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C S Mayanil

Publications and source records attributed to C S Mayanil.

16 recordsLinked to original sources
PubMed1999

The presence of transcription factors in chicken albumin, yolk and blastoderm.

Embryonic development is determined by preset intrinsic programs and extrinsic signals. To explore the possibility that transcription factors are present at the onset of development, preparations of yolk, albumin, and blastoderm from unfertilized and fertilized white Leghorn chicken eggs were screened by a panel of 16 transcription factor antibodies with Western blot techniques. Yolk was positive for 13 transcription factors, whereas blastoderm was positive for 10, and albumin was positive for 5. In yolk, several transcription factors, GATA-2, E2F-1, MyoD, and TFIID, were developmentally regulated. These results indicate that intracellular yolk and extracellular albumin contain transcription factors which presumably influence early chick embryonic development from prefertilization to the late blastoderm stage. Thus, the utility of preset maternal transcription factors within yolk and albumin complement maternally derived mRNA to determine the early development of the zygote.

Albumins↗
PubMed1998

The presence of transcription factors in fetal bovine sera.

Three sources of fetal bovine serum (FBS) were fractionated by ammonium sulfate precipitation and by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), transferred to Immobilon-P membranes, immunoblotted with a panel of transcription factor antibodies, and detected by enhanced chemiluminescence. Nine transcription factors were detected--ATF-2, SRE-ZBP, GATA-2, TFIID, Ets-1/Ets-2, E2F-1, Oct-2, p53, and AP-2; four transcription factors were not detected--Myo D, CREB, Sp2, and Wilms' tumor. The results indicated the presence of varying amounts of several transcription factors in three commercial sources and may represent heretofore unrecognized factors influencing cell culture.

Animals↗
PubMed1998

CD44H localization in primary open-angle glaucoma.

PURPOSE: Primary open-angle glaucoma (POAG) is associated with a decreased content of hyaluronan in the trabecular meshwork and in the juxtacanalicular connective tissue. In this study, the authors examined selected regions of the anterior segment to localize and determine the content of CD44H, a transmembrane multifunctional glycoprotein and the principal receptor of hyaluronan. METHODS: Sections of ethanol-fixed anterior segments of six POAG and six normal postmortem eyes were analyzed by immunostaining with and without the nonionic detergent Triton X-100, using the CD44H monoclonal antibody, and the avidin/biotin complex. They were visualized by Vector VIP substrate and were quantitated by computer-aided color image analysis. RESULTS: CD44H was expressed in all regions. Statistically significant decreased content of CD44H was observed in the POAG regions compared with normal regions--ciliary muscle (P < 0.001), ciliary stroma (P < 0.001), anterior iris (P < 0.05), iris root (P < 0.05), and trabecular meshwork (P < 0.05)--and in a subgroup of nonlaser POAG juxtacanalicular connective tissue (P < 0.05) and trabecular meshwork (P < 0.01). In sections treated with Triton X-100 a further increase in immunostaining was observed in normal eyes. As evidenced by scattergram plots of the ciliary body stroma region of the change in the optical density of CD44H between pretreatment with Triton X-100 and without Triton X-100 (y axis) versus the optical density of CD44H without Triton X-100 (x axis), individual cases of POAG were separated from normals. CONCLUSIONS: These results indicate that CD44H may represent a marker of POAG and an etiologic factor in the POAG disease process.

Aged↗
PubMed1993

Synaptic vesicle and synaptic membrane glycoproteins during pre- and postnatal development of mouse cerebral cortex, cerebellum and spinal cord.

Glycoproteins of synaptic vesicles and synaptic membranes play an important role during the process of synaptogenesis. In order to study the temporal expression of specific carbohydrates and the expression of selected neural proteins, we used peroxidase-conjugated lectin overlays on Western blots and immunoblots of synaptic vesicles and synaptic membranes isolated from pre- and postnatal mouse cerebral cortex, cerebellum and spinal cord. Our lectin overlays on Western blots showed that (1) the synaptic vesicle glycoproteins, gp80-100, gp47 and gp44, and (2) the synaptic membrane glycoproteins, gp180, gp72, gp70 and gp34, show temporal regulation of expression of carbohydrate moieties. Quite significantly, gp47 showed a decrease in the vesicles coinciding with an increase in membranes suggesting a shift in localization. Anti neural cell adhesion molecule (N-CAM) antibody cross-reacted with gp180. The developmental expression of synaptotagmin 1, a well characterized glycoprotein of synaptic vesicle, was determined by immunoblots analysis. Anti synaptosomal-associated protein 25 (SNAP-25) antibody immunoblots were performed in order to compare our results with a developmentally regulated synaptosomal protein demonstrating expression coincident with synaptogenesis. Our immunoblot studies showed that (1) N-CAM (gp180) immunoreactivity decrease with development; (2) the expression of synaptotagmin 1 and SNAP-25 increases as development progresses, and (3) synaptotagmin 1 and SNAP-25 show a shift in subcellular localization (from synaptic vesicle to synaptic membrane) during development, thereby indicating that these proteins are first identified in a vesicular fraction. Thus, our data suggest that synaptic vesicle and synaptic membrane glycoproteins show temporal regulation of specific carbohydrates as well as protein expression during development, which may be a key factor to our understanding of the process of synaptogenesis.

