Review: A Publication of LMDA, the Literary Managers and Dramaturgs of the Americas, volume 17, issue 2

Contents include: The City Project; Conference Preview; LMDA Conference 97: Dramaturg Driven!; Performance and the City Symposium and Architecture Tour; The Shakespearean Dramatug, The Book by Andrew James Hartely; Blizt Weekend; Encouraged! LMDA member Freddie Ashley is Recognized for Advancing the Arts in Georgia; The Role of the Dramaturg in the RSC\u27s Spanish Season From Golden Age Page to Stratford Stage. Issue editors: D.J. Hopkins, Shelley Orrhttps://soundideas.pugetsound.edu/lmdareview/1035/thumbnail.jp

Melanocortin receptors in GtoPdb v.2021.3

Melanocortin receptors (provisional nomenclature as recommended by NC-IUPHAR [41]) are activated by members of the melanocortin family (α-MSH, β-MSH and γ-MSH forms; δ form is not found in mammals) and adrenocorticotrophin (ACTH). Endogenous antagonists include agouti and agouti-related protein. ACTH(1-24) was approved by the US FDA as a diagnostic agent for adrenal function test, whilst NDP-MSH was approved by EMA for the treatment of erythropoietic protoporphyria. Several synthetic melanocortin receptor agonists are under clinical development

Melanocortin receptors in GtoPdb v.2023.1

Melanocortin receptors (provisional nomenclature as recommended by NC-IUPHAR [41]) are activated by members of the melanocortin family (α-MSH, β-MSH and γ-MSH forms; δ form is not found in mammals) and adrenocorticotrophin (ACTH). Endogenous antagonists include agouti and agouti-related protein. ACTH(1-24) was approved by the US FDA as a diagnostic agent for adrenal function test. setmelanotide was approved by the US FDA for weight management in patients with POMC, PCSK1 or LEPR defiency, bremelanotide was approved by the US FDA for generalized hypoactive sexual desire disorder in premenopausal women, and NDP-MSH (afamelanotide) was approved by the EMA for the treatment of erythropoietic protoporphyria. Several synthetic melanocortin receptor agonists are under clinical development

Melanocortin receptors (version 2019.4) in the IUPHAR/BPS Guide to Pharmacology Database

Melanocortin receptors (provisional nomenclature as recommended by NC-IUPHAR [36]) are activated by members of the melanocortin family (α-MSH, β-MSH and γ-MSH forms; δ form is not found in mammals) and adrenocorticotrophin (ACTH). Endogenous antagonists include agouti and agouti-related protein. ACTH(1-24) was approved by the US FDA as a diagnostic agent for adrenal function test, whilst NDP-MSH was approved by EMA for the treatment of erythropoietic protoporphyria. Several synthetic melanocortin receptor agonists are under clinical development

Desacetyl-α-melanocyte stimulating hormone and α-melanocyte stimulating hormone are required to regulate energy balance.

OBJECTIVE: Regulation of energy balance depends on pro-opiomelanocortin (POMC)-derived peptides and melanocortin-4 receptor (MC4R). Alpha-melanocyte stimulating hormone (α-MSH) is the predicted natural POMC-derived peptide that regulates energy balance. Desacetyl-α-MSH, the precursor for α-MSH, is present in brain and blood. Desacetyl-α-MSH is considered to be unimportant for regulating energy balance despite being more potent (compared with α-MSH) at activating the appetite-regulating MC4R in vitro. Thus, the physiological role for desacetyl-α-MSH is still unclear. METHODS: We created a novel mouse model to determine whether desacetyl-α-MSH plays a role in regulating energy balance. We engineered a knock in targeted QKQR mutation in the POMC protein cleavage site that blocks the production of both desacetyl-α-MSH and α-MSH from adrenocorticotropin (ACTH1-39). RESULTS: The mutant ACTH1-39 (ACTHQKQR) functions similar to native ACTH1-39 (ACTHKKRR) at the melanocortin 2 receptor (MC2R) in vivo and MC4R in vitro. Male and female homozygous mutant ACTH1-39 (Pomctm1/tm1) mice develop the characteristic melanocortin obesity phenotype. Replacement of either desacetyl-α-MSH or α-MSH over 14 days into Pomctm1/tm1 mouse brain significantly reverses excess body weight and fat mass gained compared to wild type (WT) (Pomcwt/wt) mice. Here, we identify both desacetyl-α-MSH and α-MSH peptides as regulators of energy balance and highlight a previously unappreciated physiological role for desacetyl-α-MSH. CONCLUSIONS: Based on these data we propose that there is potential to exploit the naturally occurring POMC-derived peptides to treat obesity but this relies on first understanding the specific function(s) for desacetyl-α-MSH and α-MSH

hMRAPα, but Not hMRAP2, Enhances hMC4R Constitutive Activity in HEK293 Cells and This Is Not Dependent on hMRAPα Induced Changes in hMC4R Complex N-linked Glycosylation

