PACT, a double-stranded RNA binding protein acts as a positive regulator for type I interferon gene induced by Newcastle disease virus

Virus infection triggers innate responses to host cells including production of type I interferon (IFN). Since IFN production is also induced by treatment with poly(I:C), viral double-stranded (ds) RNA has been postulated to play a direct role in the process. In the present study, we investigated the effect of dsRNA binding proteins on virus-induced activation of the IFN-beta gene. We found that PACT, originally identified as protein activator for dsRNA-dependent protein kinase (PKR) and implicated in the regulation of translation, augmented IFN-beta gene activation induced by Newcastle disease virus. Concomitantly with the augmented activity of IFN-beta enhancer, increased activity of NF-kappaB and IRF-3 and IRF-7 was observed. For the observed effect, the dsRNA-binding activity of PACT was essential. We identified residues of PACT that interact with a presumptive target molecule to exert its function. Furthermore, PACT colocalized with viral replication complex in the infected cells. Thus the observed effect of PACT is novel and PACT is involved in the regulation of viral replication and results in a marked increase of cellular IFN-beta gene expression.

7-Methylxanthine methyltransferase of coffee plants. Gene isolation and enzymatic properties

Caffeine is synthesized through sequential three-step methylation of xanthine derivatives at positions 7-N, 3-N, and 1-N. However, controversy exists as to the number and properties of the methyltransferases involved. Using primers designed on the basis of conserved amino acid regions of tea caffeine synthase and Arabidopsis hypothetical proteins, a particular DNA fragment was amplified from an mRNA population of coffee plants. Subsequently, this fragment was used as a probe, and four independent clones were isolated from a cDNA library derived from coffee young leaves. Upon expression in Escherichia coli, one of them was found to encode a protein possessing 7-methylxanthine methyltransferase activity and was designated as CaMXMT. It consists of 378 amino acids with a relative molecular mass of 42.7 kDa and shows similarity to tea caffeine synthase (35.8%) and salicylic acid methyltransferase (34.1%). The bacterially expressed protein exhibited an optimal pH for activity ranging between 7 and 9 and methylated almost exclusively 7-methylxanthine with low activity toward paraxanthine, indicating a strict substrate specificity regarding the 3-N position of the purine ring. K(m) values were estimated to be 50 and 12 microM for 7-methylxanthine and S-adenosyl-l-methionine, respectively. Transcripts of CaMXMT could be shown to accumulate in young leaves and stems containing buds, and green fluorescent protein fusion protein assays indicated localization in cytoplasmic fractions. The results suggest that, in coffee plants, caffeine is synthesized through three independent methylation steps from xanthosine, in which CaMXMT catalyzes the second step to produce theobromine.

An expression profile of active genes in human conjunctival epithelium

The purpose of this study was to describe the quantitatively and qualitatively genes expressed in in vivo human conjunctival epithelium. A cDNA library was created from human conjunctival epithelial cells obtained from 38 normal eyes by brush cytology. Poly A(+)RNA isolated from these cells was used as a template for cDNA synthesis by the vector-priming method. A 3'-directed cDNA library consisting of the cDNA moiety covering the poly A(+)RNA tail through the nearest Mbo I site was constructed and transformed into Escherichia coli. Inserts in 933 randomly chosen clones were sequenced. The resulting sequences were compared to determine frequency of appearance in the library, and to establish an expression profile of genes in the conjunctival epithelium. The sequences were sent to GenBank for gene identification. The result was an expression profile of active genes reflecting their relative abundance in the conjunctival epithelial mRNA population. The expression profile of human conjunctival epithelium showed that the most abundant gene transcript in human conjunctival epithelium was that for cytokeratin 13. Altogether 102 genes were found to be very active, including beta-2 microglobulin, lipocortin I and insulin-like growth factor binding protein-3. The gene expression profile of the conjunctival epithelium reflects the unique properties and functions of this tissue. Comparison of this expression profile with that obtained from corneal epithelium discloses clear differences and helps us better understand the physiology and pathophysiology of the ocular surface in humans.

