At a Glance

Scientists provided detailed views of two membrane receptors involved in regulating blood glucose.The result reveal brand-new insights into essential drug targets for diabetes and also obesity.

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


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One the the freshly 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 of blood glucose, or blood sugar, room tightly regulated by the body. People with diabetes have an obstacle controlling blood glucose levels. High levels of blood glucose can reason serious health difficulties over time. That can likewise be attention for her blood glucose level to dip too low. Medications such together insulin (which lowers blood glucose) and glucagon (which elevates it in one emergency) can help maintain blood glucose in a safe range. However, glucagon in particular can be challenging to administer.

Blood glucose control depends heavily on proteins dubbed G-protein-coupled receptors (GPCRs). GPCRs expectations cell membrane to relay signals from the exterior in. When activated by the binding of a substance, GPCRs trigger a cascade the responses inside the cell. These receptors room thus crucial targets for medicine development.

When blood glucose level drop, such together after an overnight fast, the pancreas releases a hormone referred to as glucagon. Glucagon binds a GPCR ~ above liver and also muscle cells referred to as the glucagon receptor, which then stimulates the cell to release glucose into the bloodstream. An additional hormone involved in glucose control is called glucagon-like peptide-1 (GLP-1). It functions by binding to an additional GPCR, the GLP-1 receptor, on cells in the pancreas. After ~ a meal, the intestine produces GLP-1, which prompts the kidneys to develop insulin. Insulin, in turn, stimulates cells to take it in glucose indigenous the blood.

The glucagon and also GLP-1 receptors space both course B GPCRs. The frameworks of several course A GPCRs have been solved, yet class B receptor haven’t been also studied due to the fact that of technical challenges. 4 international research teams report the frameworks of the glucagon and GLP-1 receptor in Nature top top June 8, 2017. Two of the teams were supported in part by bsci-ch.org, including bsci-ch.org’s nationwide Institute that Diabetes and also Digestive and Kidney conditions (NIDDK), national Institute of basic Medical sciences (NIGMS), and also National institute on medicine Abuse (NIDA).

The structure of the section of the glucagon receptor the spans cell membranes was described previously. In among the brand-new papers, an international team led by Dr. Beili Wu from the Shanghai academy of Materia Medica, Chinese Academy the Sciences, defined the framework of the complete length human glucagon receptor. The team included bsci-ch.org-funded teams headed by Drs. Wei Liu at Arizona State University and Vadim Cherezov at the college of southern California. The researchers crystallized the receptor in one inactive state and used X-ray diffraction through an X-ray free-electron laser to identify its structure.

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

Another bsci-ch.org-funded team—led through Drs. Brian Kobilka in ~ Stanford University and Georgios Skiniotis at the university of Michigan—described the framework of a GLP-1 receptor. The team offered a different technique, cryo-electron microscopy, to study the framework of the receptor in complicated with GLP-1 and also its coupled G-protein. The two other accompanying papers thorough the structure of the GLP-1 receptor as soon as bound by little molecules that impact the receptor’s activity.

“It’s difficult to overstate the prestige of G-protein-coupled receptors,” Skiniotis says. “GPCRs room targeted through about fifty percent of every drugs, and also getting such structures by cryo-electron microscopy will be crucial for further drug exploration efforts.”

The glucagon and also GLP-1 receptors space both vital drug targets for kind 2 diabetes and obesity. These results may aid inform the architecture of brand-new drugs to regulate blood glucose levels.

—by Harrison Wein, Ph.D.


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References:Structure of the full-length glucagon class 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, approve TD, Sierra RG, Weierstall U, Nelson G, Liu W, Wu Y, Ma L, Cai X, Lin G, Wu X, Geng Z, Dong Y, track 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 framework of the set off GLP-1 receptor in complicated with a G protein. Zhang Y, sunlight 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 may 24. PMID: 28538729.Crystal framework of the GLP-1 receptor bound to a peptide agonist. Jazayeri A, Rappas M, Brown AJH, Kean J, Errey JC, Robertson NJ, Fiez-Vandal C, andrew 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 might 31. PMID: 28562585.Human GLP-1 receptor transmembrane domain structure 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 might 17. PMID: 28514449.

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Funding:bsci-ch.org’s national Institute the Diabetes and Digestive and also Kidney diseases (NIDDK), nationwide Institute of basic Medical sciences (NIGMS), nationwide Institute on medicine Abuse (NIDA), and also National academy of Neurological Disorders and Stroke (NINDS); National an easy Research program of China; Chinese Academy that Sciences; National natural Science structure of China; national Health and also Family planning Commission; Shanghai science and an innovation Development Fund; national Science Foundation; GPCR Consortium; Shanghai local government; Netherlands eScience Center; Heptares Therapeutics Ltd.; set of scientific research and modern technology of China; NWO enabling Technologies project: 3D-e-Chem; European participation in scientific research and modern technology Action CM1207 GLISTEN; and National key Research and advancement Program that China.