scholarly journals Receptor-Mediated Adenylyl Cyclase Activation Through XLαs, the Extra-Large Variant of the Stimulatory G Protein α-Subunit

2002 ◽  
Vol 16 (8) ◽  
pp. 1912-1919 ◽  
Author(s):  
Murat Bastepe ◽  
Yasemin Gunes ◽  
Beatriz Perez-Villamil ◽  
Joy Hunzelman ◽  
Lee S. Weinstein ◽  
...  
Keyword(s):  
Adenylyl Cyclase ◽  
G Protein ◽  
Adrenergic Receptor ◽  
Α Subunit ◽  
Exon 2 ◽  
Amino Terminal ◽  
Stimulatory G Protein ◽  
Β2 Adrenergic Receptor ◽  
Carboxyl Terminal ◽  
G Protein Α Subunit

Abstract XLαs, the large variant of the stimulatory G protein α subunit (Gsα), is derived from GNAS1 through the use of an alternative first exon and promoter. Gsα and XLαs have distinct amino-terminal domains, but are identical over the carboxyl-terminal portion encoded by exons 2–13. XLαs can mimic some functions of Gsα, including βγ interaction and adenylyl cyclase stimulation. However, previous attempts to demonstrate coupling of XLαs to typically Gs-coupled receptors have not been successful. We now report the generation of murine cell lines that carry homozygous disruption of Gnas exon 2, and are therefore null for endogenous XLαs and Gsα (GnasE2−/E2−). GnasE2−/E2− cells transfected with plasmids encoding XLαs and different heptahelical receptors, including the β2-adrenergic receptor and receptors for PTH, TSH, and CRF, showed agonist-mediated cAMP accumulation that was indistinguishable from that observed with cells transiently coexpressing Gsα and these receptors. Our findings thus indicate that XLαs is capable of functionally coupling to receptors that normally act via Gsα.

scholarly journals Repression of Adipogenesis by Adenylyl Cyclase Stimulatory G-protein α Subunit Is Expressed within Region 146-220

1996 ◽  
Vol 271 (36) ◽  
pp. 22022-22029 ◽  
Author(s):  
Hsien-yu Wang ◽  
Gary L. Johnson ◽  
Xunxian Liu ◽  
Craig C. Malbon
Keyword(s):  
Adenylyl Cyclase ◽  
G Protein ◽  
Α Subunit ◽  
Stimulatory G Protein ◽  
G Protein Α Subunit

Altered myocardial Gs protein and adenylyl cyclase signaling in rats exposed to chronic hypoxia and normoxic recovery

2003 ◽  
Vol 94 (6) ◽  
pp. 2423-2432 ◽  
Author(s):  
Markéta Hrbasová ◽  
Jiri Novotny ◽  
Lucie Hejnová ◽  
František Kolář ◽  
Jan Neckář ◽  
...  
Keyword(s):  
Adenylyl Cyclase ◽  
G Protein ◽  
Contractile Function ◽  
Left Ventricular ◽  
Adaptation To Hypoxia ◽  
Adrenergic Stimulation ◽  
Α Subunit ◽  
Stimulatory G Protein ◽  
Membrane Bound ◽  
The Right

The present work has analyzed the consequences of chronic intermittent high-altitude hypoxia for functioning of the G protein-mediated adenylyl cyclase (AC) signaling system in the right (RV) and left ventricular (LV) myocardium in rats. Adaptation to hypoxia did not appreciably affect the number of β-adrenoceptors and the content of predominantly membrane-bound α-subunit (Gsα) of the stimulatory G protein, but it raised the amount of cytosolic Gsα in RV. The levels of myocardial inhibitory Gα protein were not altered. Activity of AC stimulated by GTP, fluoride, forskolin, or isoprotertenol was reduced by ∼50% in RV from chronically hypoxic rats, and a weaker depression was also found in LV. In addition, hypoxia significantly diminished a functional activity of membrane-bound Gsα in both RV and LV. The RV baseline contractile function was markedly increased in chronically hypoxic animals, and its sensitivity to β-adrenergic stimulation was decreased. Animals recovering from hypoxia for 5 wk still exhibited markedly elevated levels of cytosolic Gsα and significantly lower activity of AC in RV than did age-matched controls, but contractile responsiveness to β-agonists was normal.

scholarly journals Adenylyl cyclases (ACs) (version 2019.4) in the IUPHAR/BPS Guide to Pharmacology Database

2019 ◽  
Vol 2019 (4) ◽  
Author(s):  
Carmen W. Dessauer ◽  
Rennolds Ostrom ◽  
Roland Seifert ◽  
Val J. Watts
Keyword(s):  
Cyclic Amp ◽  
Adenylyl Cyclase ◽  
G Protein ◽  
Adenylyl Cyclases ◽  
Adenylyl Cyclase Activity ◽  
Α Subunit ◽  
Soluble Adenylyl Cyclase ◽  
Catalytic Domains ◽  
Stimulatory G Protein ◽  
Membrane Spanning