Early results of a prospective study of limited resection for bronchioloalveolar adenocarcinoma of the lung

BACKGROUND

We reported that bronchioloalveolar adenocarcinoma (BAC) without active fibroblastic proliferation of the lung had no lymph node and pulmonary metastasis and had a favorable prognosis. However, there has been no prospective trial regarding limited pulmonary resection for this type of BAC. The purpose of this study is to confirm the effectiveness of limited resection for histologically confirmed BAC without active fibroblastic proliferation.

METHODS

From 1996 through 1999, 42 patients who had small peripheral lung tumors (< or = 20 mm), suspected of being BAC, were enrolled in this trial. The patient population consisted of 24 men and 18 women with a mean age of 58.4 years. Limited resection was completed when BAC, without both active fibroblastic proliferation and lymph node metastasis, was confirmed histologically by intraoperative pathologic examination.

RESULTS

Limited resection was completed in 36 patients, wedge resection in 34, and segmentectomy in 2 patients. In 6 patients, the procedure was converted into lobectomy because of pathologic invasive sign in 3, active fibroblastic proliferation in 1, and for other reasons in 2 patients. All patients have been followed for a median follow-up period of 30 months and are alive without sign of recurrence.

CONCLUSIONS

Our early results indicate that limited resection may be an acceptable alternative to lobectomy for histologically confirmed BAC without active fibroblastic proliferation.

Pharmacokinetics of acetaminophen from rapidly disintegrating compressed tablet prepared using microcrystalline cellulose (PH-M-06) and spherical sugar granules

The aim of the present study was to evaluate the bioavailability of a drug from rapidly disintegrating tablets prepared using fine spherical crystalline cellulose (PH-M-06) and spherical sugar granules (Nonpareil, NP). Rapidly disintegrating tablets containing acetaminophen as the model drug in combination with a mixture of NP-108 (purified n-mannitol) and PH-M-06 were prepared. Plasma concentration profiles and pharmacokinetic parameters of acetaminophen in rabbits were investigated after oral administration of the prepared tablets. No significant difference in Cmax and AUC(0-infinity) of acetaminophen between rapidly disintegrating tablets and conventional tablets was observed after direct administration of these tablets into the stomach of rabbits. However, tmax (15 min) of acetaminophen from rapidly disintegrating tablets was significantly (p<0.05) shorter than that from conventional tablets (130 min). The same tmax was observed for rapidly disintegrating tablets and solution. When suitable excipients such as fine spherical microcrystalline cellulose (PH-M series) and spherical sugar granules (NP series) were used, rapidly disintegrating tablets could be prepared by the conventional direct compression method. According to the results of moment analysis, the mean residence time (MRT) obtained between both rapidly disintegrating and conventional tablets indicates that the mean absorption time (MAT) from these tablets is approximately 60 and 90 min, respectively. This difference in MAT between the two tablets may be caused by the difference in the sum of the mean dissolution time (MDT) and the mean disintegration time (MDIT) of these tablets. Rapidly disintegrating tablets allow rapid absorption of the drug compared with conventional tablets.

Two novel genes encoding SNF-1 related protein kinases from Arabidopsis thaliana: differential accumulation of AtSR1 and AtSR2 transcripts in response to cytokinins and sugars, and phosphorylation of sucrose synthase by AtSR2

We searched for genes encoding members of the group-3 SNF1-related protein kinase (SnRK3) family in the Arabidopsis thaliana database, and seven independent sequences were identified. Transcripts of two of them were found to accumulate differentially upon treatment with light, cytokinins and sugars. Full-length cDNAs were isolated and designated as AtSR1 and AtSR2; they encode polypeptides of 442 and 429 amino acids with relative molecular masses of 50.3 kDa and 48.2 kDa, respectively. In etiolated seedlings, no transcripts of either gene were observed. However, upon exposure to light or cytokinins, transcripts of AtSR1 but not AtSR2 began to accumulate. The induction with light was greatly reduced in the presence of a cytokinin antagonist, suggesting that cytokinins are involved in light-signaling pathways. In contrast, transcription of AtSR2, but not of AtSR1, was greatly increased by sucrose, as well as glucose and fructose. AtSR2 expressed in E. coli efficiently phosphorylated sucrose synthase in the presence of manganese ions. These results suggest that, although SnRK3 proteins may generally be involved in sugar metabolism, expression of AtSR1 and AtSR2 is differentially and distinctly regulated by various external signals, and AtSR2 may function in the regulation of sucrose synthase by specific phosphorylation.

