Isolation and characterization of a calcium-binding protein derived from mRNA termed p9Ka, pEL-98, 18A2, or 42A by the newly synthesized vasorelaxant W-66 affinity chromatography.

W-66 (N-(2-aminoethyl)-N-[2-(4-chlorocinnamylamino) ethyl]-5-isoquinolinesulfonamide), a newly synthesized isoquinolinesulfonamide, was shown to have a potent vasodilatory action and calmodulin (CaM)-antagonizing action. Using the W-66 affinity chromatographic technique, we purified two Ca(2+)-binding proteins from the EGTA-soluble fraction of bovine aorta. One was CaM and the other was an acidic protein with a molecular mass of 11 kDa. It was tentatively named "calvasculin." Calvasculin was a dimeric protein. Equilibrium dialysis showed that 1 mol of calvasculin (dimer) bound to 1.98 +/- 0.30 mol of Ca2+ in the presence of 10(-3) M Ca2+. Calvasculin failed to activate Ca2+/CaM-dependent enzymes such as myosin light chain kinase, Ca2+/CaM-dependent phosphodiesterase, or Ca2+/CaM-dependent protein kinase II and to inhibit the CaM stimulation of these enzymes. The partial amino acid sequence of calvasculin revealed a high homology to the predicted protein derived from mRNA, named pEL-98, 18A2, 42A, or p9Ka. We also examined the physicochemical and biochemical properties of calvasculin. Using the antibody specific for calvasculin, we obtained evidence that calvasculin is present in abundance in bovine aorta but not in brain, lung, heart, or testis.     

Transformation ofBacillus subtilis with the treatment by alkali cations

Summary ExposingBacillus subtilis cultures to high concentrations of alkali cations, especially K⁺, allows efficient transformation by plasmids. The method allows transformation with unfractionated plasmid DNA, monomeric plasmid DNA as well as linear plasmid DNA.B. subtilis strains, not amenable to natural transformation, were also transformed by the present method.     

19F-n.m.r. study of trifluoperazine-S100 protein interaction: effects of Ca2+ and Zn2+

19F-n.m.r. spectra were measured to investigate the effects of Ca2+ and Zn2+ on the interaction of trifluoperazine (TFP) with three S100 proteins. It was found that TFP binds to S100a and S100ao proteins irrespective of the presence of Ca2+ and Zn2+, while in the presence of Ca2+ the apparent affinity of TFP to the proteins was greater than that in its absence or in the presence of Zn2+. In contrast, the binding affinity of TRP to S100b protein in the presence and absence of metal ions was lower than to S100a and S100ao proteins. These results suggested that TFP binds to each S100 protein in two ways: one is Ca2(+)- or Zn2(+)-dependent specific manner and another is Ca2(+)- or Zn2(+)-independent non-specific manner.     

Distinct effects of different low temperatures on the induction of NAD-sorbitol dehydrogenase activity in diapause eggs of the silkworm,Bombyx mori

Summary Diapause eggs of the silkworm, Bombyx mori, exposed to 5°C and 0.5°C from 2 or 30 days after oviposition, were examined for changes in contents of glycogen, sorbitol and glycerol. Cold acclimation did not alter the profile of accumulation of sorbitol from that in eggs kept continuously at 25°C. However, acclimation at 5°C resulted in conversion of sorbitol to glycogen, while acclimation at 0.5°C was not accompanied by the utilization of sorbitol. NAD-sorbitol dehydrogenase (NAD-SDH; EC 1.1.1.14) activity was examined in the cold-acclimated eggs. The activity was induced by acclimation at 5°C but not at 0.5°C. Incubation at 0.5°C suppressed any further increase in the activity that had been induced. Temperature-directed changes in NAD-SDH activity paralleled those in sorbitol content. Hatching of the diapause eggs was monitored after cold acclimation for various periods of time and subsequent transfer to 25°C. Incubation at 0.5°C was less effective than 5°C at breaking diapause. The time required for the eggs to hatch in synchrony after acclimation at 5°C coincided with that required for the induction of NAD-SDH activity. These results show that different effects result from acclimation at 5°C and near 0°C with respect to the control of NAD-SDH activity, that utilization of sorbitol is controlled by NAD-SDH activity, and that induction of this activity is temperature-dependent. Furthermore, induction of NAD-SDH activity is involved in the termination of diapause in B. mori.Abbreviations DH diapause hormone - NAD nicotinamide-adenine-dinucleotide - NAD-SDH NAD-sorbitol-dehydrogenase     