Animals↗
PubMed1991

Subtype-specific antibodies for muscarinic cholinergic receptors. I. Characterization using transfected cells and avian and mammalian cardiac membranes.

Polyclonal antibodies to a number of synthetic peptides corresponding to sequences of human muscarinic acetylcholine receptor (mAChR) subtypes m1, m2, and m4 have been prepared, in order to obtain specific tools with which to study the properties of the different receptors. Hydrophilic peptides from each subtype were chosen from the large intracellular loop between the fifth and the sixth transmembrane domains, because these loops are distinct in each of the mAChR subtypes and contain determinants for coupling to different GTP-binding proteins, as well as potential sites for phosphorylation. Five different antibodies were prepared and tested for their reactivity and specificity toward different mAChR subtypes by immunoprecipitation of ligand-binding activity and receptor protein and by immunoblot analysis. Each of the antisera immunoprecipitated its respective mAChR subtype, as evidenced by precipitation of 50-70% of the ligand-binding activity from stably transfected cells expressing the respective mAChR subtype. Very little cross-reactivity toward other subtypes was observed. We used these subtype-specific antibodies to probe the nature of the mAChR subtypes naturally expressed in avian and mammalian cardiac membranes. In tests using the antibodies with cardiac mAChRs, differences in the avian and mammalian mAChR subtypes were detected. Only the anti-m2 antibodies reacted with mAChR from porcine heart, confirming previous pharmacological and molecular biological studies that suggested that this tissue expressed only the m2 mAChR subtype. In contrast, both the anti-m2 and anti-m4 mAChR antibodies immunoprecipitated approximately 50% of the mAChRs solubilized from chick heart membranes. The combined or successive use of anti-m2 and anti-m4 antisera in immunoprecipitation and/or immunoblotting studies with chick heart mAChRs suggested that both antibodies appeared to recognize the same population of mAChRs from that tissue. Taken together, the results show that the subtype-specific antibodies developed in this work are useful in recognizing mAChR subtypes in cells and tissues. These antibodies should be valuable tools for further study of the properties and regulation of mAChR subtypes in various preparations. Evidence that the antibodies can modify mAChR/GTP-binding protein interactions is presented in the accompanying paper.

Amino Acid Sequence↗
PubMed1991

Subtype-specific antibodies for muscarinic cholinergic receptors. II. Studies with reconstituted chick heart receptors and the GTP-binding protein G(o).

The antibodies described in the accompanying paper were used to probe the interactions of the chick heart muscarinic acetylcholine receptors (mAChRs) with the GTP-binding protein G(o). The anti-m4b antibodies, which were made against a peptide from the amino-terminal portion of the third cytoplasmic loop of the m4 mAChR subtype, were tested for their abilities to affect the coupling of the chick heart mAChR to the GTP-binding protein G(o). The purified chick heart mAChRs were reconstituted with purified G(o) in phospholipid vesicles, and their interactions were monitored in the presence or absence of the antibodies. The anti-m4b antibodies completely inhibited the ability of G(o) to promote high affinity agonist binding to the purified receptors. The anti-m4b antibodies also completely inhibited the agonist-stimulated binding of guanosine-5'-O-(3-thio)triphosphate (GTP gamma S) to G(o) and the receptor-stimulated GTPase activity of G(o). These findings indicate that the amino-terminal portion of the third cytoplasmic loop is an important determinant for G(o) to promote high affinity agonist binding to the chick heart mAChR and also for the agonist-stimulated GTP gamma S binding and GTPase activity. The anti-m4a, anti-m2, and anti-m1a antibodies, which were made against centrally located peptides of the third cytoplasmic loop of the m4, m2, and m1 mAChR subtypes, respectively, were also tested for their effects in the reconstituted receptor/G(o) system. The anti-m2 and anti-m4a antibodies also significantly reduced agonist-stimulated GTP gamma S binding, as well as GTPase activity, but did not completely abolish these functions, as was the case with anti-m4b antibodies. However, the anti-m4a and anti-m2 antibodies shared with anti-m4b antibodies the ability to markedly inhibit the ability of G(o) to promote high affinity agonist binding to the purified and reconstituted receptors. In contrast to the results obtained with the anti-m2 and anti-m4 antibodies, the anti-m1a antibodies had smaller effects on the receptor/G(o) interactions. These results suggested that central portions of the loop can also influence mAChR/G(o) interactions. Studies were als performed to test the effects of the peptides that were used as antigens on receptor-mediated GTP gamma S binding to G(o). Each of the peptides caused significant inhibition of this function, but the greatest inhibition was observed with the m4b peptide. In sum, the results suggest that multiple domains in the third cytoplasmic loop of chick heart mAChR can modulate interactions with G(o).

