Small GTPase Rin induces neurite outgrowth through Rac/Cdc42 and calmodulin in PC12 cells

The novel Ras-like small GTPase Rin is expressed prominently in adult neurons, and binds calmodulin (CaM) through its COOH-terminal–binding motif. It might be involved in calcium/CaM-mediated neuronal signaling, but Rin-mediated signal transduction pathways have not yet been elucidated. Here, we show that expression of Rin induces neurite outgrowth without nerve growth factor or mitogen-activated protein kinase activation in rat pheochromocytoma PC12 cells. Rin-induced neurite outgrowth was markedly inhibited by coexpression with dominant negative Rac/Cdc42 protein or CaM inhibitor treatment. We also found that expression of Rin elevated the endogenous Rac/Cdc42 activity. Rin mutant proteins, in which the mutation disrupted association with CaM, failed to induce neurite outgrowth irrespective of Rac/Cdc42 activation. Disruption of endogenous Rin function inhibited the neurite outgrowth stimulated by forskolin and extracellular calcium entry through voltage-dependent calcium channel evoked by KCl. These findings suggest that Rin-mediated neurite outgrowth signaling requires not only endogenous Rac/Cdc42 activation but also Rin–CaM association, and that endogenous Rin is involved in calcium/CaM-mediated neuronal signaling pathways

Shipping Conditions of Cavendish Bananas from the Philippines to Japan in Winter

現在わが国のバナナ消費量の85% を占めるフィリピン産Cavendish種バナナの流通経路を次の3段階に大別し,温度条件を中心にして輸送環境を追跡調査した. 1)プランテーション→輸出港(フィリピン) トラック輸送を含むこの工程での箱内温度は気温付近の25～28℃で,冬期にはこの工程で高温の影響を受けることはないと思われる. しかし,滞荷が生じるとパッキング・ハウスや桟橋で直射日光にさらされて,果実温度が一時的に30℃を越えることが予想される. とくに夏期には注意が必要であろう. 振動は輸送距離が短かい割には回数が多く,また3G以上の強振動が日本国内の通常の輸送状態の場合と比較してかなり多かった. 2)海上輸送(ダバオ→大阪) 5000トン級バナナボートで,目標温度13.5℃,5日間で低温輸送した. 3Aホールドでは冷却速度が遅く,大阪到着時にも14.5℃で目標には達しなかった. 一方,4Bホールドでは50時間後には目標に達し,その後も低下して12℃に至った. 今回は低温障害の発生はみられなかったが,危険性は十分にあり,今後船内での過冷却については十分注意する必要があろう. ホールド内湿度は荷積後数時間後には95% RHになり,以後そのまま保たれた. また大阪到着時のホールド内空気組成は酸素19.4% ,炭酸ガス0.20であった. 船の動揺による振動加速度は,使用した加遠度計では記録されなかった. 3)輸入港→追熟加工業者(日本) 大阪港→出雲市(バン・トラック),神戸港→米子市(二重シートがけ)の2回のトラック輸送を行なった. 峠を越える時点で,外気温は一時的に約0℃にまで低下したが,箱内温度はほとんど影饗を受けなかった. また振動は比較的少なかった

U-Th-Pb isotopic systematics of lherzolitic shergottite Yamato-793605

We have undertaken U-Th-Pb isotopic studies on lherzolitic shergottite, Yamato-793605. Four mineral separates (olivine, plagioclase, and two phases of pyroxene) and a whole-rock sample were leached with dilute acid in order to remove secondary Pb contamination. However, preferential leaching of U and Th over Pb occurred. The Pb isotopic data points of five residue fractions scattered, and a calculated Pb-Pb age does not clearly indicate either crystallization from a melt or a later disturbance to the U-Pb system, in contrast with other shergottites. The chord through U-Pb data points for pyroxene (PXl) leaches and residue intersects concordia at 4439±9 Ma and 212±62 Ma, suggesting a young disturbance event resulting in Pb loss. The later disturbance event partially reset the U-Pb system. The estimated ^U/^Pb (≡μ) value from the whole-rock residue for the source of Y-793605 is about 5,suggesting that Y-793605 was derived from a volatile-rich source environment and confirms a low-μ source for shergottites compared to volcanic rocks of the Earth

