Refolding process of ovalbumin from urea-denatured state. Evidence for the involvement of nonproductive side chain interactions in an early intermediate

Ovalbumin contains one cystine disulfide (Cys73-Cys120) and four cysteine sulfhydryls (Cys11, Cys30, Cys367, and Cys382) in a single polypeptide chain of 385 amino acid residues. The refolding mechanism of ovalbumin was investigated under disulfide-bonded and disulfide-reduced conditions using the denatured protein state, DA, as the starting protein sample. For the preparation of DA, the disulfide-intact and disulfide-reduced forms of ovalbumin were denatured by protein incubation in 9 M urea at pH 2.2. When DA was placed in a refolding buffer, pH 8.2, an intermediate state IN was produced in either the disulfide-bonded or the disulfide-reduced condition; IN showed about 60% of the native CD ellipticity at 222 nm and the intrinsic tryptophan fluorescence with the native spectrum peak but with decreased intensity. The formation of IN as detected by far UV CD ellipticity was quite rapid and finished within a mixing dead time of 20 ms. When DA was diluted with an acidic buffer, pH 2.2, a partially folded equilibrium intermediate IA with the structural characteristics equivalent to those of IN was formed. After the formations of IN and IA, the regains in CD ellipticity and tryptophan fluorescence at pH 8.2 followed biphasic kinetics in the disulfide-bonded condition but monophasic kinetics in the disulfide-reduced condition. As unexpected findings, the native disulfide in DA and IA underwent nonproductive disulfide rearrangements in the disulfide-bonded condition at an early refolding stage and then was recovered during the subsequent refolding. The integrity of overall refolding was confirmed by the observation that the proteins refolded for 20 h in the disulfide-bonded and disulfide-reduced conditions showed, on differential scanning calorimetry analyses, almost exactly the same denaturation temperatures as their native protein counterparts. These results were consistent with a refolding process for ovalbumin which includes nonproductive side chain-side chain interactions in the early intermediate IN, which requires subsequent reorganization for the correct refolding.

Mouse and human SHPS-1: molecular cloning of cDNAs and chromosomal localization of genes

SHPS-1 (SHP substrate-1) is a glycosylated receptor-like protein with three immunoglobulin-like domains in its extracellular region and four YXX(L/V/I) motifs, potential tyrosine phosphorylation and SRC homology 2 (SH2) domain binding sites, in its cytoplasmic region. Various mitogens and cell adhesion induce tyrosine phosphorylation of SHPS-1 and its subsequent association with SHP-2, and SH2 domain-containing protein tyrosine phosphatase, suggesting that SHPS-1 plays a role in cell signaling in response to both growth factors and cell adhesion. The mouse and human cDNAs encoding SHPS-1 have now been isolated. The deduced amino acid sequences of rat, human, and mouse SHPS-1 show identities of 65 to 81%. In addition to the SH2 domain binding sites, a proline-rich putative SH3 domain binding site was detected in the cytoplasmic region of SHPS-1. Northern blot analysis revealed that human SHPS-1 mRNA is most abundant in brain and that the mouse mRNA is present in embryos as early as day 7. Fluorescence in situ hybridization localized the SHPS-1 gene to human chromosome 20p13 and the F3 band of mouse chromosome 2. Furthermore, interspecific backcross analysis placed the mouse SHPS-1 locus 5.0 centimorgans distal and 1.4 centimorgans proximal to the microsatellite markers D2Mit63 and D2Mit19, respectively, in a region associated with the mutations coloboma (Cm), lethal milk (lm), and well-haarig (we).

Drug conjugate of doxorubicin with glutathione is a potent reverser of multidrug resistance in rat hepatoma cells

