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K Ko

Publications and source records attributed to K Ko.

At least 19 recordsLinked to original sources
PubMed1992

Carboxyl-terminal sequences can influence the in vitro import and intraorganellar targeting of chloroplast protein precursors.

The transit peptide of the lumenal 33-kDa oxygen-evolving polypeptide (OEE1) is capable of directing the import and targeting of the foreign protein dihydrofolate reductase (DHFR) to the thylakoid lumen. The import results from the first part of this study indicate that methotrexate cannot block the import or intraorganellar targeting of OEE1-DHFR in chloroplasts in contrast to that reported for the import of cytochrome oxidase subunit IV (COXIV)-DHFR in mitochondria. These results suggest that the fusion of the OEE1 transit sequence to DHFR affected the protein's methotrexate binding properties. We further examined and compared the transport characteristics of a number of carboxyl-terminal truncated native chloroplast precursors to determine whether carboxyl domains contribute to the import and intraorganellar targeting mechanism of these proteins. The plastid precursors chosen for this study are targeted to one of the following chloroplast compartments: the stroma, the thylakoid membrane, and the lumen. In most cases, removal of carboxyl domains had a dramatic effect on one or more stages of the translocation pathway, such as import, processing, and intraorganellar targeting. The effects of carboxyl deletions varied from precursor to precursor and were dependent on the extent of the deletion. These combined results suggest that carboxyl domains in the mature part of the proteins can influence the function of the transit peptide, and as a result play an important role in determining the import and targeting competence of chloroplast precursors.

Chloroplasts↗
PubMed1992

Isolation and characterization of a cDNA clone encoding a cognate 70-kDa heat shock protein of the chloroplast envelope.

The translocation of proteins into the endoplasmic reticulum, the mitochondrion, and the chloroplast has recently been shown to involve homologues of the highly conserved 70-kDa heat shock protein (HSP70) family. In this study, we have isolated and sequenced a full-length cDNA clone encoding a cognate 70-kDa heat shock protein of the spinach chloroplast envelope (SCE70). The cDNA insert is 2,535 base pairs long and codes for 653 amino acid residues of a protein with a predicted molecular mass of 71,731 daltons. The deduced amino acid sequence shows a high degree of homology with HSP70 proteins from other organisms. Southern genomic and RNA analyses reveal different hybridization patterns than that observed for a heat-inducible 70-kDa protein gene. The protein synthesized from the SCE70 cDNA insert co-migrates with a 70-kDa polypeptide of the chloroplast envelope following sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Western blot analysis and import studies indicate that SCE70 is associated with the chloroplast outer envelope. The import data suggest that SCE70 is targeted to the envelope membrane via a pathway different from other plastidic precursors but similar to that recently reported for outer envelope proteins SOE1 and OM14.

Amino Acid Sequence↗
PubMed1992

[Effect of botulinum A toxin injection in the management of hemifacial spasm].

The present study was carried out on the effect of botulinum A toxin, made in Japan, in the management of 30 hemifacial spasm patients. In almost all cases, alleviation of hemifacial spasm reached its peak in a few days. Availability was 93.3% and its effect lasted about 4 months. Side effects were observed in 12 patients (40%), but no serious complications were observed.

Adult↗
PubMed1991

Isolation and characterization of tomato cDNA and genomic clones encoding the ubiquitin gene ubi3.

We report here the isolation and nucleotide sequence of tomato cDNA and genomic clones encoding a ubiquitin extension protein homologous to the yeast gene ubi3. Sites similar to upstream activating sites commonly found in the promoters of yeast ribosomal genes were observed in the tomato promoter. The tomato ubi3 promoter also contained elements found in the rbcS promoter from pea. The transcription initiation site was determined to occur 66 bp upstream of the initiating Met. RFLP mapping revealed that the gene was located on chromosome 1, 23 cM from marker TG301. A ubi3 gene-specific probe hybridized to a single 800 nt transcript. Expression was reduced in heat-shocked plants and plants kept in the dark. Expression was highest in young leaves and immature green fruit and lowest in mature leaves and petals. We isolated the original cDNA clone using an antibody prepared against chloroplast polypeptides. Immunological studies did not detect ubiquitin or ubiquitin extension proteins in the chloroplast. However, higher-molecular-weight chloroplast proteins were detected with ubiquitin antisera suggesting that ubiquitin conjugates are transported into the chloroplast.

Amino Acid Sequence↗
PubMed1991

[Late results of TVSI for Ebstein's anomaly].

