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Y Emori

Publications and source records attributed to Y Emori.

At least 73 records · Page 4Linked to original sources
PubMed1993

Multiple genes for G protein-coupled receptors and their expression in lingual epithelia.

Using the polymerase chain reaction (PCR), we identified a gene family including more than 60 members which encoded similar G protein-coupled seven-transmembrane receptors. Sequence analyses of six representatives out of the 60 PCR clones showed that they had significant structural similarity to olfactory and optic receptors. Their expression is restricted in the surface of lingual epithelia.

Amino Acid Sequence↗
PubMed1993

Calpastatin has two distinct sites for interaction with calpain--effect of calpastatin fragments on the binding of calpain to membranes.

Calpain, a ubiquitously distributed intracellular cysteine protease in animals, is thought to be activated at the cell membrane in the presence of micromolar levels of calcium ions. Calpastatin, the sole specific proteinaceous inhibitor for calpain, inhibits not only proteolytic activity, but also the binding of calpain to cell membranes. The inhibition of calpain binding to membranes by calpastatin fragments was analyzed. A calpastatin peptide containing the inhibitory sequence did not inhibit the binding of calpain to membranes. On the other hand, binding was prevented by a fragment without the activity to inhibit proteolytic activity. These data indicate that calpain binds to cell membranes through a site (regulatory site) other than the active site and that calpastatin inhibits the binding of calpain to cell membranes via a site (regulatory inhibition site) other than the inhibitory sequence. Calpain and calpastatin can undergo independent interactions: interaction between the catalytic site of calpain and the inhibitory sequence of calpastatin, and interaction between the regulatory site of calpain and the regulatory inhibition site of calpastatin. The interaction between the regulatory site of calpain and the regulatory inhibition site of calpastatin is essential for the regulation of calpain activity.

Amino Acid Sequence↗
PubMed1993

The effect of combination therapy of radiation and Z-100, an arabinomannan on tumor growth in mice.

The effect of radiation combined with intraperitoneal administration of Z-100, an immunomodulatory arabinomannan extracted from Mycobacterium tuberculosis, was studied using Meth A fibrosarcoma in BALB/c mice and metastasis of Lewis lung carcinoma, 3LL, in C57BL/6 mice. In mice bearing Meth A fibrosarcoma, a moderate degree of growth inhibition was observed in the group of single therapy with Z-100 or radiation (10 Gy). When radiation was combined with Z-100, the tumor growth was significantly inhibited. In mice bearing 3LL, slight inhibition of pulmonary metastasis was observed in the group of single therapy, while significant degrees of inhibition of primary tumor growth and pulmonary metastasis were observed in the combination group. This suggests the usefulness of combined use of Z-100 in radiation therapy.

Adjuvants, Immunologic↗
PubMed1993

Two FGF-receptor homologues of Drosophila: one is expressed in mesodermal primordium in early embryos.

The fibroblast growth factor (FGF)/receptor system is thought to mediate various developmental events in vertebrates. We examined molecular structures and expression of DFR1 and DFR2, two Drosophila genes closely related to vertebrate FGF-receptor genes. DFR1 and DFR2 proteins contain two and five immunoglobulin-like domains, respectively, in the extracellular region, and a split tyrosine kinase domain in the intracellular region. In early embryos, DFR1 RNA expression, requiring both twist and snail proteins, is specific to mesodermal primordium and invaginated mesodermal cells. At later stages, putative muscle precursor cells and cells in the central nervous system (CNS) express DFR1. DFR2 expression occurs in endodermal precursor cells, CNS midline cells and certain ectodermal cells such as those of trachea and salivary duct. FGF-receptor homologues in Drosophila would thus appear essential for generation of mesodermal and endodermal layers, invaginations of various types of cells, and CNS formation.

Amino Acid Sequence↗
PubMed1993

Large-scale production and purification of an Erwinia ananas ice nucleation protein and evaluation of its ice nucleation activity.

The ice nucleation-active protein of Erwinia ananas IN-10 (inaA protein) was over-expressed as inclusion bodies in Escherichia coli in a yield of 15.3 mg of inaA protein from 60 mg of bacterial cells on a dry-matter basis. The inaA protein was purified from the inclusion bodies by solubilization with detergents to obtain a protein preparation free from sugar and lipid. This preparation had a distinct ice nucleation activity, indicating that the inaA protein per se is able to act as a nucleus.