Effect of intestinal helminthiasis on nutritional status of schoolchildren

This study was conducted in a rural agricultural area in Siniloan, Republic of the Philippines. The subjects were the school children. The nutritional status of 58 children infected with helminthiasis (Ascaris lumbricoides and Trichuris trichiura) was compared with that of 19 uninfected controls. Prevalence of Ascaris and Trichuris was 40.3% and 71.4% respectively, and 36.4% of infected children had both Ascaris and Trichuris infections. Statistically significant evidence of an adverse effect of helminthiasis on serum albumin levels was found, but no child had inadequate levels of other nutrients. Although helminthic infections increase the level of immunoglobulin E (IgE) in children endemically exposed to these parasites, there was no significant difference in the serum IgE among Ascaris or Trichuris infected groups in this study.

Functional role of Ca(2+)-binding site IV of scallop troponin C

Scallop troponin C (TnC) binds only one Ca(2+)/mol and the single Ca(2+)-binding site has been suggested to be site IV on the basis of the primary structure [K. Nishita, H. Tanaka, and T. Ojima (1994) J. Biol. Chem. 269, 3464-3468; T. Ojima, H. Tanaka, and K. Nishita (1994) Arch. Biochem. Biophys. 311, 272-276]. In the present study, the functional role of Ca(2+)-binding site IV of akazara scallop (Chlamys nipponensis akazara) TnC in Ca(2+)-regulation was investigated using a site-directed mutant with an inactivated site IV (TnC-ZEQ), N- and C-terminal half molecule mutants (TnC(N) and TnC(C)), and wild-type TnC (TnC(W)). Equilibrium dialysis using (45)Ca(2+) demonstrated that TnC(W) and TnC(C) bind 0.6-0.8 mol of Ca(2+)/mol, but that TnC-ZEQ and TnC(N) bind virtually no Ca(2+). The UV difference spectra of TnC(W) and TnC(C) showed bands at around 280-290 nm due to the perturbation of Tyr and Trp upon Ca(2+)-binding, while TnC-ZEQ and TnC(N) did not show these bands. In addition, TnC(W) and TnC(C) showed retardation of elution from Sephacryl S-200 upon the addition of 1 mM CaCl(2), unlike TnC-ZEQ and TnC(N). These results indicate that Ca(2+) binds only to site IV and that Ca(2+)-binding causes structural changes in both the whole TnC molecule and the C-terminal half molecule. In addition, TnC(W), TnC-ZEQ, and TnC(C), but not TnC(N), were shown to form soluble complexes with scallop TnI at physiological ionic strength. On the other hand, the Mg-ATPase activity of reconstituted rabbit actomyosin in the presence of scallop tropomyosin was inhibited by scallop TnI and recovered by the addition of an equimolar amount of TnC(W), TnC-ZEQ, or TnC(C), but not TnC(N). These results imply that the site responsible for the association with TnI is located in the C-terminal half domain of TnC. Ternary complex constructed from scallop TnT, TnI, and TnC(W) conferred Ca(2+)-sensitivity to the Mg-ATPase of rabbit actomyosin to the same extent as native troponin, but the TnC(N)-TnT-TnI and TnC-ZEQ-TnT-TnI complexes conferred no Ca(2+)-sensitivity, while the TnC(C)-TnT-TnI complex conferred weak Ca(2+)-sensitivity. Thus, the major functions of scallop TnC, such as Ca(2+)-binding and interaction with TnI, are located in the C-terminal domain, however, the full Ca(2+)-regulatory function requires the presence of the N-terminal domain.