For 10 adult cases of Ebstein's anomaly, tricuspid valve supraannular imposition (TVSI) without excision of native tricuspid valve were performed and its late results (6 mo. to 11.5 y, mean 6.8 years) were investigated. All cases showed the severe low output syndrome after the surgery. But the postoperative recovery of the cardiac function was smooth and there was no early death nor A-V block. Both the A-V conduction and the RV subvalvular structures were preserved in TVSI and it contributed to the postoperative good contractility of RV. In two cases, the serious postoperative ventricular tachycardia or ventricular fibrillation were experienced, one case required open cardiac massage and 6 hours long assist circulation in the other. In late stage, one patient died 9 years after the TVSI from the failure of the bioprosthetic mitral valve which had been implanted simultaneously, and the other 9 survivors returned to the class I of NYHA classification. LVDd and DS obtained by echocardiography showed significant enlargement; 29 +/- 4.5 mm and 19 +/- 4.1 mm before operation to 42 +/- 3.1 mm and 29 +/- 5.8 mm in late stage respectively. EF showed the tendency of slight decrease from the preoperative supernormal value to the normal range. RVD showed significant decrease after the surgery (58 +/- 4.2 mm to 37 +/- 4.1 mm). Bioprosthetic valve failure in tricuspid position was not experienced. PAC or PVC were seen quite often and 8 of 9 cases received medication for arrhythmia even in late stage.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

Diltiazem reduces the contractility of extraocular muscles in vitro and in vivo.

Diltiazem, a Ca-channel blocker that is used clinically for the treatment of hypertension and cardiac arrhythmias, reduces the contractility of extraocular muscles. Exposure of rabbit extraocular muscle to diltiazem in vitro reduces the sustained tension that is generated by the tonic, multiply innervated fibers, and decreases the baseline, or resting, tension of the muscle. When diltiazem is injected into a selected extraocular muscle in the rabbit in vivo, it causes a temporary weakening of the muscle, which is indicated by a deviation of eye position. These in vivo effects are of short duration, are easily reproducible, and vary with dosage. The results of this study raise the possibility that diltiazem may be used as an alternative to the surgical treatment of strabismus and other oculomotor dysfunctions including blepharospasm.

Adenosine Triphosphatases↗
PubMed1990

Isolation and characterization of cDNAs from Lycopersicon esculentum and Arabidopsis thaliana encoding the 33 kDa protein of the photosystem II-associated oxygen-evolving complex.

We have identified and isolated cDNA clones of the 33 kDa protein of the oxygen-evolving complex (OEE1) from Lycopersicon esculentum (tomato) and Arabidopsis thaliana and determined their nucleotide sequences. The cDNA clones and antibodies prepared against OEE1 were used as probes to examine the expression of the oee1 gene with respect to regulation by light, organ specificity, and ripening stage of tomato fruit. The steady-state mRNA level is regulated by light, being present in light-grown plants and absent in etiolated seedlings. The oee1 transcripts that accumulate during growth in the light were reduced to non-detectable or low levels by a 3-day dark treatment. The oee1 gene also exhibits differential expression in various organs of the tomato plant. Steady-state mRNA level was highest in immature leaves and absent in roots while the protein was most abundant in mature leaves and absent in roots. During tomato fruit ripening oee1 mRNA decreases to a low level in the pericarp while the protein level decreases below detection. The expression of oee1 appears to be under the control of a complex mechanism regulating both the amount of RNA and its translation.

Amino Acid Sequence↗
PubMed1990

An immunomodulating protein, Ling Zhi-8 (LZ-8) prevents insulitis in non-obese diabetic mice.

Ling Zhi-8 (LZ-8), a novel and recently discovered immunomodulatory protein having in vivo immuno-suppressive activity, was tested for in vivo effect against Type 1 (insulin-dependent) diabetes mellitus in the nonobese diabetic mouse, the disease having immunologically mediated aetiology in this animal. LZ-8 had mitogenic activity in vitro towards spleen cells of the non-obese diabetic mice as previously shown towards those of DBA/2 mice. Intraperitoneal administration of LZ-8 twice weekly into the mice (10.3-12.6 mg/kg body weight) from 4 weeks of age prevented insulitis and an almost normal number of insulin producing cells were observed. Extreme insulitis and reduction of the number of insulin producing cells were observed in the pancreata of the untreated non-obese diabetic mouse. No cumulative incidence of diabetes mellitus was observed in the LZ-8 treated group, while cumulative incidences of 70% and 60% were observed in an untreated group followed up to 42 weeks of age when the incidence of diabetes was defined as a plasma glucose level of greater than 11 mmol/l and as a urine glucose level of greater than 2+, respectively. T cell subset population analysis was performed to further investigate the action of LZ-8 on the non-obese diabetic mouse which revealed that LZ-8 treatment increased in L3T4'/Lyt-2+ ratio.

