Recovery of aSasa tsuboiana population after mass flowering and death

The recovery process of aSasa tsuboiana population after a mass flowering and death in 1977 was investigated by 15 years of observation in the Hira Mountains, Kinki district, western Japan. Seed production was high (6600–13 800 seeds m⁻² inSasa plots and 3900 seeds m⁻² in a forest plot) but emergent seedling density was low (14–21 seedlings m⁻²), probably because of seed predation byMicrotus montebelli occurring between seed shedding and the next spring. The seedling density had decreased further by the next year and theS. tsuboiana population recovered from only a limited number of seedlings. In spite of such a low initial density, theS. tsuboiana population was able to regenerate successfully and attained the previous full stand height in 7–16 years.Miscantbus sinensis invaded and delayed the recovery ofS. tsuboiana in one plot, butS. tsuboiana became dominant as it caught up with the height ofM. sinensis. Seedling growth patterns, such as frequent tillering, the onset of rhizome extension in the early stage of seedling growth and frequent culm production from rhizomes, played important roles in the successful regeneration ofS. tsuboiana.     

Integrated tandem affinity protein purification using the polyhistidine plus extra 4 amino acids (HiP4) tag system

Peptide tag systems are a robust biophysical and biochemical method that is widely used for protein detection and purification. Here, we developed a novel tag system termed “HiP4” (histidine plus four amino acids) whose epitope sequence comprises only seven amino acids (HHHDYDI) that partially overlap with the conventional 6x histidine tag (6xHis-tag). We produced a monoclonal antibody against the HiP4 tag that can be used in multiple immunoassays with high specificity and affinity. Using this system, we developed a tandem affinity purification (TAP) and mass spectrometry (TAP-MS) system for comprehensive protein interactome analysis. The integrated use of nickel bead purification followed by HiP4 tag immunoprecipitation made it possible to reduce nonspecific binding and improve selectivity, leading to the recovery of previously unrecognized proteins that interact with hepatitis B virus X (HBx) protein or TAR DNA-binding protein 43 (TARDBP or TDP-43). Our results indicate that this system may be viable as a simple and powerful tool for TAP-MS that can achieve low background and high selectivity in comprehensive protein–protein interaction analyses.     

Effects of low culture temperature on the induction of hsp70 mRNA and the accumulation of hsp70 and hsp105 in mouse FM3A cells.

We have shown that heat shock does not induce the synthesis of hsp70 in FM3A cells maintained at a low culture temperature of 33 degrees C although it does so in cells maintained at 37 degrees C [T. Hatayama et al. (1991) Biochem. Int. 24, 467-474]. In this paper, we show that FM3A cells maintained at 37 degrees C produced hsp70 mRNA during continuous heating at 42 degrees C or during postincubation at either 37 or 33 degrees C after being heated at 45 degrees C for 15 min, whereas cells maintained at 33 degrees C did not produce hsp70 mRNA during continuous heating at 37, 39, 42, or 45 degrees C, or during postincubation after being heated at any temperature. Thus the lack of hsp70 synthesis in cells maintained at 33 degrees C seemed to be due to the absence of hsp70 mRNA induction. Also, hsp70 was accumulated in cells maintained at 37 degrees C during continuous heating at 42 degrees C and during postincubation at 37 degrees C after heat shock at 45 degrees C, but not during postincubation at 33 degrees C. The cellular level of the constitutive hsp73 as well as the mRNA level were both similar in cells maintained at 33 and 37 degrees C. On the other hand, the cellular level of the constitutive hsp105 in cells maintained at 33 degrees C was only half of that in cells maintained at 37 degrees C. These hsp105 levels increased significantly in both types of cells after continuous heating at 39 degrees C. These findings indicate that the culture temperature affects not only the induction of hsp70 mRNA but also the accumulation of hsp70 and hsp105 in the cells.     

Action of neocarzinostatin on cell nuclei: release of specific chromatin

We report the first complete sequence of a P450 monoxygenase cytochrome. The P450_CAM from $\text{Pseudomonas}\text{putida}$ is a single polypeptide of 412 residues as determined from the isolated tryptic, clostripain, CNBr, and mild acid cleavage fragments. Significant molecular features, including secondary structure, are discussed.     