Animals↗
PubMed1989

Molecular cloning of a Chinese hamster mitochondrial protein related to the "chaperonin" family of bacterial and plant proteins.

The complete cDNA sequence of a mitochondrial protein from Chinese hamster ovary cells, designated P1, which was originally identified as a microtubule-related protein (Gupta, R.S., Ho, T.K.W., Moffat, M.R.K., and Gupta, R. (1982) J. Biol. Chem. 257, 1071-1078), has been determined. The P1 cDNA encodes a protein of 60,983 Da including a 26-amino acid putative mitochondrial targeting sequence at its N-terminal end. The deduced amino acid sequence of Chinese hamster P1 shows 97% identity to the human P1 protein. Most interestingly, the amino acid sequences of mammalian P1 proteins show extensive sequence homology (42-60% identical residues and an additional 15-25% conservative replacements) to the "chaperonin" family of bacterial, yeast, and plant proteins (viz. groEL protein of Escherichia coli, hsp 60 protein of yeast, and ribulose-1,5-bisphosphate carboxylase subunit binding protein of plant chloroplasts) and to the 60-65-kDa major antigenic protein of mycobacteria and Coxiella burnetii. The homology between mammalian P1 and other proteins begins after the putative mitochondrial presequence and extends up to the C-terminal end. Furthermore, similar to the chaperonin family of proteins, P1 appears to exist in cells as a homooligomeric complex of seven subunits and shows ATPase activity. These observations strongly indicate that P1 protein is a member of the chaperonin family and that it may be involved in a similar function in mammalian cells.

Adenosine Triphosphatases↗
PubMed1989

M-signal hypothesis--metabolic modulation of membrane functions in rat brain.

1. Monoamine oxidase (amine: oxygen oxidoreductase [deaminating], EC 1.4.3.4) (MAO) and Na+/K+ ATPase (Na+/K+-ATPase, Mg2+-dependent ATP phosphohydrolase, EC 3,1,6,3) showed reciprocal relationship in their activity patterns during experimentally perturbed situations in vivo as well as in vitro. 2. M-signal hypothesis is proposed, which attempts at explaining the regulation of plasma membrane function by the intermediate of metabolic processes in the cell. This metabolic intermediate referred to as M-signal exercise its influence on the plasma membrane Na+/K+ ATPase which is responsible for the uptake process.

Animals↗
PubMed1986

6-Aminonicotinamide: EEG changes and effects on the activities of enzymes related to glutamate metabolism in rat brain regions.

6-Aminonicotinamide (6-AN), an antimetabolite of pyridine nucleotide synthesis, caused time dependent and regionally selective changes in the activities of the enzymes related to glutamate metabolism in the brain. The NAD+- and NADP+-linked glutamate dehydrogenase showed opposite pattern of changes in cerebellum, whereas cerebral hemispheres and brain stem exhibited similar response. Glutamate oxaloacetate transaminase (aspartate aminotransferase) and malate dehydrogenase, the functional enzymes of malate-aspartate shuttle, were decreased in soluble fraction of cerebral hemispheres and increased significantly in cerebellum after 16 hours of drug administration. Glutamate pyruvate transaminase (alanine aminotransferase) also showed an increase in the activity in cerebellum and brain stem after 8 hours of drug treatment. The EEG patterns obtained from 6-AN treated animals showed periodic bursts, turning to convulsive polyspike activity between 8-16 hours, indicating the onset of comatose-like stage. The results indicate that glutamate metabolism offers considerable anaplerotic potentials following impaired energy state after 6-AN treatment.

6-Aminonicotinamide↗
PubMed1985

Kinetics of the mechanism of action of monoamine oxidase in the regulation of Na+,K+-ATPase activity in rat brain.

