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M Muguruma

Publications and source records attributed to M Muguruma.

At least 19 recordsLinked to original sources
PubMed1999

Isolation of the novel cDNA of a gene of which expression is induced by a demethylating stimulus.

We have isolated a novel cDNA clone, named AZ2, from a cDNA library of mRNA prepared from C3H10T1/2 cells that had been transiently exposed to 5-azacytidine, a potent inhibitor of DNA methyltransferase. The elucidated nucleotide sequence revealed that the 5' region of the cDNA was rich in the CpG sequence. The AZ2 cDNA contained a 1215-nucleotide open reading frame, and the expected amino acid sequence had a molecular mass of 46090. The amount of the transcript increased on 5-azacytidine treatment of C3H10T1/2 cells, and the transcript was significantly expressed in mouse testis, brain, lung, kidney, heart and ovary. Specific antibodies raised against a fusion protein including glutathione S-transferase revealed a band of an approximately 48kDa translation product for testis, brain, lung, and cultured cells that ectopically expressed the AZ2 protein. The AZ2 protein was mainly localized in the cytoplasm. The amino-terminal part of the AZ2 protein was homologous to the previously reported TANK (Cheng and Baltimore, 1996. Genes Dev. 10, 963-973) and I-TRAF (Rothe, 1996. Proc. Natl. Acad. Sci. USA 93, 8241-8246), which participate in the signal transduction cascade from the tumor necrosis factor-receptor to the transcription factor, NFkappaB. Overexpression of AZ2 inhibited TNF alpha mediated NFkappaB activation. AZ2 could be a component of a regulator of the NFkappaB activation cascade.

Amino Acid Sequence↗
PubMed1995

Organization of the functional domains in membrane cytoskeletal protein talin.

Talin, a putative homodimer of 230-kDa polypeptides, was cleaved into the N-terminal 47-kDa and C-terminal 190-kDa fragments with calpain II. The 190-kDa fragment, but not the 47-kDa fragment, was found to bind to actin. The 190-kDa fragment possessed similar levels of activities to stimulate both polymerization of G-actin and alpha-actinin-dependent gelation of F-actin as did intact talin. Limited digestions of the 190-kDa fragment with chymotrypsin and papain resulted in partial and complete reductions, respectively, of both activities, although these digests contained 95- and 46-kDa major polypeptides, respectively, which were able to bind to actin. Whereas the 190-kDa fragment generated fully cross-linked oligomeric polypeptides on treatment with 1-ethyl-3[3-(dimethylamino)-propyl]carbodiimide, the 95-kDa chymotryptic polypeptide generated heterologous polypeptides cross-linked partially with smaller polypeptides. The papain digest did not contain any cross-linkable polypeptide. Intact talin and the 47-kDa calpain fragment, but not the 190-kDa calpain fragment, were found to bind to phospholipid vesicles containing phosphatidylserine. These results indicate that the N-terminal and C-terminal domains play distinct roles in interacting with the membrane and cytoskeletal elements, respectively, and that the dimeric structure is also required for the latter interactions.

Actins↗
PubMed1994

Hepatic neoexpression and increased plasma levels of Lewis Y, a carbohydrate antigen, in chronic inflammatory liver diseases.

The clinicopathologic relevance of the hepatic expression of Lewis Y (Le(y)), a carbohydrate antigen, and its plasma levels was studied in benign and malignant liver diseases. Tissue and plasma antigens, respectively, were determined with an avidin-biotin-peroxidase complex method and a radioimmunoassay using monoclonal antibody AH6. Normal liver cells and bile ductules did not express Le(y). In the inflammatory tissues, the liver cells and proliferated bile ductules expressed Le(y). The strongest expression by the liver cells was observed in chronic active hepatitis with severe activity and that by the ductules in liver cirrhosis. Only 1 of 16 hepatocellular carcinomas expressed Le(y). The plasma levels of Le(y) increased significantly but nonspecifically in chronic persistent hepatitis, chronic active hepatitis, liver cirrhosis, and hepatocellular carcinomas. It was concluded that (1) Le(y) is an inflammation-associated but not a cancer-associated antigen; (2) the more the tissue damage advances, the more the antigen is expressed; and (3) hepatic and plasma Le(y) are, however, nonspecific markers of necroinflammatory liver diseases.

Adolescent↗
PubMed1992

Comparative studies on the extractability of collagen from aortas of stroke-prone spontaneously hypertensive and normotensive rats.

