@article{JaschkeChungHesseetal.2012,
  author    = {Jaschke, Alexander and Chung, Bomee and Hesse, Deike and Kluge, Reinhart and Zahn, Claudia and Moser, Markus and Petzke, Klaus-J{\"u}rgen and Brigelius-Floh{\´e}, Regina and Puchkov, Dmytro and Koepsell, Hermann and Heeren, Joerg and Joost, Hans-Georg and Sch{\"u}rmann, Annette},
  title     = {The GTPase ARFRP1 controls the lipidation of chylomicrons in the Golgi of the intestinal epithelium},
  series = {Human Molecular Genetics},
  volume    = {21},
  journal   = {Human Molecular Genetics},
  number    = {14},
  doi       = {10.1093/hmg/dds140},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-125658},
  pages     = {3128-3142},
  year      = {2012},
  abstract  = {The uptake and processing of dietary lipids by the small intestine is a multistep process that involves several steps including vesicular and protein transport. The GTPase ADP-ribosylation factor-related protein 1 (ARFRP1) controls the ARF-like 1 (ARL1)-mediated Golgi recruitment of GRIP domain proteins which in turn bind several Rab-GTPases. Here, we describe the essential role of ARFRP1 and its interaction with Rab2 in the assembly and lipidation of chylomicrons in the intestinal epithelium. Mice lacking Arfrp1 specifically in the intestine \((Arfrp1^{vil-/-})\) exhibit an early post-natal growth retardation with reduced plasma triacylglycerol and free fatty acid concentrations. \(Arfrp1^{vil-/-}\) enterocytes as well as Arfrp1 mRNA depleted Caco-2 cells absorbed fatty acids normally but secreted chylomicrons with a markedly reduced triacylglycerol content. In addition, the release of apolipoprotein A-I (ApoA-I) was dramatically decreased, and ApoA-I accumulated in the \(Arfrp1^{vil-/-}\) epithelium, where it predominantly co-localized with Rab2. The release of chylomicrons from Caco-2 was markedly reduced after the suppression of Rab2, ARL1 and Golgin-245. Thus, the GTPase ARFRP1 and its downstream proteins are required for the lipidation of chylo­microns and the assembly of ApoA-I to these particles in the Golgi of intestinal epithelial cells.},
  language  = {en}
}
@article{OttoFriedrichMadunićetal.2020,
  author    = {Otto, Christoph and Friedrich, Alexandra and Madunić, Ivana Vrhovac and Baumeier, Christian and Schwenk, Robert W. and Karaica, Dean and Germer, Christoph-Thomas and Sch{\"u}rmann, Annette and Sabolić, Ivan and Koepsell, Hermann, Hermann},
  title     = {Antidiabetic Effects of a Tripeptide That Decreases Abundance of Na\(^+\)-D-glucose Cotransporter SGLT1 in the Brush-Border Membrane of the Small Intestine},
  series = {ACS Omega},
  volume    = {5},
  journal   = {ACS Omega},
  number    = {45},
  doi       = {10.1021/acsomega.0c03844},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-230654},
  pages     = {29127-29139},
  year      = {2020},
  abstract  = {In enterocytes, protein RS1 (RSC1A1) mediates an increase of glucose absorption after ingestion of glucose-rich food via upregulation of Na+-D-glucose cotransporter SGLT1 in the brush-border membrane (BBM). Whereas RS1 decelerates the exocytotic pathway of vesicles containing SGLT1 at low glucose levels between meals, RS1-mediated deceleration is relieved after ingestion of glucose-rich food. Regulation of SGLT1 is mediated by RS1 domain RS1-Reg, in which Gln-Ser-Pro (QSP) is effective. In contrast to QSP and RS1-Reg, Gln-Glu-Pro (QEP) and RS1-Reg with a serine to glutamate exchange in the QSP motif downregulate the abundance of SGLT1 in the BBM at high intracellular glucose concentrations by about 50\%. We investigated whether oral application of QEP improves diabetes in db/db mice and affects the induction of diabetes in New Zealand obese (NZO) mice under glucolipotoxic conditions. After 6-day administration of drinking water containing 5 mM QEP to db/db mice, fasting glucose was decreased, increase of blood glucose in the oral glucose tolerance test was blunted, and insulin sensitivity was increased. When QEP was added for several days to a high fat/high carbohydrate diet that induced diabetes in NZO mice, the increase of random plasma glucose was prevented, accompanied by lower plasma insulin levels. QEP is considered a lead compound for development of new antidiabetic drugs with more rapid cellular uptake. In contrast to SGLT1 inhibitors, QEP-based drugs may be applied in combination with insulin for the treatment of type 1 and type 2 diabetes, decreasing the required insulin amount, and thereby may reduce the risk of hypoglycemia.},
  language  = {en}
}