scholarly journals Analyzing the Role of Receptor Internalization in the Regulation of Melanin-Concentrating Hormone Signaling

2013 ◽  
Vol 2013 ◽  
pp. 1-10
Author(s):  
Jay I. Moden ◽  
Katrina Haude ◽  
Robert Carroll ◽  
Andrew Goodspeed ◽  
Laurie B. Cook
Keyword(s):  
Receptor Internalization ◽  
Hormone Signaling ◽  
Melanin Concentrating Hormone

Neurotensin Enhances Locomotor Activity and Arousal and Inhibits Melanin-Concentrating Hormone Signaling

2019 ◽  
Vol 110 (1-2) ◽  
pp. 35-49 ◽  
Author(s):  
Talia Levitas-Djerbi ◽  
Dana Sagi ◽  
Ilana Lebenthal-Loinger ◽  
Tali Lerer-Goldshtein ◽  
Lior Appelbaum
Keyword(s):  
Locomotor Activity ◽  
Hormone Receptor ◽  
Behavioral Response ◽  
Hormone Signaling ◽  
Wild Type ◽  
Expression Levels ◽  
Physiological Processes ◽  
Melanin Concentrating Hormone ◽  
Behavioral Assays

Background: Hypothalamic neurotensin (Nts)-secreting neurons regulate fundamental physiological processes including metabolism and feeding. However, the role of Nts in modulation of locomotor activity, sleep, and arousal is unclear. We previously identified and characterized Nts neurons in the zebrafish hypothalamus. Materials and Methods: In order to study the role of Nts, nts mutant (nts–/–), and overexpressing zebrafish were generated. Results: The expression of both nts mRNA and Nts protein was reduced during the night in wild-type zebrafish. Behavioral assays revealed that locomotor activity was decreased during both day and night, while sleep was increased exclusively during the nighttime in nts–/– larvae. Likewise, inducible overexpression of Nts increased arousal in hsp70:Gal4/uas:Nts larvae. Furthermore, the behavioral response to light-to-dark transitions was reduced in nts–/– larvae. In order to elucidate potential contenders that may mediate Nts action on these behaviors, we profiled the transcriptome of 6 dpf nts–/– larvae. Among other genes, the expression levels of melanin-concentrating hormone receptor 1b were increased in nts–/– larvae. Furthermore, a portion of promelanin-concentrating hormone 1 (pmch1) and pmch2 neurons expressed the nts receptor. In addition, expression of the the two zebrafish melanin-concentrating hormone (Mch) orthologs, Mch1 and Mch2, was increased in nts–/– larvae. Conclusion: These results show that the Nts and Mch systems interact and modulate locomotor activity and arousal.

scholarly journals Parathyroid hormone induces bone formation in phosphorylation-deficient PTHR1 knockin mice

2012 ◽  
Vol 302 (10) ◽  
pp. E1183-E1188 ◽  
Author(s):  
Nabanita S. Datta ◽  
Tareq A. Samra ◽  
Abdul B. Abou-Samra
Keyword(s):  
Parathyroid Hormone ◽  
Bone Formation ◽  
Physiological Role ◽  
Receptor Internalization ◽  
Mineral Density ◽  
Trabecular Thickness ◽  
Receptor Complexes ◽  
Diaphyseal Bone ◽  
Anabolic Action

Activation of G protein-coupled receptors by agonists leads to receptor phosphorylation, internalization of ligand receptor complexes, and desensitization of hormonal response. The role of parathyroid hormone (PTH) receptor 1, PTHR1, is well characterized and known to regulate cellular responsiveness in vitro. However, the role of PTHR1 phosphorylation in bone formation is yet to be investigated. We have previously demonstrated that impaired internalization and sustained cAMP stimulation of phosphorylation-deficient (PD) PTHR1 leads to exaggerated cAMP response to subcutaneous PTH infusion in a PD knockin mouse model. To understand the physiological role of receptor internalization on PTH bone anabolic action, we examined bone parameters of wild-type (WT) and PD knockin female and male mice following PTH treatment. We found a decrease in total and diaphyseal bone mineral density in female but not in male PD mice compared with WT controls at 3–6 mo of age. This effect was attenuated at older age groups. PTH administration displayed increased bone volume and trabecular thickness in the vertebrae and distal femora of both WT and PD animals. These results suggest that PTHR1 phosphorylation does not play a major role in the anabolic action of PTH.

scholarly journals Dual Role of the β2-Adrenergic Receptor C Terminus for the Binding of β-Arrestin and Receptor Internalization

2008 ◽  
Vol 283 (46) ◽  
pp. 31840-31848 ◽  
Author(s):  
Cornelius Krasel ◽  
Ulrike Zabel ◽  
Kristina Lorenz ◽  
Susanne Reiner ◽  
Suleiman Al-Sabah ◽  
...  
Keyword(s):  
Adrenergic Receptor ◽  
Dual Role ◽  
Receptor Internalization ◽  
C Terminus ◽  
Β2 Adrenergic Receptor

scholarly journals The Role of Thyroid Hormone Signaling in the Prevention of Digestive System Cancers

2013 ◽  
Vol 14 (8) ◽  
pp. 16240-16257 ◽  
Author(s):  
Adam Brown ◽  
Rosalia Simmen ◽  
Frank Simmen
Keyword(s):  
Thyroid Hormone ◽  
Digestive System ◽  
Hormone Signaling

Abstract 321: LRP6 Regulates LDL Receptor Internalization and LDL Uptake

2012 ◽  
Vol 32 (suppl_1) ◽  
Author(s):  
Arya Mani ◽  
Gwang-Woong Go ◽  
Zhi-jia Ye ◽  
Rajvir Singh
Keyword(s):  
Cho Cells ◽  
Ldl Cholesterol ◽  
Ldl Receptor ◽  
High Serum ◽  
Skin Fibroblasts ◽  
Receptor Internalization ◽  
Cholesterol Levels ◽  
Endocytic Machinery ◽  
Ldl Uptake

Genetic variations in LRP6 gene are associated with high serum LDL cholesterol levels and atherosclerosis. We examined the role of LRP6 in LDL receptor (LDLR) mediated LDL uptake. LDL uptake was increased when LRP6 was overexpressed and reduced when it was knocked down in LDLR deficient CHO cells. Interestingly, LRP6 knockdown in wildtype CHO cells resulted in a much greater decline in LDL uptake compared to ldlA7 cells. This finding suggested interaction between LRP6 and other proteins involved in LDL uptake. Strikingly, LDL receptor internalization was severely diminished when LRP6 was knocked down and was restored after LRP6 was reintroduced. Further investigations showed that LRP6 forms a complex with the LDL endocytic machinery including LDLR, clathrin and ARH and undergoes endocytosis after stimulation with LDL. LDLR internalization was defective in skin fibroblasts of the LRP6 R611C mutation carriers. LDLR and LRP6 internalizations as well as LDL uptake were significantly impaired in wildtype CHO cells expressing LRP6 R611C mutation(figa,b). These studies introduce LRP6 as a critical modulator of receptor-mediated LDL endocytosis and identify a mechanism by which variation in LRP6 may contribute to high serum LDL levels and atherosclerosis.

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