Specific binding of a 14-3-3 protein to autophosphorylated WPK4, an SNF1-related wheat protein kinase, and to WPK4-phosphorylated nitrate reductase

WPK4 is a wheat protein kinase related to the yeast protein kinase SNF1, which plays a role in catabolite repression. To identify proteins involved in signal transduction through WPK4, we performed yeast two-hybrid screens and isolated two cDNA clones designated as TaWIN1 and TaWIN2. Both encode 14-3-3 proteins that, upon autophosphorylation, bind the C-terminal regulatory domain of WPK4. Mutational analysis through amino acid substitution revealed that TaWIN1 and TaWIN2 primarily bind WPK4 through phosphoserines at the positions 388 and 418, both located in the C-terminal region. Mutations in the conserved residues of the TaWIN1 amphipathic groove impaired the ability of TaWIN1 to bind to WPK4. A screen for in vitro phosphorylation of proteins involved in nutrient metabolism revealed a putative WPK4 substrate, nitrate reductase; its hinge 1 region was efficiently phosphorylated by WPK4. Subsequent far Western blots showed that it specifically bound TaWIN1. Since nitrate reductase has been shown to be inactivated by phosphorylation upon 14-3-3 binding, the present findings strongly suggest that WPK4 is the protein kinase responsible for controlling the nitrogen metabolic pathway, assembling the nitrate reductase and 14-3-3 complex through its phosphorylation specificity.

[Effects of low concentration of styrene monomer vapor on pregnancy]

To investigate the effects of exposure to styrene vapor on pregnancy, mice proved to be pregnant were exposed to 0, 2, 20 and 100 ppm styrene continuously for 24 hours during the period from day 0 to day 15 of gestation. A special small exposure chamber which can accurately maintain a constant low concentration of styrene vapor was made and used in the experiment. 1) In the 100 ppm group, hyperkinesis was presented in the chamber during the exposure period and inhibition of body weight gain was found (p < 0.01). No deaths occurred in any of the groups. 2) At necropsy of dams, no significant difference was found between the styrene exposed groups and the control group in any of the fertility indices, number of implantations, number of live fetuses, percentage of resorptions, or in the percentage of dead fetuses. The 100 ppm group showed lower fetal and placental weights (p < 0.01). 3) Gross necropsy of dams in the 100 ppm group showed significantly decreased adipose tissue. The liver, kidney and spleen weights were also low (p < 0.01). 4) When exposed to 100 ppm, which corresponds to 5 times the permissible concentration, i.e., 20 ppm, for 24 hours, non-pregnant dams showed no abnormality, while pregnant dams showed inhibition of body weight gain and significantly lower fetal and placental weights and maternal organ weights. Therefore, careful consideration should be given to exposure of women of childbearing age to styrene.

Cultivation of corneal epithelial cells on intact and denuded human amniotic membrane

PURPOSE

Surgery to reconstruct the ocular surface is greatly facilitated by the use of amniotic membrane, either as a biologic drape or, more recently, as a substrate for the transplantation of cultivated corneal epithelial cells. This study was designed to compare the usefulness of intact and denuded human amniotic membranes as a substrate for corneal epithelial cell culture.

METHODS

Small (3-mm-diameter) biopsy specimens of superficial cornea including epithelium were excised from the central and limbal regions in rabbits. They were cultured on human amniotic membrane with or without amniotic epithelial cells and examined by light, scanning electron, and transmission electron microscopy.

RESULTS

Cellular outgrowth from the central explants (n = 10) after 14 days in culture measured 1.82 +/- 2.62 mm2 on intact amniotic membrane and 131.83 +/- 28.31 mm2 on denuded amniotic membrane. In contrast, outgrowths from the limbal explants (n = 10) at the same time measured 4.58 +/- 4.56 and 505.39 +/- 134.20 mm2 on intact and denuded amniotic membranes, respectively. The leading edges of the outgrowths on intact amniotic membrane were much less uniform than those on denuded amniotic membrane, and, in the former, corneal epithelial cells appeared to migrate over the top of amniotic epithelial cells. Limbal cells cultivated on denuded amniotic membrane formed a nicely stratified layer that adhered well to the underlying amniotic membrane.

CONCLUSIONS

Denuded amniotic membrane appears to be an excellent substrate for the cultivation of corneal epithelial cells, with a view to transplantation.

