scholarly journals Skeletal cell YAP and TAZ redundantly promote bone development by regulation of collagen I expression and organization

2017 ◽  
Author(s):  
Christopher D. Kegelman ◽  
Devon E. Mason ◽  
James H. Dawahare ◽  
Genevieve D. Vigil ◽  
Scott S. Howard ◽  
...  
Keyword(s):  
Osteogenesis Imperfecta ◽  
Target Genes ◽  
Bone Development ◽  
Bone Matrix ◽  
Cell Lineage ◽  
Binding Domains ◽  
Conditional Deletion ◽  
Neonatal Lethality ◽  
Allele Dosage

ABSTRACTThe functions of the transcriptional co-activators YAP and TAZ in bone are controversial. Each has been observed to either promote or inhibit osteogenesis in vitro, while their roles in bone development are unknown. Here we report that combinatorial YAP/TAZ deletion from skeletal cells in mice caused osteogenesis imperfecta with severity dependent on targeted cell lineage and allele dosage. Osteocyte-conditional deletion impaired bone accrual and matrix collagen, while allele dosage-dependent deletion from all osteogenic lineage cells caused spontaneous fractures, with neonatal lethality only in dual homozygous knockouts. We identified putative target genes whose mutation in humans causes osteogenesis imperfecta and which contain promoter-proximate binding domains for the YAP/TAZ co-effector, TEAD4. Two candidates, Col1a1 and SerpinH1, exhibited reduced expression upon either YAP/TAZ deletion or YAP/TAZ-TEAD inhibition by verteporfin. Together, these data demonstrate that YAP and TAZ redundantly promote bone matrix development and implicate YAP/TAZ-mediated transcriptional regulation of collagen in osteogenesis imperfecta.

scholarly journals cAMP-Responsive Element Binding Protein: A Vital Link in Embryonic Hormonal Adaptation

Endocrinology ◽  
2013 ◽  
Vol 154 (6) ◽  
pp. 2208-2221 ◽  
Author(s):  
Maria Schindler ◽  
Sünje Fischer ◽  
René Thieme ◽  
Bernd Fischer ◽  
Anne Navarrete Santos
Keyword(s):  
Transcription Factors ◽  
Target Genes ◽  
Binding Protein ◽  
Cell Lineage ◽  
Element Binding Protein ◽  
A Cell ◽  
Responsive Element ◽  
Camp Responsive Element Binding

Abstract The transcription factor cAMP responsive element-binding protein (CREB) and activating transcription factors (ATFs) are downstream components of the insulin/IGF cascade, playing crucial roles in maintaining cell viability and embryo survival. One of the CREB target genes is adiponectin, which acts synergistically with insulin. We have studied the CREB-ATF-adiponectin network in rabbit preimplantation development in vivo and in vitro. From the blastocyst stage onwards, CREB and ATF1, ATF3, and ATF4 are present with increasing expression for CREB, ATF1, and ATF3 during gastrulation and with a dominant expression in the embryoblast (EB). In vitro stimulation with insulin and IGF-I reduced CREB and ATF1 transcripts by approximately 50%, whereas CREB phosphorylation was increased. Activation of CREB was accompanied by subsequent reduction in adiponectin and adiponectin receptor (adipoR)1 expression. Under in vivo conditions of diabetes type 1, maternal adiponectin levels were up-regulated in serum and endometrium. Embryonic CREB expression was altered in a cell lineage-specific pattern. Although in EB cells CREB localization did not change, it was translocated from the nucleus into the cytosol in trophoblast (TB) cells. In TB, adiponectin expression was increased (diabetic 427.8 ± 59.3 pg/mL vs normoinsulinaemic 143.9 ± 26.5 pg/mL), whereas it was no longer measureable in the EB. Analysis of embryonic adipoRs showed an increased expression of adipoR1 and no changes in adipoR2 transcription. We conclude that the transcription factors CREB and ATFs vitally participate in embryo-maternal cross talk before implantation in a cell lineage-specific manner. Embryonic CREB/ATFs act as insulin/IGF sensors. Lack of insulin is compensated by a CREB-mediated adiponectin expression, which may maintain glucose uptake in blastocysts grown in diabetic mothers.