A recent study has suggested that degraded adducts smaller than 2 kDa in molecular weight of bovine serum albumin (BSA)-conjugated doxorubicin (DXR) (BSA-DXR) might exhibit cytotoxicity against multidrug resistant (MDR) cells. To investigate this notion further, intracellular accumulation and cytotoxicity of DXR coupled to several small peptides, such as glycylglycine (diGly), glycylglycylglycine (triGly), reduced glutathione (GSH) and oxidized glutathione (GSSG), were investigated using DXR-sensitive (AH66P) and DXR-resistant (AH66DR) rat hepatoma cell lines. Against both AH66P and AH66DR cells, diGly-conjugated DXR (diGly-DXR) and triGly-conjugated DXR (triGly-DXR) demonstrated the same cytotoxic activity as DXR, and the accumulation of both conjugates in the two cell lines was almost similar to that of DXR. After treatment of AH66DR cells with 5 microM verapamil [an inhibitor of P-glycoprotein (Pgp)], the intracellular levels of diGly-DXR and triGly-DXR were markedly increased and consequent cytotoxicity was improved. On the other hand, GSH-conjugated DXR (GSH-DXR) showed 9- and 7.5-fold more cytotoxic activity than BSA-DXR against AH66P and AH66DR cells, respectively. GSH-DXR accumulated rapidly in AH66DR cells, probably by the same mechanism as in AH66P cells, because the treatment of AH66DR cells with verapamil did not cause a significant increase in the intracellular drug level as compared with that in cells treated without verapamil. The levels of cytotoxicity and accumulation of GSSG-DXR were the same as those of BSA-DXR for both cell lines. These results indicate that GSH-DXR exerts potent cytotoxicity against both cell lines among the peptide DXR conjugates examined because of the rapid uptake and high accumulation of GSH-DXR similar to that of DXR without efflux.

Lack of vacuolar proton ATPase association with the cytoskeleton in osteoclasts of osteosclerotic (oc/oc) mice

We examined the pathogenetic mechanism underlying the lack of bone resorption in osteosclerotic oc/oc mice. An immunoelectron microscopic analysis revealed that in the osteoclasts of these mice, no ruffled borders formed, and that vacuolar H+-ATPase (V-ATPase) was present throughout the cytoplasm but not on the apical membranes. The activity of V-ATPase in oc/oc mice was similar to that in normal mice. In normal spleen cell-derived osteoclast-like cells (OCLs), immunoreactivity for V-ATPase was detected in association with Triton X-100-insoluble cellular structure, but not in oc/oc spleen cell-derived OCLs. Moreover, in renal proximal convoluted tubules of oc/oc mice, the basal striation did not form. These results suggest that osteosclerosis in oc/oc mice is possibly due to the dissociation of V-ATPase and cytoskeleton in osteoclasts.

[Experimental study on the pathogenesis of mitral annular calcification: calcium deposits in mitral complex lesions induced by vagal stimulation in rabbits]

Cervical vagal stimulation in rabbits frequently causes peculiar mitral complex lesions which are detected by deposition of colloidal carbon. The present study examined the effects of vagal stimulation on the calcium (Ca) contents in the mitral complex lesions. Anesthetized rabbits were forced into the supine position with electrocardiographic monitoring. The animals were divided into those with vagal stimulation (n = 37), and those without manipulation as controls (n = 25). Colloidal carbon (1 ml) was intravenously injected into the animals on the next day. All animals were sacrificed after 1 week. After perfusion of the heart by heparinized saline, Ca content per g myocardium in the mitral annulus, papillary muscle, free wall or apex in the left ventricle was measured by the atomic absorption method. Immediately after vagal stimulation, bigeminy due to premature ventricular contractions was observed in 76%, and systolic murmur was heard in 30%. Mitral complex lesions detected by carbon deposits were found in 73% of the rabbits with vagal stimulation. Ca content in the mitral annulus or papillary muscle was significantly greater than that in the free wall or apex (p < 0.001). Ca content in the mitral annulus was significantly greater in the rabbits with vagal stimulation than in the control group (p < 0.001). In the former group, Ca content in the mitral annulus in animals with mitral complex lesions was significantly greater than that in those without mitral complex lesions (p < 0.01). These results suggest that these mitral complex lesions might provide an experimental model of mitral annular calcification, and that the autonomic nervous system and arrhythmia might be involved in the mechanism of this calcification.