Amino Acid Sequence↗
PubMed1993

Expression of oryzacystatin cDNA using yeast artificial chromosome under ADH promoter in baker's yeast.

We constructed an expression vector into a yeast artificial chromosome (YAC) harboring the cDNA for oryzacystatin, a cysteine proteinase inhibitor from rice, under the control of the yeast ADH promoter. When the expression vector was introduced into Saccharomyces cerevisiae in the form of either an artificial chromosome or a circular plasmid, transformants carrying the DNA grew well in a selective medium. However, the content of the introduced DNA decreased significantly during passages in non-selective YPD medium. The stability of the introduced DNA was enhanced in selected clones obtained as colonies viable in selective medium after many passages in YPD medium. The stable transformants thus obtained expressed the mRNA for oryzacystatin at levels as high as those of intrinsic yeast ADH.

Alcohol Dehydrogenase↗
PubMed1992

Identification of four FGF receptor genes in Medaka fish (Oryzias latipes).

Four types of cDNA clones encoding tyrosine kinases highly homologous to mammalian fibroblast growth factor receptors (FGF-R) were isolated from Medaka fish (Oryzias latipes) by the reverse transcription-polymerase chain reaction. Comparison of the four deduced amino acid sequences with four known mammalian FGF-Rs indicated that four FGF-R species corresponding to mammalian FGF-Rs exist universally in vertebrates including fishes, although FGF-R4 might have diverged sequences between fishes and mammals. Each of four FGF-R genes is transcribed to various extents as multiple mRNAs possibly by alternative splicing in adult fishes.

Amino Acid Sequence↗
PubMed1992

Isolation and characterization of a Xenopus cDNA which encodes a homeodomain highly homologous to Drosophila Distal-less.

A novel homeobox gene of Xenopus was isolated from the ovary cDNA library. The homeodomain of the encoded protein was homologous to that of Drosophila Distal-less (Dll), and the gene was termed Xdll. The mRNA exists in a large amount in ovary, and in a small amount in testis, but was not detected in muscle, kidney, gut, and liver. The mRNA also occurs in a large amount in oocytes and is maintained in unfertilized eggs and cleavage stage embryos as a maternal mRNA at a low but distinctly detectable level. The amount of the mRNA per embryo increases gradually in later stages by zygotic expression. Embryo dissection experiment revealed that the transcript is abundant in the anterior region at the neurula stage, suggesting that Xdll may play a role in the establishment of the structures in the anterior part of the embryo.

Amino Acid Sequence↗
PubMed1992

Isolation and characterization of rat 3Y1 fibroblast clones overexpressing the src homology region of phospholipase C-gamma 2.

To examine the regulatory function of the src-related SH2 and SH3 (SH2/SH3) region of phospholipase C-gamma 2 (PLC-gamma 2), we expressed this region of rat PLC-gamma 2 cDNA in rat 3Y1 fibroblasts and isolated and characterized a number of clones (approximately 20 clones). An increase of endogenous tyrosine kinase activity was observed in all cell clones that highly expressed a translational product of the SH2/SH3 domain. Moreover, endogenous phosphatidylinositol 4,5-bisphosphate hydrolyzing activity was also enhanced in these clones, and PLC-gamma 1 seemed to be preferentially activated among endogenous PLC isozymes. Genistein, an inhibitor of tyrosine kinase, inhibited this activation of PLC-gamma 1, and tyrosine phosphorylation was observed on PLC-gamma 1 molecules, indicating the involvement of tyrosine kinases in the PLC-gamma 1 activation. These results suggest that the SH2/SH3 region of PLC-gamma would function as a multidirectional regulator which controls at least two major signaling pathways: tyrosine kinase and phosphatidylinositol 4,5-bisphosphate hydrolysis.

Animals↗
PubMed1992

Purification of recombinant SH2/SH3 proteins of phospholipase C-gamma 1 and -gamma 2 and their inhibitory effect on PIP2-hydrolysis induced by both types of phospholipase C-gamma.