Cooperative interactions between paired domain and homeodomain

Development ◽  
1996 ◽  
Vol 122 (9) ◽  
pp. 2639-2650 ◽  
Author(s):  
S. Jun ◽  
C. Desplan
Keyword(s):  
Dna Binding ◽  
Dna Sequences ◽  
Target Genes ◽  
Cooperative Interaction ◽  
Paired Domain ◽  
Cooperative Interactions ◽  
Dna Binding Domains ◽  
Binding Domains

The Pax proteins are a family of transcriptional regulators involved in many developmental processes in all higher eukaryotes. They are characterized by the presence of a paired domain (PD), a bipartite DNA binding domain composed of two helix-turn-helix (HTH) motifs, the PAI and RED domains. The PD is also often associated with a homeodomain (HD) which is itself able to form homo- and hetero-dimers on DNA. Many of these proteins therefore contain three HTH motifs each able to recognize DNA. However, all PDs recognize highly related DNA sequences, and most HDs also recognize almost identical sites. We show here that different Pax proteins use multiple combinations of their HTHs to recognize several types of target sites. For instance, the Drosophila Paired protein can bind, in vitro, exclusively through its PAI domain, or through a dimer of its HD, or through cooperative interaction between PAI domain and HD. However, prd function in vivo requires the synergistic action of both the PAI domain and the HD. Pax proteins with only a PD appear to require both PAI and RED domains, while a Pax-6 isoform and a new Pax protein, Lune, may rely on the RED domain and HD. We propose a model by which Pax proteins recognize different target genes in vivo through various combinations of their DNA binding domains, thus expanding their recognition repertoire.

scholarly journals Structure-based analyses of Salmonella RcsB variants unravel new features of the Rcs regulon

2021 ◽  
Author(s):  
Juanjo Huesa ◽  
Joaquín Giner-Lamia ◽  
M Graciela Pucciarelli ◽  
Francisco Paredes-Martínez ◽  
Francisco García-del Portillo ◽  
...  
Keyword(s):  
Dna Binding ◽  
Target Genes ◽  
Structural Data ◽  
Enteric Bacteria ◽  
Target Sequence ◽  
Active Conformation ◽  
Functional Studies ◽  
Binding Domains

Abstract RcsB is a transcriptional regulator that controls expression of numerous genes in enteric bacteria. RcsB accomplishes this role alone or in combination with auxiliary transcriptional factors independently or dependently of phosphorylation. To understand the mechanisms by which RcsB regulates such large number of genes, we performed structural studies as well as in vitro and in vivo functional studies with different RcsB variants. Our structural data reveal that RcsB binds promoters of target genes such as rprA and flhDC in a dimeric active conformation. In this state, the RcsB homodimer docks the DNA-binding domains into the major groove of the DNA, facilitating an initial weak read-out of the target sequence. Interestingly, comparative structural analyses also show that DNA binding may stabilize an active conformation in unphosphorylated RcsB. Furthermore, RNAseq performed in strains expressing wild-type or several RcsB variants provided new insights into the contribution of phosphorylation to gene regulation and assign a potential role of RcsB in controlling iron metabolism. Finally, we delimited the RcsB box for homodimeric active binding to DNA as the sequence TN(G/A)GAN4TC(T/C)NA. This RcsB box was found in promoter, intergenic and intragenic regions, facilitating both increased or decreased gene transcription.

scholarly journals Plastin 3 in X-Linked Osteoporosis: Imbalance of Ca2+-Dependent Regulation Is Equivalent to Protein Loss