[Intracellular distribution of bovine serum albumin-conjugated doxorubicin and multidrug resistance]

The intracellular distribution of bovine serum albumin (BSA)-conjugated [14C] doxorubicin (DXR) was investigated in a rat hepatoma cell line (AH66P) and its anthracycline resistant subline (AH66DR). After the conjugate had been taken up into the cells by endocytosis and degraded in the lysomes, active adducts with a molecular mass of approximately 2 kDa were distributed to target organellae such as nuclei and mitochondria. Drug accumulation in the nuclear fraction was lower in AH66DR cells than in AH66P cells, but the level of drug radioactivity in the DNA fraction, which was extracted from the same nuclear fraction, was higher in the AH66DR cells than in AH66P cells. It is presumed from these results that the intercalated level of the drug into DNA was sufficient to exhibit cytotoxicity against AH66DR cells as well as AH66P cells. A part of the active adducts was effluxed from AH66DR cells by P glycoprotein (Pgp) in the same manner as DXR because the efflux of the adducts was suppressed by verapamil, an inhibitor of Pgp. The IC50 values of BSA DXR conjugate was decreased from 120 nM to 2 nM for AH66DR cells and from 3 nM to 0.6 nM for AH66P cells by the co-treatment with 5/M verapamil, respectively.

[Motor paresis with cheiro-oral topography due to small infarct in the internal capsule or the corona radiata]

We reported five patients having presented only with clumsy hand and dysarthria which resulted from motor paresis confined to one side of the fingers and the ipsilateral face and tongue. All of them were right-handed, and their manifestation was transient. They had no abnormalities of muscle tonus and sensation, and no ataxia. The features of these cases differed from those of the dysarthria-clumsy hand syndrome because of absence of ataxia, and could be distinguished from pure motor hemiplegia by a motor paresis with cheiro-oral topography. MRI examinations showed a localized lesion at the border between internal capsule and corona radiata (two cases), or in the corona radiata just over this region (three cases). In the former cases in which the internal capsule was involved, we confirmed the lesion in the genu and anterior half of the posterior limb of the internal capsule. The lesion was on the left side in all five patients. It has been known that the pyramidal tract consists of the large and small fibers. The large ones are localized in the posterior part of the posterior limb of the internal capsule, and the damage of them produces sustained and serious motor paralysis. The small ones are widely distributed in the genu and the posterior limb of the internal capsule. The findings of our study suggest that the small fibers have adjacent somatotopy for the hand and mouth in the region of the genu and the anterior part of the posterior limb of the internal capsule, and that the damage of them may lead to mild, transient motor paresis without spasticity.

Frontal midline theta rhythm in young healthy adults

In this study, we examined the relationship between the frontal midline (Fm) theta rhythm that appears when a healthy subject is engaged in mental tasks and the theta rhythm which appears in the frontal region of healthy subjects during light drowsiness. The samples for this study were obtained from 465 EEGs of healthy Japan Air Self Defense Force personnel. The 39 who had frontal theta rhythm during light drowsiness were selected to be included in the theta group. For the control group, 34 subjects were randomly selected from the remaining 426 without frontal theta rhythm. When these subjects were reexamined, the rate of appearance of the frontal midline theta rhythm which appears during light drowsiness was 87.2% in the theta group and 0% in the control group. The rate of appearance of the Fm theta was 94.9% in the theta group and 3.0% in the control group. The two types of frontal theta rhythms closely resembled each other in frequency (94.6%) and distribution (83.8%). Except for the results of the hypomania (Ma) scores, there was no remarkable difference between the two groups when the MMPI was administered. The results of our study suggest that there is a close correlation between the frontal theta rhythm that appears during light drowsiness and the Fm theta.

A recurring translocation, t(3;6)(q27;p21), in non-Hodgkin's lymphoma results in replacement of the 5' regulatory region of BCL6 with a novel H4 histone gene

3q27 translocations affecting the BCL6 gene can involve not only immunoglobulin genes (IG) but also other as yet uncharacterized chromosomal loci as partners. Here, we describe cloning of the junctional area of a recurring translocation, t(3;6)(q27;p21), in non-Hodgkin's lymphoma of B-cell type and isolation of clones from 6p21; high resolution fluorescence in situ hybridization mapped the clones to sub-band 6p21.3. Nucleotide sequence analysis of a fragment from the junctional area of 6p21 revealed the presence of a novel H4 histone gene that was included in the histone gene cluster on this particular region, and the same fragment detected approximately 380-bp transcripts in hematological tumor cells. Breakpoints on 3q27 of two cases carrying t(3;6) were immediately 3' of the BCL6 exon 1, and the H4 histone gene was substituted for the 5' regulatory elements of BCL6. Because H4 gene expression is tightly coupled to DNA replication, this study suggested an immediate mechanism for deregulated expression of BCL6, leading to the development of non-Hodgkin's lymphoma.