Epithelial barrier function and ultrastructure of gelatinous drop-like corneal dystrophy

PURPOSE

Recently, mutations in the M1S1 gene have been identified as responsible for gelatinous drop-like corneal dystrophy (GDLD). How the abnormal M1S1 gene product causes GDLD is not known, although evidence suggests that it may compromise corneal epithelial function. This investigation attempted to determine the effect of the abnormal M1S1 gene product by assessing epithelial barrier function and epithelial ultrastructure in GDLD corneas.

METHODS

Epithelial barrier function was assessed on the basis of fluorescein uptake. The method used a modified slit-lamp fluorophotometer. High-resolution scanning electron and atomic force microscopy was used to investigate the amyloid deposits and epithelial cell structure.

RESULTS

Epithelial permeability was orders of magnitude higher in GDLD corneas than normal. The structure of the amyloid deposits was characterized, and clear abnormalities in epithelial morphology and cell junctions were observed.

CONCLUSIONS

The high epithelial permeability observed in GDLD corneas was directly correlated with abnormalities in epithelial structure, including irregular cell junctions. This suggests that the abnormal M1S1 gene product may affect epithelial cell junctions resulting in increased cell permeability in GDLD corneas.

Screening of wound-responsive genes identifies an immediate-early expressed gene encoding a highly charged protein in mechanically wounded tobacco plants

In order to identify genes that are temporally and spatially regulated during wound response, a cDNA population in mechanically wounded tobacco leaves was screened by the fluorescence differential display method. Of 28 clones initially identified to have altered levels of transcripts within 3 h of wounding, eight were characterized. Although each clone showed a unique pattern of transcript accumulation, one distinct clone was further characterized because of its immediate-early response. Its transcripts began to accumulate 10 min after wounding, reached a maximum level within 1 h and disappeared after 2 h. The response, which occurred repeatably and systemically, was observed by the treatment with propionic acid or erythrosin B, indicating that cytosolic acidification could be one of the signals for immediate-early response of this gene. The cDNA encodes a polypeptide of 513 amino acids with a relative molecular mass of 60,952. The putative polypeptide is rich in lysine (K), glutamic acid (E) and aspartic acid (D), which constitute up to 70% of total amino acids, and was therefore designated as KED. The KED polypeptide is composed of a highly hydrophilic N-terminal region and a relatively hydrophobic C-terminal region, suggesting that KED may function through electrostatic interactions with cellular components.

Changes in plasma arginine vasopressin concentration during lactation in rats

BACKGROUND AND PURPOSE

The objectives of the study reported here were to determine whether a change in the plasma arginine vasopressin (AVP) concentration occurred in lactating, compared with non-lactating rats and to examine the involvement of suckling with plasma AVP concentration.

METHODS

Experiments were performed on 86 female Wister Imamichi rats, 12 weeks old at parturition, with fast lactation. On day 13 of lactation, AVP concentration and plasma osmotic pressure were measured in lactating and non-lactating rats.

RESULTS

Plasma AVP concentration was always higher in rats of the lactating groups than in non-lactating controls (1.06 +/- 0.28 pg/ml), and a conspicuous increase in AVP concentration was seen during the postsuckling period (1.70-0.61 pg/ml before vs. 2.56 +/- 1.31 pg/ml after suckling, P < 0.05). Plasma osmotic pressure in lactating rats with 12 pups (296.6 +/- 5.2 mOsmol/kg x H2O) was lower than that in rats of the removed control groups (306.7 +/- 5.7 mOsmol/kg x H2O).

CONCLUSION

On the basis of these results, it appears that "low plasma osmotic pressure-high AVP status" develops in the lactating period, similar to pregnancy, through resetting of the regulatory mechanism of the AVP system. It was concluded that suckling stimulation could release AVP, which could dilute the blood with water resulting in the increase in circulating blood volume.

