Polymorphisms in the trace amine receptor 4 (TRAR4) gene on chromosome 6q23.2 are associated with susceptibility to schizophrenia

Several linkage studies across multiple population groups provide convergent support for a susceptibility locus for schizophrenia--and, more recently, for bipolar disorder--on chromosome 6q13-q26. We genotyped 192 European-ancestry and African American (AA) pedigrees with schizophrenia from samples that previously showed linkage evidence to 6q13-q26, focusing on the MOXD1-STX7-TRARs gene cluster at 6q23.2, which contains a number of prime candidate genes for schizophrenia. Thirty-one screening single-nucleotide polymorphisms (SNPs) were selected, providing a minimum coverage of at least 1 SNP/20 kb. The association observed with rs4305745 (P=.0014) within the TRAR4 (trace amine receptor 4) gene remained significant after correction for multiple testing. Evidence for association was proportionally stronger in the smaller AA sample. We performed database searches and sequenced genomic DNA in a 30-proband subsample to obtain a high-density map of 23 SNPs spanning 21.6 kb of this gene. Single-SNP analyses and also haplotype analyses revealed that rs4305745 and/or two other polymorphisms in perfect linkage disequilibrium (LD) with rs4305745 appear to be the most likely variants underlying the association of the TRAR4 region with schizophrenia. Comparative genomic analyses further revealed that rs4305745 and/or the associated polymorphisms in complete LD with rs4305745 could potentially affect gene expression. Moreover, RT-PCR studies of various human tissues, including brain, confirm that TRAR4 is preferentially expressed in those brain regions that have been implicated in the pathophysiology of schizophrenia. These data provide strong preliminary evidence that TRAR4 is a candidate gene for schizophrenia; replication is currently being attempted in additional clinical samples.     

Quantum algorithm for programmed cell death of Caenorhabditis elegans

During the development of Caenorhabditis elegans, through cell divisions, a total of exactly 1090 cells are generated, 131 of which undergo programmed cell death (PCD) to result in an adult organism comprising 959 cells. Of those 131, exactly 113 undergo PCD during embryogenesis, subdivided across the cell lineages in the following fashion: 98 for AB lineage; 14 for MS lineage; and 1 for C lineage. Is there a law underlying these numbers, and if there is, what could it be? Here we wish to show that the count of the cells undergoing PCD complies with the cipher laws related to the algorithms of Shor and of Grover.     

Biochemical basis for the requirement of kinase activity for Cbl-dependent ubiquitinylation and degradation of a target tyrosine kinase

Members of the Cbl family of ubiquitin ligases have emerged as crucial negative regulators of tyrosine kinase signaling. These proteins preferentially interact with and target activated tyrosine kinases for ubiquitinylation, thereby facilitating the lysosomal sorting of receptor tyrosine kinases or proteasomal degradation of nonreceptor tyrosine kinases. Recent work has indicated a crucial role of the target kinase activity in Cbl-dependent ubiquitinylation and degradation, but the biochemical basis for this requirement is not understood. Here, we have used the Src-family kinase Fyn, a well characterized Cbl target, to address this issue. Using defined Fyn mutants, we demonstrate that the kinase activity of Fyn is crucial for its Cbl-dependent ubiquitinylation and degradation, but a low level of ubiquitinylation and degradation of kinase-inactive Fyn mutants was consistently observed. Mutational induction of an open conformation enhanced the susceptibility of kinase-active Fyn to Cbl but was insufficient to promote the ubiquitinylation and degradation of kinase-inactive Fyn. Notably, the Cbl-dependent degradation of Fyn did not require the Fyn-mediated phosphorylation of Cbl. Finally, we show that the major determinant of the susceptibility of Fyn protein to Cbl-dependent ubiquitinylation and degradation is the extent to which it physically associates with Cbl; kinase activity of Fyn serves as a critical determinant to promote its association with Cbl, which we demonstrate is mediated by multiple protein-protein interactions. Our results strongly suggest that promotion of association with Cbl is the primary mechanism by which the kinase activity of the targets of Cbl contributes to their susceptibility to Cbl.     

Side-chain contributions to membrane protein structure and stability

The molecular forces that stabilize membrane protein structure are poorly understood. To investigate these forces we introduced alanine substitutions at 24 positions in the B helix of bacteriorhodopsin and examined their effects on structure and stability. Although most of the results can be rationalized in terms of the folded structure, there are a number of surprises. (1) We find a remarkably high frequency of stabilizing mutations (17%), indicating that membrane proteins are not highly optimized for stability. (2) Helix B is kinked, with the kink centered around Pro50. The P50A mutation has no effect on stability, however, and a crystal structure reveals that the helix remains bent, indicating that tertiary contacts dominate in the distortion of this helix. (3) We find that the protein is stabilized by about 1kcal/mol for every 38A(2) of surface area buried, which is quite similar to soluble proteins in spite of their dramatically different environments. (4) We find little energetic difference, on average, in the burial of apolar surface or polar surface area, implying that van der Waals packing is the dominant force that drives membrane protein folding.     

