神经细胞中多巴胺d1和d5受体不同亚细胞分布和胞内转运的特性

Abstract

Objective To explore the possible differential trafficking properties of the dopamine D1-like receptor subtypes, D1 receptor and D5 receptor. Methods To visualize distributions of dopamine D1-like receptor subtypes at subcellular level, the yellow and cyan variants of green fluorescent protein (GFP) were used to tag D1 and D5 receptors. After transfection with the tagged dopamine receptors, the neuroblastoma cells NG108-15 were treated with D1 agonist SKF38393 or acetylcholine (ACh). Then we observed the subcellular distributions of the tagged receptors under the confocal microscopy and tried to determine trafficking properties by comparing their distribution patterns before and after the drug treatment. Results In resting conditions, D1 receptors located in the plasma membrane of NG108-15 cells, while D5 receptors located in both plasma membrane and cytosol. With the pre-treatment of SKF38393, the subcellular distribution of D1 receptors was changed. The yellow particle-like fluorescence of tagged D1 receptors appeared in the cytosol, indicating that D1 receptors were internalized into cytosol from the cell surface. Same situation also occurred in ACh pre-treatment. In contrast, the subcellular distribution of D5 receptors was not changed after SKF38393 or ACh treatment, indicating that D5R was not translocated to cell surface. Interestingly, when D1 and D5 receptors were co-expressed in the same cell, both kept their distinct subcellular distribution patterns and the trafficking properties. Conclusion Our present study reveals that in NG108-15 nerve cells, dopamine D1 and D5 receptors exhibit differential subcellular distribution patterns, and only D1 receptor has a marked trafficking response to the drug stimulation. We further discuss the potential role of the differential trafficking properties of D1-like receptors in complex modulation of DA signaling.

Sorting Nexin 1 Loss Results in D5 Dopamine Receptor Dysfunction in Human Renal Proximal Tubule Cells and Hypertension in Mice

“…Heydorn et al (18) previously reported that SNX1 interacted with the carboxyl terminus of D 5 R. We confirmed this interaction and further elucidated the distribution of the D 5 R and SNX1 in hPTCs and the human kidney. In hPTCs, D 5 R is found at the plasma membrane and cytoplasm in the basal state, in contrast to the predominantly intracellular expression of D 1 R (38), although D 1 R is localized to the plasma membrane in neuroblastoma cells NG108 -15 (39). On the other hand, SNX1 exists in both membrane and cytoplasmic pools in hPTCs, similar to previous observations in HeLa cells.…”

Differential subcellular distribution of rat brain dopamine receptors and subtype-specific redistribution induced by cocaine

“…Our present data is consistent with the hypothesis that decreased D1-Gs coupling results from redistribution of signaling components. A recent study conducted with D 1 and D 5 receptor-expressing cells observed a similar behavior of these two receptors in response to agonist: D 1 receptors translocated from the plasma membrane to intracellular sites while D 5 receptors did not undergo a significant shift when exposed to agonist (He et al, 2009). It is generally understood that excessive or persistent stimulation can induce internalization of G protein-coupled receptors, leading to lysosomal degradation of the receptors or subsequent recycling of the receptors back to the plasma membrane.…”

“…Previously published immunohistochemical analyses of D 5 receptors in brain indicated that this receptor was present primarily in the somal cytoplasm in tissues where the receptor was expressed (Ariano et al, 1997; Bergson et al, 1995; Ciliax et al, 2000; Khan et al, 2000; Oda et al). Similarly, in cultured cells D 1 receptors were localized to the plasma membrane, whereas D 5 receptor immunoreactivity was high in the somal cytoplasm and also present on the cell surface (He et al, 2009). The present determination that D 5 receptors do not sediment at 300,000g suggests that these receptors are associated with a microvesicular membrane of high lipid content, rendering it difficult to sediment.…”

“…While it is clear from receptor trafficking experiments that synaptic dopamine concentration drives the subcellular location or endosomal transport of dopamine receptors (Dumartin et al, 1998; Dumartin et al, 2000; He et al, 2009; Sun et al, 2003), it is still unknown if transmitter concentrations or exposure duration might influence the intra-membrane distribution of specific receptor subtypes, and how such influences may relate to physicochemical or functional receptor interactions or chronic alterations in receptor function.…”

Novel role of sorting nexin 5 in renal D 1 dopamine receptor trafficking and function: implications for hypertension

“…Considering the temporal profile of their association, it is conceivable that SNX5, D 1 R, and GRK4 may reside in the same membrane microdomain that facilitates the formation of macromolecular signaling complexes, similar to what has been described for other GPCRs that activate adenylyl cyclase (40). D 1 R and GRK4 are present in the plasma membrane (41, 42), where they both reside in lipid rafts (39, 40, 43). SNX5 is partly localized in the lipid rafts, and fenoldopam treatment increases the SNX5 abundance in these rafts (unpublished results).…”