The molecular states of collagen in the aortas of age-matched stroke-prone spontaneously hypertensive (SHRSP) and normotensive Wistar Kyoto rats (WKY) were studied by analyzing its extractability under defined conditions. The monomeric and oligomeric collagen extractable with 0.5 M acetic acid/6 M urea from aortic homogenates of 9-month-old SHRSP and WKY comprised approx. 0.6 and 2.0%, respectively, of the total collagen. On incubation of the acetic acid/urea-extracted residues with pepsin at 4 degrees C, the levels of the collagen alpha 1(I) and alpha 2(I) chains solubilized from the SHRSP residues were both less than 50% of those from the WKY residues. When the residues were incubated with pepsin at 15 or 25 degrees C, the differences became smaller. When the acetic acid/urea residues were hydrolyzed with cyanogen bromide, nearly identical peptide maps were obtained for SHRSP and WKY. The aortas from 2-month-old SHRSP and WKY contained much larger proportions of acid/urea-extractable collagen than those of the older rats (8.2 and 13% of the respective total collagen). The levels of the alpha 1(I) and alpha 2(I) chains solubilizable from the respective residues by pepsin at 4 degrees C were similar to each other. These results indicate that aortic collagen fibrils in SHRSP are stiffened more prominently than those in WKY.

Aging↗
PubMed1992

Augmentation of alpha-actinin-induced gelation of actin by talin.

Interactions among the three major constituents of focal adhesions, talin, actin, and alpha-actinin, were studied. No evidence was obtained for the direct interaction between talin and alpha-actinin. Both talin and alpha-actinin increased the rate and extent of polymerization of actin, and their effects were additive. Whereas talin alone exhibited very little actin-gelating activity, it potentiated markedly the gelation in the presence of alpha-actinin and lowered the concentration of alpha-actinin necessary for the gel formation. Its gelation-potentiating activity on prepolymerized actin was much smaller than observed on G-actin. Treatment of talin with a cross-linking reagent, 1-ethyl-3[3-(dimethylamino)propyl]carbodiimide or dimethyl suberimidate, resulted in the formation of its oligomeric polypeptides. The complexes of talin and G-actin were also demonstrated with the cross-linking reagents and fluorescence-labeled actin. These results indicate that talin is able to cross-link some limited regions of actin filaments.

Actinin↗
PubMed1992

[Aspergillosis involving the thoracic spinal cord--an autopsy case].

A 63 year old male complained of persistent backache and productive cough. The chest X-ray revealed the fungus ball at the left apical-posterior segment and Aspergillus fumigatus was cultured from the sputum. He was treated on fulconazole and miconazole. Six months later, motor and sensory paralysis below the mamillary level and urinary and stool incontinence developed. A magnetic resonance image disclosed the destruction of the second thoracic spinal vertebra involved by the cavitated fungus ball of the left lung. Continuous peroral administration of antifungal drugs was not successful, and he expired with severe dyspnea. The autopsy revealed an extensive granulomatous and purulent change of the epidural and subdural spaces of the second to fifth thoracic spinal cord. Subdural inflammation extended to the lower thoracic and lower cervical level. Thoracic spinal cord revealed an extensive myelomalacia predominantly involving the left lateral white column, and also anterior and posterior columns. Small areas of the white matter were cystic. The left anterior horn cells revealed severe central chromatolysis. Moderate lymphocytic and plasma cell infiltration was found around the vessels within the cord. A few thrombi were found in the vein near the anterior nerve root. Central nervous system involvement of pulmonary aspergillosis is quite uncommon. However, there are a few reports of patients with paraplegia secondary to the spinal extension by aspergillus infection. Sheth et al. described that epidural and subdural granulomatous change with aspergillus abscesses and spinal cord myelomalacia is comparable to metastatic carcinoma. However, the aspergillus infection in the spinal cord is more extensive and destructive.(ABSTRACT TRUNCATED AT 250 WORDS)

Aspergillosis↗
PubMed1991

Long-term intermittent administration of interferon-alpha in patients with chronic non-A, non-B hepatitis.

IFN-alpha was administered intermittently over a 6 month period in 39 patients with chronic non-A, non-B hepatitis confirmed by peritoneoscopy and liver biopsy. Three million units of IFN-alpha were administered 3 times a week for the first 6 months then twice, then once a week. In 26 patients (67%), GPT decreased and remained within the normal range during the course of administration, and in 9 patients (23%) GPT remained normal for over 6 months after the discontinuation of IFN-alpha. There was no significant difference of efficacy among 3 groups liver histology groups (CPH, CAH-2A, and CAH-2B), but GPT decreased significantly in patients with sporadic hepatitis compared to patients with a history of blood transfusion. Furthermore, GPT decreased significantly in patients with a history of a blood transfusion within the preceding 2 years compared to patients with a history of a blood transfusion over 7 years ago. GPT increased markedly after an early tapering to 2 doses weekly, but it did not increase after a 6 month administration. In conclusion, the long-term administration of 300 million unit IFN-alpha, 3 times weekly for 6 months, about 2.5 hundred million units in total, is thought to be an effective way to control chronic NANB hepatitis.