Adenylyl cyclase, E.C. 4.6.1.1, converts ATP to cyclic AMP and pyrophosphate. Mammalian membrane-delimited adenylyl cyclases (nomenclature as approved by the NC-IUPHAR Subcommittee on Adenylyl cyclases [9]) are typically made up of two clusters of six TM domains separating two intracellular, overlapping catalytic domains that are the target for the nonselective activators Gαs (the stimulatory G protein α subunit) and forskolin (except AC9, [21]). adenosine and its derivatives (e.g. 2',5'-dideoxyadenosine), acting through the P-site,are inhibitors of adenylyl cyclase activity [27]. Four families of membranous adenylyl cyclase are distinguishable: calmodulin-stimulated (AC1, AC3 and AC8), Ca2+- and Gβγ-inhibitable (AC5, AC6 and AC9), Gβγ-stimulated and Ca2+-insensitive (AC2, AC4 and AC7), and forskolin-insensitive (AC9) forms. A soluble adenylyl cyclase (AC10) lacks membrane spanning regions and is insensitive to G proteins.It functions as a cytoplasmic bicarbonate (pH-insensitive) sensor [5].

scholarly journals The Stimulatory G Protein α-Subunit Gsα Is Imprinted in Human Thyroid Glands: Implications for Thyroid Function in Pseudohypoparathyroidism Types 1A and 1B

2003 ◽  
Vol 88 (9) ◽  
pp. 4336-4341 ◽  
Author(s):  
Jie Liu ◽  
Beth Erlichman ◽  
Lee S. Weinstein
Keyword(s):  
G Protein ◽  
Human Thyroid ◽  
Pcr Analysis ◽  
Specific Expression ◽  
Α Subunit ◽  
Albright Hereditary Osteodystrophy ◽  
Camp Generation ◽  
Gsα Gene ◽  
Stimulatory G Protein ◽  
G Protein Α Subunit

The stimulatory G protein α-subunit Gsα couples receptors to adenylyl cyclase and is required for hormone-stimulated cAMP generation. In Albright hereditary osteodystrophy, heterozygous Gsα null mutations only lead to PTH, TSH, and gonadotropin resistance when inherited maternally [pseudohypoparathyroidism type 1A; (PHP1A)]. Maternal-specific expression of Gsα in specific hormone targets could explain this observation. Using hot-stop PCR analysis on total RNA from six normal human thyroid specimens, we showed that the majority of the Gsα mRNA (72 ± 3%) was derived from the maternal allele. This is consistent with the presence of TSH resistance in patients with maternal Gsα null mutations (PHP1A) and the absence of TSH resistance in patients with paternal Gsα mutations (pseudopseudohypoparathyroidism). Patients with PTH resistance in the absence of Albright hereditary osteodystrophy (PHP1B) have an imprinting defect of the Gsα gene resulting in both alleles having a paternal epigenotype, which would lead to a more moderate level of thyroid-specific Gsα deficiency. We found evidence of borderline TSH resistance in 10 of 22 PHP1B patients. This study provides further evidence for tissue-specific imprinting of Gsα in humans and provides a potential mechanism for mild to moderate TSH resistance in PHP1A and borderline resistance in some patients with PHP1B.

scholarly journals Identification of G Protein α Subunit-Palmitoylating Enzyme

2008 ◽  
Vol 29 (2) ◽  
pp. 435-447 ◽  
Author(s):  
Ryouhei Tsutsumi ◽  
Yuko Fukata ◽  
Jun Noritake ◽  
Tsuyoshi Iwanaga ◽  
Franck Perez ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Plasma Membrane ◽  
G Protein ◽  
Adrenergic Receptor ◽  
Fluorescence Recovery After Photobleaching ◽  
G Protein Coupled Receptors ◽  
Α Subunit ◽  
Cytoplasmic Face ◽  
G Protein Α Subunit ◽  
G Protein Coupled

ABSTRACT The heterotrimeric G protein α subunit (Gα) is targeted to the cytoplasmic face of the plasma membrane through reversible lipid palmitoylation and relays signals from G-protein-coupled receptors (GPCRs) to its effectors. By screening 23 DHHC motif (Asp-His-His-Cys) palmitoyl acyl-transferases, we identified DHHC3 and DHHC7 as Gα palmitoylating enzymes. DHHC3 and DHHC7 robustly palmitoylated Gαq, Gαs, and Gαi2 in HEK293T cells. Knockdown of DHHC3 and DHHC7 decreased Gαq/11 palmitoylation and relocalized it from the plasma membrane into the cytoplasm. Photoconversion analysis revealed that Gαq rapidly shuttles between the plasma membrane and the Golgi apparatus, where DHHC3 specifically localizes. Fluorescence recovery after photobleaching studies showed that DHHC3 and DHHC7 are necessary for this continuous Gαq shuttling. Furthermore, DHHC3 and DHHC7 knockdown blocked the α1A-adrenergic receptor/Gαq/11-mediated signaling pathway. Together, our findings revealed that DHHC3 and DHHC7 regulate GPCR-mediated signal transduction by controlling Gα localization to the plasma membrane.

Stimulatory G-protein α-subunit mRNA levels are not increased in autopsied cerebral cortex from patients with bipolar disorder

1996 ◽  
Vol 42 (1) ◽  
pp. 45-50 ◽  
Author(s):  
L. Trevor Young ◽  
Vida Asghari ◽  
Peter P. Li ◽  
Stephen J. Kish ◽  
Margaret Fahnestock ◽  
...  
Keyword(s):  
Bipolar Disorder ◽  
Cerebral Cortex ◽  
G Protein ◽  
Mrna Levels ◽  
Α Subunit ◽  
Subunit Mrna ◽  
Stimulatory G Protein ◽  
G Protein Α Subunit
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