2021 ◽  
Vol 8 ◽  
Author(s):  
Christopher L. Schwebach ◽  
Elena Kudryashova ◽  
Dmitri S. Kudryashov
Keyword(s):  
Osteogenesis Imperfecta ◽  
Actin Cytoskeleton ◽  
Bone Development ◽  
Genetic Disorder ◽  
Cellular Structures ◽  
Protein Loss ◽  
Pathogenic Variants ◽  
Recent Advances ◽  
Intracellular Ca

Osteogenesis imperfecta is a genetic disorder disrupting bone development and remodeling. The primary causes of osteogenesis imperfecta are pathogenic variants of collagen and collagen processing genes. However, recently variants of the actin bundling protein plastin 3 have been identified as another source of osteogenesis imperfecta. Plastin 3 is a highly conserved protein involved in several important cellular structures and processes and is controlled by intracellular Ca2+ which potently inhibits its actin-bundling activity. The precise mechanisms by which plastin 3 causes osteogenesis imperfecta remain unclear, but recent advances have contributed to our understanding of bone development and the actin cytoskeleton. Here, we review the link between plastin 3 and osteogenesis imperfecta highlighting in vitro studies and emphasizing the importance of Ca2+ regulation in the localization and functionality of plastin 3.

Control of osteocyte dendrite formation by Sp7 and its target gene osteocrin

2021 ◽  
Author(s):  
Jialiang S Wang ◽  
Tushar Kamath ◽  
Fatemeh Mirzamohammadi ◽  
Daniel Rotter ◽  
Hironori Hojo ◽  
...  
Keyword(s):  
Gene Networks ◽  
Target Gene ◽  
Target Genes ◽  
Bone Matrix ◽  
Bone Diseases ◽  
Dendrite Formation ◽  
Skeletal Disease ◽  
Mineralized Bone Matrix

Osteocytes use an elaborate network of dendritic connections to control bone remodeling. Some osteoblasts embed within mineralized bone matrix, change shape, and become osteocytes. The molecular circuitry that drives dendrite formation during "osteocytogenesis" is poorly understood. Here we show that deletion of Sp7, a gene linked to rare and common skeletal disease, in mature osteoblasts and osteocytes causes severe defects in osteocyte dendrites. Unbiased profiling of Sp7 target genes and binding sites reveals unexpected repurposing of this transcription factor to drive dendrite formation. Osteocrin is a Sp7 target gene that promotes osteocyte dendrite formation and rescues phenotypic and molecular defects in Sp7-deficient mice. Single-cell RNA-sequencing demonstrates overt defects in osteocyte maturation in vivo in the absence of Sp7. Sp7-dependent gene networks enriched in developing osteocytes are associated with rare and common human skeletal traits. Moreover, humans homozygous for the osteogenesis imperfecta-causing SP7R316C mutation show dramatic defects in osteocyte morphology. Genes that mark osteocytes in vivo and that are regulated by Sp7 in vitro are highly enriched in neurons, highlighting shared features between osteocytic and neuronal connectivity. Taken together, these findings reveal a crucial role for Sp7 and its target gene Osteocrin in osteocytogenesis, demonstrating that pathways that control osteocyte development influence human bone diseases.

Identification of androgen-selective androgen-response elements in the human aquaporin-5 and Rad9 genes

2008 ◽  
Vol 411 (3) ◽  
pp. 679-686 ◽  
Author(s):  
Udo Moehren ◽  
Sarah Denayer ◽  
Michael Podvinec ◽  
Guy Verrijdt ◽  
Frank Claessens
Keyword(s):  
Dna Binding ◽  
Glucocorticoid Receptors ◽  
Target Genes ◽  
Aquaporin 5 ◽  
Band Shift ◽  
Strong Activity ◽  
Response Elements ◽  
Dna Binding Domains ◽  
Binding Domains

