An adrenaline (and gold?) rush for the GPCR community.

G-Protein-coupled receptors are one of the largest protein families found in metazoans. Using several novel strategies, the first atomic resolution structures of a receptor that is activated by a diffusible ligand have been determined.     

Age validation and variation in growth,mortality and population structure of Liza argentea and Myxus elongatus (Mugilidae) in two temperate Australian estuaries

This study investigated variation in the rates of growth and mortality, and age and fork‐length (L_F) compositions of two exploited species of Mugilidae, Liza argentea and Myxus elongatus, in two south‐east Australian estuaries (Lake Macquarie and St Georges Basin). An ageing protocol was developed by counting opaque growth zones on sectioned otoliths which was validated by periodically examining the otoliths of captive‐reared young‐of‐the‐year fishes, and marginal increment analysis of wild fishes. The maximum recorded age was 17 years for L. argentea and 12 years for M. elongatus, which is greater than generally observed in other species of mugilids. Growth models of each species significantly differed between sexes and, except for male L. argentea, between estuaries. Fishes from Lake Macquarie generally had a greater mean L_F at age than those from St Georges Basin and females of both species generally attained a greater maximum L_F and age than males. Gillnet catches of L. argentea were of similar L_F and age compositions in both estuaries, whereas the age composition of catches of M. elongatus in Lake Macquarie contained a greater proportion of younger fish. Estimates of total, natural and fishing mortality were greater for M. elongatus than L. argentea across both estuaries, and estimates of total mortality were greatest for both species in Lake Macquarie. The data indicate that neither species has been overfished in these estuaries.     

Mass balance and life cycle assessment of biodiesel from microalgae incorporated with nutrient recycling options and technology uncertainties

This article presents mass balances and a detailed life cycle assessment (LCA) for energy and greenhouse gases (GHGs) of a simulated microalgae biodiesel production system. Key parameters of the system include biomass productivity of 16 and 25 g m^?2 day^?1 and lipid content of algae of 40% and 25% for low and normal nitrogen conditions respectively. Based on an oil extraction efficiency from wet biomass of 73.6% and methane yields from anaerobically digested lipid‐extracted biomass of 0.31 to 0.34 l per gram of volatile solids, the mass balance shows that recycling growth media and recovering nutrients from residual biomass through anaerobic digestion can reduce the total demand for nitrogen by 66% and phosphorus by 90%. Freshwater requirements can be reduced by 89% by recirculating growth media, and carbon requirements reduced by 40% by recycling CO₂ from biogas combustion, for normal nitrogen conditions. A variety of technology options for each step of the production process and allocation methods for coproducts used outside the production system are evaluated using LCA. Extensive sensitivity and scenario analysis is also performed to provide better understanding of uncertainty associated with results. The best performing scenario consists of normal nitrogen cultivation conditions, bioflocculation and dissolved air flotation for harvesting, centrifugation for dewatering, wet extraction with hexane, transesterification for biodiesel production, and anaerobic digestion of biomass residual, which generates biogas used in a combined heat and power unit for energy recovery. This combination of technologies and operating conditions results in life cycle energy requirements and GHG emissions of 1.02 MJ and 71 g CO₂‐equivalent per MJ of biodiesel, with cultivation and oil extraction dominating energy use and emissions. Thus, even under optimistic conditions, the near‐term performance of this biofuel pathway does not achieve the significant reductions in life cycle GHG emissions hoped for from second‐generation biofuel feedstocks.     

SiRNA-Induced Mutation in HIV-1 Polypurine Tract Region and Its Influence on Viral Fitness

Converting single-stranded viral RNA into double stranded DNA for integration is an essential step in HIV-1 replication. Initial polymerization of minus-strand DNA is primed from a host derived tRNA, whereas subsequent plus-strand synthesis requires viral primers derived from the 3′ and central polypurine tracts (3′ and cPPTs). The 5′ and 3′ termini of these conserved RNA sequence elements are precisely cleaved by RT-associated RNase H to generate specific primers that are used to initiate plus-strand DNA synthesis. In this study, siRNA wad used to produce a replicative HIV-1 variant contained G(-1)A and T(-16)A substitutions within/adjacent to the 3′PPT sequence. Introducing either or both mutations into the 3′PPT region or only the G(-1)A substitution in the cPPT region of NL4-3 produced infectious virus with decreased fitness relative to the wild-type virus. In contrast, introducing the T(-16)A or both mutations into the cPPT rendered the virus(es) incapable of replication, most likely due to the F185L integrase mutation produced by this nucleotide substitution. Finally, the effects of G(-1)A and T(-16)A mutations on cleavage of the 3′PPT were examined using an in vitro RNase H cleavage assay. Substrate containing both mutations was mis-cleaved to a greater extent than either wild-type substrate or substrate containing the T(-16)A mutation alone, which is consistent with the observed effects of the equivalent nucleotide substitutions on the replication fitness of NL4-3 virus. In conclusion, siRNA targeting of the HIV-1 3′PPT region can substantially suppress virus replication, and this selective pressure can be used to generate infectious virus containing mutations within or near the HIV-1 PPT. Moreover, in-depth analysis of the resistance mutations demonstrates that although virus containing a G(-1)A mutation within the 3′PPT is capable of replication, this nucleotide substitution shifts the 3′-terminal cleavage site in the 3′PPT by one nucleotide (nt) and significantly reduces viral fitness.     

