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T Nohno

Publications and source records attributed to T Nohno.

At least 37 records · Page 2Linked to original sources
PubMed1995

Truncated type II receptor for BMP-4 induces secondary axial structures in Xenopus embryos.

BRK-3 is a vertebrate type II receptor for BMP-4 distantly related to invertebrate type II receptors for BMP-2/BMP-4/dpp, such as daf-4 and punt. BRK-3 has a long carboxy-terminal sequence following intracellular kinase domain and is capable of forming a high-affinity complex with a type I receptor, BRK-2. To examine the role of BRK-2 + BRK-3 receptor complex in BMP signaling during early embryogenesis, the dominant-negative form of BRK-3 was ectopically expressed in the Xenopus embryos. A secondary body axis expressing the Sonic hedgehog and N-CAM genes is induced by injecting mRNA encoding truncated form of BRK-3 into ventral marginal region, implicating the BMP signaling in axial mesoderm induction. Formation of the secondary axis depends on whether the deletion extends into the kinase domain, not into the carboxy-terminal tail, suggesting that the kinase domain, but not the tail region, is essential for BMP signaling.

Amino Acid Sequence↗
PubMed1995

Identification of a human type II receptor for bone morphogenetic protein-4 that forms differential heteromeric complexes with bone morphogenetic protein type I receptors.

Bone morphogenetic proteins (BMPs) comprise the largest subfamily of TGF-beta-related ligands and are known to bind to type I and type II receptor serine/threonine kinases. Although several mammalian BMP type I receptors have been identified, the mammalian BMP type II receptors have remained elusive. We have isolated a cDNA encoding a novel transmembrane serine/threonine kinase from human skin fibroblasts which we demonstrate here to be a type II receptor that binds BMP-4. This receptor (BRK-3) is distantly related to other known type II receptors and is distinguished from them by an extremely long carboxyl-terminal sequence following the intracellular kinase domain. The BRK-3 gene is widely expressed in a variety of adult tissues. When expressed alone in COS cells, BRK-3 specifically binds BMP-4, but cross-linking of BMP-4 to BRK-3 is undetectable in the absence of either the BRK-1 or BRK-2 BMP type I receptors. Cotransfection of BRK-2 with BRK-3 greatly enhanced affinity labeling of BMP-4 to the type I receptor, in contrast to the affinity labeling pattern observed with the BRK-1 + BRK-3 heteromeric complex. Furthermore, a subpopulation of super-high affinity binding sites is formed in COS cells upon cotransfection only of BRK-2 + BRK-3, suggesting that the different heteromeric BMP receptor complexes have different signaling potential.

Base Sequence↗
PubMed1995

A chicken Wnt gene, Wnt-11, is involved in dermal development.

We have isolated a new member of the Wnt gene family, Wnt-11, from chick embryo cDNA library and examined the expression pattern during embryogenesis by in situ hybridization. The Wnt-11 gene encodes Cys-rich secretory protein distantly related to Wnt-1 through Wnt-8 from the mouse and Xenopus. Expression of the Wnt-11 gene became evident at stage 14 in the dorsolateral region of somites and gradually restricted to the dermatome at stage 19 and later. In contrast to the other Wnt genes, Wnt-11 was not expressed in the neuroepithelium throughout stages 14-26. At stage 24 and later, Wnt-11 was expressed in the subectodermal mesenchyme of the limb and feather buds. The unique expression pattern of Wnt-11 in the paraxial mesoderm and dermatome suggests that Wnt-11 may play an important role in dermal development.

Amino Acid Sequence↗
PubMed1995

An additional limb can be induced from the flank of the chick embryo by FGF4.

To elucidate what initiates formation of the limb, we have attempted to induce an additional limb from the flank of the chick embryo by infecting retrovirus or implanting cells. We report here that an additional limb can be formed from the flank when we implant fibroblast growth factor 4 (Fgf4)-expressing cells into the lateral plate mesoderm at the pre-limb bud stage. In a newly formed limb bud, expressions of both Sonic hedgehog and chick Fgf4, which are authentic morphogenetic signals from the zone of polarizing activity and the apical ectodermal ridge, respectively, are induced by the implanted cells. Thus, it is concluded that the competence for limb development is present along the flank of the chick embryo and that FGF4 applied ectopically at the pre-limb bud stage can alter the developmental fate of flank cells to become limb cells. The present experimental system will contribute to a further elucidation on how the limb is formed.

Animals↗
PubMed1995

Involvement of the Sonic hedgehog gene in chick feather formation.

