Biotransformation of endorphins by a synaptosomal plasma membrane preparation of rat brain and by human serum.

β-Endorphin (β-LPH 61–91), γ-endorphin (61–77), des-tyrosine-γ-endorphin (62–77), α-endorphin (61–76), and β-LPH 61–69 either labeled with [¹²⁵I] at the N-terminal 61-tyrosine residue or unlabeled were incubated with a crude synaptosomal plasma membrane fraction of rat brain or in human serum. At different time intervals the release of [¹²⁵I]-tyrosine or the change in immunoreactivity of the endorphins was determined. The cSPM preparation displayed both high aminopeptidase and endopeptidase activities. In contrast, human serum mainly contained aminopeptidase activity. The data suggest that functional endorphin metabolism may occur at the synaptosomal plasma membrane. These membranes may potentially be involved in the formation of behaviorally active endorphin fragments.     

CircR2Disease v2.0: An Updated Web Server for Experimentally Validated circ RNA–disease Associations and Its Application

With accumulating dysregulated circular RNAs(circRNAs) in pathological processes,the regulatory functions of circRNAs, especially circRNAs as microRNA(miRNA) sponges and their interactions with RNA-binding proteins(RBPs), have been widely validated. However, the collected information on experimentally validated circRNA–disease associations is only preliminary.Therefore, an updated CircR2Disease database providing a comprehensive resource and web tool to clarify the relationships between circRNAs...     

A Yeast BiFC-seq Method for Genome-wide Interactome Mapping

Genome-wide physical protein±protein interaction(PPI) mapping remains a major challenge for current technologies. Here, we reported a high-efficiency BiFC-seq method, yeastenhanced green fluorescent protein-based bimolecular fluorescence complementation(y EGFPBiFC) coupled with next-generation DNA sequencing, for interactome mapping. We first applied y EGFP-BiFC method to systematically investigate an intraviral network of the Ebola virus.Two-thirds(9/14) of known interactions of EBOV were recap...     

Global Landscape of Native Protein Complexes in Synechocystis sp. PCC 6803

Synechocystis sp. PCC 6803(hereafter: Synechocystis) is a model organism for studying photosynthesis, energy metabolism, and environmental stress. Although known as the first fully sequenced phototrophic organism, Synechocystis still has almost half of its proteome without functional annotations. In this study, by using co-fractionation coupled with liquid chromatographytandem mass spectrometry(LC-MS/MS), we define 291 multi-protein complexes, encompassing24,092 protein±protein interactions(PPIs...     

Battling for Ribosomes: Translational Control at the Forefront of the Antiviral Response

In the early stages of infection, gaining control of the cellular protein synthesis machinery including its ribosomes is the ultimate combat objective for a virus. To successfully replicate, viruses unequivocally need to usurp and redeploy this machinery for translation of their own mRNA. In response, the host triggers global shutdown of translation while paradoxically allowing swift synthesis of antiviral proteins as a strategy to limit collateral damage. This fundamental conflict at the level of translational control defines the outcome of infection. As part of this special issue on molecular mechanisms of early virus–host cell interactions, we review the current state of knowledge regarding translational control during viral infection with specific emphasis on protein kinase RNA-activated and mammalian target of rapamycin-mediated mechanisms. We also describe recent technological advances that will allow unprecedented insight into how viruses and host cells battle for ribosomes.     

CO2 Saturation and Trophic Shift Induced by Microbial Metabolic Processes in a River-Dominated Ocean Margin (Tropical Shallow Lagoon,Chilika, India)

An effort has been made for the first time in Asia's largest brackish water lagoon, Chilika, to investigate the spatio-temporal variability in primary productivity (PP), bacterial productivity (BP), bacterial abundance (BA), bacterial respiration (BR) and bacterial growth efficiency (BGE) in relation to partial pressure of CO₂ (pCO₂) and CO₂ air–water flux and the resultant trophic switchover. Annually, PP ranged between 24 and 376 µg C L^?1 d^?1 with significantly low values throughout the monsoon (MN), caused by light limitation due to inputs of riverine suspended matter. On the contrary, BP and BR ranged from 11.5 to 186.3 µg C L^?1 d^?1 and from 14.1 to 389.4 µg C L^?1 d^?1, respectively, with exceptionally higher values during MN. A wide spatial and temporal variation in the lagoon trophic status was apparent from BP/PP (0.05–6.4) and PP/BR (0.10–18.2) ratios. The seasonal shift in net pelagic production from autotrophy to heterotrophy due to terrestrial organic matter inputs via rivers, enhanced the bacterial metabolism during the MN, as evident from the high pCO₂ (10,134 µatm) and CO₂ air–water flux (714 mm m^?2 d^?1). Large variability in BGE and BP/PP ratios especially during MN led to high bacteria-mediated carbon fluxes which was evident from significantly high bacterial carbon demand (BCD >100% of PP) during this season. This suggested that the net amount of organic carbon (either dissolved or particulate form) synthesized by primary producers in the lagoon was not sufficient to satisfy the bacterial carbon requirements. Lagoon sustained low to moderate autotrophic–heterotrophic coupling with annual mean BCD of 231% relative to the primary production, which depicted that bacterioplankton are the mainstay of the lagoon biogeochemical cycles and principal players that bring changes in trophic status. Study disclosed that the high CO₂ supersaturation and oxygen undersaturation during MN was attributed to the increased heterotrophic respiration (in excess of PP) fuelled by allochthonous organic matter. On a spatial scale, lagoon sectors such as south sector, central sector and outer channel recorded “net autotrophic,” while the northern sector showed “net heterotrophic” throughout the study period.     

New versatile cloning and sequencing vectors based on bacteriophage M13

A new pair of cloning and sequencing vectors based on bacteriophage M13mp7 has been developed. These vectors (M13tg130 and M13tg131) contain, in addition to the EcoRI, BamHI, HindIII, SmaI, SalI and PstI sites present in other vectors [cf., M13mp8 and M13mp9, Messing and Vieira, Gene 19 (1982) 269-276], unique restriction recognition sequences for the enzymes EcoRV, KpnI, SphI, SstI and XbaI. A restriction site for the enzyme BglII has been incorporated into the polylinker region of one of the vector pair to permit rapid discrimination between the two vectors.     

Quantitative structure–activity relationship analysis using deep learning based on a novel molecular image input technique

Quantitative structure–activity relationship (QSAR) analysis uses structural, quantum chemical, and physicochemical features calculated from molecular geometry as explanatory variables predicting physiological activity. Recently, deep learning based on advanced artificial neural networks has demonstrated excellent performance in the discipline of QSAR research. While it has properties of feature representation learning that directly calculate feature values from molecular structure, the use of this potential function is limited in QSAR modeling. The present study applied this function of feature representation learning to QSAR analysis by incorporating 360° images of molecular conformations into deep learning. Accordingly, I successfully constructed a highly versatile identification model for chemical compounds that induce mitochondrial membrane potential disruption with the external validation area under the receiver operating characteristic curve of ≥0.9.