Lobster G-protein coupled receptor kinase that associates with membranes and G? in response to odorants and neurotransmitters

Xu, Fuqiang; Bose, Soma C.; McClintock, Timothy S.

doi:10.1002/(sici)1096-9861(19991227)415:4<449::aid-cne3>3.0.co;2-u

Cited by 8 publications

(5 citation statements)

References 52 publications

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“…To test whether the lobster PI3K protein may be activated by G proteins, we looked for an interaction with both of the Gα and Gβ subunits previously shown to be present in lobster olfactory tissue (Xu et al. 1997, 1998, 1999; Xu and McClintock 1999).…”

Section: Resultsmentioning

confidence: 99%

Phosphoinositide 3‐kinase mediated signaling in lobster olfactory receptor neurons

Corey

Bobkov

Pezier

et al. 2010

Journal of Neurochemistry

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In vertebrates and some invertebrates, odorant molecules bind to G protein-coupled receptors on olfactory receptor neurons (ORNs) to initiate signal transduction. Phosphoinositide 3-kinase (PI3K) activity has been implicated physiologically in olfactory signal transduction, suggesting a potential role for a G protein-coupled receptor-activated class I PI3K. Using isoform-specific antibodies, we identified a protein in the olfactory signal transduction compartment of lobster ORNs that is antigenically similar to mammalian PI3Kc and cloned a gene for a PI3K with amino acid homology with PI3Kb. The lobster olfactory PI3K co-immunoprecipitates with the G protein a and b subunits, and an odorant-evoked increase in phosphatidylinositol (3,4,5)-trisphosphate can be detected in the signal transduction compartment of the ORNs. PI3Kc and b isoform-specific inhibitors reduce the odorant-evoked output of lobster ORNs in vivo. Collectively, these findings provide evidence that PI3K is indeed activated by odorant receptors in lobster ORNs and further support the potential involvement of G protein activated PI3K signaling in olfactory transduction. Keywords: lobster, olfactory receptor neuron, olfactory signal transduction, phosphatidylinositol (3,4,5)-trisphosphate, phosphoinositide 3-kinase. requires a closer examination of the potential involvement of PI signaling. Some of the first evidence for the potential involvement of PI signaling in olfactory transduction came from lobster ORNs. Activation of lobster ORNs is GTP-dependent and can be blocked by anti-sera specific for Ga q (Fadool et al. 1995), suggesting that signal transduction in lobster ORNs involves G protein activation. Receptor activation stimulates PLC and the resulting IP 3 presumably targets an IP 3 receptor (Munger et al. 2000) to increase intracellular calcium (Fadool and Ache 1992), arguing for a potential role for canonical PI signaling. However, PLC does not appear to be the only PI-based signaling pathway in these cells. PI3K antagonists reduce the odorant-evoked receptor potential and addition of either exogenous phosphatidylinositol (4,5)-bisphosphate (PIP 2 ) or phosphatidylinositol (3,4,5)-trisphosphate (PIP 3 ) modulates the suspected output channel of the cells (Zhainazarov and Ache 1999;Zhainazarov et al. 2001). This evidence for the involvement of both the PLC and the PI3K pathway makes lobster ORNs a useful animal model in which to study the integrated role of PI signaling in olfactory transduction.If PI3K-mediated signaling is involved in olfactory transduction, it should be possible to show that the appropriate enzyme is present in the transduction compartment and can be activated by odorants sufficiently fast to account for activation of the ORNs. Here, building upon previous evidence of PI3K signaling in lobster ORNs, we show that a PI3K is expressed by lobster ORNs, that PI3K signaling is likely activated by G proteins, and that it localizes to the transduction compartment (outer dendrites). We confirm that odorants can rapidly an...

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Section: Resultsmentioning

confidence: 99%

Phosphoinositide 3‐kinase mediated signaling in lobster olfactory receptor neurons

Corey

Bobkov

Pezier

et al. 2010

Journal of Neurochemistry

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“…Gene products typically enriched in neurons that we detected included N-cadherin, long-chain fatty acid-CoA ligase, ciboulot, phospholipase C, adenylyl cyclase, calmegin, Down syndrome cell adhesion molecule (Dscam), neuroligin, dorfin, orcokinin, synaptotagmin, failed axon connnections (Fax), trophinin, glutamate synthase, ionotropic glutamate and GABA receptors, GABA receptor-associated protein, chloride channels, and Na ϩ -K ϩ -ATPases. Some of these sequences, like those of phospholipase C, adenylyl cyclase, ionotropic receptors, and ion channels, are already known to be expressed by olfactory sensory neurons or are implicated in their physiology (21,39,40,79,83,84).…”

Section: Resultsmentioning

confidence: 99%

Gene expression and specificity in the mature zone of the lobster olfactory organ

