(S)NO Signals: Translocation, Regulation, and a Consensus Motif

Abstract

metals in all biological systems (Stamler, 1994). The S-nitrosothiol (SNO) and metal nitrosyl (MNO) products and Nikolaus J. Sucher ‡ § have intrinsic reactivities that enable local action. The * Departments of Medicine, Cell Biology, NO group is transferred by covalent exchange mecha- † Chemistry and Biochemistry nisms including thiol/nitrosothiol (RSNO/R'S Ϫ ⇔ R'SNO/ Duke University RS Ϫ ) or nitrosothiol/metal (SNO/M ⇔ MNO/S) exchange. Durham, North CarolinaThis mode of intra-and intercellular communication has ‡ Laboratory of Cellular and Molecular Neuroscience advantages over free diffusion and is better established Children's Hospital in vivo (Stamler et al., 1992a;Jia et al., 1996). Harvard Medical SchoolNO also exploits reactions with O 2 /O 2 Ϫ to complete the Boston, Massachusetts armamentarium of species responsible for "NO" effects (Table 1; Stamler et al., 1992b). This is well exemplified Nitric oxide (NO) is a signaling molecule that has capin the immune system in work by DeGroote and Fang tured our imagination. According to the common view, (DeGroote et al., 1996). These researchers found that NO diffuses over a large sphere of influence, moving bacterial virulence is conferred by a gene that protects freely through membranes of target cells to raise levels against the lethal effects of SNOs produced by the (muof cGMP. In the brain, NO influences synaptic plasticity, rine) host, whereas NO is harmless against the same apoptosis, neuronal development, and even complex bacteria. Molecular recognition of the SNO onslaught behavioral responses. This image has been reinforced and the activation of bacterial resistance is achieved by by observations in the cardiovascular and immune sys-S-nitrosylation of proteins involved in defense (Hauslatems, for example, the relaxation of blood vessels by den et al., 1996). Thus, in this system, S-nitrosylation is cGMP, and the killing of tumor cells and bacteria by the the signal and the regulator of the response. macrophage NO synthase (NOS).A similar NO signal is used by mammalian cells. Images can also be misleading. First, a wide sphere For example, the endothelium-derived relaxation factor of NO diffusion implies that it travels down concentration (EDRF)/NO-mediated relaxation of blood vessels occurs gradients that are established by extracellular sinks partly by direct activation of a potassium channel (Lancaster, 1994;Stamler, 1996). The problem with this through reactions of EDRF with critical thiols (Bolotina picture is that NO cannot achieve local action: it would et al., 1994). Likewise in the heart, SNO and peroxynitrite be leaving cells more rapidly than it reacts within. Sec-(OONO Ϫ ) directly activate calcium channels by a redox ond, we have come to appreciate that many NO signals mechanism that opposes the effects of cGMP (Campbell are cGMP independent. These pathways, typically et al., 1996). Ion channel activation may also account grouped under the broad heading of "redox", have not for NO/SNO-mediated relaxations of third to fourth order been i...

S-Nitrosylation and uncompetitive/fast off-rate (UFO) drug therapy in neurodegenerative disorders of protein misfolding

“…In general, a consensus motif of amino acids comprised of nucleophilic residues (generally an acid and a base) surround a critical cysteine, which increases the cysteine sulfhydryl's susceptibility to S-nitrosylation. 46,47 Our group first identified the physiological relevance of S-nitrosylation by showing that NO and related RNS exert paradoxical effects via redox-based mechanisms -NO is neuroprotective via S-nitrosylation of NMDA receptors (as well as other subsequently discovered targets, including caspases), and yet can also be neurodestructive by formation of peroxynitrite (or, as later discovered, reaction with additional molecules such as parkin, PDI, GAPDH, and MMP-9) (Figure 1). 6,8,9,12,14,16,17,[19][20][21][22]48 Over the past decade, accumulating evidence has suggested that S-nitrosylation can regulate the biological activity of a great variety of proteins, in some ways akin to phosphorylation.…”

Identification of the Cysteine Nitrosylation Sites in Human Endothelial Nitric Oxide Synthase

“…NO can produce both single cysteine S-nitrosylations as in case of Ha-Ras (Lander et al, 1997), caspase 3 (Rossig et al, 1999), and nuclear factor-kappa B (Marshall and Stamler, 2001) and multiple cysteine S-nitrosylations in case of Nethylmaleimide Sensitive Factor (NSF) (Matsushita et al, 2003) and the ryanodine receptor (Voss et al, 2004). Consensus S-nitrosylation motifs have been postulated by Stamler et al (1997). These motifs have been suggested to contain hydrophilic residues adjacent to the specific cysteine either in the primary structure (Stamler et al, 1997) or brought together by three-dimensional (3D) conformations (Ascenzi et al, 2000(Ascenzi et al, , 2001.…”

“…Consensus S-nitrosylation motifs have been postulated by Stamler et al (1997). These motifs have been suggested to contain hydrophilic residues adjacent to the specific cysteine either in the primary structure (Stamler et al, 1997) or brought together by three-dimensional (3D) conformations (Ascenzi et al, 2000(Ascenzi et al, , 2001. However, our previous studies, utilizing short peptide sequences, suggested that S-nitrosylation may be independent of the amino acids surrounding the cysteine residue.…”

How widespread is stable protein S-nitrosylation as an end-effector of protein regulation?

“…Kinases are often co-localised with their substrates, with additional selectivity achieved by consensus motifs in the primary sequence of a target protein that is phosphorylated. Similarly, targets of S-nitrosation can localise with NO synthase (NOS) enzymes [8], and may contain linear amino acid consensus motifs [23], thus mirroring key features of kinase-mediated phosphorylation. Furthermore, denitrosylase enzymes that remove NO from proteins are described to play the corresponding role of phosphatases in phospho-regulated proteins [22].…”

“…Indeed, a consensus motif for S-nitrosation was proposed in 1994 when it was found that many protein S-nitrosothiols have basic or acidic amino acid preceding the cysteine followed by an acidic amino acid [55]. From this a consensus motif consisting of a core of three residues (K/R/H/D/E)-C-(D/E) was proposed to predict S-nitrosation in hydrophobic protein domains [23]. The computational prediction software GPS-SNO (http://sno.biocuckoo.org/) was used to analyze 467 experimentally verified S-nitrosothiol sites in 302 proteins, to develop algorithms that computationally 'predict' Snitrosation from a primary sequence alone.…”