The Src Homology 3 Domain-containing Guanine Nucleotide Exchange Factor Is Overexpressed in High-grade Gliomas and Promotes Tumor Necrosis Factor-like Weak Inducer of Apoptosis-Fibroblast Growth Factor-inducible 14-induced Cell Migration and Invasion via Tumor Necrosis Factor Receptor-associated Factor 2

Glioblastoma (GB) is the highest grade of primary adult brain tumors, characterized by a poorly defined and highly invasive cell population. Importantly, these invading cells are attributed with having a decreased sensitivity to radiation and chemotherapy. TNF-like weak inducer of apoptosis (TWEAK)-Fn14 ligand-receptor signaling is one mechanism in GB that promotes cell invasiveness and survival and is dependent upon the activity of multiple Rho GTPases, including Rac1. Here we report that Src homology 3 domain-containing guanine nucleotide exchange factor (SGEF), a RhoG-specific guanine nucleotide exchange factor, is overexpressed in GB tumors and promotes TWEAK-Fn14-mediated glioma invasion. Importantly, levels of SGEF expression in GB tumors inversely correlate with patient survival. SGEF mRNA expression is increased in GB cells at the invasive rim relative to those in the tumor core, and knockdown of SGEF expression by shRNA decreases glioma cell migration in vitro and invasion ex vivo. Furthermore, we showed that, upon TWEAK stimulation, SGEF is recruited to the Fn14 cytoplasmic tail via TRAF2. Mutation of the Fn14-TRAF domain site or depletion of TNF receptor-associated factor 2 (TRAF2) expression by siRNA oligonucleotides blocked SGEF recruitment to Fn14 and inhibited SGEF activity and subsequent GB cell migration. We also showed that knockdown of either SGEF or RhoG diminished TWEAK activation of Rac1 and subsequent lamellipodia formation. Together, these results indicate that SGEF-RhoG is an important downstream regulator of TWEAK-Fn14-driven GB cell migration and invasion.     

THE EFFECTS OF INJURY PREVENTION WARM-UP PROGRAMMES ON KNEE STRENGTH IN MALE SOCCER PLAYERS

The study investigates the effects of the 11+ and HarmoKnee injury prevention programmes on knee strength in male soccer players. Under-21-year-old players (n=36) were divided equally into: the 11+, HarmoKnee and control groups. The programmes were performed for 24 sessions (20-25 min each). The hamstrings and quadriceps strength were measured bilaterally at 60°·s^-1, 180°·s^-1 and 300°·s^-1. The concentric quadriceps peak torque (PT) of the 11+ increased by 27.7% at 300°·s^-1 in the dominant leg (p<0.05). The concentric quadriceps PT of HarmoKnee increased by 36.6%, 36.2% and 28% in the dominant leg, and by 31.3%, 31.7% and 20.05% at 60°·s^-1, 180°·s^-1 and 300°·s^-1 in the non-dominant leg respectively. In the 11+ group the concentric hamstring PT increased by 22%, 21.4% and 22.1% at 60°·s^-1, 180°·s^-1 and 300°·s^-1, respectively in the dominant leg, and by 22.3%, and 15.7% at 60°·s^-1 and 180°·s^-1, in the non-dominant leg. In the HarmoKnee group the hamstrings in the dominant leg showed an increase in PT by 32.5%, 31.3% and 14.3% at 60°·s^-1, 180°·s^-1 and 300°·s^-1, and in the non-dominant leg hamstrings PT increased by 21.1% and 19.3% at 60°·s^-1 and 180°·s^-1 respectively. The concentric hamstrings strength was significantly different between the 11+ and control groups in the dominant (p=0.01) and non-dominant legs (p=0.02). The HarmoKnee programme enhanced the concentric strength of quadriceps. The 11+ and HarmoKnee programmes are useful warm-up protocols for improving concentric hamstring strength in young professional male soccer players. The 11+ programme is more advantageous for its greater concentric hamstring strength improvement compared to the HarmoKnee programme.     

Solution structure of the mature HIV-1 protease monomer: insight into the tertiary fold and stability of a precursor

We present the first solution structure of the HIV-1 protease monomer spanning the region Phe1-Ala95 (PR1-95). Except for the terminal regions (residues 1-10 and 91-95) that are disordered, the tertiary fold of the remainder of the protease is essentially identical to that of the individual subunit of the dimer. In the monomer, the side chains of buried residues stabilizing the active site interface in the dimer, such as Asp25, Asp29, and Arg87, are now exposed to solvent. The flap dynamics in the monomer are similar to that of the free protease dimer. We also show that the protease domain of an optimized precursor flanked by 56 amino acids of the N-terminal transframe region is predominantly monomeric, exhibiting a tertiary fold that is quite similar to that of PR1-95 structure. This explains the very low catalytic activity observed for the protease prior to its maturation at its N terminus as compared with the mature protease, which is an active stable dimer under identical conditions. Adding as few as 2 amino acids to the N terminus of the mature protease significantly increases its dissociation into monomers. Knowledge of the protease monomer structure and critical features of its dimerization may aid in the screening and design of compounds that target the protease prior to its maturation from the Gag-Pol precursor.     