Replacement of a single-channel with a multichannel cochlear implant as an upgrade

The removal of a functioning cochlear implant in order to upgrade to a more advanced device is a critical issue to many otologists, since we currently have no means to predict the results preoperatively. This paper reports on two patients who successfully upgraded from a single-channel to a multichannel implant. The new implants outperformed the original devices in both the live-voice test and the videotaped test. The patients stated that the hearing quality afforded by the multichannel implant was much better than that provided by the original implant.

Glutathione-doxorubicin conjugate expresses potent cytotoxicity by suppression of glutathione S-transferase activity: comparison between doxorubicin-sensitive and -resistant rat hepatoma cells

The cytotoxic mechanism of a conjugate of doxorubicin (DXR) and glutathione (GSH) via glutaraldehyde (GSH-DXR) was investigated using DXR-sensitive (AH66P) and -resistant (AH66DR) rat hepatoma cells. GSH-DXR accumulated in AH66DR cells as well as in AH66P cells without efflux by P-gp and exhibited the potent cytocidal activity against both cells compared with DXR. To examine whether thiol from GSH-DXR affected the expression of cytotoxicity, two conjugates of DXR, with modified peptides containing alanine or serine substituted for cysteine in GSH were prepared and their cytotoxicities determined. Substitution of these amino acids for cysteine resulted in an approximately two- to fourfold reduction in cytotoxic activity against both cell lines compared with the effect of GSH-DXR. Depletion of intracellular GSH by treatment of both cells with buthionine sulphoximine did not change the cytotoxic activity of DXR, BSA-DXR or GSH-DXR. By co-treating the cells with tributyltin acetate, an inhibitor of glutathione S-transferase (GST), and either DXR, BSA-DXR or GSH-DXR, the cytotoxicity was markedly increased. Interestingly, GSH-DXR showed non-competitive inhibition of GST activity and its IC50 value was 1.3 microM. These results suggested that the inhibition of GST activity by GSH-DXR must be an important contribution to the expression of potent cytotoxicity of the drug.

In vivo anti-tumour effect of 3'-sulphonoquinovosyl 1'-monoacylglyceride isolated from sea urchin (Strongylocentrotus intermedius) intestine

Extracts from sea urchin intestine were screened for new anti-tumour drugs. Four glycolipids, 3'-sulphonoquinovosyl-1', 2'-diacylglyceride (A-4), 3'-sulphonoquinovosyl-1'-monoacylglyceride (2'-lyso A-4, A-5), NeuGc(alpha)2-6Glc(beta)1-1ceramide (A-6) and HSO3-8NeuGc(alpha)2-6Glc(beta)1-1ceramide (A-7), were isolated from the intestine of sea urchin, Strongylocentrotus intermedius, and characterized by means of proton nuclear magnetic resonance spectroscopy and fast atom bombardment mass spectrometry. When tested for cytotoxic activity against tumour cells in vitro, A-5 showed significant activity, but A-4, -6 and -7 did not. In addition, the hydrophilic derivatives of A-4 or -5 had no cytotoxicity. Furthermore, the anti-tumour effects on nude mice bearing solid tumours of a human lung adenocarcinoma cell line A-549 were evaluated in vivo using A-4 and -5. As a result, A-5 was found to be significantly effective in suppressing the growth of solid tumours, whereas A-4 had no effect. Pathologically, the solid tumours showed haemorrhagic necrosis areas after treatment with A-5. In this study, we have demonstrated the anti-tumour effect of sulphonoquinovosyl-lysoglyceride (A-5), which provides important information that this sulpholipid could be a useful drug for cancer chemotherapy.