Electrotransformation of intact cells ofBrevibacterium flavum MJ-233

Summary Electroporation allowed transformation of intact cells ofBrevibacterium flavum MJ-233. The two plasmids used for electroporation were pCRY2 (6.3 kilobases) and pCRY3 (8.2 kilobases). Both plasmids contain the chloramphenicol-resistance gene and the autonomous replication origin inB. flavum MJ-233. The efficiency of electrotransformation was optimal with cells harvested at the middle log phase of growth, and was imporved by the addition of 1.0U/ml of penicillin G to the culture medium. The optimum yield of transformants per g DNA was 5×10⁴ when the cell suspension was pulsed at a cell density of 1×10¹⁰/ml and at a DNA amount of 1.0g.     

Connexin43 Is Another Gap Junction Protein in the Peripheral Nervous System

Abstract: That many cells express more than one connexin (Cx) led us to examine whether Cxs other than Cx32 are expressed in the PNS. In addition to Cx32 mRNA, Cx43 and Cx26 mRNAs were detected in rat sciatic nerve by northern blot analysis. Cx43 mRNA, but not Cx26 mRNA, was expressed in both the primary Schwann cell culture and immortalized Schwann cell line (T93). The steady-state levels of the Cx43 mRNA in the primary Schwann cell culture increased 2.0-fold with 100 µ M forskolin, whereas that of P₀ increased 7.0-fold. Immunoreactivity to Cx43 was detected on western blots of cultured Schwann cells, T93 cells, and sciatic nerves but not on blots of PNS myelin. Immunohistochemical study using human peripheral nerves revealed that anti-Cx43 antibody stained cytoplasm around nucleus of Schwann cells but not myelin, confirming western blot results. Although P₀ expression was markedly decreased by crush injury of the sciatic nerves, Cx43 expression showed no apparent change. Developmental profiles showed that Cx43 expression in the sciatic nerve increased rapidly after birth, peaked at about postnatal day 6, and then decreased gradually to a low level. In adult rats, the Cx43 mRNA value was much lower than that of Cx32. These findings suggest that Cx43 is localized in Schwann cell bodies and that, compared with P₀, its expression is less influenced by axonal contact and cyclic AMP levels. The high expression on postnatal day 6 indicates that Cx43 may be related to PNS myelination. Cx43 is another gap junction, but its function appears to differ from that of Cx32, as judged by the differences in their localization and developmental profiles.     

A Nonneuronal Isoform of Cell Adhesion Molecule L1: Tissue-Specific Expression and Functional Analysis

Abstract: The cell adhesion molecule L1 is a multifunctional protein in the nervous system characterizing cell adhesion, migration, and neurite outgrowth. In addition to full-length L1, we found an alternatively spliced variant lacking both the KGHHV sequence in the extracellular part and the RSLE sequence in the cytoplasmic part of L1. This L1 variant was expressed exclusively in nonneuronal cells such as Schwann cells, astrocytes, and oligodendrocytes, in contrast to the expression of the full-length L1 in neurons and cells of neuronal origin. To investigate the functions of the L1 variant, we established cell lines transfected with a cytoplasmic short L1 (L1cs) cDNA that lacks only the 12-bp segment encoding for the RSLE sequence. The promoting activities of homophilic cell adhesion, neurite outgrowth, and neuronal cell migration of L1cs-transfected cells (L4-2) were similar to those of full-length L1-transfected cells (L3-1), but the cell migratory activity of L4-2 itself was clearly lower than that of L3-1. In conclusion, the short form of L1 is a nonneuronal type, in contrast to the neuronal type of the full-length L1. Deletion of the four amino acids RSLE in the cytoplasmic region of L1 markedly reduced cell migratory activity, suggesting an importance of the RSLE sequence for the signaling events of neuronal migration mediated by L1.