Patrick Nef | Université de Genève (original) (raw)

Papers by Patrick Nef

Journal of Virology

Long-acting antiretrovirals could provide a useful alternative to daily oral therapy for HIV-1 in... more Long-acting antiretrovirals could provide a useful alternative to daily oral therapy for HIV-1 infected individuals. Building on a bi-specific molecule with adnectins targeting CD4 and gp41, a potential long-acting biologic, GSK3732394, was developed with three independent and synergistic modes of HIV entry inhibition that potentially could be self-administered as a long-acting subcutaneous injection. Starting with the bi-specific inhibitor, an alpha-helical peptide inhibitor was optimized as a linked molecule to the anti-gp41 adnectin, with each separate inhibitor exhibiting at least single digit nanomolar (or lower) potency and a broad spectrum. Combination of the two adnectins and peptide activities into a single molecule was shown to have synergistic advantages in potency, resistance barrier and in the ability to inhibit HIV-1 infections at low levels of CD4 receptor occupancy, showing that GSK3732394 can work in trans on a CD4+ T cell. Addition of a human serum albumin molecule...

Biochemical and Biophysical Research Communications, 1994

Neuron, Jan 4, 2001

On a radial temperature gradient, C. elegans worms migrate, after conditioning with food, toward ... more On a radial temperature gradient, C. elegans worms migrate, after conditioning with food, toward their cultivation temperature and move along this isotherm. This experience-dependent behavior is called isothermal tracking (IT). Here we show that the neuron-specific calcium sensor-1 (NCS-1) is essential for optimal IT. ncs-1 knockout animals show major defects in IT behavior, although their chemotactic, locomotor, and thermal avoidance behaviors are normal. The knockout phenotype can be rescued by reintroducing wild-type NCS-1 into the AIY interneuron, a key component of the thermotaxis network. A loss-of-function form of NCS-1 incapable of binding calcium does not restore IT, whereas NCS-1 overexpression enhances IT performance levels, accelerates learning (faster acquisition), and produces a memory with slower extinction. Thus, proper calcium signaling via NCS-1 defines a novel pathway essential for associative learning and memory.

Journal of Commercial Biotechnology, 2010

News in physiological sciences : an international journal of physiology produced jointly by the International Union of Physiological Sciences and the American Physiological Society, 1998

Three models for the perception of odor molecules are suggested for the first time by experimenta... more Three models for the perception of odor molecules are suggested for the first time by experimental data. These studies illustrate how the nose may smell. Moreover, they suggest additional role(s) for odor receptors within and outside the olfactory system.

Molecular Biology of Neuroreceptors and Ion Channels, 1989

The Journal of biological chemistry, Jan 30, 1994

VILIP and NCS-1, neural-specific, 22-kDa Ca(2+)-binding proteins possessing four EF-hands, were e... more VILIP and NCS-1, neural-specific, 22-kDa Ca(2+)-binding proteins possessing four EF-hands, were expressed in Escherichia coli to study their divalent cation properties. Flow dialysis (Ca2+ binding) and equilibrium gel filtration (Mg2+ binding) revealed that both recombinant proteins possess only two active metal-binding sites, which can accommodate either Ca2+ or Mg2+. VILIP binds cations without cooperativity with intrinsic affinity constants K'Ca of 1.0 x 10(6) M-1 and K'Mg of 4.8 x 10(3) M-1.Mg2+ antagonizes Ca2+ binding by shifting the isotherms to higher free Ca2+ concentrations without changing their shape. The competition equation yields a K'Mg, comp value of 180 M-1 for both sites. NCS-1 binds two Mg2+ without cooperativity with K'Mg of 8.3 x 10(4) M-1 and two Ca2+ with very strong positive cooperativity (nH = 1.96). In the absence of Mg2+ the K'Ca1 and K'Ca2 values are 8.9 x 10(4) and 1.4 x 10(8) M-1, respectively, which represent an allosteric incre...