Assignment of rat thromboxane synthase gene (Tbxas) to chromosome 4q21-->q22 by fluorescence in situ hybridization

Thromboxane A2 plays physiological and pathophysiological roles in many tissues. We isolated a cDNA for rat thromboxane synthase from the kidney and here show the location of rat thromboxane synthase gene (Tbxas) on rat chromosome 4q21-->q22 by fluorescence in situ hybridization to metaphase chromatin of rat lymphocytes.

An N-linked high-mannose type oligosaccharide, expressed at the major outer membrane protein of Chlamydia trachomatis, mediates attachment and infectivity of the microorganism to HeLa cells

The structure of the carbohydrate of the 40-kD major outer membrane component of Chlamydia trachomatis and its role in defining infectivity of the organism were investigated. The oligosaccharides were released from the glycoprotein by N-glycanase digestion, coupled to a 2-aminopyridyl residue, and subjected to two-dimensional sugar mapping technique. The major fractions consisted of "high-mannose type" oligosaccharides containing 8-9 mannose residues. Bi- and tri-antennary "complex type" oligosaccharides having terminal galactose were detected as minor components. These oligosaccharides were N-linked and contained no sialic acid. This structural profile is consistent with our previous characterization based on lectin-binding and glycosidase digestion. Functional specificity of identified chlamydial oligosaccharides was analyzed using glycopeptides fractionated from ovalbumin and structurally defined oligosaccharides from other sources. The glycopeptide fraction having high-mannose type oligosaccharide, as compared to those having complex or hybrid-type, showed a stronger inhibitory effect on attachment and infectivity of chlamydial organisms to HeLa cells. Among high-mannose type oligosaccharides, the strongest inhibition was observed with mannose 8 as compared with mannose 6, 7, or 9. These results indicate that a specific high-mannose type oligosaccharide linked to the major outer membrane protein of C. trachomatis mediates attachment and infectivity of the organism to HeLa cells.

TNF receptor p55 plays a major role in centrally mediated increases of serum IL-6 and corticosterone after intracerebroventricular injection of TNF

The aim of this work was to study the relative role of the two TNF receptors (p55 and p75) in the central actions of TNF, studying the elevation of serum corticosterone (CS) and IL-6 levels after injection of recombinant murine (rm)TNF (intracerebroventricularly (i.c.v.)) in normal or p55-deficient (p55 -/-) mice. rmTNF induced high serum IL-6 levels and doubled serum CS in normal mice, whereas no elevation of serum IL-6 or CS was induced in p55 -/- mice. However, a normal CS response was observed in p55 -/- mice after LPS (2.5 microg, i.c.v.). p55 -/- mice also responded, although to a lesser extent than p55 +/+, in terms of LPS-induced IL-6 production. We also injected two agonist Abs specific for the two receptors, alpha p55 and alpha p75. While alpha p55 injected i.c.v. induced a marked elevation in CS and IL-6, alpha p75 induced CS (although less than alpha p55) but no IL-6. rmTNF, which binds both receptors, was more potent in inducing IL-6 and CS than injection of rhTNF, which in mice binds only p55. Finally, we investigated the role of p55 and p75 in IL-6 induction by TNF in a murine brain endothelioma. The results resembled closely those obtained in vivo: rmTNF was more potent than rhTNF and only alpha p55, and not alpha p75, induced IL-6 production. These data indicate that p55 plays a major role in TNF activation of the hypothalamus-pituitary-adrenal axis and in the centrally mediated induction of peripheral IL-6 by TNF, but p75, despite having little IL-6 inductive properties by itself, seems to potentiate p55 induction of IL-6.

TNF receptor p55 plays a major role in centrally mediated increases of serum IL-6 and corticosterone after intracerebroventricular injection of TNF

