Phosphorylation of Fanconi anemia protein, FANCA, is regulated by Akt kinase

Phosphorylation of the Fanconi anemia complementation group A (FANCA) protein is thought to be important for the function of the FA pathway. However, the kinase for FANCA (so-called FANCA-PK) remains to be identified. FANCA has a consensus sequence for Akt kinase near serine 1149 (Ser1149), suggesting that Akt can phosphorylate FANCA. We performed in vitro kinase assays using as substrate either a GST-fusion wild-type (WT) FANCA fragment or a GST-fusion FANCA fragment containing a mutation from serine to alanine at 1149 (FANCA-S1149A). These experiments confirmed that FANCA is phosphorylated at Ser 1149, in vitro. However, (32)P-orthophosphate labeling experiments revealed that FANCA-S1149A was more efficiently phosphorylated than WT-FANCA. Furthermore, phosphorylation of wild-type FANCA was blocked by coexpression of a constitutively active (CA)-Akt and enhanced by a dominant-negative (DN) Akt. Our results suggest that Akt is a negative regulator of FANCA phosphorylation.     

Inhibitory effect of medium-chain-length fatty acids on synthesis of polyhydroxyalkanoates from volatile fatty acids by Ralstonia eutropha

Medium-chain-length fatty acids, such as nonanoic (9:0) and octanoic (8:0) acids, are more toxic to Ralstonia eutropha than volatile fatty acids such as acetic, propionic and butyric acids. Nonanoic acid was degraded to acetic and propionic acids via -oxidation by Ralstonia eutropha for cell growth and synthesis of polyhydroxyalkanoates (PHAs). In a mixture of the fatty acids, utilization of nonanoic acid was depressed by acetic and propionic acids, and vice versa. The PHA accumulation from the volatile fatty acids was decreased from 53% (w/w) of dry cell mass to 23% due to the nonanoic acid. Similar phenomena were also observed with octanoic acid and its metabolic intermediates, acetic and butyric acids.     

Induction of alpha-fetoprotein-specific CD4- and CD8-mediated T-cell response using RNA-transfected dendritic cells

alpha-Fetoprotein (AFP) may be a possible target for a hepatocellular carcinoma (HCC)-specific vaccination. But some studies have demonstrated that dendritic cells (DCs) treated with AFP become dysfunctional. So in this study, we try to transfect AFP mRNA into DCs and observe the ability of DCs to induce AFP-specific CD4(+) and CD8(+) T cells. We hope that AFP can be processed and presented by DCs directly, rather than released to the cultures. So there will be no AFP negative effect on the function of DCs. In the study, immature DCs generated from peripheral blood mononuclear cells (PBMCs) of HLA-A2(+) HCC patients were transfected with AFP mRNA. Then the transfected, matured DCs were used to stimulate autologous T cells. The results showed that the expressions of membrane molecules of DCs after transfection were increased dramatically, and interleukin-12 (IL-12) p70 release in the supernatant was elevated significantly. There was only a minority of AFP release in the supernatants of transfected DCs. CTLs induced by the transfected DCs recognized HLA-matched AFP positive HepG2 cell line specifically and the AFP-specific proliferative T-cell responses could also be induced. These findings indicate that this AFP mRNA transfection strategy could generate fully functional DCs, which could induce specific T cells to recognize AFP(+) HCC cells.     

Neonatal anesthesia for studies of hamster parental behavior when infanticidal aggression is a possibility

Experiments involving investigation of the neuroendocrine basis for paternal care in rodents risk activation of aggressive behavior toward pups. To minimize pain and suffering during tests of parental responsiveness requiring retrieval of a displaced pup to its nest, a method of anesthetizing the pup was developed in Djungarian hamsters, Phodopus campbelli. A surgical plane of anesthesia, as measured by criteria, such as respiratory depression, loss of the pedal reflex, and failure to increase respiratory rate or to vocalize in response to handling, was achieved by use of intraperitoneal administration of a combination of ketamine and xylazine. Both parents (tested separately) expressed normal behavior toward anesthetized pups. In random order, a saline-injected or anesthetized pup was displaced from its nest in the home cage. There were no differences in pick-up or retrieval rates between saline and anesthetized pups for either parent. A third test using an unmanipulated pup confirmed that parental behavior was not reduced toward an anesthetized pup. However, if anesthetized pups were tested first among littermates, retrieval by males was less likely. This method will, therefore, underestimate retrieval behavior in males, but not females. Adult male hamsters that had never been parents also expressed expected behavior by attacking the pup in 45% of cases. This method provides an efficient and effective means of protecting pups while allowing adults to express a wide range of parental and infanticidal behaviors. It also has application in behavioral screening of transgenic strains toward unrelated young.     

Imidazo[1,2-b]pyridazines: a potent and selective class of cyclin-dependent kinase inhibitors

Modification of imidazo[1,2-a]pyridine CDK inhibitors lead to identification of less lipophilic imidazo[1,2-b]pyridazine series of CDK inhibitors. Although several equivalent compounds from these two series have similar structure and show similar CDK activity, the SAR of the two series differs significantly. Protein inhibitor structure determination has confirmed differences in binding mode and given some understanding of these differences in SAR. Potent and selective imidazo[1,2-b]pyridazine inhibitors of CDK2 have been identified, which show >1 microM plasma levels following a 2mg/kg oral dose to mice.     

East learns from West: Asiatic honeybees can understand dance language of European honeybees

The honeybee waggle dance, through which foragers advertise the existence and location of a food source to their hive mates, is acknowledged as the only known form of symbolic communication in an invertebrate. However, the suggestion, that different species of honeybee might possess distinct 'dialects' of the waggle dance, remains controversial. Furthermore, it remains unclear whether different species of honeybee can learn from and communicate with each other. This study reports experiments using a mixed-species colony that is composed of the Asiatic bee Apis cerana cerana (Acc), and the European bee Apis mellifera ligustica (Aml). Using video recordings made at an observation hive, we first confirm that Acc and Aml have significantly different dance dialects, even when made to forage in identical environments. When reared in the same colony, these two species are able to communicate with each other: Acc foragers could decode the dances of Aml to successfully locate an indicated food source. We believe that this is the first report of successful symbolic communication between two honeybee species; our study hints at the possibility of social learning between the two honeybee species, and at the existence of a learning component in the honeybee dance language.     

Yak lactate dehydgogenase A4: purification, properties, and cDNA cloning

Lactate dehydrogenase A4 (LDH-A4) was purified for yak skeletal muscle. Michaelis constant (Km) analysis showed that yak LDH-A4 for pyruvate was significantly higher than that of cattle. cDNA cloning of LDH-A revealed two amino acid substitutions between yak and cattle. We suggest that the higher Km of yak LDH-A4 might be a result of molecular adaptation to a hypoxic environment.     

Genome sequence of Agrobacterium tumefaciens strain F2, a bioflocculant-producing bacterium

Agrobacterium tumefaciens F2 is an efficient bioflocculant-producing bacterium. But the genes related to the metabolic pathway of bioflocculant biosynthesis in strain F2 are unknown. We present the draft genome of A. tumefaciens F2. It could provide further insight into the biosynthetic mechanism of polysaccharide-like bioflocculant in strain F2.