No-go decay and nonstop are mRNA surveillance pathways that detect translational stalling degrade the underlying mRNA, allowing correct translation of genetic code. In eukaryotes, protein complex Pelota (yeast Dom34) Hbs1 GTPase recognizes stalled ribosome containing defective mRNA. Recently, we found archaeal (aPelota) associates with elongation factor 1α (aEF1α) to act in pathway, which accounts for lack an ortholog archaea. Here present structure aPelota GTP-bound aEF1α determined at...

Modulation of voltage-gated potassium (Kv) channels by auxiliary subunits is central to the physiological function in brain and heart1,2. Native Kv4 tetrameric form macromolecular ternary complexes with two β-subunits-intracellular Kv channel-interacting proteins (KChIPs) transmembrane dipeptidyl peptidase-related (DPPs)-to evoke rapidly activating inactivating A-type currents, which prevent backpropagation action potentials1-5. However, modulatory mechanisms channel remain largely unknown....

Endogenous parathyroid hormone (PTH) and PTH-related peptide (PTHrP) bind to the receptor 1 (PTH1R) activate stimulatory G-protein (Gs) signaling pathway. Intriguingly, two ligands have distinct physiological properties: PTH evokes prolonged Gs activation, whereas PTHrP transient activation with reduced bone-resorption effects. The molecular actions are ascribed differences in ligand recognition dissociation kinetics. Here, we report cryoelectron microscopic structures of six forms human...

RNA-guided CRISPR-Cas nucleases are widely used as versatile genome-engineering tools. Recent studies identified functionally divergent type V Cas12 family enzymes. Among them, Cas12c2 binds a CRISPR RNA (crRNA) and trans-activating crRNA (tracrRNA) recognizes double-stranded DNA targets with short TN PAM. Here, we report the cryo-electron microscopy structures of Cas12c2-guide binary complex RNA-target ternary complex. The revealed that tracrRNA form an unexpected X-junction architecture,...

Glutamate is a pivotal excitatory neurotransmitter in mammalian brains, but excessive glutamate causes numerous neural disorders. Almost all extracellular retrieved by the glial transporter, Excitatory Amino Acid Transporter 2 (EAAT2), belonging to SLC1A family. However, some cancers, EAAT2 expression enhanced and resistance therapies metabolic disturbance. Despite its crucial roles, detailed structural information about has not been available. Here, we report cryo-EM structures of human...

Comparative features of the dorsal tongue epithelia in musk shrews, mongooses and rats were described. The shapes filiform papillae different each species. distribution pattern was similar both shrews mongoose, that form changed gradually from lingual apex to posterior part body. By contrast, types distributed on definite areas surface rat. Microridges interpapillar shrew mongoose presented a clear outline, but those rat not so distinct. In all species, upper did show any distinct microridges.

First steps of translocation elucidated Ribosomes synthesizing membrane or secretory proteins are targeted to the endoplasmic reticulum (ER) in eukaryotic cells by signal recognition particle (SRP). Upon reaching ER, SRP interacts with its receptor promote transfer sequence protein-conducting channel translocon. Kobayashi et al. studied ribosomal complex that forms on which and interact newly synthesized protein The observed organization assembly reveals roles multiple eukaryotic-specific...

Co-translational protein targeting to membranes by the signal recognition particle (SRP) is a universally conserved pathway from bacteria humans. In mammals, SRP and its receptor (SR) have many additional RNA features components compared bacterial system, which were recently shown play regulatory roles. Due complexity, mammalian process mechanistically not well understood. particular, it clear how recognizes translating ribosomes with exposed sequences GTPase activity of SR regulated. Here,...

The tongue in four species of penguin was investigated by light microscopy and scanning electron microscopy, with special reference to the lingual papillae.1) middle contains a pair long cartilages tendons accompanied striated muscle bundles.2) Large, spine-like, caudally directed papillae (filiform-like papillae) densely cover dorsal surface tongue, apparently serving catch fishes.3) By epithelium are seen as thick cornified layer, but lateral lower surfaces have thinner layer.4) connective...

