Alicyclic acid metabolism in plants 3. Fate of 14C-shikimate and 14C-quinate in mung bean plants

Young mung bean plants (Phaseolus mungo) were exposed to ¹⁴C-shikimateor ¹⁴C-quinate in the light. After 8 or 23.5 hr of incubationat 25°C, radioactivities in free and bound amino acids,organic acids, soluble and insoluble carbohydrates, ether-solublefraction and lignin were determined. Shikimic and quinic acidswere separated by the combined use of paper-chromatography andcolumn chromatography. Specific activity of formed quinate orshikimate was only slightly lower than that of fed shikimateor quinate. Specific activities of phenylalanine, tyrosine andbound tryptophan were high as compared with those of non-aromaticamino acids. Discussion is focused upon the interconversionbetween shikimate and quinate, and their roles in the biosynthesisof aromatic amino acids. (Received November 15, 1968; )     

Partial Synchronization of Carrot Cell Culture by Auxin Deprivation

A strain of carrot cells (Daucus carota cv. Kintoki) grew exponentially in the presence of 2,4-dichlorophenoxyacetic acid (2,4-D, 1 mg/1) with a doubling time of about 2 days. When those cells were transferred to a medium lacking 2,4-D, they continued to grow at almost the same rate for about a week. When the cells were again transferred to the auxin-free medium, the rate of cell division gradually decreased. After the cell division had ceased, cells were returned to the ordinary 2,4-D medium. A burst of cell divisions occurred after about 2 days. Timing of DNA synthesis and of mitosis suggested that the cells had been arrested at G₁ phase. In a medium containing indoleacetic acid instead of 2,4-D, the auxin was rapidly degraded and the culture was similarly synchronized as in the auxin-omitted medium.     

Cytokinin Activity of Benzoylaminodeazapurines, Pentanoylaminodeazapurines and their Corresponding Purine Analogs in Five Bioassays

Cytokinin activities of 6-benzoylamino-1, 6-benzoylamino-3-, 6-pentanoylamino-1- and 6-pentanoylamino-3-deazapurines and their corresponding purine analogs, 6-benzoylaminopurine and 6-pentanoylaminopurine, were examined using five bioassay systems, tobacco callus growth, bud formation on tobacco callus, lettuce seed germination, fresh weight increase of radish cotyledons and retardation of chlorophyll degradation in radish cotyledons. 6-Benzoylamino- and 6-pentanoylamino-1-deazapurines showed stronger cytokinin activity than their corresponding purine analogs in all bioassays used. In tobacco callus growth, 6-benzoylamino-1-deazapurine was nearly as active as zeatin, one of the most active adenylate cytokinins. On the other hand, 6-benzoylamino- and 6-pentanoylamino-3-deazapurines were as active as or less active than corresponding purine analogs.     

Crystal Structures of Human Dipeptidyl Peptidase Ⅳ in its Apo and Diprotin B-complexed Forms

Dipeptidyl peptidase Ⅳ (DPPIV), which belongs to the prolyl oligopeptidase family of serine proteases, is known to have a variety of regulatory biological functions and has been shown to be implicated in type 2 diabetes. It is therefore important to develop selective human DPPIV (hDPPIV) inhibitors. In this study, we determined the crystal structure of apo hDPPIV at 1.9 A resolution. Our high-resolution crystal structure of apo hDPPIV revealed the presence of sodium ion and glycerol molecules at the active site. In order to elucidate the hDPPIV binding mode and substrate specificity, we determined the crystal structure of hDPPIV-diprotin B (Val-Pro-Leu) complex at 2.1 A resolution, and clarified the difference in binding mode between diprotin B and diprotin A (Ile-Pro-Ile) into the active site of hDPPIV. Comparison between our crystal structures and the reported apo hDPPIV structures revealed that positively charged functional groups and conserved water molecules contributed to the interaction of ligands with hDPPIV. These results are useful for the design of potent hDPPIV inhibitors.     