The aim of this work was to study the relative role of the two TNF receptors (p55 and p75) in the central actions of TNF, studying the elevation of serum corticosterone (CS) and IL-6 levels after injection of recombinant murine (rm)TNF (intracerebroventricularly (i.c.v.)) in normal or p55-deficient (p55 -/-) mice. rmTNF induced high serum IL-6 levels and doubled serum CS in normal mice, whereas no elevation of serum IL-6 or CS was induced in p55 -/- mice. However, a normal CS response was observed in p55 -/- mice after LPS (2.5 microg, i.c.v.). p55 -/- mice also responded, although to a lesser extent than p55 +/+, in terms of LPS-induced IL-6 production. We also injected two agonist Abs specific for the two receptors, alpha p55 and alpha p75. While alpha p55 injected i.c.v. induced a marked elevation in CS and IL-6, alpha p75 induced CS (although less than alpha p55) but no IL-6. rmTNF, which binds both receptors, was more potent in inducing IL-6 and CS than injection of rhTNF, which in mice binds only p55. Finally, we investigated the role of p55 and p75 in IL-6 induction by TNF in a murine brain endothelioma. The results resembled closely those obtained in vivo: rmTNF was more potent than rhTNF and only alpha p55, and not alpha p75, induced IL-6 production. These data indicate that p55 plays a major role in TNF activation of the hypothalamus-pituitary-adrenal axis and in the centrally mediated induction of peripheral IL-6 by TNF, but p75, despite having little IL-6 inductive properties by itself, seems to potentiate p55 induction of IL-6.

Molecular and functional heterogeneity of inward rectifier potassium channels in brain and heart

We have cloned cDNAs encoding three background inward rectifier potassium channels from a mouse brain cDNA library. We designated them mouse brain (MB)- IRK1, MB-IRK2, and MB-IRK3, based on their amino acid sequences and the electrophysiological properties of currents expressed in Xenopus oocytes. Xenopus oocytes injected with cRNAs derived from these clones expressed K+ currents that showed classical inward rectifier potassium channel characteristics at whole cell current level and that were blocked by Ba2+ and Ca+ in a concentration- and voltage- dependent manner. The single channel recordings revealed, however, that the unitary conductance of MB-IRKI was approximately 22pS; MB-IRK2, approximately 34pS; and MB-IRK3, approximately 12pS. By Northern blot analysis, MB-IRKI was more predominantly expressed in forebrain than in cerebellum, and vice versa in the case MB-IRK2. MB-IRK3 was expressed specifically in forebrain. On the other hand, MB-IRK1 and MB-IRK2, but not MB-IRK3, were expressed in heart. These results indicate the heterogeneity of the molecular structure and functional role of the two transmembrane region type of background inward rectifier potassium channels in brain and heart.

Multiple interactions of IgG with its core oligosaccharide can modulate recognition by complement and human Fc gamma receptor I and influence the synthesis of its oligosaccharide chains

Glycosylation at Asn297 within the CH2 domains of IgG is important for recognition by the effector ligands Fc gammaR and C. Protein engineering has been used to replace amino acid residues within the extensive oligosaccharide interaction site that contact the core hexasaccharide (GlcNAc2Man3GlcNAc). Replacement of residues Phe241, Val264, or Asp265, in particular, results in reduced recognition of human chimeric anti-nitroiodophenacetyl IgG3 produced in Chinese hamster ovary cells, by guinea pig C and human C1q. Replacement of residues Val264 or Asp265, in particular, results in reduced superoxide production triggered through human Fc gammaRI expressed on U937 cells. These results suggest that noncovalent interactions of multiple amino acid residues of IgG with oligosaccharide residues that include the primary and secondary GlcNAc are necessary for optimal recognition of IgG by human Fc gammaRI and C1q. Replacement of residues 241, 243, 264, 265, or 301 with alanine in each case resulted in increased galactosylation and sialylation relative to the wild-type oligosaccharide chains. In particular, for the mutant FA243 there was much increased sialylation of its oligosaccharide chains (73%) relative to the wild-type (4%). Thus, even single residue replacements within the oligosaccharide interaction site of the C region can influence galactosylation and sialylation of its oligosaccharide chains. These data suggest a protein engineering route to the production of more homogeneously glycosylated IgG molecules with or without compromised biologic activities.