In order to examine physiological function of the SH2/SH3 region of phospholipase C-gamma (Z region), we independently expressed cDNA fragments corresponding to the SH2/SH3 region of PLC-gamma 1 and PLC-gamma 2 in Escherichia coli. Although these recombinant proteins were recovered in particulate fractions by centrifugation of cell extracts, they were successfully solubilized by guanidium hydrochloride and then purified to homogeneity by heparin column chromatography. The molecular mass of the proteins was 45 kDa (derived from PLC-gamma 1 and designated as rP45Z) and 38 kDa (derived from PLC-gamma 2 and designated as rP38Z), which was consistent with that as expected from inserted cDNA. We determined the effect of purified rP45Z or rP38Z on PIP2-hydrolyzing activity of either PLC-gamma 1 or PLC-gamma 2 and found that these proteins strongly suppressed the rate of PLC-dependent PIP2-hydrolysis. Furthermore, both rP45Z and rP38Z were phosphorylated at tyrosine residue by epidermal growth factor receptors and their inhibitory effect on PIP2-hydrolysis was significantly decreased by this phosphorylation. These results indicate that the Z region might be involved in autoregulation of PLC-gamma as intrinsic negative regulator.

Animals↗
PubMed1992

Dual Bar homeo box genes of Drosophila required in two photoreceptor cells, R1 and R6, and primary pigment cells for normal eye development.

In the Bar mutation of Drosophila, ommatidial differentiation is known to be suppressed in the anterior portion of the eye. Our structural analysis shows that the Bar region contains a pair of homeo box genes, BarH1 and BarH2. These genes encode polypeptides similar in size and sequence and share a common homeo domain that is identical in sequence except for putative trans-activator-binding sites. We also show, by mosaic analysis and immunostaining with anti-BarH1/BarH2 antibodies, that BarH1 and BarH2 are not only specifically coexpressed but also functionally required in R1/R6 prephotoreceptors and primary pigment cells in developing ommatidia. In R1/R6, the expression of BarH1 and BarH2 appears to be regulated by rough and glass gene products. BarH1 and BarH2 proteins are essential to normal lens formation, formation of three types of pigment cells, and elimination of excess cells from mature ommatidia. Taken together, our results suggest that Bar homeo domain proteins may play key roles in the fate-determination processes of pigment cells and cone cells.

Amino Acid Sequence↗
PubMed1992

Subtype determination of Drosophila embryonic external sensory organs by redundant homeo box genes BarH1 and BarH2.

BarH1 and BarH2 are two closely related homeo box genes that form a small complex at the Bar locus on the X chromosome of Drosophila. By immunostaining, we showed that BarH1 and BarH2 proteins are coexpressed in cells belonging to the central and peripheral nervous systems in embryos. In external sensory (es) organs, their expression was particularly apparent in thecogens (glial cells) and neurons at late development. Although deletion of BarH2 caused no appreciable morphological change in es organs, the simultaneous deletion of BarH1 and BarH2 led to a homeotic change in these organs with consequent conversion from campaniform-like sensilla to trichoid sensilla. In contrast, the overexpression of either BarH1 or BarH2 resulted in opposite morphological change. It would thus follow that BarH1 and BarH2 are a pair of redundant homeo box genes required for the subtype specification of es organs.

Animals↗
PubMed1991

Identification of seven novel protein-tyrosine kinase genes of Drosophila by the polymerase chain reaction.

We used the polymerase chain reaction to identify 7 novel tyrosine-kinase genes (dtk1 to -7) in Drosophila melanogaster, dtk4 coded for a part of the kinase catalytic domain nearly identical in sequence to that of the human receptor for insulin-like growth factor 1, whereas sequences encoded by dtk1 and dtk2 were highly homologous to that of the chicken fibroblast growth factor receptor.

Alleles↗
PubMed1991

Molecular cloning and gibberellin-induced expression of multiple cysteine proteinases of rice seeds (oryzains).

We screened a cDNA library of germinating rice seeds with a cDNA for aleurain (cysteine proteinase from barley) and obtained three distinct types of cDNA clones encoding three species of cysteine proteinases (oryzains alpha, beta, and gamma). The deduced amino acid sequences are distinct in part, but, on the whole, are similar to one another. The three sequences all contain the catalytic triad Cys25-His159-Asn175 (papain numbering). The three oryzains are similar to one another and also to other known cysteine proteinases such as papain and cathepsin H with respect to the sequences around the active site residues and the COOH-terminal Trp-rich region. Amino acid sequence comparison revealed that oryzains alpha and beta are similar not only to each other (70% similarity) but also to actinidin and papain (about 50%), whereas oryzain gamma was rather similar to aleurain (85%) and cathepsin H (60%). Northern blot analysis revealed that the mRNAs for the three oryzains are expressed only in seeds, not in shoots or roots, and show different expression profiles during germination and when the seeds are treated with gibberellic acid. Oryzains alpha and gamma are expressed continuously during germination with a maximum expression 5 days from the start of germination, but are present in neither ripening nor ripened seeds. On the other hand, oryzain beta is expressed not only during germination, but also in ripened seeds before germination. It was noted that the expression of the three oryzain mRNAs is enhanced in different manners by gibberellic acid but is not enhanced by other plant hormones such as auxin. The induction of oryzain beta mRNA is transient, reaching a maximum in 4 h from the addition of giberellic acid and diminishing rapidly thereafter, while the induction of oryzain alpha and gamma mRNAs continues over 5 days. Thus, multiple systems involving cysteine proteinases must be differentially involved in the germination process, probably under hormonal control.