Adjuvants, Immunologic↗
PubMed1990

Systematic variation in myosin expression along extraocular muscle fibres of the adult rat.

Monoclonal antibodies (McAB) specific for fast (C14) and slow (S58) myosin, and a myosin antigenically similar to neonatal/embryonic myosin in mammals (ALD180), were used to characterize the myosin distribution in orbital layer fibres of rat extraocular muscles (EOM) in relation to innervation patterns. The orbital layer is composed of both singly-innervated (SIF) and multiply-innervated (MIF) fibres. The SIFs have the characteristics of twitch fibres, while the MIFs, in addition to possessing many small endings characteristic of tonic fibres, also have an en-plaque-like innervation in the endplate band resembling that of the adjacent SIFs. Myosin expression in MIFs and SIFs is unusual and varies systematically along the length of the fibres. Both SIFs and MIFs label with ALD180, but this labelling is absent in both fibre types in the endplate band region, where all fibres label with C14. Distally and also proximally to the endplate band, SIFs label with both ALD180 and C14, while the MIFs, innervated by many small, superficial endings in these regions, label with ALD180 only. This pattern of myosin expression could also be demonstrated in isolated fibres. The results are discussed in relation to the hypothesis that both populations of orbital layer fibres express constitutively both fast and the neonatal-like myosin, and that superimposed on this constitutive expression twitch or tonic innervation acts locally to selectively suppress either neonatal-like or fast myosin, respectively.

Adenosine Triphosphatases↗
PubMed1989

Complete amino acid sequence of an immunomodulatory protein, ling zhi-8 (LZ-8). An immunomodulator from a fungus, Ganoderma lucidium, having similarity to immunoglobulin variable regions.

The complete amino acid sequence of a novel immunomodulatory protein, ling zhi-8 (LZ-8), isolated from a fungus, Ganoderma lucidium (Kino, K., Yamashita, A., Yamaoka, K., Watanabe, J., Tanaka, S., Ko, K., Shimizu, K., and Tsunoo, H. (1989) J. Biol. Chem. 264, 472-478), was determined by protein sequencing. The polypeptide consists of 110 amino acid residues with an acetylated amino end and has a molecular mass of 12,420 Da including an amino-end blocking group. There is no attachment site for an Asn-linked oligosaccharide chain, consistent with the very low carbohydrate content of LZ-8. These results indicate that the native form of LZ-8 with a molecular mass of 24 kDa is a homodimer of the LZ-8 polypeptide whose sequence is described here. Furthermore, the LZ-8 chain shows considerable similarity to the variable region of immunoglobulin heavy chain both in its sequence and in its predicted secondary structure. The interesting possibility that LZ-8 is related to an ancestral protein of the immunoglobulin superfamily is also discussed.

Adjuvants, Immunologic↗
PubMed1989

Isolation and characterization of a new immunomodulatory protein, ling zhi-8 (LZ-8), from Ganoderma lucidium.

A novel protein with mitogenic activity in vitro and immunomodulating activity in vivo has been isolated from the mycelial extract of an Oriental medicinal fungus, ling zhi (Ganoderma lucidium). This protein was named ling zhi-8 (LZ-8) and its biochemical and immunological properties are described. LZ-8 was purified by two chromatographic systems, gel filtration and followed by ion-exchange, using an in vitro bioassay measuring blast-formation stimulatory activity toward mouse spleen lymphocytes to monitor purification. Analysis by several types of electrophoresis revealed a single band, with the molecular weight differing slightly depending on the system employed. Under reduced conditions, sodium dodecyl sulfate-polyacrylamide gel electrophoresis using the method of Laemmli, U.K. ((1970) Nature 227, 680-685) indicated an apparent Mr = 17,100, while under nonreduced conditions an apparent Mr = 17,500 was found; and, using Tricine-sodium dodecyl sulfate-polyacrylamide gel electrophoresis, a value of apparent Mr = 13,100 was obtained. LZ-8 has an isoelectric point of 4.4, and sugar analysis indicated a low carbohydrate content (1.3%). Half-cysteine, histidine, and methionine were not detected from the analysis of amino acid composition after further purification of LZ-8 by reversed-phase high performance liquid chromatography. LZ-8 was capable of hemagglutinating sheep red blood cells, but no such activity was observed toward human red blood cells (A, B, AB, and O types). In vivo, LZ-8 prevents the production of systemic anaphylaxis reaction in mice if it has been administered repeatedly, and reduction of antibody production is the suggested mechanism. The mechanisms of hemagglutination of sheep red blood cells and of blast-formation stimulation of mouse spleen cells are also discussed.