The molecular mechanisms of translation termination and mRNA surveillance in archaea remain unclear. In eukaryotes, eRF3 HBS1, which are homologous to the tRNA carrier GTPase EF1α, respectively bind eRF1 Pelota decipher stop codons or facilitate surveillance. However, genome-wide searches have failed detect any orthologs both GTPases. Here, we report crystal structure aRF1 from an archaeon, Aeropyrum pernix , present strong evidence that authentic archaeal EF1α acts as a for aPelota. binding...

The effectiveness of an H 2 /O torch igniter, which injects combustion gas, and a plasma igniter in promoting ignition /air mixture within supersonic combustor was investigated analytically experimentally. First, bulk temperature radical concentration O were estimated by asymptotic analysis. Those the also obtained equilibrium calculation. Second, gas sampling conducted to determine injectant equivalence ratio region ignition, namely, recirculation at base rearward-facing step. Then, time...

A scramjet combustor, which has a constant cross-sectional area combustor (designated as 1), and diverging 2), was examined with both single two-stage fuel injection to determine whether it could be operated in the ramjet mode. The directly connected facility nozzle, Mach number at exit of nozzle being 2.4. Total temperature total pressure were 800 K 1.0 MPa, respectively. Pitot measurements gas sampling for an equivalence ratio (Φ) 0.2 showed that there separated region supersonic core...

Connective tissue papillae underlying epithelial cell layers of the lingual newborn mongrel dogs were exposed by long term hydrochloric acid treatment and observed scanning electron microscopy.Each filiform ovoid shape (100-130μm in diameter) contained a connective papilla representing smaller elliptical protrusion (90-100μm length, 70-80μm width). Its overview showed horse-shoe shape, opening anteriorly. posterior curvature projected conical node with rounded apex.Each fungiform (150μm...

The morphological structure of the lingual papillae and their connective tissue cores (CTC) in a rabbit were studied using LM SEM compared to that other animal species. Externally, filiform distributed on anterior surface dorsal tongue short conical with round base had flat area upper half. CTC roughly triangular plate-like top. Several small protrusions found both inclined planes triangle. Spearhead-like edge prominence branched posteriorly wide prominence. These slightly ramified differed...

The pancreatic islet cells of the toads (Bufo vulgaris formosus) captured in December was observed by electron microscope.1. Pancreatic toad can be classified into A-, B-, third, fourth and fifth types. A- B-cells are most common, whereas third type less common least common.2. α-granules A-cells agree ultrastructural properties with those other animal species vertebrate. Each them consists a spherical granule core high density smooth limiting membrane applied closely to it; lucent space...

ネコの舌粘膜の上皮を塩酸長期処理法で剥離し, 固有層乳頭の表面を走査電子顕微鏡で観察した。前舌中央部には大型の糸状乳頭が分布するが, 舌尖を含むこれらの周辺部は小型の糸状乳頭によって取り囲まれる。両者の境界部には中問型が存在する。糸状乳頭に混じって茸状乳頭が散在性にみられる。舌後部には有郭乳頭がV字形に並び, これより後方の舌根部には巨大円錐乳頭が密生する。固有層乳頭の形は小型糸状乳頭では円筒状で, 中型では小突起が輪状に並び, 大型では太い主突起が一本加わり後方にのびる。茸状乳頭の固有層乳頭はサンゴ様を呈し, 頂上にいくつか円い陥凹部をもつ。有郭乳頭では上皮が剥離されると小さな凹凸が現れる。舌根部の巨大円錐乳頭でも小さな凹凸が多数現れるが, 先端部では少ない。これらの基部に後舌腺の導管が開口する。

The lingual papillae and the connective tissue cores (CTC) of American beaver were examined by light scanning electron microscopy. tongue was about 9 cm in length, 3.5 width, has a prominence. Four types (filiform, fungiform, vallate foliate papillae) observed. filiform can be classified into three large dorm-like papillae). Filiform distributed on anterior posterior prominence consisted thick main process several small accessory processes. After removal epithelium, CTCs had U-shaped,...

The structure of the lingual papillae and ultrastructure surface dorsal epithelial cells squirrel monkeys were observed by scanning electron microscopy. Filiform distributed over entire tongue, except for radix zone. Fungiform scattered among these filiform papillae. In middle posterior end body, a single vallate papilla was located. Higher magnification epithelium revealed that prominent microridges elevated intercellular borders occurred widely in basofrontal area papillae, interpapillar...