TY  - JOUR
A1  - Meir, Michael
A1  - Maurus, Katja
A1  - Kuper, Jochen
A1  - Hankir, Mohammed
A1  - Wardelmann, Eva
A1  - Rosenwald, Andreas
A1  - Germer, Christoph-Thomas
A1  - Wiegering, Armin
T1  - The novel KIT exon 11 germline mutation K558N is associated with gastrointestinal stromal tumor, mastocytosis, and seminoma development
JF  - Genes, Chromosomes & Cancer
N2  - Familial gastrointestinal stromal tumors (GIST) are dominant genetic disorders that are caused by germline mutations of the type III receptor tyrosine kinase KIT. While sporadic mutations are frequently found in mastocytosis and GISTs, germline mutations of KIT have only been described in 39 families until now. We detected a novel germline mutation of KIT in exon 11 (p.Lys-558-Asn; K558N) in a patient from a kindred with several GISTs harboring different secondary somatic KIT mutations. Structural analysis suggests that the primary germline mutation alone is not sufficient to release the autoinhibitory region of KIT located in the transmembrane domain. Instead, the KIT kinase module becomes constitutively activated when K558N combines with different secondary somatic mutations. The identical germline mutation in combination with an additional somatic KIT mutation was detected in a second patient of the kindred with seminoma while a third patient within the family had a cutaneous mastocytosis. These findings suggest that the K558N mutation interferes with the juxtamembranous part of KIT, since seminoma and mastocystosis are usually not associated with exon 11 mutations.
KW  - germline mutation
KW  - GIST
KW  - KIT
KW  - mastocytosis
KW  - seminoma
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-257476
VL  - 60
IS  - 12
ER  - 
TY  - JOUR
A1  - Trujillo‐Viera, Jonathan
A1  - El‐Merahbi, Rabih
A1  - Schmidt, Vanessa
A1  - Karwen, Till
A1  - Loza‐Valdes, Angel
A1  - Strohmeyer, Akim
A1  - Reuter, Saskia
A1  - Noh, Minhee
A1  - Wit, Magdalena
A1  - Hawro, Izabela
A1  - Mocek, Sabine
A1  - Fey, Christina
A1  - Mayer, Alexander E.
A1  - Löffler, Mona C.
A1  - Wilhelmi, Ilka
A1  - Metzger, Marco
A1  - Ishikawa, Eri
A1  - Yamasaki, Sho
A1  - Rau, Monika
A1  - Geier, Andreas
A1  - Hankir, Mohammed
A1  - Seyfried, Florian
A1  - Klingenspor, Martin
A1  - Sumara, Grzegorz
T1  - Protein Kinase D2 drives chylomicron‐mediated lipid transport in the intestine and promotes obesity
JF  - EMBO Molecular Medicine
N2  - Lipids are the most energy‐dense components of the diet, and their overconsumption promotes obesity and diabetes. Dietary fat content has been linked to the lipid processing activity by the intestine and its overall capacity to absorb triglycerides (TG). However, the signaling cascades driving intestinal lipid absorption in response to elevated dietary fat are largely unknown. Here, we describe an unexpected role of the protein kinase D2 (PKD2) in lipid homeostasis. We demonstrate that PKD2 activity promotes chylomicron‐mediated TG transfer in enterocytes. PKD2 increases chylomicron size to enhance the TG secretion on the basolateral side of the mouse and human enterocytes, which is associated with decreased abundance of APOA4. PKD2 activation in intestine also correlates positively with circulating TG in obese human patients. Importantly, deletion, inactivation, or inhibition of PKD2 ameliorates high‐fat diet‐induced obesity and diabetes and improves gut microbiota profile in mice. Taken together, our findings suggest that PKD2 represents a key signaling node promoting dietary fat absorption and may serve as an attractive target for the treatment of obesity.
KW  - chylomicron
KW  - fat absorption
KW  - intestine
KW  - obesity
KW  - protein kinase D2/PKD2/PRKD2
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-239018
VL  - 13
IS  - 5
ER  -