<div><p>MRAP1 but not MRAP2, is essential for melanocortin receptor 2 functional expression. Human MRAP1 splice variant (hMRAPα) and human MRAP2 (hMRAP2) also interact with the other melanocortin receptor subtypes <i>in vitro</i>, although the physiological significance of these interactions is unknown. Previously we showed that HA-hMC4R co-expression with hMRAPα, but not hMRAP2, specifically alters HA-hMC4R complex N-linked glycosylation. hMRAPα-FLAG also enhances hMC4R constitutive activity <i>in vitro</i>. Here we directly compare hMRAPα and hMRAP2 effects on hMC4R constitutive activity in HEK293 cells. In contrast to hMRAPα, co-expression with hMRAP2 had no effect on HA-hMC4R or untagged hMC4R constitutive coupling to adenylyl cyclase. We used fixed and live cell imaging of HA-hMC4R and hMC4R-eGFP respectively, to further characterise effects of hMRAPα on hMC4R subcellular trafficking. hMRAPα-FLAG co-expression did not alter the partitioning of either HA-hMC4R or hMC4R-eGFP into either the ER or the Golgi apparatus, therefore the hMRAPα effect on hMC4R complex N-linked glycosylation is probably not due to hMC4R retention in the ER. We also observed that unlike HA-hMC4R, hMC4R-eGFP lacks complex glycosylation both in the presence and absence of hMRAPα, although both HA-hMC4R and hMC4R-eGFP exhibited increased constitutive coupling to adenylyl cyclase following co-expression with hMRAPα. We conclude that hMRAPα and not hMRAP2 modulates hMC4R constitutive activity. Furthermore, hMRAPα does not increase hMC4R constitutive activity by altering hMC4R complex N-linked glycosylation. Instead we hypothesise that hMRAPα alters hMC4R conformational states leading to increased hMC4R constitutive activity.</p></div

hMC4R-eGFP lacked complex N-linked glycosylation when expressed in HEK293 cells.

<p>HEK293 cells were transiently co-transfected with hMC4R-eGFP and hMRAPα, hMRAPα-FLN or the empty vector pcDNA 3.1 and western blotting was performed with anti-GFP antibody (A). Lysates for the same transfections were also treated with PNGase F and endoglycosidase H to characterise hMC4R-eGFP N-linked glycosylation (B). Molecular masses (kDa) are indicated on the left side of the western blots. Bands of interest are indicated with (◀). 1–4; 1–10, lane numbers.</p

Comparison of hMC4R and hMC4R-eGFP coupling to adenylyl cyclase.

<p>hMC4R or hMC4R-eGFP was transiently co-expressed with the empty vector pcDNA 3.1 (A). hMRAPα or hMRAPα-FLN were transiently co-expressed with hMC4R (B) or hMC4R-eGFP (C). hMC4R or hMC4R-eGFP coupling to adenylyl cyclase was stimulated with increasing concentrations of α-MSH for 1 hour and adenylyl cyclase activity measured. Raw data (A) or normalised data (B and C) from at least 3 independent experiments performed in duplicate were pooled and plotted as mean ± s.e.m. Best-fit values for baseline and maximum responses and EC₅₀ for these curves are shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0140320#pone.0140320.t002" target="_blank">Table 2</a>.</p

hMRAPα-FLAG, but not hMRAP2-FLAG, enhances HA-hMC4R constitutive activity in HEK293 cells.

<p>HA-hMC4R was transiently co-expressed with the empty vector pcDNA 3.1, hMRAPα-FLAG or hMRAP2-FLAG in HEK293 cells (A) and HA-hMC4R coupling to adenylyl cyclase was stimulated with increasing concentrations of α-MSH for 1 hour and adenylyl cyclase activity measured. Normalised data from 3 independent experiments performed in duplicate were pooled and plotted as mean ± s.e.m. Best-fit values for baseline and maximum responses and EC₅₀ for these curves are shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0140320#pone.0140320.t001" target="_blank">Table 1</a>. To determine whether hMRAP2-FLAG is co-expressed with HA-hMC4R, HA-hMC4R and hMRAP2-FLAG were transiently transfected into HEK293 cells and confocal microscopy was performed (B-D). Representative single slices through the approximate centre of each cell are shown. HEK293 cells were counterstained with Hoechst or DAPI to determine signal orientation. The white arrow indicates signal overlap between HA-hMC4R and hMRAP2-FLAG. Scale bars = 10μm.</p