[An experience with the Ross operation utilizing cryopreserved pulmonary homografts procured by and stored in our homograft valve bank]

Eight patients, 4 males and 4 females ranging in age from 10 to 54 years (mean 27 +/- 13 years) underwent the Ross operation using a cryopreserved pulmonary homograft harvested by and cryopreserved in our institutional "Tissue Bank". Seven patients had a congenital bicuspid aortic valve and 3 patients had had healed infective endocarditis of the aortic valve. Four young female patients wanted to have a baby after operation. The Ross procedure was carried out utilizing aortic root replacement techniques in all patients. All patients survived and are currently in NYHA class 1, but 2 cardiac events occurred in 2 patients during the mean follow-up term of 29 +/- 19 months. The one was the anastomic stenosis between the homograft and distal pulmonary artery treated by balloon dilatation and the other was ventricular tachycardia eventually managed by the insertion of an ICD. Pulmonary autograft valve regurgitation is present in 3 patients, but it is not progressive up to the present time. Pulmonary homograft valves function well in all patients. The Ross operation for adolescents and young adults should become more popular along with more easy availability of homograft valves based upon the establishment of the "Homograft Valve Bank" system in Japan.

Diverse response of rice and maize genes encoding homologs of WPK4, an SNF1-related protein kinase from wheat, to light, nutrients, low temperature and cytokinins

The wheat gene WPK4 encodes a 56-kDa protein kinase that belongs to group 3 of the SNF1-related protein kinase family (SnRK3), and is up-regulated by light and cytokinins and down-regulated by sucrose. In order to determine whether or not this particular regulation pattern is general among plant species, we isolated and characterized homologous genes from rice and maize. Two rice genes, OsPK4 and OsPK7, encode proteins comprising 508 and 520 amino acids, and show, respectively, 75% and 76% sequence similarity to WPK4. OsPK4 and OsPK7 proteins produced in Escherichia coli were able to phosphorylate themselves and myelin basic proteins, the reaction requiring magnesium and/or manganese ions. Transcripts of OsPK4 were detected in all tissues tested, and amounts were increased upon illumination, nutrient deprivation and treatment with cytokinins. In contrast, transcripts of OsPK7 were not found in any tissues except in mature leaves at low levels, and did not accumulate under any of the stress conditions examined. A maize gene, ZmPK4, encodes a protein with 518 amino acids that shows 74% similarity to WPK4. Its transcripts were constitutively expressed in all tissues, regardless of light, nutrient and cytokinin status, but were increased upon exposure to low temperature. These results indicate that, despite the sequence similarity between their products, genes for SnRK3 proteins are differentially regulated in response to environmental stimuli.

Secreted proteins of tobacco cultured BY2 cells: identification of a new member of pathogenesis-related proteins

Cultured cells of tobacco BY2 secrete more than 100 proteins into culture medium. Six major proteins were purified, and partial protein sequences were determined. Five of them were found to be similar to an ascorbic acid oxidase, three peroxidase isozymes and a beta-1,3-exoglucanase, respectively. A cDNA clone encoding the remaining polypeptide, whose amino acid sequence showed no similarity with earlier reported proteins, was isolated. It encoded a putative 27 kDa protein of 242 amino acids with resemblance to WCI-5, a wheat protein induced by benzo(1,2,3)thiadiazole-7-carbothioic acid S-methyl ester (BTH) which activates genes involved in systemic acquired resistance. Transcripts of this clone accumulated upon tobacco mosaic virus infection, mechanical wounding and drought treatment, an induction profile that satisfies the definition of pathogenesis-related (PR) proteins by van Loon et al. (Plant Mol. Biol. Rep. 12 (1994) 245). No similar PR proteins have so far been reported, and therefore our newly designated NtPRp27 points to the existence of a novel PR protein family in tobacco plants.

Amniotic membrane as a substrate for cultivating limbal corneal epithelial cells for autologous transplantation in rabbits

PURPOSE

To examine the viability of using human amniotic membrane as substrate for culturing corneal epithelial cells and transplanting them onto severely injured rabbit eyes.

METHODS

An ocular-surface injury was created in the right eye of eight rabbits by a lamellar keratectomy extending 5 mm outside the limbus. Next, from the limbal region of the uninjured left eyes of five of these animals, a small biopsy of corneal epithelial cells was taken and cultured on acellular human amniotic membrane. One month later, the invading conjunctiva that covered the corneal surface of all eight injured eyes was surgically removed. Five of the eyes then received grafts of amniotic membrane containing autologous cultured epithelial cells, whereas the other three received grafts of acellular amniotic membrane alone.

