Four of the seven zinc fingers of the Evi-1 myeloid-transforming gene are required for sequence-specific binding to GA(C/T)AAGA(T/C)AAGATAA.

Expression of the Evi-1 gene is activated in murine myeloid leukemias by retroviral insertions and in human acute myelogenous leukemia by translocations and inversions involving chromosome band 3q26 where the gene resides. Aberrant expression of the Evi-1 gene has been shown to interfere with myeloid differentiation, which is proposed to be the basis for its role in leukemias. The Evi-1 gene encodes a 145-kDa DNA-binding protein containing two domains of seven and three Cys2-His2 zinc fingers. Previous studies identified a portion of the consensus DNA-binding sequence for the first domain of zinc fingers. The experiments presented here extend these studies and demonstrate that the first domain recognizes a consensus of 15 nucleotides consisting of GA(C/T)AAGA(T/C)AAGATAA. The first three fingers of the first domain do not detectably bind DNA but contribute to the binding by conferring a relative specificity for GACAA verses GATAA in the first position. The first three fingers also contribute to optimal binding of the 15-nucleotide consensus sequence.     

Effect ofNocardia rubra cell-wall skeleton on cancer prevention in humans

Summary The retired workers at the chemical weapons plant in Japan are regarded as a high-risk group for cancers. Under the Cancer Preventive Program,Nocardia rubra cell-wall skeleton (N-CWS) was administered to 80 workers directly involved in the production of sulfur mustard and 66 workers engaged in work related to sulfur mustard production. Untreated workers whose age, sex, duties and duration of work at this factory were individually matched to the N-CWS-treated workers were used as controls. During a 4.5-year observation period, development of cancers was found in 7 treated workers and 17 untreated controls. After elimination of the influence of the difference in smoking level, the incidence of subjects who developed cancers was compared statistically between the N-CWS-treated workers and the untreated controls and a significant suppression of development of cancers was noted in the N-CWS-treated workers. Thus, it was concluded that the administration of N-CWS could prevent cancer development in humans.     

Degradation of endogenous proteins and internalized asialofetuin in primary cultured hepatocytes of rats

1. The effects of various metabolic and enzyme inhibitors on the degradation of endogenous proteins and internalized asialofetuin were examined in the primary cultured hepatocytes of rats. 2. The results showed the important physiological role of bestatin-sensitive aminopeptidases in the degradation of endogenous and internalized proteins as well as in the degradation of both long- and short-lived proteins.     

Electron spray ionization mass study on dioxygenation process in the reaction of catecholatoiron(III) complexes with molecular oxygen

The oxygenation reactions of two catecholatoiron(III) complexes, [Fe(TPA)(3,5-di-tert-butylcatecholate)]BPh₄ (1) and [Fe(TPA)(4-chlorocatecholate)]BPh₄ (2) (TPA = tris(pyridin-2-ylmethyl)amine), with O₂ have been investigated by means of ESI-MS spectrometry to elucidate the detailed mechanisms of oxygen atom insertion from O₂ into the catecholate ligands promoted by iron(III) complexes. Both 1 and 2 gave products formed by incorporation of two oxygen atoms into the catecholate ligands; 2,4-di-tert-butylmuconolactone for 1 and cis-dienelactone for 2. ESI-MS spectra of the products formed by the reaction with ¹⁸O₂ revealed the following points: (1) Two oxygen atoms of 2,4-di-tert-butylmuconolactone are mostly derived from ¹⁸O₂. (2) cis-Dienelactone is obtained as a mixture of mono- and double-¹⁸O-labeled species with a ratio of 50:50. These results suggest that the second oxygen atom is incorporated into muconic anhydride through nucleophilic attack on the carbonyl groups of muconic anhydride by the ¹⁸O-oxo-group of the metal center, and that this process competes with dissociation of muconic anhydride from the metal center.     

Elongation factor 2 in the liver and skeletal muscle of mice is decreased by starvation

We examined whether starvation affected the amount of EF-2 protein as well as the level of its mRNA in the liver and skeletal muscle of mice, to understand the molecular mechanism for nutritional adaptation of protein-turnover. Although the amount of EF-2 was diminished by starvation in each of the tissues examined, the amount of EF-2 mRNA did not decrease in parallel with the protein.     

