Soluble adenylyl cyclase is required for netrin-1 signaling in nerve growth cones

Background:The affinity of soluble adenylyl cyclase (sAC) for its substrate ATP suggested that it might be sensitive to fluctuations in ATP. Results: In sAC-overexpressing and glucose-responsive cells, sAC-generated cAMP reflects intracellular ATP levels. Conclusion: sAC can be an ATP sensor inside cells. Significance: sAC serves as a metabolic sensor via regulation by three cellular metabolites: ATP, bicarbonate, and calcium.

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“…5A) but not by KH7.15 (Fig. 5B), which is a compound structurally related to KH7 but inert against sAC (30).…”

Section: Sac Is Necessary For Physiological Glucose-induced Insulinmentioning

confidence: 95%

CO2/HCO3−- and Calcium-regulated Soluble Adenylyl Cyclase as a Physiological ATP Sensor

Zippin

Chen

Straub

et al. 2013

Journal of Biological Chemistry

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110

120

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“…Microdomains of cAMP are generated in cardiac myocytes (1), regional domains of cAMP are present in neurons (2,3), and cAMP diffusion is restricted by rapid degradation by phosphodiesterases (4) that limit the duration of cAMP signaling (5,6). However, little is known about spatial compartmentalization and temporal dynamics of cAMP in neuronal growth cones, despite the importance of cAMP for axon pathfinding in response to a wide range of molecular guidance cues, including Netrin-1 (7)(8)(9)(10)(11), semaphorins (12), Slits, and ephrins (13).…”

mentioning

confidence: 99%

Spatial and temporal second messenger codes for growth cone turning

Nicol

Hong

Spitzer

2011

Proc. Natl. Acad. Sci. U.S.A.

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Cyclic AMP (cAMP) and calcium are ubiquitous, interdependent second messengers that regulate a wide range of cellular processes. During development of neuronal networks they are critical for the first step of circuit formation, transducing signals required for axon pathfinding. Surprisingly, the spatial and temporal cAMP and calcium codes used by axon guidance molecules are unknown. Here, we identify characteristics of cAMP and calcium transients generated in growth cones during Netrin-1-dependent axon guidance. In filopodia, Netrin-1-dependent Deleted in Colorectal Cancer (DCC) receptor activation induces a transient increase in cAMP that causes a brief increase in calcium transient frequency. In contrast, activation of DCC in growth cone centers leads to a transient calciumdependent cAMP increase and a sustained increase in frequency of calcium transients. We show that filopodial cAMP transients regulate spinal axon guidance in vitro and commissural axon pathfinding in vivo. These growth cone codes provide a basis for selective activation of specific downstream effectors.cyclic AMP dynamics | calcium dynamics | compartmentalization | photoactivated adenylyl cyclase alpha | cyclic AMP oscillations C yclic AMP (cAMP) is a major cellular second messenger that activates and integrates multiple intracellular signaling pathways. Microdomains of cAMP are generated in cardiac myocytes (1), regional domains of cAMP are present in neurons (2, 3), and cAMP diffusion is restricted by rapid degradation by phosphodiesterases (4) that limit the duration of cAMP signaling (5, 6). However, little is known about spatial compartmentalization and temporal dynamics of cAMP in neuronal growth cones, despite the importance of cAMP for axon pathfinding in response to a wide range of molecular guidance cues, including Netrin-1 (7-11), semaphorins (12), Slits, and ephrins (13).Calcium is another ubiquitous second messenger involved in axon pathfinding, mediating responses to axon guidance molecules. In addition to axon steering, calcium modulates axon outgrowth and retraction (14,15). A sustained gradient of calcium across the growth cone is thought to be generated by asymmetric activation of axon guidance receptors, and to be the relevant calcium signal for axon pathfinding (16). Spontaneous fast and spatially restricted filopodial calcium transients are also sufficient to steer axons (17, 18). The frequency of slower transients in the entire growth cone controls the rate of axon extension in vivo and in vitro (19). The regulation of these transients by axon guidance cues has not been investigated.Filopodia are critical for axon pathfinding (20), and clues to their operation are provided by subcellular localization of signaling components. Filopodial enrichment of regulatory subunit II of protein kinase A, a major effector of cAMP, is required for growth cone attraction mediated by intracellular gradients of cAMP or PACAP (21). Modulation of spontaneous calcium transients in filopodia regulates axon turning (17). Temporal regulation o...

