Tissue-specific expression of three distinct types of rabbit protein kinase C

We examined the structure of protein kinase C in an attempt to understand the molecular events connecting protein kinase C activation with the cellular response. Rabbit complementary DNA clones coding for three distinct types of protein kinase C, named alpha, beta and gamma, have been identified and sequenced. The deduced amino acid sequence for alpha, beta and gamma (673, 671 and 672 amino acids, respectively) are closely related. Kinases alpha and beta share an identical N-terminal sequence of 621 amino acid residues and their messenger RNAs arise from a single gene. The C-terminal halves of alpha, beta and gamma are protein kinase domains and are highly homologous to other protein kinases. The mRNAs for alpha, beta and gamma are expressed in various tissues with strikingly different tissue specificities. The one for gamma is found ubiquitously among various tissues, while those for alpha and beta predominate in the brain.     

The possibility of centrifugal to the retina in the rat

Summary In rats, glutamic acid decarboxylase activity increased in the proximal portion of the optic nerve after its ligation, whereas the activities of choline acetyltransferase and tyrosine hydroxylase remained constant. Possible centrifugal neurons to the retina are GABAergic.     

The genetics of a soluble acidic protein in skeletal muscle

Zusammenfassung Ein Hauptbestandteil von wässerigem Skelettmuskelextrakt ist ein dimeres, saures Protein mit einem Molekulargewicht von 120 000. In der WachtelCoturnix coturnix japonica und in der KröteBufo americanus wird dieses Protein von einem einzelnen autosomalen Locus kontrolliert.

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Supported by grants No. CA 10619 and No. CA 05138 from the National Institutes of Health, U.S. Public Health Service.

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This work was performed during Dr. Wohnus' sabbatical leave from Bennington College, Bennington, Vermont.     

Electric-field control of ferromagnetism

It is often assumed that it is not possible to alter the properties of magnetic materials once they have been prepared and put into use. For example, although magnetic materials are used in information technology to store trillions of bits (in the form of magnetization directions established by applying external magnetic fields), the properties of the magnetic medium itself remain unchanged on magnetization reversal. The ability to externally control the properties of magnetic materials would be highly desirable from fundamental and technological viewpoints, particularly in view of recent developments in magnetoelectronics and spintronics. In semiconductors, the conductivity can be varied by applying an electric field, but the electrical manipulation of magnetism has proved elusive. Here we demonstrate electric-field control of ferromagnetism in a thin-film semiconducting alloy, using an insulating-gate field-effect transistor structure. By applying electric fields, we are able to vary isothermally and reversibly the transition temperature of hole-induced ferromagnetism.     

Immunology and functional genomics of Behçet's disease

Behçet's disease (BD) is a multisystemic inflammatory disorder. Although the cause and pathogenesis of BD are still unclear, there is evidence for genetic, immunologic and infectious factors at the onset or in the course of BD. This review focusses on the functional genomics and immunology of BD. HLA-B51 is the major disease susceptibility gene locus in BD. An increased number of T cells in the peripheral blood and in the involved tissues have been reported. However, the T cells at the sites of inflammation appear to be a phenotypically distinct subset. There is also a significant T cell proliferative response to mycobacterial 65-kDa heat shock protein peptides. Homologous peptides derived from the human 60-kDa heat shock protein were observed in BD patients. There is evidence that natural killer T cells may also play a role in BD.Received 27 November 2002; accepted 4 March 2003     

Two cell types in monoamine-containing ‘liquor contacting’ neuron system on the frog brain

Summary By means of an immunofluorescent technique, liquor contacting neurons, serotonergic in nature were demonstrated in the paraventricular organ and in the nucleus infundibularis dorsalis, and neurons catecholaminergic in nature were noted in the preoptic recess organ and in the caudal part of the 4th ventricle.     

Chlorophyll b and phycobilins in the common ancestor of cyanobacteria and chloroplasts.

Photosynthetic organisms have a variety of accessory pigments, on which their classification has been based. Despite this variation, it is generally accepted that all chloroplasts are derived from a single cyanobacterial ancestor. How the pigment diversity has arisen is the key to revealing their evolutionary history. Prochlorophytes are prokaryotes which perform oxygenic photosynthesis using chlorophyll b, like land plants and green algae (Chlorophyta), and were proposed to be the ancestors of chlorophyte chloroplasts. However, three known prochlorophytes (Prochloron didemni, Prochlorothrix hollandica and Prochlorococcus marinus) have been shown to be not the specific ancestors of chloroplasts, but only diverged members of the cyanobacteria, which contain phycobilins but lack chlorophyll b. Consequently it has been proposed that the ability to synthesize chlorophyll b developed independently several times in prochlorophytes and in the ancestor of chlorophytes. Here we have isolated the chlorophyll b synthesis genes (chlorophyll a oxygenase) from two prochlorophytes and from major groups of chlorophytes. Phylogenetic analyses show that these genes share a common evolutionary origin. This indicates that the progenitors of oxygenic photosynthetic bacteria, including the ancestor of chloroplasts, had both chlorophyll b and phycobilins.     

Phosphoglucomutase polymorphism in the rainbow trout,Salmo gairdneri

Zusammenfassung Es wird aufgrund von Stärke-Gel-Zymogrammanalysen der Phosphoglukomutase in 72 Forellen (Salmo gairdneri) die Existenz eines polymorphen und zweier nicht variierender Gene ermittelt. Der Polymorphismus beruht auf 2 Allelen mit übereinstimmenden Frequenzen im Hardy-Weinberg-Gleichgewicht.

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Supported in part by a grant No. CA-05138 from the National Cancer Institute, U.S. Public Health Service and in part by Animal Resources grant No. FR00433.     

Dehydroepiandrosterone sulfate-binding sites in plasma membrane from human uterine cervical fibroblasts.

Dehydroepiandrosterone sulfate (DHA-S) plays a critical role in cervical dilatation at labor. Incubation of cervical fibroblasts with [3H]DHA-S caused a rapid and saturable increase in cellular radioactivity: an apparent equilibrium was reached by 2 min. There was no detectable conversion of DHA-S into DHA or oestradiol. When the fibroblasts loaded with [3H]DHA-S were homogenized and fractionated, the specific radioactivity in the plasma membrane fraction was enriched approximately 8- to 9-fold compared with the whole homogenate; only low amounts of radioactivity were observed in the other subcellular fractions. The binding of DHA-S to plasma membrane preparations showed saturation kinetics with an apparent equilibrium dissociation constant (Kd) of 12 nM, and the binding capacity (Bmax) was calculated to be 1.25 fmol/mg protein. Neither DHA nor oestrone sulfate affected [3H]DHA-S binding to the plasma membrane. The plasma membranes of skin fibroblasts did not show specific binding sites for DHA-S. These findings demonstrate the presence of specific binding sites for DHA-S in the plasma membrane of cervical stroma cells. The fetal adrenal steroid may exert its action on cervical ripening at least in part through membrane-associated binding sites, or receptors.