Mutant alleles of <Emphasis Type="Italic">FAD2-1A</Emphasis> and <Emphasis Type="Italic">FAD2-1B</Emphasis>combine to produce soybeans with the high oleic acid seed oil trait

Background  

The alteration of fatty acid profiles in soybean [Glycine max (L.) Merr.] to improve soybean oil quality is an important and evolving theme in soybean research to meet nutritional needs and industrial criteria in the modern market. Soybean oil with elevated oleic acid is desirable because this monounsaturated fatty acid improves the nutrition and oxidative stability of the oil. Commodity soybean oil typically contains 20% oleic acid and the target for high oleic acid soybean oil is approximately 80% of the oil; previous conventional plant breeding research to raise the oleic acid level to just 50-60% of the oil was hindered by the genetic complexity and environmental instability of the trait. The objective of this work was to create the high oleic acid trait in soybeans by identifying and combining mutations in two delta-twelve fatty acid desaturase genes, FAD2-1A and FAD2-1B.     

Isotopic insight into host–endosymbiont relationships in Liolaemid lizards

Nitrogen isotopes have been widely used to investigate trophic levels in ecological systems. Isotopic enrichment of 2–5‰ occurs with trophic level increases in food webs. Host–parasite relationships deviate from traditional food webs in that parasites are minimally enriched relative to their hosts. Although this host–parasite enrichment pattern has been shown in multiple systems, few studies have used isotopic relationships to examine other potential symbioses. We examined the relationship between two gut-nematodes and their lizard hosts. One species, Physaloptera retusa, is a documented parasite in the stomach, whereas the relationship of the other species, Parapharyngodon riojensis (pinworms), to the host is putatively commensalistic or mutualistic. Based on the established trophic enrichments, we predicted that, relative to host tissue, parasitic nematodes would be minimally enriched (0–1‰), whereas pinworms, either as commensals or mutualists, would be significantly enriched by 2–5‰. We measured the ¹⁵N values of food, digesta, gut tissue, and nematodes of eight lizard species in the family Liolaemidae. Parasitic worms were enriched 1±0.2‰ relative to host tissue, while the average enrichment value for pinworms relative to gut tissue was 6.7±0.2‰. The results support previous findings that isotopic fractionation in a host–parasite system is lower than traditional food webs. Additionally, the larger enrichment of pinworms relative to known parasites suggests that they are not parasitic and may be several trophic levels beyond the host.     

An Approach to Integrating Occupational Safety and Health into Life Cycle Assessment: Development and Application of Work Environment Characterization Factors

Integrating occupational safety and health (OSH) into life cycle assessment (LCA) may provide decision makers with insights and opportunities to prevent burden shifting of human health impacts between the nonwork environment and the work environment. We propose an integration approach that uses industry‐level work environment characterization factors (WE‐CFs) to convert industry activity into damage to human health attributable to the work environment, assessed as disability‐adjusted life years (DALYs). WE‐CFs are ratios of work‐related fatal and nonfatal injuries and illnesses occurring in the U.S. worker population to the amount of physical output from U.S. industries; they represent workplace hazards and exposures and are compatible with the life cycle inventory (LCI) structure common to process‐based LCA. A proof of concept demonstrates application of the WE‐CFs in an LCA of municipal solid waste landfill and incineration systems. Results from the proof of concept indicate that estimates of DALYs attributable to the work environment are comparable in magnitude to DALYs attributable to environmental emissions. Construction and infrastructure‐related work processes contributed the most to the work environment DALYs. A sensitivity analysis revealed that uncertainty in the physical output from industries had the most effect on the WE‐CFs. The results encourage implementation of WE‐CFs in future LCA studies, additional refinement of LCI processes to accurately capture industry outputs, and inclusion of infrastructure‐related processes in LCAs that evaluate OSH impacts.     

SNAREs Interact with Retinal Degeneration Slow and Rod Outer Segment Membrane Protein-1 during Conventional and Unconventional Outer Segment Targeting

Mutations in the photoreceptor protein peripherin-2 (also known as RDS) cause severe retinal degeneration. RDS and its homolog ROM-1 (rod outer segment protein 1) are synthesized in the inner segment and then trafficked into the outer segment where they function in tetramers and covalently linked larger complexes. Our goal is to identify binding partners of RDS and ROM-1 that may be involved in their biosynthetic pathway or in their function in the photoreceptor outer segment (OS). Here we utilize several methods including mass spectrometry after affinity purification, in vitro co-expression followed by pull-down, in vivo pull-down from mouse retinas, and proximity ligation assay to identify and confirm the SNARE proteins Syntaxin 3B and SNAP-25 as novel binding partners of RDS and ROM-1. We show that both covalently linked and non-covalently linked RDS complexes interact with Syntaxin 3B. RDS in the mouse is trafficked from the inner segment to the outer segment by both conventional (i.e., Golgi dependent) and unconventional secretory pathways, and RDS from both pathways interacts with Syntaxin3B. Syntaxin 3B and SNAP-25 are enriched in the inner segment (compared to the outer segment) suggesting that the interaction with RDS/ROM-1 occurs in the inner segment. Syntaxin 3B and SNAP-25 are involved in mediating fusion of vesicles carrying other outer segment proteins during outer segment targeting, so could be involved in the trafficking of RDS/ROM-1.