RESULTS

A confluent primary culture of limbal corneal epithelial cells was established on acellular human amniotic membrane after 14 days. Cells were partially stratified and fairly well attached to the underlying amniotic membrane, although a fully formed basement membrane was not evident. The three rabbits that received amniotic membrane transplantation alone all had total epithelial defects on the graft in the early postoperative period. Eyes that were grafted with amniotic membrane that contained cultivated epithelial cells, however, were all successfully epithelialized up to 5 days after surgery.

CONCLUSION

Autologous transplantation of cultivated corneal epithelium is feasible by using acellular amniotic membrane as a carrier.

Bacillus thuringiensis Cry1Aa toxin-binding region of Bombyx mori aminopeptidase N

The Bacillus thuringiensis Cry1Aa toxin-binding region of Bombyx mori aminopeptidase N (APN) was analyzed, to better understand the molecular mechanism of susceptibility to the toxin and the development of resistance in insects. APN was digested with lysylendopeptidase and the ability of the resulting fragments to bind to Cry1Aa and 1Ac toxins was examined. The binding abilities of the two toxins to these fragments were different. The Cry1Aa toxin bound to the fragment containing 40-Asp to 313-Lys, suggesting that the Cry1Aa toxin-binding site is located in the region between 40-Asp and 313-Lys, while Cry1Ac toxin bound exclusively to mature APN. Next, recombinant APN of various lengths was expressed in Escherichia coli cells and its ability to bind to Cry1Aa toxin was examined. The results localized the Cry1Aa toxin binding to the region between 135-Ile and 198-Pro.

Itai-itai disease is not associated with polymorphisms of the estrogen receptor alpha gene

Itai-itai (or ouch-ouch) disease is a syndrome accompanied by bone mineral disorders, and which may be related to oral cadmium exposure. Itai-itai predominantly affects postmenopausal women with a history of multiple childbirths. Recently, it has been reported that polymorphisms of the estrogen receptor alpha (ERalpha) gene are associated with postmenopausal reduction of bone mineral density in Japanese women. However, estrogen receptors have never been studied in itai-itai disease. In this study, we examined the genotypic distributions of PvuII and XbaI restriction fragment length polymorphisms (RFLPs) of the ERalpha gene in patients with itai-itai disease and compared them with those of control subjects. The RFLPs are represented here as Pp (PvuII) and Xx (XbaI); the capital and small letters signify the absence and presence of restriction sites, respectively. The genotypic distributions of the patient group were: PP, 14.8%; Pp, 55.6%; pp, 29.6%; XX, 7.4%; Xx, 29.6%; and xx, 63.0%. These distributions were similar to those observed for the control groups, hence no pattern of genotypic distribution was observed that could be related to itai-itai disease. We conclude that RFLPs of the ERalpha gene may not be associated with itai-itai disease.

Sucrose and Cytokinin Modulation of WPK4, a Gene Encoding a SNF1-Related Protein Kinase from Wheat

WPK4, a gene encoding a putative protein kinase, was initially identified in wheat (Triticum aestivum) and shown to be up-regulated by light, nutrient deprivation, and cytokinins. To confirm that WPK4 has protein kinase activity, the protein was produced in Escherichia coli as a fusion protein with glutathione S-transferase. The purified protein exhibited autophosphorylation activity and phosphorylated both myelin basic protein and a peptide fragment of rice 3-hydroxy-3-methylglutaryl-coenzyme A reductase. Levels of WPK4 transcripts in wheat seedlings were increased and decreased by the removal and addition of sucrose (Suc), respectively, to the culture medium. The introduction of the N-terminal kinase region of WPK4 into the yeast snf1 mutant cells, which cannot utilize Suc as a carbon source, rescued growth in Suc-containing medium. Cytokinins up-regulated the accumulation of WPK4 transcripts, but their effects were cancelled by the addition of Suc. Our results suggest that Suc negatively regulates the signaling pathway in which transcriptional activation of WPK4 is mediated by cytokinins.