Stepanyan

Day

Urban

et al. 2006

Physiological Genomics

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expression and specificity in the mature zone of the lobster olfactory organ. Physiol Genomics 25: 224 -233, 2006; doi:10.1152/physiolgenomics.00276.2005.-The lobster olfactory organ is an important model for investigating many aspects of the olfactory system. To facilitate study of the molecular basis of olfaction in lobsters, we made a subtracted cDNA library from the mature zone of the olfactory organ of Homarus americanus, the American lobster. Sequencing of the 5Ј-end of 5,184 cDNA clones produced 2,389 distinct high-quality sequences consisting of 1,944 singlets and 445 contigs. Matches to known sequences corresponded with the types of cells present in the olfactory organ, including specific markers of olfactory sensory neurons, auxiliary cells, secretory cells of the aesthetasc tegumental gland, and epithelial cells. The wealth of neuronal mRNAs represented among the sequences reflected the preponderance of neurons in the tissue. The sequences identified candidate genes responsible for known functions and suggested new functions not previously recognized in the olfactory organ. A cDNA microarray was designed and tested by assessing mRNA abundance differences between two of the lobster's major chemosensory structures: the mature zone of the olfactory organ and the dactyl of the walking legs, a taste organ. The 115 differences detected again emphasized the abundance of neurons in the olfactory organ, especially a cluster of mRNAs encoding cytoskeletal-associated proteins and cell adhesion molecules such as 14-3-3, actins, tubulins, trophinin, Fax, Yel077cp, suppressor of profilin 2, and gelsolin. microarray; bioinformatics; crustacea; neurogenesis LOBSTERS ARE IMPORTANT MODELS for studying olfaction. Lobster olfactory sensory neurons are large compared with most other animal species. This advantage is one reason that they were the first olfactory sensory neurons investigated by patch-clamp electrophysiology, and, more broadly, the first neurons of any type used for patch clamping in situ in tissue sections (2). This approach led to numerous discoveries such as hyperpolarizing receptor potentials, modulation of sensory neuron sensitivity by neuroactive compounds, presynaptic inhibition of olfactory sensory neurons, dual olfactory transduction pathways, and regulation of olfactory transduction by phosphatidylinositols (1, 49 -51, 76, 83, 84 ). Equally important to the success of the lobster as a model is an understanding of the chemistry and behavioral significance of odors in crustaceans to the extent where specific behaviors can be evoked by synthetic odors consisting of mixtures of amino acids and nucleotides (13,14). The development of associative conditioning tests for lobsters provided further behavioral measures that could be directly correlated with physiology, thereby allowing pioneering studies into the perception of odor mixtures (for reviews, see Refs. 19 and 20). The means to investigate chemistry, behavior, and physiology in a single organism has made the lobster a significant model for the stu...

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“…The cDNA library, screening methods, and plasmid rescue methods were as described previously (McClintock et al 1992;Xu et al 1999). Automated sequencing of purified plasmid DNA was performed at the University of Pennsylvania DNA Sequencing Facility.…”

Section: Lobstersmentioning

confidence: 99%

“…2000). The sensory neurons detect water-soluble odorants via heterotrimeric G-protein-coupled receptor pathways, with phospholipase C activation as the main pathway (Ache and Zhainazarov 1995;Ache et al 1998;Xu et al 1999;Bobkov and Ache 2005). Relatively little is known about the auxiliary cells, although they clearly help plug the base of aesthetasc setae, and in P. argus, they express ectoATPases that degrade the odorant, ATP (Grünert and Ache 1988;Gleeson et al 1991Gleeson et al , 1992.…”

Section: Introductionmentioning

confidence: 99%

Olfactory specific chymotrypsin-like serine protease from the aesthetasc tegumental gland of the lobster, Homarus americanus

2005

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Numerous proteases and protease inhibitors are expressed in the lobster olfactory organ. One of these proteases, olfactory enriched transcript 03 (OET-03), is particularly interesting because its mRNA is expressed only in one cell type of the olfactory organ of the American lobster, Homarus americanus. We have obtained a full-length cDNA clone of OET-03. The predicted amino acid sequence is equally divided between a novel N-terminal domain and a conserved serine protease catalytic domain at the C-terminus. Heterologous expression in HEK293 cells allowed protease assays demonstrating that OET-03 cleaved a specific serine protease substrate, N-alpha benzoyl-L-arginine p-nitroanilide, but did not cleave a substrate of metalloproteases and cysteine proteases. OET-03 protease activity was significantly inhibited by the chymotrypsin-like protease inhibitor, tosyl-L-phenylalanine chloromethyl ketone, but not by the general protease inhibitor, phenylmethylsulfonyl fluoride. Immunoreactivity for OET-03 was detected only in the cells previously shown to contain OET-03 mRNA. The cytoplasm of these cells was filled with enlarged smooth endoplasmic reticulum (a characteristic of secretory cells) that appeared to expand into large electron-translucent areas at the ventral end of the cell. The ventral ends of these secretory cells were apposed to phalloidin-labeled triangular structures reminiscent of the beginnings of the ducts of crustacean tegumental glands. This putative gland was found only in association with the aesthetasc sensory units of the olfactory organ, hence the name, aesthetasc tegumental gland.

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Lobster G-protein coupled receptor kinase that associates with membranes and G? in response to odorants and neurotransmitters

Cited by 8 publications

References 52 publications

Phosphoinositide 3‐kinase mediated signaling in lobster olfactory receptor neurons

Phosphoinositide 3‐kinase mediated signaling in lobster olfactory receptor neurons

Gene expression and specificity in the mature zone of the lobster olfactory organ

Olfactory specific chymotrypsin-like serine protease from the aesthetasc tegumental gland of the lobster, Homarus americanus

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