The AR (androgen receptor) is known to influence the expression of its target genes by binding to different sets of AREs (androgen-response elements) in the DNA. One set consists of the classical steroid-response elements which are partial palindromic repeats of the 5′-TGTTCT-3′ steroid-receptor monomer-binding element. The second set contains motifs that are AR-specific and that are proposed to be partial direct repeats of the same motif. On the basis of this assumption, we used an in silico approach to identify new androgen-selective AREs in the regulatory regions of known androgen-responsive genes. We have used an extension of the NUBIScan algorithm to screen a collection of 85 known human androgen-responsive genes compiled from literature and database searches. We report the evaluation of the most promising hits resulting from this computational search by in vitro DNA-binding assays using full-size ARs and GRs (glucocorticoid receptors) as well as their isolated DBDs (DNA-binding domains). We also describe the ability of some of these motifs to confer androgen-, but not glucocorticoid-, responsiveness to reporter-gene expression. The elements found in the aquaporin-5 and the Rad9 (radiation-sensitive 9) genes showed selective AR versus GR binding in band-shift assays and a strong activity and selectivity in functional assays, both as isolated elements and in their original contexts. Our data indicate the validity of the hypothesis that selective AREs are recognizable as direct 5′-TGTTCT-3′ repeats, and extend the list of currently known selective elements.

TFII-I and AP2α Co-Occupy the Promoters of Key Regulatory Genes Associated with Craniofacial Development

2018 ◽  
Vol 55 (6) ◽  
pp. 865-870
Author(s):  
Paige Miranda ◽  
Badam Enkhmandakh ◽  
Dashzeveg Bayarsaihan
Keyword(s):  
Transcription Factors ◽  
Neural Crest ◽  
Progenitor Cells ◽  
Target Genes ◽  
Embryonic Stem ◽  
Cell Lineage ◽  
Neural Crest Cell ◽  
Multisystem Disorder ◽  
Genes Encoding

Objectives: The aim of this study is to define the candidate target genes for TFII-I and AP2α regulation in neural crest progenitor cells. Design: The GTF2I and GTF2IRD1 genes encoding the TFII-I family of transcription factors are prime candidates for the Williams-Beuren syndrome, a complex multisystem disorder characterized by craniofacial, skeletal, and neurocognitive deficiencies. AP2α, a product of the TFAP2A gene, is a master regulator of neural crest cell lineage. Mutations in TFAP2A cause branchio-oculo-facial syndrome characterized by dysmorphic facial features and orofacial clefts. In this study, we examined the genome-wide promoter occupancy of TFII-I and AP2α in neural crest progenitor cells derived from in vitro-differentiated human embryonic stem cells. Results: Our study revealed that TFII-I and AP2α co-occupy a selective set of genes that control the specification of neural crest cells. Conclusions: The data suggest that TFII-I and AP2α may coordinately control the expression of genes encoding chromatin-modifying proteins, epigenetic enzymes, transcription factors, and signaling proteins.

Direct regulatory interaction of the eyeless protein with an eye-specific enhancer in the sine oculis gene during eye induction in Drosophila

Development ◽  
1999 ◽  
Vol 126 (10) ◽  
pp. 2253-2260 ◽  
Author(s):  
T. Niimi ◽  
M. Seimiya ◽  
U. Kloter ◽  
S. Flister ◽  
W.J. Gehring
Keyword(s):  
Target Genes ◽  
Ectopic Expression ◽  
Direct Interaction ◽  
Loss Of Function ◽  
Eyes Absent ◽  
Sine Oculis ◽  
Dna Binding Domains ◽  
Binding Domains ◽  
Eye Morphogenesis

