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31.
Hideyuki Yoshida Caleb A. Lareau Ricardo N. Ramirez Samuel A. Rose Barbara Maier Aleksandra Wroblewska Fiona Desland Aleksey Chudnovskiy Arthur Mortha Claudia Dominguez Julie Tellier Edy Kim Dan Dwyer Susan Shinton Tsukasa Nabekura YiLin Qi Bingfei Yu Michelle Robinette Christophe Benoist 《Cell》2019,176(4):897-912.e20
32.
Brassica S-Proteins Accumulate in the Intercellular Matrix along the Path of Pollen Tubes in Transgenic Tobacco Pistils 总被引:2,自引:5,他引:2 下载免费PDF全文
Kandasamy MK Dwyer KG Paolillo DJ Doney RC Nasrallah JB Nasrallah ME 《The Plant cell》1990,2(1):39-49
A tobacco plant transformed with a Brassica oleracea SLG-22 gene was analyzed by immunocytochemical methods to determine the localization of the transgene-encoded protein product. Immunolabeling was observed in the pistil along the path followed by pollen tubes after pollination. S-antigen accumulated in the intercellular matrix of the transmitting tissue of the style and its continuation in the basal portion of the stigma and outside a few special cells of the placental epidermis of the ovary. This pattern of S-antigen distribution closely resembles that described for the S-associated glycoproteins of self-incompatible Nicotiana alata and differs from its distribution in B. oleracea. 相似文献
33.
The roles of Ca2+ mobilization in development of tension induced by acetylcholine (ACh, 0.1–100 µM) in swine tracheal smooth muscle strips were studied. Under control conditions, ACh induced a transient increase in free cytosolic calcium concentration ([Ca2+]i) that declined to a steady-state level. The peak increase in [Ca2+]i correlated with the magnitude of tension at each [ACh] after a single exposure to ACh, while the steady-state [Ca2+]i did not. Removal of extracellular Ca2+ had little effect on peak [Ca2+]i but greatly reduced steady-state increases in [Ca2+]i and tension. Verapamil inhibited steady-state [Ca2+]i only at [ACh]<1 µM. After depletion of internal Ca2+ stores by 10 min exposure to ACh in Ca2+-free solution and then washout of ACh for 5 min in Ca2+-free solution, simultaneous re-exposure to ACh in the presence of 2.5 mM Ca2+ increased [Ca2+]i to the control steady-state level without overshoot. The tension attained was the same as control for each [ACh] used. Continuous exposure to successively increasing [ACh] (0.1–100 µM) also reduced the overshoot of [Ca2+]i at 10 and 100 µM ACh, yet tension reached control levels at each [ACh] used. We conclude that the steady-state increase in [Ca2+]i is necessary for tension maintenance and is dependent on Ca2+ influx through voltage-gated calcium channels at 0.1 µM ACh and through a verapamil-insensitive pathway at 10 and 100 µM. The initial transient increase in calcium arises from intracellular stores and is correlated with the magnitude of tension only in muscles that have completely recovered from previous exposure to agonists. 相似文献
34.
Mosyak L Wood A Dwyer B Buddha M Johnson M Aulabaugh A Zhong X Presman E Benard S Kelleher K Wilhelm J Stahl ML Kriz R Gao Y Cao Z Ling HP Pangalos MN Walsh FS Somers WS 《The Journal of biological chemistry》2006,281(47):36378-36390
Nogo receptor (NgR)-mediated control of axon growth relies on the central nervous system-specific type I transmembrane protein Lingo-1. Interactions between Lingo-1 and NgR, along with a complementary co-receptor, result in neurite and axonal collapse. In addition, the inhibitory role of Lingo-1 is particularly important in regulation of oligodendrocyte differentiation and myelination, suggesting that pharmacological modulation of Lingo-1 function could be a novel approach for nerve repair and remyelination therapies. Here we report on the crystal structure of the ligand-binding ectodomain of human Lingo-1 and show it has a bimodular, kinked structure composed of leucine-rich repeat (LRR) and immunoglobulin (Ig)-like modules. The structure, together with biophysical analysis of its solution properties, reveals that in the crystals and in solution Lingo-1 persistently associates with itself to form a stable tetramer and that it is its LRR-Ig-composite fold that drives such assembly. Specifically, in the crystal structure protomers of Lingo-1 associate in a ring-shaped tetramer, with each LRR domain filling an open cleft in an adjacent protomer. The tetramer buries a large surface area (9,200 A2) and may serve as an efficient scaffold to simultaneously bind and assemble the NgR complex components during activation on a membrane. Potential functional binding sites that can be identified on the ectodomain surface, including the site of self-recognition, suggest a model for protein assembly on the membrane. 相似文献
35.
