.
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Affiliation(s)
- J Carlos Villaescusa
- Department of Cell Biology and Functional Genomics, DIBIT, H. San Raffaele, Università Vita Salute San Raffaele, Via Olgettina 58, 20132 Milan, Italy
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Hisa T, Spence SE, Rachel RA, Fujita M, Nakamura T, Ward JM, Devor-Henneman DE, Saiki Y, Kutsuna H, Tessarollo L, Jenkins NA, Copeland NG. Hematopoietic, angiogenic and eye defects in Meis1 mutant animals. EMBO J 2004; 23:450-9. [PMID: 14713950 PMCID: PMC1271748 DOI: 10.1038/sj.emboj.7600038] [Citation(s) in RCA: 228] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2003] [Accepted: 11/20/2003] [Indexed: 11/08/2022] Open
Abstract
Meis1 and Hoxa9 expression is upregulated by retroviral integration in murine myeloid leukemias and in human leukemias carrying MLL translocations. Both genes also cooperate to induce leukemia in a mouse leukemia acceleration assay, which can be explained, in part, by their physical interaction with each other as well as the PBX family of homeodomain proteins. Here we show that Meis1-deficient embryos have partially duplicated retinas and smaller lenses than normal. They also fail to produce megakaryocytes, display extensive hemorrhaging, and die by embryonic day 14.5. In addition, Meis1-deficient embryos lack well-formed capillaries, although larger blood vessels are normal. Definitive myeloerythroid lineages are present in the mutant embryos, but the total numbers of colony-forming cells are dramatically reduced. Mutant fetal liver cells also fail to radioprotect lethally irradiated animals and they compete poorly in repopulation assays even though they can repopulate all hematopoietic lineages. These and other studies showing that Meis1 is expressed at high levels in hematopoietic stem cells (HSCs) suggest that Meis1 may also be required for the proliferation/self-renewal of the HSC.
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Affiliation(s)
- Tomoyuki Hisa
- Center for Cancer Research, Mouse Cancer Genetics Program, National Cancer Institute, Frederick, MD, USA
| | - Sally E Spence
- Center for Cancer Research, Mouse Cancer Genetics Program, National Cancer Institute, Frederick, MD, USA
| | - Rivka A Rachel
- Center for Cancer Research, Mouse Cancer Genetics Program, National Cancer Institute, Frederick, MD, USA
| | - Masami Fujita
- Center for Cancer Research, Mouse Cancer Genetics Program, National Cancer Institute, Frederick, MD, USA
| | - Takuro Nakamura
- The Cancer Institute, Japanese Foundation for Cancer Research, Tokyo, Japan
| | - Jerrold M Ward
- Center for Cancer Research, Veterinary and Tumor Pathology Section, National Cancer Institute, Frederick, MD, USA
| | - Deborah E Devor-Henneman
- Center for Cancer Research, Veterinary and Tumor Pathology Section, National Cancer Institute, Frederick, MD, USA
| | - Yuriko Saiki
- The Cancer Institute, Japanese Foundation for Cancer Research, Tokyo, Japan
| | - Haruo Kutsuna
- Department of Hematology, Osaka City University Medical School, Osaka, Japan
| | - Lino Tessarollo
- Center for Cancer Research, Mouse Cancer Genetics Program, National Cancer Institute, Frederick, MD, USA
| | - Nancy A Jenkins
- Center for Cancer Research, Mouse Cancer Genetics Program, National Cancer Institute, Frederick, MD, USA
| | - Neal G Copeland
- Center for Cancer Research, Mouse Cancer Genetics Program, National Cancer Institute, Frederick, MD, USA
- Center for Cancer Research, Mouse Cancer Genetics Program, National Cancer Institute, Frederick, MD 21702-1201, USA. Tel.: +1 301 846 1260; Fax: +1 301 846 6666; E-mail:
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