Activation of rat glutathione transferases in class mu by active oxygen species

The activities of rat glutathione transferases (GSTs) 3-3, 3-4, 4-4 in Class mu towards 1-chloro-2,4-dinitrobenzene (CDNB) but not 1,2-dichloro-4-nitrobenzene were increased up to 5-fold during preincubation with 0.4 mM xanthine and xanthine oxidase in 50 mM potassium phosphate, pH 7.8, containing 0.1 mM EDTA. The activated GST 3-4, purified by S-hexylglutathione affinity chromatography after the treatment, had a higher specific activity (130 units/mg) than that of the nontreated (35 units/mg), the Km and Vmax values for glutathione or CDNB also were increased. Other rat GSTs in Class alpha and pi were inactivated by the same treatment. In the presence of superoxide dismutase, the activation of GST 3-4 did not occur.     

Camellidins,Antifungal Saponins Isolated from Camellia japonica

Two triterpenoid saponins were isolated from an aqueous or a methanolic extract of camellia (Camellia japonica) leaf. They had an antifungal activity characterized by abnormal germination of conidia. These saponins were composed of 3βhydroxy-18β-acetoxy-28-norolean-12-en-16-one or 3β, 8β-dihydroxy-28-norolean-12-en-16-one as aglycon, and d-glucuronic acid, dglucose and two moles of dgalactose as the sugar moiety. The authors have named these new saponins “Camellidin,” which might have value for studies in the fields of phytopathology and biochemistry.     

Synthesis of Isoprenyl Chalcone “Sophoradin”

Nicotine has been found an effective photosensitizer for DDT. At DDT: nicotine (1:5), DDT along with its formed degradation products DDD, DDE and DBP disappeared within 18 and 60 days under UV and sunlight respectively. Because of persistence, nicotine proved a superior photosensitizer to N,N′-diethylaniline. In DDT emulsifiable concentrates it led to high alkalinity but no DDT degradation up to 60 days at 20~25°C. 0.1 and 0.5% DDT emulsions from these formulations showed no adverse effect on Daucus carrota, Vicia faba, Brassica oleracea var. botrytis, and Dahlia sp., but showed mild to severe phytotoxicity against Pisum sativum and Cicer arietinum; caused by high concentration of nicotine. On Clerodendrum sp. in sunlight, these formulations showed over 20% faster DDT loss between 3~15 days of application. DDT-nicotine mixtures showed no synergism against Tribolium castaneum Herbst.     

Identification of alpha-tubulin as an hsp105alpha-binding protein by the yeast two-hybrid system

Hsp105alpha is a mammalian stress protein that belongs to the HSP105/110 family. Hsp105alpha prevents stress-induced apoptosis in neuronal cells and binds to Hsp70/Hsc70 and suppresses the Hsp70 chaperone activity in vitro. In this study, to further elucidate the function of Hsp105alpha, we searched for Hsp105alpha-binding proteins by screening a mouse FM3A cell cDNA library with full-length Hsp105alpha using the yeast two-hybrid system and obtained alpha-tubulin as an Hsp105alpha-binding protein. Hsp105alpha bound directly to alpha-tubulin both in vitro and in vivo. Indirect immunofluorescence analysis with anti-Hsp105 and anti-alpha-tubulin antibodies indicated that Hsp105alpha was colocalized with microtubules. Furthermore, the disorganization of microtubules induced by heat shock was prevented in Hsp105alpha-overexpressing COS-7 cells. These findings suggested that Hsp105alpha associates with alpha-tubulin and microtubules in cells and plays a role in protection of microtubules under conditions of stress.     

Phosphorylation of the 105-kDa heat shock proteins, HSP105alpha and HSP105beta, by casein kinase II

The 105-kDa heat shock protein alpha (HSP105alpha) and HSP105beta are mammalian heat shock proteins that belong to the HSP105/HSP110 family. Both HSP105alpha and HSP105beta consist of acidic and basic isoforms. Here we report that the acidic isoforms are serine phosphorylated HSP105alpha or HSP105beta. Furthermore, using an in-gel kinase assay with HSP105alpha or HSP105beta as the substrate, the protein kinase that phosphorylates HSP105alpha and HSP105beta was identified as casein kinase II. Since phosphorylated HSP105alpha is especially prominent in the brain compared to other tissues of mice and rats, the phosphorylation of HSP105alpha by casein kinase II may be biologically significant.