A Novel Ribosomopathy Caused by Dysfunction of RPL10 Disrupts Neurodevelopment and Causes X-Linked Microcephaly in Humans

Neurodevelopmental defects in humans represent a clinically heterogeneous group of disorders. Here, we report the genetic and functional dissection of a multigenerational pedigree with an X-linked syndromic disorder hallmarked by microcephaly, growth retardation, and seizures. Using an X-linked intellectual disability (XLID) next-generation sequencing diagnostic panel, we identified a novel missense mutation in the gene encoding 60S ribosomal protein L10 (RPL10), a locus associated previously with autism spectrum disorders (ASD); the p.K78E change segregated with disease under an X-linked recessive paradigm while, consistent with causality, carrier females exhibited skewed X inactivation. To examine the functional consequences of the p.K78E change, we modeled RPL10 dysfunction in zebrafish. We show that endogenous rpl10 expression is augmented in anterior structures, and that suppression decreases head size in developing morphant embryos, concomitant with reduced bulk translation and increased apoptosis in the brain. Subsequently, using in vivo complementation, we demonstrate that p.K78E is a loss-of-function variant. Together, our findings suggest that a mutation within the conserved N-terminal end of RPL10, a protein in close proximity to the peptidyl transferase active site of the 60S ribosomal subunit, causes severe defects in brain formation and function.     

The effect of physiological concentrations of sex hormones,insulin, and glucagon on growth of breast and prostate cells supplemented with unmodified human serum

The majority of cell culture studies have assessed the effect of hormones on cancer cell growth using media supplemented with charcoal-treated fetal bovine serum (CTS). We aimed to determine whether using a system more reflective of the human condition by changing the charcoal-treated serum to an untreated pooled human serum (PHS) resulted in the same hormone responses in breast and prostate cell lines. MCF-7 breast cancer, MCF-10A non-transformed breast, and LNCaP prostate cancer cell lines supplemented with PHS were treated with high and low physiological concentrations of six hormones (17β-estradiol, dehydroepiandosterone (DHEA), dihydrotestosterone (DHT), testosterone, insulin, and glucagon). Cell growth was measured after 72 h of incubation. All hormones stimulated growth of MCF-7 cells (p < 0.05). MCF-10A cell growth was inhibited by DHEA, DHT, and testosterone (p < 0.05), unaffected by 17β-estradiol and glucagon, and stimulated by insulin (p < 0.05). LNCaP cell growth was stimulated by the highest concentration of DHEA and DHT (p < 0.05) and inhibited by the highest concentration of 17β-estradiol (p < 0.05), while insulin and testosterone, had no effect. Overall, PHS lowered the magnitude of the effect of hormones on cell growth in comparison to CTS. Due to the presence of all serum constituents, our model represents a more appropriate physiological environment for determining the effect of hormones on cancer cell growth. Further studies are required to determine the mechanisms by which added hormones interact with the constituents of untreated human serum.     

Ablation of rat TRPV1-expressing Adelta/C-fibers with resiniferatoxin: analysis of withdrawal behaviors, recovery of function and molecular correlates

Microglia are the resident macrophages in the central nervous system. In the spinal cord dorsal horn, microglia stay in resting condition during physiological sensory processing, and are activated under pathological conditions such as peripheral nerve injury. In cases such as this, the nearby resting microglia increase their motility and accumulate at the site of injury. However, direct evidence to support that nerve activity can enhance the motility of microglia has not yet to be reported. In this study we investigated whether the activation of spinal microglia under in vivo nerve injury may be mimicked by neuronal activity in the spinal cord slice preparation. We found that local application of spinal excitatory neurotransmitters, such as glutamate and substance P did not cause any change in the motility of microglial cells in the spinal cord dorsal horn. The motility of microglial cells is unlikely modulated by other transmitters, neuromodulators and chemokines, because similar applications such as GABA, serotonin, noradrenaline, carbachol, fractalkine or interleukin did not produce any obvious effect. Furthermore, low or high frequency stimulation of spinal dorsal root fibers at noxious intensities failed to cause any enhanced extension or retraction of the microglia processes. By contrast, focal application of ATP triggered rapid and robust activation of microglial cells in the spinal dorsal horn. Our results provide the first evidence that the activation of microglia in the spinal cord after nerve injury is unlikely due solely to neuronal activity, non-neuronal factors are likely responsible for the activation of nerve injury-related microglial cells in the spinal dorsal horn.