Enzymatic Functions and Structures of CD38 and Homologs

Hc, Lee

doi:10.1159/000058774

Cited by 104 publications

(80 citation statements)

References 82 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Little is known concerning the metabolic pathway for NAADP generation. What is clear is that members of the ADP-ribosyl cyclase family of multi-functional enzymes can produce several molecules involved in Ca 2+ homoeostasis including NAADP in vitro [69]. What is not clear, is whether these enzymes catalyze NAADP generation in vivo (see [35]).…”

Section: Discussionmentioning

confidence: 99%

Recruitment of NAADP-sensitive acidic Ca2+ stores by glutamate

Pandey

Chuang

Lewis

et al. 2009

Biochemical Journal

View full text Add to dashboard Cite

NAADP (nicotinic acid–adenine dinucleotide phosphate) is an unusual second messenger thought to mobilize acidic Ca2+ stores, such as lysosomes or lysosome-like organelles, that are functionally coupled to the ER (endoplasmic reticulum). Although NAADP-sensitive Ca2+ stores have been described in neurons, the physiological cues that recruit them are not known. Here we show that in both hippocampal neurons and glia, extracellular application of glutamate, in the absence of external Ca2+, evoked cytosolic Ca2+ signals that were inhibited by preventing organelle acidification or following osmotic bursting of lysosomes. The sensitivity of both cell types to glutamate correlated well with lysosomal Ca2+ content. However, interfering with acidic compartments was largely without effect on the Ca2+ content of the ER or Ca2+ signals in response to ATP. Glutamate but not ATP elevated cellular NAADP levels. Our results provide evidence for the agonist-specific recruitment of NAADP-sensitive Ca2+ stores by glutamate. This links the actions of NAADP to a major neurotransmitter in the brain.

show abstract

Section: Discussionmentioning

confidence: 99%

Recruitment of NAADP-sensitive acidic Ca2+ stores by glutamate

Pandey

Chuang

Lewis

et al. 2009

Biochemical Journal

View full text Add to dashboard Cite

show abstract

“…The primary amino acid sequence and the partial crystal structure of these three major ADP-ribosyl cyclases have been resolved (51)(52)(53). Analysis of the sequence and structural data indicates that the mammalian and invertebrate ADP-ribosyl cyclases have 25 to 30% identity in their primary structure (54,55). CD38, the typical mammalian ADP-ribosyl cyclase, is a 45-kD type II transmembrane protein expressed in a wide variety of tissues (44).…”

Section: Adp-ribosyl Cyclase Cd38 and Cyclic Adp-ribose In Airway Smentioning

confidence: 99%

“…CD38 possesses a relatively long extracellular domain (carboxyl terminal) and shorter cytoplasmic and transmembrane domains (55). The single catalytic domain responsible for the multiple enzymatic activities also is located at the extracellular portion of the protein (63).…”

Section: Adp-ribosyl Cyclase Cd38 and Cyclic Adp-ribose In Airway Smentioning

confidence: 99%

Calcium Signaling in Airway Smooth Muscle

Jude¹,

Wylam²,

Walseth³

et al. 2008

Proceedings of the American Thoracic Society

View full text Add to dashboard Cite

Contractility of airway smooth muscle requires elevation of intracellular calcium concentration. Under resting conditions, airway smooth muscle cells maintain a relatively low intracellular calcium concentration, and activation of the surface receptors by contractile agonists results in an elevation of intracellular calcium, culminating in contraction of the cell. The pattern of elevation of intracellular calcium brought about by agonists is a dynamic process and involves the coordinated activities of ion channels located in the plasma membrane and the sarcoplasmic reticulum. Among the signaling molecules involved in this dynamic calcium regulation in airway smooth muscle cells are inositol 1,4,5-trisphosphate and cyclic ADPribose, which mobilize calcium from the sarcoplasmic reticulum by acting via the inositol 1,4,5-trisphosphate and ryanodine receptors, respectively. In addition, calcium influx from the extracellular space is critical for the repletion of the intracellular calcium stores during activation of the cells by agonists. Calcium influx can occur via voltage-and receptor-gated channels in the plasma membrane, as well as by influx that is triggered by depletion of the intracellular stores (i.e., store-operated calcium entry mechanism). Transient receptor potential proteins appear to mediate the calcium influx via receptor-and store-operated channels. Recent studies have shown that proinflammatory cytokines regulate the expression and activity of the pathways involved in intracellular calcium regulation, thereby contributing to airway smooth muscle cell hyperresponsiveness. In this review, we will discuss the specific roles of cyclic ADP-ribose/ryanodine receptor channels and transient receptor potential channels in the regulation of intracellular calcium in airway smooth muscle cells. DYNAMIC INTRACELLULAR CALCIUM REGULATION IN AIRWAY SMOOTH MUSCLE CELLSExposure of airway smooth muscle (ASM) cells to contractile agonists results in a biphasic elevation of intracellular calcium concentration ([Ca 21 ] i ) that is characterized by an initial rapid and transient rise in calcium, followed by a decline to a lower, sustained steady-state concentration above the basal level (1-3). This biphasic [Ca 21 ] i response results from calcium influx from the extracellular space and release of calcium from the intracellular stores (i.e., the sarcoplasmic reticulum [SR]). Earlier studies have attributed the initial rapid and transient phase of the [Ca 21 ] i response to release from the SR, while the sustained phase of the response was thought to be due to influx from the extracellular space (2-6). Recent investigations using the improved temporal and spatial resolution features of real-time confocal microscopy have shed light on the dynamics of the [Ca 21 ] i response in ASM cells. These studies have shown that the biphasic [Ca 21 ] i response of ASM cells elicited by contractile agonists in reality consists of propagating regenerative calcium oscillations that originate at a location within a cell and propagate...

show abstract

“…; and (2) how does CD38, whose short intracellular domain lacks consensus sequences, cross-talk with its partners such as BCR? Related to the first question, the groups of De Flora [8] and Lee [9], based on experimental and structural data, have suggested that CD38 could function as a channel\transporter for catalytically formed cADPR leading to increased intracellular Ca# + levels. However, Lund et al [10] have shown that CD38 signalling in B-cells was independent from its catalytic activity.…”

Section: Introductionmentioning

confidence: 99%