Japan's nationwide long‐term monitoring survey of seaweed communities known as the “Monitoring Sites 1000”: Ten‐year overview and future perspectives

“Monitoring Sites 1000” – Japan's long‐term monitoring survey was established in 2003, based on the Japanese Government policy for the conservation of biodiversity. Ecological surveys have been conducted on various types of ecosystems at approximately 1000 sites in Japan for 15 years now and are planned to be carried out for 100 years. Since 2008, seaweed communities had been monitored at six sites, featuring the kelp (e.g. Saccharina and Ecklonia; Laminariales) and Sargassum (Fucales) communities in the subarctic and temperate regions of Japan. Annual surveys were carried out during the season when these canopy‐forming seaweeds are most abundant. A non‐destructive quadrat sampling method, with permanent quadrats placed along transects perpendicular to the shoreline, was used to determine species composition, coverage, and vertical distribution of seaweeds at these sites; while destructive sampling was done every 5 years to determine biomass. The occurrence of canopy‐forming species Saccharina japonica (var. japonica) and Ecklonia cava have appeared to be stable at the Muroran (southwestern part of Hokkaido Island) and Shimoda (Pacific coast of middle Honshu Island) sites, respectively; whereas the coverage of Ecklonia radicosa (= Eckloniopsis radicosa) at the Satsuma‐Nagashima site in southern part of Kyushu Island was highly variable until its sudden disappearance from the habitat in 2016. Thalli of E. radicosa lost most of their blades through browsing by herbivorous fish, and thus, this may be one of the causes of the decline. A shift in the community structure related to environmental changes had also been observed at some other sites. Pre‐ and post‐disaster data revealed the impact of the 2011 earthquake and tsunami disasters, including a shift in the vertical distribution of Ecklonia bicyclis (= Eisenia bicyclis) to shallower depths at the Shizugawa site in the Pacific coast of northern Honshu Island, due to seafloor subsidence.     

Effect of Starvation,Refeeding and Hydrocortisone Administration on Turnover of Myofibrillar Proteins Estimated by Urinary Excretion of Nτ-Methylhistidine in the Rat

Quantitative changes in fractional catabolic and synthetic rates of the myosin-actin pool in rat muscle under starvation and refeeding, during growth or after treatment with hydrocortisone were studied by estimating urinary excretion of N^τ-methylhistidine (3-methyl- histidine; Me-His).

Following deprivation of food, urinary Me-His output increased from 0.35 mg/day to 0.45 mg/day during first 2 day in spite of decreasing body Me-His pool. This high rate of Me-His excretion was maintained for the following 4 days of starvation and then decreased. When rats were refed a 20% casein diet after 10 days of starvation, Me-His excretion continued to decrease even after 3 days of refeeding. On the fifth day of refeeding, it began to rise progressively. During starvation, fractional catabolic rate of myosin-actin was about 3.7 %/day in comparison with 2.6 %/day of fed rats. After refeeding, the fractional catabolic rate decreased rapidly to a minimum value of 1.7 %/day on the third day. After that, it reached to a value of 2.6 %/day of fed rats. On the other hand, fractional synthetic rate of myosin-actin dropped immediately after fasting and the low rate of about 0.4 %/day was maintained during starvation period. Fractional synthetic rate recovered quickly after refeeding.

Urinary output of nitrogen and creatinine rose quickly on the first day after administration of hydrocortisone and on the second day it fell to their normal value. While Me-His excretion increased after injection of hydrocortisone up to 0.52 mg/day on the second day and this high excretion rate remained until the following day. From these results, it was shown that administration of hydrocortisone to rats enhances catabolism and reduces synthesis of myosin-actin. The results also show that the effect of this hormone on myofibrillar protein catabolism appears to last longer than its effect on nitrogen metabolism in the whole body judged from urinary nitrogen output.

Fractional rates of catabolism and synthesis of rat myosin-actin were 3.3 %/day (half- life of 21 days) and 7.2%/day, respectively, at the growth stage of 129 g body weight. These rates were 2.3 %/day (half-life of 30 days) and 2.8 %/day, respectively, at the mature stage of 363 g body weight.

Under the dietary conditions in this experiment, fractional synthetic rate changed far more dramatically than catabolic rate. This suggests that mass of muscle protein is primarily regulated by the rate of synthesis, although the rate of catabolism should not be neglected.     

Responses to desiccation stress in bryophytes and an important role of dithiothreitol-insensitive non-photochemical quenching against photoinhibition in dehydrated states

The effects of air drying and hypertonic treatments in the dark on seven bryophytes, which had grown under different water environments, were studied. All the desiccation-tolerant species tested lost most of their PSII photochemical activity when photosynthetic electron transport was inhibited by air drying, while, in all the sensitive species, the PSII photochemical activity remained at a high level even when photosynthesis was totally inhibited. The PSI reaction center remained active under drying conditions in both sensitive and tolerant species, but the activity became non-detectable in the light only in tolerant species due to deactivation of the cyclic electron flow around PSI and of the back reaction in PSI. Light-induced non-photochemical quenching (NPQ) was found to be induced not only by the xanthophyll cycle but also by a DeltapH-induced, dithiothreitol-insensitive mechanism in both the desiccation-tolerant and -intolerant bryophytes. Both mechanisms are thought to have an important role in protecting desiccation-tolerant species from photoinhibition under drying conditions. Fluorescence emission spectra at 77K showed that dehydration-induced quenching of PSII fluorescence was observed only in tolerant species and was due to neither state 1-state 2 transition nor detachment of light-harvesting chlorophyll protein complexes from PSII core complexes.The presence of dehydration-induced quenching of PSI fluorescence was also suggested.