The translocation of photosynthetic products from mesophyll into midrib in tobacco plant III. The transformation of translocated 14C-sugars in the veins

¹⁴C-U-sugars were introduced into tobacco plants through themesophyll, the veins of the first order of branching, and themidrib, and ¹⁴C-compounds in the veins and the midrib whichtranslocated towards the base of the midrib were traced duringthe period of 120 min after the ¹⁴C-sugar introductions. 1) When ¹⁴C-U-sucrose was introduced into the leaf, no matterwhat the means of feeding was, most of the ¹⁴C which translocatedbasipetally in the veins and the midrib was found in the formof sucrose. 2) When ¹⁴C-U-glucose or ¹⁴C-U-fructose was administered tothe leaf dirough the cut vein of the first order of branching,most of the ¹⁴C which translocated basipetally in the veinsand the midrib was found in the form of sucrose. 3) ¹⁴C-U-glucose or ¹⁴C-U-fructose injected into the vascularbundles of the midrib was translocated basipetally, as such,10 and 30 min after injection; and at 30 min, the amount ofthe ¹⁴C-sucrose in the midrib attained 9–22% of the 80%ethanol-soluble ¹⁴C in the midrib. 4) When ¹⁴C-U-glucose or ¹⁴C-U-fructose was supplied to themesophyll, the radioactivities of these hexoses were predominantin the first and second veins soon after application, then decreasingwith a concomitant increase in the radioactivity of the ¹⁴C-sucrose. From these results, it was inferred that in the veins of thefirst and second order of branching, glucose and fructose whichmoved from the mesophyll did not translocate as such, but wereutilized for the synthesis of sucrose available for translocationvia the midrib to the stem. ¹A part of this paper was presented at the Crop Science Societyof Japan, in April, 1969 (Received December 8, 1969; )     

Distribution of the Argentine ant, Linepithema humile, along the Seto Inland Sea, western Japan: Result of surveys in 2003–2005

The distribution of the Argentine ant, Linepithema humile, was investigated in 65 cities or towns along the Seto Inland Sea, western Japan in 2003–2005. Our results include all available information of their distribution in Japan until 2005. Argentine ants have invaded Aichi Prefecture (Tahara‐shi), Hyogo Prefecture (Kobe‐shi), Hiroshima Prefecture (Hiroshima‐shi, Fuchu‐cho, Hatsukaichi‐shi, Ono‐cho and Otake‐shi), and Yamaguchi Prefecture (Iwakuni‐shi and Yanai‐shi). The most widespread distribution was found around Hatsukaichi‐shi including the westernmost part of Hiroshima‐shi and the easternmost of Ono‐cho.     

High temperature causes arrest of cell cycle in G2 phase in BmN cells derived from the silkworm, Bombyx mori

Abstract.  The influence of temperature on the insect cell line, BmN, derived from the silkworm, Bombyx mori is investigated. These cells proliferate at an accelerated pace as the temperature increases from 22 to 30 °C, but the growth rate slows at 34 °C, and proliferation stops at 38 °C. At high temperatures, abnormal cellular morphology is observed. Cells treated at 38 °C have cytoplasmic bilateral protrusions and they gradually aggregate and float in the medium. BmN cells without proliferation at 38 °C are viable but have reduced DNA synthesis. At high temperatures, the cell cycle of BmN cells halts at the G₂ phase. After heat treatment of the larvae, an accumulation of larval haemocytes with high DNA content is found, which suggests that the cell cycle arrest at G₂ also occurs in the silkworm at high temperatures.     

INCORPORATION OF AMINO ACIDS INTO SEA URCHIN EGGS STIMULATED INSUFFICIENTLY WITH AN ACTIVATING REAGENT

Investigations were performed on the incorporation of valine-¹⁴C and leucine-³H into sea urchin eggs which were stimulated insufficiently with an activating reagent. Materials used were Pseudocentrotus, Hemicentrotus and Anthocidaris. An insufficient stimulation enhanced the incorporation of amino acids into the eggs, although it provoked no visible cortical changes. The amount of incorporation in this case was 1.6 to 2.7 times as much as that into untreated eggs. In fully activated eggs, the amount of incorporation was more than 4 times that in untreated eggs. The fact that the incorporation of amino acids is increased without accompanying breakdown of the cortical granules indicates that the increase may be linked to an invisible change, probably the fertilizationwave, which is caused by an insufficient stimulation.