Rb-Sr isotopic systematics of lherzolitic shergottite Yamato-793605

We have undertaken a Rb-Sr isotopic study of the lherzolitic shergottite, Yamato (Y)-793605. The acid-leaching experiment designed to remove secondary Pb contamination during previous work with U-Th-Pb systematics did not significantly affect the Rb-Sr systematics. A Rb-Sr internal isochron obtained for combined data of leachates and residues yielded an age of 173±14Ma with an initial ^Sr/^Sr ratio of 0.71042±0.00007,using λ (^Rb)=1.402×10^y^. The Rb-Sr age, initial ^Sr/^Sr ratio and trace element abundance pattern of Y-793605 are all similar to those of lherzolitic shergottites, ALH 77005 and LEW 88516. We favor the 173Ma age for the time of igneous crystallization, because this interpretation is more consistent with characteristics of both the isotopic systematics and mineral chemistry. A minor disturbance of U-Pb systems observed in residue fractions indicate that shock event(s) occurred more recently, without affecting Rb-Sr system

Pyrene is highly emissive when attached to the RNA duplex but not to the DNA duplex: the structural basis of this difference

Through binding and fluorescence studies of oligonucleotides covalently attached to a pyrene group via one carbon linker at the sugar residue, we previously found that pyrene-modified RNA oligonucleotides do not emit well in the single-stranded form, yet the attached pyrene emits with a significantly high quantum yield upon binding to a complementary RNA strand. In sharp contrast, similarly modified pyrene–DNA probes exhibit very weak fluorescence both in the double-stranded and single-stranded forms. The pyrene-modified RNA oligonucleotides therefore provide a useful tool for monitoring RNA hybridization. The purpose of this paper is to present the structural basis for the different fluorescence properties of pyrene-modified RNA/RNA and pyrene-modified DNA/DNA duplexes. The results of absorption, fluorescence anisotropy and circular dichroism studies all consistently indicated that the pyrene attached to the RNA duplex is located outside of the duplex, whereas the pyrene incorporated into the DNA duplex intercalates into the double helix. (1)H NMR measurements unambiguously confirmed that the pyrene attached to the DNA duplex indeed intercalates between the base pairs of the duplex. Molecular dynamics simulations support these differences in the local structural elements around the pyrene between the pyrene–RNA/RNA and the pyrene–DNA/DNA duplexes

Vasopressin-independent renal urinary concentration: Increased rBSC1 and enhanced countercurrent multiplication

Vasopressin-independent renal urinary concentration: Increased rBSC1 and enhanced countercurrent multiplication.BackgroundA close association between the expression of the sodium transporter, rat bumetanide sensitive cotransporter (rBSC), in thick ascending limb of Henle and urinary concentration has been reported. However, direct evidence for this association and the mechanism of rBSC1 expression are still to be elucidated.MethodsBrattleboro (BB) rats weighing approximately 200g were dehydrated by water restriction for 4 hours, which induced around a 5% body weight reduction. Although plasma arginine vasopressin (AVP) was undetectable even after the water restriction, BB rats concentrated urine from 182 ± 23 (mean ± SD) at baseline to 404 ± 65 mOsm/kg · H2O.ResultsUrinary volume was reduced from 5.8 ± 1.8 to 1.4 ± 0.6mL/h. This treatment significantly increased sodium and urea accumulation in the renal medulla and reduced urinary sodium excretion. rBSC1 signals for both mRNA and protein were increased in dehydrated rats, although aquaporin type 2 (AQP2) expression was not enhanced in dehydrated BB rats. Subcutaneous infusion of desmopressin acetate (DDAVP) intensified rBSC1 signals of BB rats more than those in dehydrated condition.ConclusionDehydration increased rBSC1 expression and enhanced countercurrent multiplication even in AVP deficiency. These results supply strong evidence for the association between rBSC1 expression and urinary concentration, and indicate the presence of an AVP-independent mechanism for urine concentration