Amino Acid Sequence↗
PubMed1991

Deduced primary structure of a Xenopus proteasome subunit XC3 and expression of its mRNA during early development.

Proteasome is a non-lysosomal proteinase complex ubiquitously distributed in eukaryotic cells. We isolated here the cDNA clone for one of the proteasome subunits (XC3) from Xenopus ovary cDNA libraries using rat RC3 cDNA as a prove. The cDNA is 885 bp long and encodes 234 amino acids. The deduced amino acid sequence is highly homologous (95.3%) to those of rat RC3 and human HC3 subunits. The mRNA for XC3 is one of the maternal mRNAs and detected at all the embryonic stages investigated, but its level changes in a characteristic way especially at the gastrula stage. We suggest that the highly conserved XC3 subunit plays an essential role in proteasome function and also that during Xenopus embryogenesis mRNA for XC3 subunit is replaced from maternal to newly-synthesized one probably around the gastrula stage.

Amino Acid Sequence↗
PubMed1991

Functional analyses of the domain structure of microtubule-associated protein-4 (MAP-U).

Bovine microtubule-associated protein-4 (MAP-4), which was previously named MAP-U, consists of an amino-terminal projection domain (N-domain) and a carboxyl-terminal microtubule-binding domain (C-domain) (Aizawa, H., Emori, Y., Murofushi, H., Kawasaki, H., Sakai, H., and Suzuki, K. (1990) J. Biol. Chem. 265, 13849-13855). The C-domain contains a region rich in proline (Pro-rich region) and a region containing four assembly-promoting sequences (AP sequence region) which is shared by MAP-2 and tau. We purified a series of truncated fragments of MAP-4 expressed in Escherichia coli. An N-domain fragment did not bind to microtubules, while a C-domain fragment promoted microtubule assembly. Both of the fragments corresponding to the Pro-rich region (P fragment) and the AP sequence region (A4 fragment) promoted tubulin polymerization, although the A4 fragment had lower activity than intact MAP-4 and P fragment. A4 fragment produced morphologically normal microtubules whereas P fragment produced abnormal microtubules such as duplex microtubules and tight bundles of microtubules with diverse diameters. We concluded that both Pro-rich and AP sequence regions take part in the promotion of tubulin polymerization, and that the former is important for the MAP to bind to microtubules with high efficiency and the latter is essential for the formation of microtubules with normal morphology.

Amino Acid Sequence↗
PubMed1991

Identification of a different-type homeobox gene, BarH1, possibly causing Bar (B) and Om(1D) mutations in Drosophila.

The Bar mutation B of Drosophila melanogaster and optic morphology mutation Om(1D) of Drosophila ananassae result in suppression of ommatidium differentiation at the anterior portion of the eye. Examinations was made to determine the genes responsible for these mutations. Both loci were found to share in common a different type of homeobox gene, which we call "BarH1." Polyptides encoded by D. melanogaster and D. ananassae BarH1 genes consist of 543 and 604 amino acids, respectively, with homeodomains identical in sequence except for one amino acid substitution. A unique feature of these homeodomains is that the phenylalanine residue in helix 3, conserved in all metazoan homeodomains so far examined, is replaced by a tyrosine residue. By Northern blotting, considerably more BarH1 RNA was detected in the Bar mutant than in wild type. P element-mediated transformation showed Bar-like eye malformation to be induced by transient overexpression of the BarH1 gene in the late third-instar larvae. Somatic recombination analysis indicated normal gene functions of the Bar region, including the BarH1 gene, to be required for normal eye morphogenesis.

Amino Acid Sequence↗