To elucidate the molecular mechanisms of chick feather formation, we observed expression patterns of the Sonic hedgehog (Shh) gene, which is one of the vertebrate homologs of the Drosophila segment polarity gene, hedgehog, and encodes a signaling molecule functioning in limb pattern formation and motor neuron induction. We found that the Shh gene is also expressed in the apical region of the feather placodes and then in nine to eleven longitudinal stripes along feather filaments. The stripe was found to correspond to one of the outer marginal zones of each barb ridge, termed the zone of Shh expression. No significant expression signal was detected in the scale bud of developing legs. Thus, Shh is likely to function as an epithelial signaling molecule in epithelio-mesenchymal interaction during feather formation. Furthermore, since genes of bone morphogenetic protein-2 (BMP-2) and fibroblast growth factor-4 (FGF-4) are coexpressed with Shh during feather formation as observed in limb morphogenesis, interactions among FGF-4, Shh and BMP-2 may be involved in formation of feather filaments and barbs in a similar fashion as elucidated in limb pattern formation.

Animals↗
PubMed1995

Cloning and characterization of Wnt-4 and Wnt-11 cDNAs from chick embryo.

We have isolated two members of the Wnt gene family, Wnt-4 and Wnt-11, from chick embryo cDNA library, and determined the entire coding sequences. The Wnt-4 and Wnt-11 genes encode secretory proteins composed of 351 and 354 amino acids, respectively, both having 24 Cys residues conserved among other Wnt family members. Alignment of the deduced amino acid sequences reveals that chicken Wnt-4 and Wnt-11 are most similar to Xenopus Wnt-4 and mouse Wnt-11; respectively. Northern blot analysis indicates the Wnt-4 expression at 1.5 kilobase and the Wnt-11 expression at 2.0 kilobase in the chick embryo.

Amino Acid Sequence↗
PubMed1994

Involvement of androgen-induced growth factor (FGF-8) gene in mouse embryogenesis and morphogenesis.

Androgen-induced growth factor (AIGF/FGF-8) has purified from a mouse mammary carcinoma cell line and its cDNA cloning revealed that AIGF is the eighth member of the fibroblast growth factor family. To clarify a biological role of FGF-8, Northern blot analysis of various adult tissues was carried out, but no expression was found. However, whole mount in situ hybridization of 7.5- to 14.5-day gestation (E7.5-14.5) embryos revealed six predominant expression domains: [1]primitive streak region (E7.5-9.75); [2]midbrain-hindbrain border (E8.0-10.5); [3]rostral forebrain (E8.0-10.5); [4]limb ectoderm and apical ectodermal ridge (E9.25-13.5); [5]nasal placode and epithelium (E9.5-12.5); and [6]branchial arch ectoderm (E8.5-11.5). The embryonic expression pattern suggests a unique role of FGF-8 in mouse development, especially in gastrulation, brain development, and limb and facial morphogenesis.

Animals↗
PubMed1994

Regional expression of the Cwnt-4 gene in developing chick central nervous system in relationship to the diencephalic neuromere D2 and a dorsal domain of the spinal cord.

Members of the Wnt gene family code for cysteine-rich, secreted proteins, which are differentially expressed in the developing brain and possibly act as an intercellular signaling molecule. A Wnt gene, e.g., Wnt-1 is known to be essential for specification of the midbrain cell fate. Since other members of the Wnt genes are likely to be also involved in development of the brain, we searched chick Wnt members expressing in specific domains of the brain. We found several novel Wnt members expressing specifically in the central nervous system of chick embryos. One of the genes was intensely expressed in a segment of the diencephalon at stages 14 and 20 and in a dorsal region of the spinal cord at stage 20. Although the expression patterns differ from those of mouse or Xenopus Wnt-4, the gene is highly homologous to the mouse or frog Wnt-4. Thus, we designated the gene as Cwnt-4 (chick Wnt-4). Our results suggested that Cwnt-4 is involved in segmentation of the forebrain into the neuromere D2 and in differentiation of the dorsal region of the spinal cord.

Amino Acid Sequence↗
PubMed1994

Repression of in vitro transcription of the Escherichia coli fnr and nar X genes by FNR protein.

In facultative anaerobes, the anaerobic expression of respiratory genes is regulated by a transcriptional activator, FNR. Transcription in vitro of the E. coli fnr gene was repressed by its product, FNR. The transcription of the E. coli narX gene encoding the nitrate sensor protein was likewise repressed. DNA truncation experiments for fnr and narX genes indicated that multiple anaero-boxes in each promoter region are essential for repression by the FNR protein, but they also suggest that factor-independent upstream activation signals are operating with these promoters.

Bacterial Proteins↗
PubMed1994

Expression patterns of two fibroblast growth factor receptor genes during early chick eye development.

The expression patterns of two distinct types of fibroblast growth factor receptor (FGFR) genes, FGFR1 and FGFR2, were compared during early chick eye development. In situ hybridization was performed with riboprobes synthesized from cDNA fragments of FGFRs cloned by the polymerase chain reaction method. FGFR1 was expressed in the prospective lens, neural retina, pigment epithelium and mandibular mesenchyme. In contrast, FGFR2 was expressed predominantly in the periocular mesenchyme of a 2.5 day-old embryo. In the 5.5-day-old embryo, transcripts of FGFR2 were detected in the prospective corneal epithelium. The results suggest that expression patterns of FGFR1 and FGFR2 are complementary and ligands of each FGFR might be involved differentially in early chick eye development. It is concluded that the action of FGFs on pigment epithelium and lens cells reported so far, probably occurs through FGFR1, and both types of FGFR are involved in head mesenchymal development.

