Retinol-binding protein 2 (RBP2) binds monoacylglycerols and modulates gut endocrine signaling and body weight.

Publication Type:

Journal Article

Source:

Sci Adv, Volume 6, Issue 11, p.eaay8937 (2020)

Abstract:

<p>Expressed in the small intestine, retinol-binding protein 2 (RBP2) facilitates dietary retinoid absorption. -deficient ( ) mice fed a chow diet exhibit by 6-7 months-of-age higher body weights, impaired glucose metabolism, and greater hepatic triglyceride levels compared to controls. These phenotypes are also observed when young mice are fed a high fat diet. Retinoids do not account for the phenotypes. Rather, RBP2 is a previously unidentified monoacylglycerol (MAG)-binding protein, interacting with the endocannabinoid 2-arachidonoylglycerol (2-AG) and other MAGs with affinities comparable to retinol. X-ray crystallographic studies show that MAGs bind in the retinol binding pocket. When challenged with an oil gavage, mice show elevated mucosal levels of 2-MAGs. This is accompanied by significantly elevated blood levels of the gut hormone GIP (glucose-dependent insulinotropic polypeptide). Thus, RBP2, in addition to facilitating dietary retinoid absorption, modulates MAG metabolism and likely signaling, playing a heretofore unknown role in systemic energy balance.</p>

PDB: 
2-AG (PDB 6BTH) and to AEA (PDB 6BTI)
Detector: 
PILATUS
EIGER
Beamline: 
24-ID-C
24-ID-E