Facile functional analysis of insect odorant receptors expressed in the fruit fly: validation with receptors from taxonomically distant and closely related species

With the advent of genomic sequences and next-generation sequencing technologies (RNA-Seq), multiple repertoires of olfactory proteins in various insect species are being unraveled. However, functional analyses are lagging behind due in part to the lack of simple and reliable methods for heterologous expression of odorant receptors (ORs). While the Xenopus oocyte recording system fulfills some of this lacuna, this system is devoid of other olfactory proteins, thus testing only the “naked” ORs. Recently, a moth OR was expressed in the majority of neurons in the antennae of the fruit fly using Orco-GAL4 to drive expression of the moth OR. Electroantennogram (EAG) was used to de-orphanize the moth OR, but generic application of this approach was brought to question. Here, we describe that this system works with ORs not only from taxonomically distant insect species (moth), but also closely related species (mosquito), even when the fruit fly has highly sensitive innate ORs for the odorant being tested. We demonstrate that Orco-GAL4 flies expressing the silkworm pheromone receptor, BmorOR1, showed significantly higher responses to the sex pheromone bombykol than the control lines used to drive expression. Additionally, we show that flies expressing an OR from the Southern house mosquito, CquiOR2, gave significantly stronger responses to the cognate odorants indole and 2-methylphenol than the “background noise” recorder from control lines. In summary, we validate the use of Orco-GAL4 driven UAS-OR lines along with EAG analysis as a simple alternative for de-orphanization and functional studies of insect ORs in an intact olfactory system.     

重组PAI—2基因在NIH3T3细胞中的活性表达

构建了人ＰＡＩ—２ｃＤＮＡ睥达质粒，以ＮＩＨ３Ｔ３为转染宿主细胞，ＮｏｒｔｈｅｒｎＢｌｏｔ，ＷｅｓｔｅｒｎＢｌｏｔ和ＰＡＩ活性扩散试验结果表明人ＰＡＩ—２ｃＤＮＡ可以在ＮＩＨ３Ｔ３细胞中正确表达出ＰＡＩ—２蛋白，且具有抑制ＰＡ的活性，同时未能检测到ＮＩＨ３Ｔ３细胞表达ＰＡＩ—２蛋白质．为探讨ＰＡ—ＰＡＩ—２系统的调控机制打下基础．     

SEC65 gene product is a subunit of the yeast signal recognition particle required for its integrity.

Protein targeting to the endoplasmic reticulum (ER) in mammalian cells is catalysed by the signal recognition particle (SRP), which consists of six protein subunits and an RNA subunit. Saccharomyces cerevisiae SRP is a 16S particle, of which only two subunits have been identified: a protein subunit, SRP54p, which is homologous to the mammalian SRP54 subunit, and an RNA subunit, scR1 (ref. 3). The sec65-1 mutant yeast cells are temperature-sensitive for growth and defective in the translocation of several secreted and membrane-bound proteins. The DNA sequence of the SEC65 gene suggests that its product is related to mammalian SRP19 subunit and may have a similar function. Here we show that SEC65p is a subunit of the S. cerevisiae SRP and that it is required for the stable association of another subunit, SRP54p, with SRP. Overexpression of SRP54p suppresses both growth and protein translocation defects in sec65-1 mutant cells.     

The earliest Acheulean from Konso-Gardula.

Konso-Gardula is a palaeoanthropological area discovered by the 1991 Palaeoanthropological Inventory of Ethiopia in the southern Main Ethiopian Rift. The Konso-Gardula sediments span the period about 1.3-1.9 million years ago. They contain rich Acheulean archaeological occurrences. Vertebrate fossils include early Homo.     

Supraphysiological dosages of vitamins and their implications in man

Summary Some recent evidence on the benefits and hazards of elevated dosages of vitamins is summarized. Special emphasis is given on the safety of vitamins A, D, K₁ and B₆. Furthermore, the possibly beneficial effects of vitamins for athletic performance as well as the preventive potential of antioxidative vitamins and of carotenoids against cancer are discussed.     

Human oestrogen receptor cDNA: sequence, expression and homology to v-erb-A

We have cloned and sequenced the complete complementary DNA of the oestrogen receptor (ER) present in the breast cancer cell line MCF-7. The expression of the ER cDNA in HeLa cells produces a protein that has the same relative molecular mass and binds oestradiol with the same affinity as the MCF-7 ER. There is extensive homology between the ER and the erb-A protein of the oncogenic avian erythroblastosis virus.     

Competitive inhibitors of neurohypophyseal hormones on adenylate cyclase from the toad urinary bladder

Zusammenfassung Adenylat-Cyclase in plasmamembranreichen Präparationen des Epitheliums von der Harnblase der Kröte wird durch Arginine-Vasopressin aktiviert. Diese Aktivierung wird durch mehre Oxytocinanaloge, die alle eine Substitution des Glutaminrestes in Position 4 des Hormones durch Leucin oder Isoleucin gemeinsam haben, kompetitiv gehemmt. Der stärkste Antagonist der Serie ist [2,4-diisoleucin]-Oxytocin und die antagonistische Aktivität nimmt in der Reihenfolge [4-Leucin]-, [2-Isoleucin-4-leucin]-, [2,4-Dileucin]- und [2-Phenylalanin-4-leucin]-Oxytocin ab. Die Resultate werden an Hand der Oxytocinkonformation diskutiert.

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Supported by United States Public Health Service grants No. AM-13567 (RW), by the Life Sciences Foundation, Inc., and by the National Science Foundation No. GB-30716X (VJH).

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Neurohypophyseal hormone analogs are denoted in accordance with the IUPAC-IUB [Tentative Rules (Biochemistry6, 362, 1967)].     

Position of the methionine residue in bovine neurophysin II

Zusammenfassung Durch Spaltung mit CNBr wurde gezeigt, dass Neurophysin II aus Rinderhypophyse nur eine Methionin-Einheit enthält und dass die N-terminale Sequenz Ala-Met ist.

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This work was supported by NIH Grants No. AM-13567, No. AM-10080, by NSF Grant No. GB-17046 and by the City University of New York. The authors are indebted to Dr.L. Abrash for helpful discussion and MissM. Wahrenburg and Mr.V. S. Sapirstein for the assays.

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Predoctoral fellow of the Department of Physiology.