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“…Low-serum media contained DMEM plus 2% FBS, 1% DHS, 1% L-glutamine, and antibiotics. sAC-overexpressing stable PC12 cells were generated by infection with a lentivirus expressing the full-length isoform of human sAC (Wu et al 2006), and control, lacZ-overexpressing stable PC12 cells were generated by infection with a lentivirus expressing LacZ protein. Both mutant PC12 cell lines were selected and maintained in selection media containing 1 μg/ml blasticidin.…”

Section: Cell Culturementioning

confidence: 99%

“Soluble” adenylyl cyclase‐generated cyclic adenosine monophosphate promotes fast migration in PC12 cells

Young

Mehdi

Stohl

et al. 2007

J of Neuroscience Research

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In a model for neuronal movement, PC12 cells undergo fast migration in response to nerve growth factor (NGF) and phorbol ester (PMA). We previously showed that NGF increases intracellular cAMP via activation of soluble adenylyl cyclase (sAC). In this report, we demonstrate that sAC activation is an essential component of NGF-+PMA-induced fast migration in PC12 cells. Interestingly, PMA also raises intracellular cAMP but does so by stimulating transmembrane adenylyl cyclases (tmAC); however, this tmAC-generated cAMP does not contribute to fast migration. Therefore, cells must possess independent pools of cAMP capable of modulating distinct functions.Keywords adenylyl cyclase; nerve growth factor; neuron; compartmentalization; protein kinase C Neuronal migration and differentiation constitute key processes in the development of the central nervous system. The rat pheochromocytoma cell line PC12 has been extensively used as a model for the morphological changes that accompany both processes. When treated with nerve growth factor (NGF) for long periods (48-72 hr), PC12 cells extend neurites in a process analogous to differentiation of sympathetic neurons (Levi-Montalcini and Angeletti, 1968;Greene and Tischler, 1982;Vaudry et al., 2002). Conversely, when PC12 cells, plated on laminin-coated surfaces, are simultaneously stimulated with NGF and phorbol 12-myristate-13-acetate (PMA), the cell body recedes away from points of attachment to the plate surface, and the cells assume a crescent shape (Glowacka and Wagner, 1990). The latter phenomenon is rapid (observable within 1 hr of NGF + PMA addition) and has been considered a model for "fast neuronal migration."The signaling cascades that mediate the fast migration process have not been adequately described. Specifically, it is known that PMA exerts its effects via the activation of protein kinase C (PKC), which was independently shown to be essential for cell motility in primary (Choe et al., 2003). NGF has been shown to promote the survival and differentiation of multiple neuronal populations within the central nervous system (LeviMontalcini and Angeletti, 1968), but the signaling mechanisms involved in NGF-induced neuritogenesis remain controversial (Vaudry et al., 2002).We recently identified "soluble" adenylyl cyclase (sAC) as the source of cAMP downstream of NGF and a mediator of NGF-induced activation of the monomeric GTPase Rap1 in PC12 cells (Stessin et al., 2006). sAC is a ubiquitously expressed cAMP source in mammalian cells, distinct from the classically described trans-membrane adenylyl cyclases (tmACs) in its subcellular localization and biochemical profile. In this report, we demonstrate that the NGFsAC signaling axis is also required for fast migration. We also show that stimulation of PC12 cells with PMA results in cAMP elevation via tmACs, but, unlike sAC-generated cAMP, tmAC-generated cAMP does not contribute to the fast migration phenomenon. These results reveal the existence of distinct pools of cAMP, which are generated by independent sour...

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Soluble adenylyl cyclase is required for netrin-1 signaling in nerve growth cones

Cited by 92 publications

References 49 publications

CO2/HCO3−- and Calcium-regulated Soluble Adenylyl Cyclase as a Physiological ATP Sensor

CO2/HCO3−- and Calcium-regulated Soluble Adenylyl Cyclase as a Physiological ATP Sensor

Spatial and temporal second messenger codes for growth cone turning

“Soluble” adenylyl cyclase‐generated cyclic adenosine monophosphate promotes fast migration in PC12 cells

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