$Research paper thumbnail of Study in pig coronary smooth muscle cell subcellular fractions of the activity of various enzymes involved in lipid metabolism and of the beta-receptor adenylate cyclase couple$

Comparative biochemistry and physiology. B, Comparative biochemistry, 1984

Pig coronary smooth muscle cells contain a highly active fatty acid beta-oxidation system as well... more Pig coronary smooth muscle cells contain a highly active fatty acid beta-oxidation system as well as significant activities of other enzymes involved in lipid metabolism, i.e. palmitoyl-CoA synthetase, glycerophosphate acyl transferase, acetyl-CoA carboxylase and fatty acid synthetase. Purified plasma membranes of pig coronary smooth muscle cells contain stereospecific (-)-[3H]dihydroalprenolol binding sites of high affinity (Kd = 5.4 nM) and characteristic of the beta 1 subtype. They also contain an adenylate cyclase activity which is stimulated by 5'-guanylyl-imidodiphosphate (Gpp(NH)p) and, to a lesser degree, by (-)-isoproterenol.

The EMBO journal, 1988

Four genes encode the related protein subunits that assemble to form the nicotinic acetylcholine ... more Four genes encode the related protein subunits that assemble to form the nicotinic acetylcholine receptor (nAChR) at the motor endplate of vertebrates. We have isolated from the chicken genome four additional members of the same gene family whose protein products, termed alpha 2, alpha 3, alpha 4 and n alpha (non-alpha) probably define three distinct neuronal nAChR subtypes. The neuronal nAChR genes have identical structures consisting of six protein-coding exons and specify proteins that are best aligned with the chicken endplate alpha subunit, whose gene we have also characterized. mRNA transcripts encoding alpha 4 and n alpha are abundant in embryonic and in adult avian brain, whereas alpha 2 and alpha 3 transcripts are much scarcer. The same set of neuronal genes probably exists in all vertebrates since their counterparts have also been identified in the rat genome.

Physiological Genomics, 2003

The early molecular events in the perception of bitter taste start with the binding of specific w... more The early molecular events in the perception of bitter taste start with the binding of specific water-soluble molecules to G protein-coupled receptors (GPCRs) encoded by the Tas2r family of taste receptor genes. The identification of the complete TAS2R receptor family repertoire in mouse and a comparative study of the Tas2r gene families in mouse and human might help to better understand bitter taste perception. We have identified, cloned, and characterized 13 new mouse Tas2r sequences, 9 of which encode putative functional bitter taste receptors. The encoded proteins are between 293 and 333 amino acids long and share between 18% and 54% sequence identity with other mouse TAS2R proteins. Including the 13 sequences identified, the mouse Tas2r family contains ∼30% more genes and 60% fewer pseudogenes than the human TAS2R family. Sequence and phylogenetic analyses of the proteins encoded by all mouse and human Tas2r genes indicate that TAS2R proteins present a lower degree of sequence ...

Nicotinic Acetylcholine Receptors in the Nervous System, 1988

Cytogenetic and Genome Research, 2002

The sense of taste is a chemosensory system responsible for basic food appraisal. Humans distingu... more The sense of taste is a chemosensory system responsible for basic food appraisal. Humans distinguish between five primary tastes: bitter, sweet, sour, salty and umami. The molecular events in the perception of bitter taste are believed to start with the binding of specific water-soluble molecules to G-protein-coupled receptors encoded by the TAS2R/T2R family of taste receptor genes. TAS2R receptors are

Proceedings of the National Academy of Sciences, 1997

In vertebrates, odors are thought to be detected by a multigene family encoding several hundreds ... more In vertebrates, odors are thought to be detected by a multigene family encoding several hundreds of seventransmembrane-domain G-protein-coupled receptors found in fish, rat, mouse, dog, and human. Recently, the putative odorant receptor (OR) gene family in the chicken has been characterized. Twelve members have been isolated and subdivided into six subfamilies. Herein, we have further characterized the chicken olfactory receptor subfamily 7 (COR7) composed of two highly related genes (named COR7a and COR7b) which are 98.5% identical. By in situ hybridization experiments, both COR7a and COR7b transcripts were detected in the olfactory epithelium from embryonic day 6 (E6) to the new born stage. Within the olfactory epithelium, the spatial distribution of COR7a and COR7b labeled cells was random. We also observed that every individual positive cell did not coexpress the COR7a and COR7b genes. Interestingly, the COR7b gene was found to be transiently expressed in the notochord from E2 to E6, whereas COR7a or any of the other known members of the COR gene family were not detected in this mesodermal tissue. These data suggest that, in addition to its potential role as an OR in the olfactory system, COR7b may also have a function in the notochord that is essential for the dorsoventral organization of the neural tube and of the somitic mesoderm. We also discuss the possible role(s) of a putative OR present in both the notochord and the sensory olfactory epithelium. The publication costs of this article were defrayed in part by page charge payment. This article must therefore be hereby marked ''advertisement'' in accordance with 18 U.S.C. §1734 solely to indicate this fact.