Dwyer DS 《Proteins》2006,63(4):939-948
The electronic properties of amino acid side-chains are emerging as an important factor in the preference for secondary structure in proteins. These properties have not been fully characterized, nor has their role in the behavior of peptides been explored in any detail. The present studies sought to evaluate several possibilities: 1) that hydrophilicity can be expressed solely in electronic terms, 2) that substituent effects of side-chains extend across the peptide bond, and (3) nearest-neighbor effects in dipeptides correlate with secondary structural preferences. Quantum mechanics (QM) calculations were used to define the electronic properties of individual amino acids and dipeptides. It was found that the hydrophilicity of an amino acid side-chain can be accurately represented as a function of the electron densities of its component atoms. In addition, the nature of an amino acid in the second position of a dipeptide affects the electronic properties (Mulliken populations and electron densities) of the main-chain atoms of the first residue. Certain electronic features of the dipeptides strongly correlated with propensity for secondary structure. Specifically, Mulliken population data at the Calpha atom and N atom predicted preference for alpha-helices versus coil and strand conformations, respectively. Analysis of dipeptides arrayed in either helical or extended structures revealed lengthening of main-chain bonds in the alpha-helical conformations. A thorough characterization of the electronic properties of amino acids and short peptide segments may provide a better understanding of the forces that determine secondary structure in proteins. 相似文献
36.
CJ Cooksey 《Biotechnic & histochemistry》2016,91(6):438-444
Malachite green was discovered independently by two researchers in Germany in the 19th century and found immediate employment as a dye and a pigment. Subsequently, other uses, such as staining biological specimens, emerged. A much later application was the control of fungal and protozoan infections in fish, for which the dye remains popular, although illegal in many countries owing to a variety of toxicity problems. In solution, malachite green can exist as five different species depending on the pH. The location of the positive charge of the colored cation on a carbon atom or a nitrogen atom is still debated. The original names of this dye, and their origins, are briefly surveyed. 相似文献
37.
Diana O Rios‐Szwed Hironori Suzuki Andreas Kniss Frank Löhr Soichi Wakatsuki Volker Dötsch Ivan Dikic Renwick CJ Dobson David G McEwan 《EMBO reports》2017,18(8):1382-1396
Through the canonical LC3 interaction motif (LIR), [W/F/Y]‐X1‐X2‐[I/L/V], protein complexes are recruited to autophagosomes to perform their functions as either autophagy adaptors or receptors. How these adaptors/receptors selectively interact with either LC3 or GABARAP families remains unclear. Herein, we determine the range of selectivity of 30 known core LIR motifs towards individual LC3s and GABARAPs. From these, we define a I nteraction 相似文献
38.
39.
Jessica K. Holien Benjamin Seibt Veena Roberts Evelyn Salvaris Michael W. Parker Peter J. Cowan Karen M. Dwyer 《Bioorganic & medicinal chemistry letters》2018,28(2):202-206
Adenosine is considered the canonical ligand for the adenosine 2B receptor (A2BR). A2BR is upregulated following kidney ischemia augmenting post ischemic blood flow and limiting tubular injury. In this context the beneficial effect of A2BR signaling has been attributed to an increase in the pericellular concentration of adenosine. However, following renal ischemia both kidney adenosine monophosphate (AMP) and adenosine levels are substantially increased. Using computational modeling and calcium mobilization assays, we investigated whether AMP could also be a ligand for A2BR.The computational modeling suggested that AMP interacts with more favorable energy to A2BR compared with adenosine. Furthermore, AMPαS, a non-hydrolyzable form of AMP, increased calcium uptake by Chinese hamster ovary (CHO) cells expressing the human A2BR, indicating preferential signaling via the Gq pathway. Therefore, a putative AMP-A2BR interaction is supported by the computational modeling data and the biological results suggest this interaction involves preferential Gq activation. These data provide further insights into the role of purinergic signaling in the pathophysiology of renal IRI. 相似文献
40.