Animals↗
PubMed1994

Diurnal regulation of per repeat family in the suprachiasmatic nucleus of rat brain.

We have recently reported fluctuations in the expression of the period repeat sequence, pp2.5, during light-dark cycles in the suprachiasmatic nucleus (SCN) of rat. Presently, we performed in situ hybridization which shows that the fluctuation of pp2.5 expression continues during constant darkness conditions in the SCN of rat. The light exposure during subjective night but not subjective day triggered its elevated expression in a time-dependent manner which is parallel to that of c-fos expression. In this review, the cloning and characterization of multiple per repeat sequences from mouse genom and rat brain mRNA were summarized. The abundance of a novel per repeat mRNA (designated as RB15) fluctuates during a light-dark cycle in the SCN. These findings suggest that per repeat sequence may have a role for the mammalian circadian rhythms. The evolutionary relationship between the mammarian per repeat sequence and the Drosophila period gene is also discussed.

Animals↗
PubMed1993

A chicken homeobox gene related to Drosophila paired is predominantly expressed in the developing limb.

We identified a homeobox-containing gene, Prx-1, isolated from the chick limb bud cDNA library. The homeodomain sequence is related to Drosophila paired and goose-berry and mouse Pax-3, Pax-6, and Pax-7. The deduced amino acid sequence of the Prx-1 gene product reveals the absence of a paired-box sequence and extensive similarity to mouse S8 and MHox homeodomain proteins, thus constituting a new class of homeobox gene. Using an in situ hybridization method, the Prx-1 gene is shown to be expressed predominantly in the limb bud and visceral arches. At early stages of limb development, distal mesodermal cells express the homeobox gene with an apparent gradient along the proximal-distal axis. The signal is absent in the apical and nonridge ectoderm. Removal of the apical ectodermal ridge had no apparent effect on the subsequent expression of Prx-1 in the limb mesenchyme. The Prx-1-expressing cells are later confined to the interdigital and perichondrial regions. The Prx-1 transcripts are also detectable in the mesenchyme of the visceral arches and facial primordia subjacent to the ectoderm. The Prx-1 gene is weakly expressed in somites and condensing vertebrae. No signal is detectable in neural tube and ectodermal epithelium. These results suggest that the Prx-1 homeodomain protein is involved in the differentiation of bone, muscle, and other tissues of mesodermal origin during limb development.

Amino Acid Sequence↗
PubMed1993

MRC-5, human embryonic lung fibroblasts, induce the duplication of the developing chick limb bud.

The anteroposterior (A-P) axis pattern of the chick limb is likely to be controlled by a small region of mesenchyme cells at the posterior margin of the limb bud (ZPA, zone of polarizing activity). In this study, we found that MRC-5 fibroblast cells had the capacity for duplicated-pattern formation of the chick limb along the A-P axis when grafted to the anterior region of the limb bud. MRC-5 cells were effective only during pre-limb bud stages, and the leg bud was more responsive than the wing bud. Grafted cells remained at the base of the limb bud when limb development proceeded. These results suggest that the products of MRC-5 cells are involved in three possible processes of duplicated-pattern formation: induction of the polarizing activity; maintenance of this activity, which is present weakly at pre-limb bud stages; and determination of A-P axis as the ZPA factor(s). By allowing the use of a small number of cells of embryonic tissues with polarizing activity, the analysis of duplicate formation with the MRC-5 cell line provides a powerful tool for elucidating the molecular nature of the ZPA.

3T3 Cells↗
PubMed1993

A new receptor protein kinase from chick embryo related to type II receptor for TGF-beta.

We have isolated cDNA encoding a new member of protein kinase family from chicken embryo cDNA library. The deduced amino acid sequence comprises a cysteine-rich extracellular domain, a single hydrophobic transmembrane domain, and a cytoplasmic serine/threonine kinase domain. Two short inserts are contained in the kinase domain. The primary structure shows that it belongs to the receptor-type serine/threonine kinase subfamily and is most similar to Daf-1. Conserved cysteine residues in the ectodomain suggest the protein as a receptor for a peptide growth factor of TGF-beta family.

Amino Acid Sequence↗
PubMed1993

Nucleotide sequence of a cDNA encoding the chicken receptor protein kinase of the TGF-beta receptor family.

We have isolated RPK-2 cDNA from chick embryo cDNA library that encodes a receptor protein kinase of the TGF-beta receptor subfamily. The deduced amino acid sequence reveals the presence of a hydrophobic transmembrane helix and a kinase domain distantly related to type II receptor for TGF-beta. The kinase domain sequence is most similar to RPK-1 identified recently in the chick embryo. Several cysteine residues are contained in the amino-terminal ectodomain, suggesting the protein as a receptor for a peptide growth factor of the TGF-beta family.

Amino Acid Sequence↗