Kinetic studies on the action of monoamine oxidase (MAO) in the regulation of Na+,K+-ATPase were performed using 3-methoxy-4-hydroxybenzaldehyde (MHB), which is an analogue of 3-methoxy-4-hydroxy-phenylacetylaldehyde (product of MAO-catalysed reaction with dopamine as substrate). It was observed that at 2.6 microM MHB, the activation of Na+,K+-ATPase may be the result of the removal of the inhibitory Ca2+, thereby increasing the Vmax. Double-reciprocal plots of Pi versus MHB showed that Ca2+ counteracted the effect of the aldehyde not by changing the Km, but be decreasing the Vmax of the Na+,K+-ATPase stimulation. The removal of 3',5'-cyclic AMP-dependent protein kinase from the microsomes by sodium dodecyl sulphate treatment abolished the activation and/or inhibition of the Na+,K+-ATPase by aldehyde; it can therefore be inferred that 3',5'-cyclic AMP-dependent protein kinase is involved in the regulation of Na+,K+-ATPase.

Animals↗
PubMed1985

Malate-aspartate shuttle enzymes in rat brain regions, liver and heart during alloxan diabetes and insulin replacement.

Regionally selective and time-dependent variations were observed in the activity of brain aspartate aminotransferase at early phases of diabetes. Malate dehydrogenase activity showed an opposite pattern of changes in soluble and particulate fractions of cerebral hemispheres and brain stem, with cerebellum showing consistent increase in the activity. The activity of both the enzymes increased significantly in liver, in contrast to heart where malate dehydrogenase activity decreased in particulate fraction. Insulin treatment to diabetic animals restored the enzymes to near control levels at early stages of diabetes, except in liver. The results indicate that malate-aspartate shuttle is probably stimulated under diabetic conditions to enable glycolysis to continue and ATP levels to be restored partially, particularly in cerebellum and liver.

Animals↗
PubMed1984

Comparison of the properties of semipurified mitochondrial and cytosolic monoamine oxidases from rat brain.

Mitochondrial and cytosolic monoamine oxidases were purified 220- and 129-fold, respectively, from rat brain. The purification procedure involved extraction (without the use of detergents for mitochondrial monoamine oxidase), ammonium sulfate precipitation, and chromatography on Sephadex G-25 and a DEAE-cellulose column. The properties of both enzymes with kynuramine as substrate, including Km values and pH optima at different kynuramine concentrations; the Rf values on polyacrylamide gel electrophoresis; and the thermal inactivation patterns were different. 2-Mercaptoethanol, together with heat treatment, released the flavin and decreased the enzyme activity differentially for the two enzymes. The absorption spectrum showed a "Red shift" in the absorption maxima when the spectra of the non-Triton-treated purified preparations were compared with those of the Triton-treated ones, thus possibly revealing that the mitochondrial and the cytosolic monoamine oxidases may be two different enzyme entities.

Animals↗
PubMed1983

Mechanism of the involvement of monoamine oxidase in the regulation of (Na+ + K+)-ATPase in rat brain.

Increasing concentrations of dopamine fail to give a biphasic response to (Na+ + K+)-ATPase activity in various subcellular fractions of rat brain preincubated with monoamine oxidase inhibitors, viz. 1 X 10(-4) M clorgyline and 1 X 10(-4) M deprenyl. The product of the monoamine-oxidase-catalysed reaction with dopamine as substrate is 3-methoxy-4-hydroxyphenylacetaldehyde. An analogue of this product is 3-methoxy-4-hydroxybenzaldehyde. This analogue, when incubated with the subcellular fractions which had been preincubated with monoamine oxidase inhibitors and dopamine, gave a more pronounced biphasic response to (Na+ + K+)-ATPase activity than that observed in the fractions incubated with dopamine alone.

Animals↗
PubMed1982

Changes in monoamine oxidase activity in rat brain during alloxan diabetes.

The effect of alloxan diabetes on the activity of monoamine oxidase was studied in three regions of the rat brain at various time intervals after the onset of diabetes. It was observed that monoamine oxidase activity was decreased at early time intervals after diabetes, followed by a recovery in all three regions of the brain. A reversal of the effect was observed with insulin administration to the diabetic rats.

Animals↗
PubMed1982

Na+,K+-ATPase and Mg2+-ATPase activities in different regions of rat brain during alloxan diabetes.

The effect of alloxan diabetes on the activities of Na+,K+-ATPase and Mg2+-ATPase was studied in three regions of rat brain at various time intervals after the onset of diabetes. It was observed that Na+,K+-ATPase activity increased at early time intervals after diabetes, followed by a recovery to near control levels in all three regions of the brain. There was an overall increase in Mg2+-ATPase activity in all the regions. A reversal of the effect was observed with insulin administration to the diabetic rats.

Adenosine Triphosphatases↗