At a Glance

Scientists noted detailed views of 2 membrane receptors affiliated in managing blood glucose.The result reveal brand-new insights into vital drug targets because that diabetes and obesity.

You are watching: When the blood glucose level rises after a meal, the first organ to respond is the:

One of the recently reported G-protein-coupled receptor structures: an triggered GLP-1 receptor complicated with bound GLP-1 in orange. Yan Zhang, Bingfa Sun, et al, Nature
Levels that blood glucose, or blood sugar, space tightly managed by the body. People with diabetes have difficulty controlling blood glucose levels. High level of blood glucose can reason serious health difficulties over time. It can likewise be danger for her blood glucose level to dip too low. Medicines such together insulin (which lowers blood glucose) and glucagon (which elevates that in an emergency) can assist maintain blood glucose in a safe range. However, glucagon in certain can be daunting to administer.

Blood glucose regulate depends heavily on proteins dubbed G-protein-coupled receptors (GPCRs). GPCRs expectations cell membranes to relay signal from the external in. Once activated by the binding of a substance, GPCRs cause a cascade of responses inside the cell. This receptors are thus important targets for drug development.

When blood glucose levels drop, such together after an overnight fast, the pancreas releases a hormone dubbed glucagon. Glucagon binding a GPCR top top liver and also muscle cells referred to as the glucagon receptor, which climate stimulates the cell to relax glucose right into the bloodstream. Another hormone involved in glucose control is called glucagon-like peptide-1 (GLP-1). It works by binding to an additional GPCR, the GLP-1 receptor, on cell in the pancreas. ~ a meal, the intestine to produce GLP-1, i beg your pardon prompts the kidneys to produce insulin. Insulin, in turn, stimulates cell to take in glucose from the blood.

The glucagon and also GLP-1 receptors are both course B GPCRs. The frameworks of several class A GPCRs have been solved, however class B receptor haven’t been as well studied since of technical challenges. 4 international study teams reported the frameworks of the glucagon and also GLP-1 receptors in Nature top top June 8, 2017. Two of the groups were supported in component by, including’s national Institute that Diabetes and also Digestive and also Kidney diseases (NIDDK), nationwide Institute of basic Medical sciences (NIGMS), and National academy on medicine Abuse (NIDA).

The structure of the section of the glucagon receptor that spans cell membranes was described previously. In among the brand-new papers, an global team led through Dr. Beili Wu indigenous the Shanghai academy of Materia Medica, Chinese Academy that Sciences, described the structure of the complete length person glucagon receptor. The team contained groups headed by Drs. Wei Liu in ~ Arizona State University and also Vadim Cherezov at the college of southerly California. The researchers crystallized the receptor in an inactive state and also used X-ray diffraction with an X-ray free-electron laser to determine its structure.

“The structure offers a clear photo of a full-length class B GPCR at high resolution, and also helps us recognize how various domains cooperate in modulating the receptor function at the molecule level,” Wu says.

Another team—led through Drs. Brian Kobilka at Stanford University and also Georgios Skiniotis at the college of Michigan—described the framework of a GLP-1 receptor. The team supplied a various technique, cryo-electron microscopy, to study the structure of the receptor in complicated with GLP-1 and also its combination G-protein. The two other accompanying papers comprehensive the framework of the GLP-1 receptor as soon as bound by tiny molecules that influence the receptor’s activity.

“It’s tough to overstate the prestige of G-protein-coupled receptors,” Skiniotis says. “GPCRs are targeted through about half of every drugs, and getting such structures by cryo-electron microscopy will be vital for more drug discovery efforts.”

The glucagon and GLP-1 receptors room both vital drug targets for kind 2 diabetes and obesity. These outcomes may aid inform the style of new drugs to control blood glucose levels.

—by Harrison Wein, Ph.D.

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References:Structure that the full-length glucagon course B G-protein-coupled receptor. Zhang H, Qiao A, Yang D, Yang L, Dai A, de Graaf C, Reedtz-Runge S, Dharmarajan V, Zhang H, Han GW, grant TD, Sierra RG, Weierstall U, Nelson G, Liu W, Wu Y, Ma L, Cai X, Lin G, Wu X, Geng Z, Dong Y, song G, Griffin PR, Lau J, Cherezov V, Yang H, Hanson MA, Stevens RC, Zhao Q, Jiang H, Wang MW, Wu B. Nature. 2017 Jun 8;546(7657):259-264. Doi: 10.1038/nature22363. Epub 2017 might 17. PMID: 28514451.Cryo-EM structure of the caused GLP-1 receptor in facility with a G protein. Zhang Y, sun B, Feng D, Hu H, Chu M, Qu Q, Tarrasch JT, Li S, sun Kobilka T, Kobilka BK, Skiniotis G. Nature. 2017 Jun 8;546(7657):248-253. Doi: 10.1038/nature22394. Epub 2017 might 24. PMID: 28538729.Crystal structure of the GLP-1 receptor bound come a peptide agonist. Jazayeri A, Rappas M, Brown AJH, Kean J, Errey JC, Robertson NJ, Fiez-Vandal C, andrews SP, Congreve M, Bortolato A, Mason JS, Baig AH, Teobald I, Doré AS, Weir M, Cooke RM, Marshall FH. Nature. 2017 Jun 8;546(7657):254-258. Doi: 10.1038/nature22800. Epub 2017 may 31. PMID: 28562585.Human GLP-1 receptor transmembrane domain framework in facility with allosteric modulators. Tune G, Yang D, Wang Y, de Graaf C, Zhou Q, Jiang S, Liu K, Cai X, Dai A, Lin G, Liu D, Wu F, Wu Y, Zhao S, Ye L, Han GW, Lau J, Wu B, Hanson MA, Liu ZJ, Wang MW, Stevens RC. Nature. 2017 Jun 8;546(7657):312-315. Doi: 10.1038/nature22378. Epub 2017 may 17. PMID: 28514449.

See more: I Wish I Knew What I Know Now Now, I Wish I Knew What I Know Now’s nationwide Institute of Diabetes and also Digestive and Kidney diseases (NIDDK), nationwide Institute of general Medical sciences (NIGMS), nationwide Institute on medicine Abuse (NIDA), and also National academy of Neurological Disorders and also Stroke (NINDS); National simple Research regime of China; Chinese Academy that Sciences; National herbal Science foundation of China; national Health and also Family plan Commission; Shanghai scientific research and an innovation Development Fund; national Science Foundation; GPCR Consortium; Shanghai regional government; Netherlands eScience Center; Heptares Therapeutics Ltd.; set of scientific research and technology of China; NWO permitting Technologies project: 3D-e-Chem; European collaboration in scientific research and modern technology Action CM1207 GLISTEN; and also National crucial Research and breakthrough Program that China.