Adult↗
PubMed1990

Direct interactions between talin and actin.

Talin was purified from chicken gizzard by a modification of the method of L. Molony et al. [J. Biol. Chem.(1987) 262, 7790-7795]. Unlike the talin purified by the previous method, the talin purified by the new method was found to bind to both F- and G-actin: Talin cosedimented with F-actin. On gel filtration of a mixture of talin and G-actin, a complex of talin and action was obtained. Talin stimulated the polymerization rate of G-actin. A major proteolytic fragment of talin that retained the binding ability to F-actin was also identified. These results indicate that talin can bind directly to actin and suggest that talin plays a key role in the organization of actin filaments at the actin-membrane attachment sites in vivo also.

Actins↗
PubMed1990

Protein kinase C phosphorylates both the light chains and the head portion of the heavy chains of brain myosin.

Protein kinase C phosphorylated both the 19/21-kDa regulatory light chains and heavy chains of bovine brain myosin. The major phosphorylation sites of the light chains were on their threonyl residues, while those for myosin light chain kinase were on their seryl residues. Whereas several non-muscle regular myosins have been reported to be phosphorylated by different types of protein kinases at the non-helical small segments at the tail ends of the heavy chains, the phosphorylation sites for protein kinase C were localized on the head portion of the heavy chains of brain myosin. The possible role of phosphorylation of brain myosin by protein kinase C in the regulation of motility of neural cells is discussed.

Animals↗
PubMed1990

The hepatocellular expression of a carbohydrate antigen 'sialyl Lewis X' in chronic hepatitis. A novel histological marker for active hepatic necroinflammation.

The hepatocellular expression of the carbohydrate antigen sialyl monomeric Lewis X (SMLex) and sialyl oligomeric Lewis X(SOLex) in chronic hepatitis was examined using specific monoclonal antibodies. Both of these sialyl Lewis X (SLex) antigens were membranously expressed in chronic hepatitis in spite of their absence in normal liver. Although SMLex was detected in mild hepatic inflammation, the expression of SOLex was associated only with moderate to severe necroinflammation. Hepatocellular expression of these antigens increased significantly as histological diagnosis advanced. Chronological observation also showed the change of SLex expression according to the histological change. The present observations suggest that hepatocellular SLex is a novel histological marker with a close correlation to the severity of necroinflammation in chronic hepatitis.

Biomarkers↗
PubMed1988

Polarity and length of actin filaments at the fascia adherens of the cardiac intercalated disk.

Digestion of canine and bovine intercalated disks with a calcium-activated protease (CAF) removes the electron-dense material similar to that found at the Z-line and presumably consisting primarily of alpha-actinin. The major filaments exposed by CAF are actin, and the polarity is away from the intercalated disk, as was confirmed by decoration with heavy meromyosin. The length of actin filaments associated with the fascia adherens region at the concave region is 1.2- to 2.2-fold that of actin filaments (I-filaments) in the sarcomere and varies depending on the interdigitation of the membrane at the cell junction. Actin filaments at the intercalated disk seem to be attached (or very close) to the membrane in a direct, rather than looping, manner.

Actins↗
PubMed1988

Hepatocellular expression of a novel glycoprotein with sialylated difucosyl Lex activity in the active inflammatory lesions of chronic liver disease.

Hepatic expression of sialylated difucosyl Lex antigen (SDLex, NeuAc alpha 2-3Gal beta 1-4(Fuc alpha 1-3)GlcNAc beta 1-3Gal beta 1-4(Fuc alpha 1-3)GlcNAc beta 1-) was studied with monoclonal antibody FH6, which defines this structure. Hepatocytes in the severe form of chronic active hepatitis and liver cirrhosis strongly expressed SDLex. The antigen was only weakly and focally detected in chronic persistent hepatitis. The mild form of chronic active hepatitis showed intermediate expression. SDLex expressed along the liver cell membranes displayed a honeycomb pattern when extensively expressed in the severe form of chronic active hepatitis or in liver cirrhosis. Cytoplasmic expression was faint and focal. Preferential tissue distribution was at the periphery of the hepatic lobules where the distruction of the limiting plate was present. The antigen was also expressed in sinusoidal lining cells and polymorphonuclear cells but not in the biliary epithelia. Hepatocytes expressing SDLex did not express related carbohydrate antigens, ie, Type 2 chain N-acetyllactosamine, Lex, and sialylated Lea. On subcellular fractionation, the microsome fraction contained the majority of the antigen activity. SDS-PAGE and Western blot analysis revealed one major SDLex-active glycoprotein with an apparent molecular weight of 110 kilodaltons. This glycoprotein was different from SDLex-active glycoproteins found in the sera of cancer patients. No ganglioside showed FH6 reactivity. These results indicate that liver cells in active inflammatory lesion expressed a novel glycoprotein carrying SDLex antigen in honeycomblike membrane-associated pattern.

