GPR173

GPR173 is a highly conserved G protein-coupled receptor (GPCR) that plays a significant role in the regulation of the hypothalamic-pituitary-gonadal (HPG) axis, which is central to reproductive function.{{cite journal | vauthors = McIlwraith EK, Loganathan N, Belsham DD | title = Regulation of Gpr173 expression, a putative phoenixin receptor, by saturated fatty acid palmitate and endocrine-disrupting chemical bisphenol A through a p38-mediated mechanism in immortalized hypothalamic neurons | journal = Molecular and Cellular Endocrinology | volume = 485 | issue = | pages = 54–60 | date = April 2019 | pmid = 30716364 | doi = 10.1016/j.mce.2019.01.026 }}{{cite journal | vauthors = Liang H, Zhao Q, Lv S, Ji X | title = Regulation and physiological functions of phoenixin | journal = Frontiers in Molecular Biosciences | volume = 9 | issue = | pages = 956500 | date = 2022 | pmid = 36090042 | pmc = 9456248 | doi = 10.3389/fmolb.2022.956500 | doi-access = free }} It is expressed in the brain and ovaries, where it is considered the putative receptor for the peptide hormone phoenixin (PNX).

Activation of GPR173 by phoenixin potentiates the secretion of luteinizing hormone (LH) in response to gonadotropin-releasing hormone (GnRH), thereby promoting ovarian cycling and supporting reproductive processes. Beyond reproduction, GPR173 has been implicated in diverse physiological functions such as food intake regulation, learning and memory, anxiety, inflammatory responses, and cardiac protection, largely through its modulation by phoenixin.

Additionally, GPR173 may act as a receptor for cholecystokinin (CCK) in certain brain regions, mediating inhibitory synaptic plasticity and potentially serving as a therapeutic target for disorders involving excitation-inhibition imbalance.{{cite journal | vauthors = He L, Shi H, Zhang G, Peng Y, Ghosh A, Zhang M, Hu X, Liu C, Shao Y, Wang S, Chen L, Sun W, Su J, Chen X, Zhang L, Chan YS, Pei D, Tortorella M, Guo Y, Yan H, He J | title = A Novel CCK Receptor GPR173 Mediates Potentiation of GABAergic Inhibition | journal = The Journal of Neuroscience| volume = 43 | issue = 13 | pages = 2305–2325 | date = March 2023 | pmid = 36813575 | pmc = 10072296 | doi = 10.1523/JNEUROSCI.2035-22.2023 | url = }} The expression of GPR173 can be influenced by nutritional and environmental factors, indicating its role as a sensor and mediator in integrating external signals with neuroendocrine pathways.

Recent studies have found GPR173 may act as the receptor for the peptides phoenixin-14 (PNX-14) and phoenixin-20 (PNX-20).{{Cite journal | vauthors = Belsham DD, Mcilwraith EK | title = Phoenixin: uncovering its receptor, signaling and functions | journal = Acta Pharmacologica Sinica | volume = 39 | issue = 5 | pages = 774–778 | date = May 2018 | pmid = 29671415 | doi = 10.1038/aps.2018.13 | pmc = 5943909 | language = en | issn = 1745-7254 }}{{Cite journal | vauthors = Luo V, Belsham DD, Treen AK | title = Phoenixin Activates Immortalized GnRH and Kisspeptin Neurons Through the Novel Receptor GPR173 | journal = Molecular Endocrinology | volume = 30 | issue = 8 | pages = 872–888 | date = 2016-08-01 | pmid = 27268078 | doi = 10.1210/me.2016-1039 | pmc = 5414621 | issn = 0888-8809 }}{{Cite journal | vauthors = Tullock CW, Mathews SK, Garcia-Galiano D, Elias CF, Samson WK, Yosten GL, Stein LM | title = Hypothalamic action of phoenixin to control reproductive hormone secretion in females: importance of the orphan G protein-coupled receptor Gpr173 | journal = American Journal of Physiology. Regulatory, Integrative and Comparative Physiology | volume = 311 | issue = 3 | pages = R489–R496 | date = September 2016 | pmid = 27440717 | pmc = 5142227 | doi = 10.1152/ajpregu.00191.2016 | issn = 0363-6119 }} Both Phoenixins are alternate cleavage products of SMIM20.

• SREB
• SMIM20

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{{G protein-coupled receptors}}

Category:G protein-coupled receptors

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