Chemical and physical properties of the extracellular matrix are required for the actin ring formation in osteoclasts

To examine the effect of extracellular matrix on osteoclast polarization, we focused on the actin organization in osteoclasts, using murine osteoclast-like multinucleated cells (OCLs) formed in cocultures of osteoblastic cells and bone marrow cells. When OCLs were cultured on either a plastic plate, calcified dentine, or calcium phosphate thin films in the presence of fetal bovine serum (FBS), they similarly formed ringed structures of F-actin dots (actin rings). However, OCLs placed on demineralized dentine or type I collagen gel matrix (collagen gel) failed to form actin rings. In the absence of FBS, actin ring formation in OCLs was induced on plastic plates coated with vitronectin, fibronectin, or type I collagen, but not on those coated with laminin, poly-L-lysine, or bovine serum albumin. Actin ring formation appeared to depend on integrins, since the GRGDS, but not the GRGES, peptide inhibited it in a dose-dependent manner. Moreover, immunoelectron microscopic examination revealed that vacuolar proton ATPase (V-ATPase) was localized along the apical membrane in much higher densities than the basolateral membrane in OCLs placed on plastic coverslips. In OCLs placed on collagen gel, however, V-ATPase was found to be distributed throughout the cytoplasm without polarity. These results suggest that actin ring formation in osteoclasts was dependent on matrix substrates, matrix proteins and integrins, and was closely related to osteoclast function.

A novel membrane glycoprotein, SHPS-1, that binds the SH2-domain-containing protein tyrosine phosphatase SHP-2 in response to mitogens and cell adhesion

Protein tyrosine phosphatases (PTPases), such as SHP-1 and SHP-2, that contain Src homology 2 (SH2) domains play important roles in growth factor and cytokine signal transduction pathways. A protein of approximately 115 to 120 kDa that interacts with SHP-1 and SHP-2 was purified from v-src-transformed rat fibroblasts (SR-3Y1 cells), and the corresponding cDNA was cloned. The predicted amino acid sequence of the encoded protein, termed SHPS-1 (SHP substrate 1), suggests that it is a glycosylated receptor-like protein with three immunoglobulin-like domains in its extracellular region and four YXX(L/V/I) motifs, potential tyrosine phosphorylation and SH2-domain binding sites, in its cytoplasmic region. Various mitogens, including serum, insulin, and lysophosphatidic acid, or cell adhesion induced tyrosine phosphorylation of SHPS-1 and its subsequent association with SHP-2 in cultured cells. Thus, SHPS-1 may be a direct substrate for both tyrosine kinases, such as the insulin receptor kinase or Src, and a specific docking protein for SH2-domain-containing PTPases. In addition, we suggest that SHPS-1 may be a potential substrate for SHP-2 and may function in both growth factor- and cell adhesion-induced cell signaling.

[Clinical effects of beni-koji in mild essential hypertension--a multi-center double-blind comparison with placebo]

Antihypertensive effects of beni-koji were studied using 29 outpatients with mild hypertension in a placebo-controlled double-blind comparative fashion. After a 4-week vehicle (apple juice) run-in period, 13 patients were assigned to receive beni-koji aqueous extracts containing juice once daily (27 g of beni-koji eq. per day) for 8 weeks and 16 were assigned to vehicle. Two patients assigned to the vehicle group did not complete the study. In addition to casual blood pressure, 24-hr non-invasive ambulatory blood pressure (ABP) was monitored in 6 patients given the beni-koji drink and 5 patients given the vehicle. 1) In the beni-koji group, both casual systolic and diastolic pressure decreased significantly during the treatment period (from 150 +/- 10/96 +/- 6 mmHg to 140 +/- 10/89 +/- 10 mmHg, p < 0.01). The averages of the 24-hr blood pressure recorded in ABP (24-BP) also significantly decreased (from 141 +/- 17/95 +/- 13 mmHg to 132 +/- 21/86 +/- 10 mmHg, p < 0.05) when compared with those of the control period. Casual pressure normalized (less than 140/90 mmHg) in 4 patients who received beni-koji. Circadian variation of the blood pressure by ABP showed a significant decrease during the daytime. 2) In the vehicle group, casual systolic pressure did not change significantly (from 155 +/- 8 mmHg to 151 +/- 12 mmHg), but diastolic pressure decreased significantly (98 +/- 7 mmHg to 93 +/- 6 mmHg). Casual blood pressure did not normalize in any of the patients and 24-BP did not change significantly. 3) Summative evaluation of safety showed that no problems appeared in the beni-koji group. In conclusion, beni-koji appears to be an effective and safe food material for mild essential hypertension. The mechanism of the antihypertensive effect of beni-koji still remains to be investigated.