Proceedings of the National Academy of Sciences, 1984

We have cloned and sequenced a fragment of the chicken genome approximately 9 kilobases in length... more We have cloned and sequenced a fragment of the chicken genome approximately 9 kilobases in length that comprises the genes encoding the 6 and 'y subunits of the nicotinic acetyicholine receptor. The two genes are homologous and have identical structures: both consist of 12 exons, some of which precisely correspond to predicted structural domains of the receptor subunits. The 8 and y subunit gehes are encoded by the same DNA strand and are very closely linked, there being only 740 base pairs between the last codon of 8 and the initiator codon of y. Blot analysis demonstrates that the genes

Neuroscience, 1999

In vivo, neuronal over-expression of the anti-apoptotic protein Bcl-2 prevents axotomy-induced mo... more In vivo, neuronal over-expression of the anti-apoptotic protein Bcl-2 prevents axotomy-induced motoneuron death and prolongs life in a mouse model of familial amyotrophic lateral sclerosis. The mechanism of these protective effects is still unknown. We have examined, in situ, the influence of Bcl-2 over-expression on the messenger RNA level of two pro-apoptotic, bax and cpp32, and one anti-apoptotic, bcl-xl, regulators of neuronal death. In neonates wild-type mice, cpp32 mRNA was increased in axotomized, dying motoneurons. No changes in bax and bcl-xl messenger RNAs expression were detected. A similar course was observed in protected axotomized neonate motoneurons of transgenic mice over-expressing Bcl-2. In adult wild-type mice no motoneuron death was detected one week after axotomy: bax and cpp32 messenger RNAs were increased and bcl-xl messenger RNA was decreased. Four weeks after the lesion, 60% of the lesioned facial motoneurons had disappeared. In the remaining motoneurons only cpp32 messenger RNA expression was superior to control level. In Bcl-2 transgenic mice, no axotomy-induced facial motoneurons death was detected but the course of the neosynthesis of cell death genes messenger RNAs was similar to wild-type mice. Bax, Bcl-x and CPP32 immunoreactivity were increased in facial motoneurons after axotomy. Thus, fatal axotomy induces cell death genes bax and cpp32 messenger RNAs neosynthesis which is not prevented by athanatal Bcl-2 over-expression. This suggests that the protective effect of Bcl-2 results from interactions with Bax and CPP32 at the post-translation level without repercussion at the messenger RNA level. Axotomy induces cell death messenger RNA neosynthesis potentially harmful at long-term despite Bcl-2 over-expression. 1999 IBRO. Published by Elsevier Science Ltd.

NeuroReport, 2002

The olfactory system in both vertebrates and invertebrates can recognize and distinguish thousand... more The olfactory system in both vertebrates and invertebrates can recognize and distinguish thousands of chemical signals. Olfactory receptors are responsible for the early molecular events in the detection of volatile compounds and the perception of smell. Recently, candidate olfactory receptor genes have been identified in several organisms, but their characterization is far from been completed due to the difficulty to functionally express them in heterologous systems. To circumvent such difficulty, we expressed a mammalian olfactory gene, rat I7, in the nematode. We generated transgenic worms expressing I7 in AWA or AWB chemosensory neurons and performed behavioural assays using different concentrations of the rat I7 receptor agonist octanal. Pure octanal was repellent for wild-type worms whereas a 1:10 dilution was attractant. Expression of I7 in AWB neurons counteracted the volatile attraction to diluted octanal observed in control wild-type worms. Furthermore, expression of I7 in AWA neurons counteracted the volatile avoidance to pure octanal observed in wild-type worms. These results indicate that it is possible to functionally express mammalian olfactory receptors in providing a research tool to efficiently search for specific olfactory receptor ligands and to extend our understanding of the molecular basis of olfaction.