Small molecules blocking the entry of severe acute respiratory syndrome coronavirus into host cells

Severe acute respiratory syndrome coronavirus (SARS-CoV) is the pathogen of SARS, which caused a global panic in 2003. We describe here the screening of Chinese herbal medicine-based, novel small molecules that bind avidly with the surface spike protein of SARS-CoV and thus can interfere with the entry of the virus to its host cells. We achieved this by using a two-step screening method consisting of frontal affinity chromatography-mass spectrometry coupled with a viral infection assay based on a human immunodeficiency virus (HIV)-luc/SARS pseudotyped virus. Two small molecules, tetra-O-galloyl-beta-D-glucose (TGG) and luteolin, were identified, whose anti-SARS-CoV activities were confirmed by using a wild-type SARS-CoV infection system. TGG exhibits prominent anti-SARS-CoV activity with a 50% effective concentration of 4.5 microM and a selective index of 240.0. The two-step screening method described here yielded several small molecules that can be used for developing new classes of anti-SARS-CoV drugs and is potentially useful for the high-throughput screening of drugs inhibiting the entry of HIV, hepatitis C virus, and other insidious viruses into their host cells.     

A novel polypeptide from Cervus nippon Temminck proliferation of epidermal cells and NIH3T3 cell line

A novel polypeptide, velvet antler polypeptide (VAPPs), having a stimulary effect on proliferation of some cell was isolated from the velvet antler of sika deer (Cervus nippon Temminck). This polypeptide consists of a single chain of 32 amino-acid residues VLSAT DKTNV LAAWG KVGGN APAFG AEALE RM. VAPPs showed marked stimulary effect on rat epidermal cells and NIH3T3 cell line (dose range from 10-40 mg x L(-1) and 5-80 mg x L(-1), respectively).     

Viral serotype and the transgene sequence influence overlapping adeno-associated viral (AAV) vector-mediated gene transfer in skeletal muscle

BACKGROUND: The overlapping approach was developed recently to expand the adeno-associated viral (AAV) packaging capacity. In this approach, a gene is split into two partially overlapping fragments and separately packaged into an upstream and a downstream vector, respectively. Transgene expression is achieved in co-infected cells after homologous recombination. Despite the promising proof-of-principle results in the lung, the efficiency has been very disappointing in skeletal muscle. Here we examined two potential rate-limiting factors including AAV serotype and the transgene sequence. METHODS: To study serotype effect, we delivered AAV-2, -5 and -6 overlapping vectors (5 x 10(8) vg particles of the upstream and the downstream vectors, respectively) and 5 x 10(8) vg particles of the intact gene vector to the tibialis anterior muscles of 7-week-old C57Bl/6 mice, respectively. To determine the effect of transgene sequence, we compared LacZ and alkaline phosphatase (AP) overlapping vectors. Transduction efficiency was quantified 6 weeks later by scoring the percentage of transgene-positive myofibers. RESULTS: AAV-2 overlapping vectors barely resulted in detectable transduction. Transduction efficiency was significantly improved in AAV-5 and AAV-6. The highest level was achieved in AAV-6 that reached 42% and 96% of that of the intact gene vector for the LacZ gene and the AP gene, respectively. Surprisingly, AAV-6 overlapping vector resulted in higher transduction than did AAV-2 and AAV-5 intact gene vectors. CONCLUSIONS: Our findings suggest that AAV serotype and the transgene sequence play critical roles in the overlapping approach. AAV-6 holds great promise for overlapping vector-mediated muscle gene therapy.     

Preliminary results on nematicidal activity from culture filtrates of Basidiomycetes against the pine wood nematode,Bursaphelenchus xylophilus (Aphelenchoididae)

One hundred and eighty one fungal species that were isolated from the fresh fruiting bodies collected in the Mountains of Pu Er County of Yunnan Province, China were tested on the pine wood nematode,Bursaphelenchus xylophilus in vitro. Each fungal species was grown in Czapek broth and potato dextrose broth (PDB). Fifteen filtrates fromAmauroderma austrosinense, Amauroderma macer, Filoboletus sp.,Laccaria tortilis, Lactarius gerardii, Lentinula edodes, Oudemansiella longipes, Oudemansiella mucida, Peziza sp.,Pleurotus sp.,Sinotermitomyces carnosus (two strains),Strobilomyces floccopus, Termitomyces albuminosus, Tylopilus striatulus grown on PDB were found to be pathogenic to the tested nematodes. Eleven filtrates fromAmanita junguillea, Amanita sp.,Daedalea sepiaria, Fistulina hepatica, Omphalotus olearius, Oudemansiella mucida, Peziza sp.,Pleurotus pulmatus, Ramaria sp.,Tricholoma conglobatum, Tylopilus striatulus grown on Czapek broth were also pathogenic to the nematodes. When screening for nematicidal potential of fungi, it is important to study the growth medium conditions necessary to obtain the optimal nematicidal effect as fungal filtrates growing on different liquid media showed a very inconsistent toxicity towards nematodes.