The Pax-6 gene encodes a transcription factor with two DNA-binding domains, a paired and a homeodomain, and is expressed during eye morphogenesis and development of the nervous system. Pax-6 homologs have been isolated from a wide variety of organisms ranging from flatworms to humans. Since loss-of-function mutants in insects and mammals lead to an eyeless phenotype and Pax-6 orthologs from distantly related species are capable of inducing ectopic eyes in Drosophila, we have proposed that Pax-6 is a universal master control gene for eye morphogenesis. To determine the extent of evolutionary conservation of the eye morphogenetic pathway, we have begun to identify subordinate target genes of Pax-6. Previously we have shown that expression of two genes, sine oculis (so) and eyes absent (eya), is induced by eyeless (ey), the Pax-6 homolog of Drosophila. Here we present evidence from ectopic expression studies in transgenic flies, from transcription activation studies in yeast, and from gel shift assays in vitro that the EY protein activates transcription of sine oculis by direct interaction with an eye-specific enhancer in the long intron of the so gene.

scholarly journals Binding of the Vestigial co-factor switches the DNA-target selectivity of the Scalloped selector protein

Development ◽  
2001 ◽  
Vol 128 (17) ◽  
pp. 3295-3305 ◽  
Author(s):  
Georg Halder ◽  
Sean B. Carroll
Keyword(s):  
Dna Binding ◽  
Target Genes ◽  
Binding Specificity ◽  
General Mechanism ◽  
Binding Selectivity ◽  
Binding Domains ◽  
Dna Binding Specificity ◽  
Selector Protein

The formation and identity of organs and appendages are regulated by specific selector genes that encode transcription factors that regulate potentially large sets of target genes. The DNA-binding domains of selector proteins often exhibit relatively low DNA-binding specificity in vitro. It is not understood how the target selectivity of most selector proteins is determined in vivo. The Scalloped selector protein controls wing development in Drosophila by regulating the expression of numerous target genes and forming a complex with the Vestigial protein. We show that binding of Vestigial to Scalloped switches the DNA-binding selectivity of Scalloped. Two conserved domains of the Vestigial protein that are not required for Scalloped binding in solution are required for the formation of the heterotetrameric Vestigial-Scalloped complex on DNA. We suggest that Vestigial affects the conformation of Scalloped to create a wing cell-specific DNA-binding selectivity. The modification of selector protein DNA-binding specificity by co-factors appears to be a general mechanism for regulating their target selectivity in vivo.

scholarly journals Tenascin is associated with chondrogenic and osteogenic differentiation in vivo and promotes chondrogenesis in vitro.

1987 ◽  
Vol 105 (6) ◽  
pp. 2569-2579 ◽  
Author(s):  
E J Mackie ◽  
I Thesleff ◽  
R Chiquet-Ehrismann
Keyword(s):  
Endochondral Ossification ◽  
Culture Medium ◽  
Bone Development ◽  
Bone Matrix ◽  
Immunofluorescent Staining ◽  
Tissue Culture Plastic ◽  
Osteogenic Cells ◽  
Wing Bud

The tissue distribution of the extracellular matrix glycoprotein, tenascin, during cartilage and bone development in rodents has been investigated by immunohistochemistry. Tenascin was present in condensing mesenchyme of cartilage anlagen, but not in the surrounding mesenchyme. In fully differentiated cartilages, tenascin was only present in the perichondrium. In bones that form by endochondral ossification, tenascin reappeared around the osteogenic cells invading the cartilage model. Tenascin was also present in the condensing mesenchyme of developing bones that form by intramembranous ossification and later was present around the spicules of forming bone. Tenascin was absent from mature bone matrix but persisted on periosteal and endosteal surfaces. Immunofluorescent staining of wing bud cultures from chick embryos showed large amounts of tenascin in the forming cartilage nodules. Cultures grown on a substrate of tenascin produced more cartilage nodules than cultures grown on tissue culture plastic. Tenascin in the culture medium inhibited the attachment of wing bud cells to fibronectin-coated substrates. We propose that tenascin plays an important role in chondrogenesis by modulating fibronectin-cell interactions and causing cell rounding and condensation.

Sign in / Sign up

Export Citation Format

Share Document