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R Figueroa A Soto G González M Pieber C Romero J C Tohá 《Journal of theoretical biology》1972,36(2):321-326
The messenger RNAs of 72 natural proteins built using only the first two bases of their animo acid codons show that antiparallel auto-complementarities of four or more successive bases are avoided. Supported by this fact, the third base of each codon of the mRNA of human heart cytochrome c was selected, choosing every time (with a computer) that base which induced the lowest number of antiparallel anti-complementarities of four or more successive bases with all the nucleotides of the rest of messenger. The cytochrome messenger found has no antiparallel auto-complementarity of five or more successive bases and only 51 of four. Thus at 37 °C, a monotenic structure of messenger would be preferred. 相似文献
514.
A toxic diterpenoid diester and a monoester were isolated from the fruits of Aleurites fordii. The structure of the monoester was found to be 13-O-acetyl-16-hydroxyphorbol by transforming it into bisdehydrophorbol-(12,20)-diacetate. The structure of the toxic constituent was established as 12-O-palmityl-13-O-acetyl-16-hydroxyphorbol by partial synthesis from the monoester. 相似文献
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Katsuhiro Nishiyama Jiro Okada Yoshihiro Toh 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》2007,193(9):963-971
The behavioral responses to attractive and aversive odors were examined in blinded adult male cockroaches under tethered-walking
conditions. A sex pheromone-like stimulant derived from adult virgin females and artificially synthesized limonene were used
as attractive and aversive odor sources, respectively. When a searching animal was stimulated with the attractive female-derived
odor, the horizontal deflections of both the antennae were increased, and in most cases the vertical antennal positions were
shifted downward. The stimulation also significantly decreased the walking speed of the animal. These behavioral changes imply
a careful search in the immediate surroundings. The aftereffect of the sex pheromone was more pronounced on locomotion than
on antennal movement. On the other hand, stimulation with the aversive odor (limonene) tended to suppress active antennal
movement, and also increased the walking speed. Immediately after the withdrawal of the aversive odor, the active movement
of the antennae was resumed, and the walking speed rapidly decreased to a level approximately the same as that of the control
period. These results indicate that the responses to the qualitatively opposite types of odor are reciprocal to each other
with regard to both antennal movement and locomotion. 相似文献
517.
Background
Structural alignment of RNAs is becoming important, since the discovery of functional non-coding RNAs (ncRNAs). Recent studies, mainly based on various approximations of the Sankoff algorithm, have resulted in considerable improvement in the accuracy of pairwise structural alignment. In contrast, for the cases with more than two sequences, the practical merit of structural alignment remains unclear as compared to traditional sequence-based methods, although the importance of multiple structural alignment is widely recognized. 相似文献518.
Hirotaka Toh Takashi Nozawa Atsuko Minowa-Nozawa Miyako Hikichi Shintaro Nakajima Chihiro Aikawa 《Autophagy》2020,16(2):334-346
ABSTRACTAutophagy selectively targets invading bacteria to defend cells, whereas bacterial pathogens counteract autophagy to survive in cells. The initiation of canonical autophagy involves the PIK3C3 complex, but autophagy targeting Group A Streptococcus (GAS) is PIK3C3-independent. We report that GAS infection elicits both PIK3C3-dependent and -independent autophagy, and that the GAS effector NAD-glycohydrolase (Nga) selectively modulates PIK3C3-dependent autophagy. GAS regulates starvation-induced (canonical) PIK3C3-dependent autophagy by secreting streptolysin O and Nga, and Nga also suppresses PIK3C3-dependent GAS-targeting-autophagosome formation during early infection and facilitates intracellular proliferation. This Nga-sensitive autophagosome formation involves the ATG14-containing PIK3C3 complex and RAB1 GTPase, which are both dispensable for Nga-insensitive RAB9A/RAB17-positive autophagosome formation. Furthermore, although MTOR inhibition and subsequent activation of ULK1, BECN1, and ATG14 occur during GAS infection, ATG14 recruitment to GAS is impaired, suggesting that Nga inhibits the recruitment of ATG14-containing PIK3C3 complexes to autophagosome-formation sites. Our findings reveal not only a previously unrecognized GAS-host interaction that modulates canonical autophagy, but also the existence of multiple autophagy pathways, using distinct regulators, targeting bacterial infection.Abbreviations: ATG5: autophagy related 5; ATG14: autophagy related 14; ATG16L1: autophagy related 16 like 1; BECN1: beclin 1; CALCOCO2: calcium binding and coiled-coil domain 2; GAS: group A streptococcus; GcAV: GAS-containing autophagosome-like vacuole; LAMP1: lysosomal associated membrane protein 1; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MTORC1: mechanistic target of rapamycin kinase complex 1; Nga: NAD-glycohydrolase; PIK3C3: phosphatidylinositol 3-kinase catalytic subunit type 3; PtdIns3P: phosphatidylinositol-3-phosphate; PtdIns4P: phosphatidylinositol-4-phosphate; RAB: RAB, member RAS oncogene GTPases; RAB1A: RAB1A, member RAS oncogene family; RAB11A: RAB11A, member RAS oncogene family; RAB17: RAB17, member RAS oncogene family; RAB24: RAB24, member RAS oncogene family; RPS6KB1: ribosomal protein S6 kinase B1; SLO: streptolysin O; SQSTM1: sequestosome 1; ULK1: unc-51 like autophagy activating kinase 1; WIPI2: WD repeat domain, phosphoinositide interacting 2 相似文献