Adjuvants, Immunologic↗
PubMed1989

Targeting of proteins to the thylakoid lumen by the bipartite transit peptide of the 33 kd oxygen-evolving protein.

Various chimeric precursors and deletions of the 33 kd oxygen-evolving protein (OEE1) were constructed to study the mechanism by which chloroplast proteins are imported and targeted to the thylakoid lumen. The native OEE1 precursor was imported into isolated chloroplasts, processed and localized in the thylakoid lumen. Replacement of the OEE1 transit peptide with the transit peptide of the small subunit of ribulose-1,5-bisphosphate carboxylase, a stromal protein, resulted in redirection of mature OEE1 into the stromal compartment of the chloroplast. Utilizing chimeric transit peptides and block deletions we demonstrated that the 85 residue OEE1 transit peptide contains separate signal domains for importing and targeting the thylakoid lumen. The importing domain, which mediates translocation across the two membranes of the chloroplast envelope, is present in the N-terminal 58 amino acids. The thylakoid lumen targeting domain, which mediates translocation across the thylakoid membrane, is located within the C-terminal 27 residues of the OEE1 transit peptide. Chimeric precursors were constructed and used in in vitro import experiments to demonstrate that the OEE1 transit peptide is capable of importing and targeting foreign proteins to the thylakoid lumen.

Algal Proteins↗
PubMed1989

[Study of long-survival cases with liver metastasis of colorectal cancer by hepatic arterial infusion chemotherapy].

We performed arterial infusion chemotherapy through hepatic artery in 33 patients with liver metastasis of colorectal cancer. Regarding the survival rate, the 1-year survival rate was 55.6% and the 5-year rate was 27.8% in cases of H2, and 1-year as 28.9% in H3. According to criteria of Saito-Koyama, the response rate was 24.2%, including 2 CR and 6 PR cases. There were more patients with H2 factor and without peritoneal dissemination who survived for one year and more. The dose of 5-FU was 9.6 +/- 3.6 g in case of longer survivals and 5.1 +/- 3.0 g in non-responders. There were significant differences between them. The pretreatment value of CEA was lower than 100 ng/ml in 8 of 11 longer survivals, and the CEA values were decreased after this treatment in 9 of 11 responders. On the other hand, it was noted that the non-responders had a higher level of CEA such as more than 100 ng/ml, and in these cases CEA was not decreased after treatment. There are two favourable responders who are still living 9 and 5 years after successful treatment. Their pretreatment value of CEA was lower at 13.6 and 23.8 ng/ml, respectively, and these levels were decreased to 1.0 ng/ml with administration of 5-FU with ADM and 5-FU with MMC. It was concluded that arterial infusion chemotherapy was good for treatment of metastatic liver tumors from colorectal cancers.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1988

A light-entrained circadian clock controls transcription of several plant genes.

Diurnal oscillations in steady-state mRNA levels and transcription rates were measured for seven transcripts (five of which encode chloroplast-localized proteins) in tomato seedlings: photosystem I and photosystem II chlorophyll a/b binding proteins (CAB/I and CAB/II), small subunit of RuBisCO (RBCS), actin, subunit II of the photosystem I reaction center (PSAD), subunit I of the photosystem II oxygen-evolving enzyme (OEE1), and a biotin-binding protein of unknown function. CAB/II mRNA levels were found to oscillate greater than 20-fold, showing a peak at noon, while only marginal diurnal oscillations are seen in RBCS transcripts. The oscillations are at least partially controlled at the transcriptional level. Transcription rates of both CAB/II and RBCS, measured by nuclear run-on experiments, were found to oscillate, with a peak around 8 a.m. Transcription rates of the 'biotin' clone also oscillated, with a peak around noon. Transfer of plants to constant darkness or constant light conditions alters the amplitude of the transcriptional oscillation, but does not abolish it, suggesting that it is at least partially controlled by a circadian clock. The oscillations are still visible after three days in complete darkness, and have a period very close to 24 h. The oscillator phase can be reset by out-of-phase light treatment.

Cell Nucleus↗