Acute Disease↗
PubMed1983

Identification of two forms of myosin light chain kinase in turkey gizzard.

Two forms of myosin light chain kinase from turkey gizzard are separable by ion-exchange chromatography. One is the well-characterized 130,000 Mr enzyme. Purification of the second form by affinity chromatography on calmodulin--Sepharose showed it to consist of two polypeptide chains of Mr 136,000 and 141,000. This form of the enzyme required Ca2+ and calmodulin for activity, was specific for the Mr 20,000 light chain of myosin, and appeared to phosphorylate the same site on the light chain as the Mr 130,000 enzyme. The low-Mr gizzard kinase may be a proteolytic fragment of a higher-Mr species or these may represent different isoenzymes.

Animals↗
PubMed1981

A new 220,000 dalton protein located in the Z lines of vertebrate skeletal muscle.

A new protein with a chain weight of approximately 220,000 was isolated from 0.6 M KI extracts of I-Z-I brushes of rabbit and chicken skeletal muscles, using (NH4)2SO4 precipitation and three column chromatographic procedures in succession. It was only possible to separate the high molecular weight protein from actin and alpha-actinin in the presence of 6 M urea or 0.1% sodium dodecyl sulfate (SDS). The purified protein migrated as a single band on SDS gel electrophoresis. The amino acid composition of the 220,000 dalton protein was distinct from any known proteins found in myofibrils, e.g., alpha-actinin and actin binding protein (ABP; filamin). An indirect immunofluorescence technique revealed that the new protein was exclusively located in the Z lines of myofibrils of chicken breast muscle. There is, however, a possibility that the 220,000 dalton protein is identical with synemin recently isolated from chicken gizzard (Granger, B.L. and Lazarides, E. (1980) Cell 22, 727).

Amino Acids↗
PubMed1980

Sinus histiocytosis with massive lymphadenopathy in a Japanese adult with unusually elevated EBV antibody titers.

A 35-year-old Japanese male was presented with massive lymphadenopathy in bilateral preauricular and submandibular regions for five years' duration without any complaints despite of no specific treatments. Laboratory examinations revealed neurtrophilia, elevated BSR, hypergammaglobulinemia with elevated IgG and IgM, positive CRP and RA, low percentage of T-cells in peripheral blood, impaired PHA blast transformation, and elevated EBV titers against viral capsid, early and nuclear antigens. Biopsy specimens demonstrated massive histiocytosis with hemophagocytosis in the sinuses and predominant mature plasma cells in the medulla, which were fairly well consistent with "sinus histiocytosis with massive lymphadenopathy" (ROSAI and DORFMAN). Ultrastructural study revealed histiocytes exhibiting avid phagocytosis of blood cells, epithelioid histiocytes with poor phagocytic activity, foamy storage histiocytes loaded with a large number of osmiophilic lipid granules and giant cells of various types. Pathogenesis of this apparently benign disease entity was briefly discussed, and its refractoriness against any specific therapy was emphasized.

Adult↗
PubMed1980

Contributionof Z-line constituents to the formation of the contraction bands of chicken myofibrils on addition of Mg2+-ATP.

1. Z-line constituents contributing to the formation of the contraction bands in chicken myofibrils were investigated by using the rabbit calcium-activated factor (CAF). 2. CAF digestion hampered the formation of the contraction bands and increased the amount of soluble proteins which are apparently derived from the Z-line. Among several proteins released by CAF digestion, a 95,000 dalton component, which corresponds to alpha-actinin, was predominant, followed by a 220,000 dalton component and several other proteins. 3. An apparent inverse relationship between the formation of the contraction bands and the release of Z-line proteins was observed. It is concluded that the presence of Z-line, including at least the two components mentioned above, is essential for the formation of the contraction bands.

Actinin↗