TY  - JOUR
A1  - Rieck, Christoph Paul Kurt
A1  - Geiger, Daniel
A1  - Munkert, Jennifer
A1  - Messerschmidt, Katrin
A1  - Petersen, Jan
A1  - Strasser, Juliane
A1  - Meitinger, Nadine
A1  - Kreis, Wolfgang
T1  - Biosynthetic approach to combine the first steps of cardenolide formation in Saccharomyces cerevisiae
JF  - Microbiologyopen
N2  - A yeast expression plasmid was constructed containing a cardenolide biosynthetic module, referred to as CARD II, using the AssemblX toolkit, which enables the assembly of large DNA constructs. The genes cloned into the vector were (a) a Δ5‐3β‐hydroxysteroid dehydrogenase gene from Digitalis lanata, (b) a steroid Δ5‐isomerase gene from Comamonas testosteronii, (c) a mutated steroid‐5β‐reductase gene from Arabidopsis thaliana, and (d) a steroid 21‐hydroxylase gene from Mus musculus. A second plasmid bearing an ADR/ADX fusion gene from Bos taurus was also constructed. A Saccharomyces cerevisiae strain bearing these two plasmids was generated. This strain, termed “CARD II yeast”, was capable of producing 5β‐pregnane‐3β,21‐diol‐20‐one, a central intermediate in 5β‐cardenolide biosynthesis, starting from pregnenolone which was added to the culture medium. Using this approach, five consecutive steps in cardenolide biosynthesis were realized in baker's yeast.
Y1  - 2019
U6  - https://doi.org/10.1002/mbo3.925
SN  - 2045-8827
VL  - 8
IS  - 12
PB  - Wiley
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Geiger, Daniel L.
A1  - Kocyan, Alexander
T1  - Studies on Oberonia 3. Aberrant flowers and other floral modifications in the orchid genus Oberonia
JF  - Nordic Journal of botany
N2  - Orchid flowers are amongst the most conspicuous attractions that plants have generated over evolutionary epochs. However, organ homology in particular of androecium and gynoecium of orchid flowers have been, and are still, the subject of long-term discussion. Studies of aberrant - teratologic - flowers have traditionally helped to clarify organ identity in orchids. We here present for the first time teratological flowers within the florally smallest and inconspicuous orchid genus Oberonia and illustrate them by light and scanning electron microscopy. Pseudopeloria with half of a lateral petal transformed into a lip was found in O. costeriana J.J.Sm. and O. mucronata (D.Don) Ormerod & Seidenf. A supernumerary lip is known from O. mucronata. Oberonia rufilabris Lindl. is documented with multiple aberrations: triple gynostemium and a total of 10 tepals, twin flowers, and duplicate lips. We interpret these aberrations in light of known floral developmental and organ identity information.
Y1  - 2018
U6  - https://doi.org/10.1111/njb.01699
SN  - 0107-055X
SN  - 1756-1051
VL  - 36
IS  - 1-2
PB  - Wiley
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Zirafi, Onofrio
A1  - Kim, Kyeong-Ae
A1  - Ständker, Ludger
A1  - Mohr, Katharina B.
A1  - Sauter, Daniel
A1  - Heigele, Anke
A1  - Kluge, Silvia F.
A1  - Wiercinska, Eliza
A1  - Chudziak, Doreen
A1  - Richter, Rudolf
A1  - Möpps, Barbara
A1  - Gierschik, Peter
A1  - Vas, Virag
A1  - Geiger, Hartmut
A1  - Lamla, Markus
A1  - Weil, Tanja
A1  - Burster, Timo
A1  - Zgraja, Andreas
A1  - Daubeuf, Francois
A1  - Frossard, Nelly
A1  - Hachet-Haas, Muriel
A1  - Heunisch, Fabian
A1  - Reichetzeder, Christoph
A1  - Galzi, Jean-Luc
A1  - Perez-Castells, Javier
A1  - Canales-Mayordomo, Angeles
A1  - Jimenez-Barbero, Jesus
A1  - Gimenez-Gallego, Guillermo
A1  - Schneider, Marion
A1  - Shorter, James
A1  - Telenti, Amalio
A1  - Hocher, Berthold
A1  - Forssmann, Wolf-Georg
A1  - Bonig, Halvard
A1  - Kirchhoff, Frank
A1  - Münch, Jan
T1  - Discovery and Characterization of an Endogenous CXCR4 Antagonist
JF  - Cell reports
N2  - CXCL12-CXCR4 signaling controls multiple physiological processes and its dysregulation is associated with cancers and inflammatory diseases. To discover as-yet-unknown endogenous ligands of CXCR4, we screened a blood-derived peptide library for inhibitors of CXCR4-tropic HIV-1 strains. This approach identified a 16 amino acid fragment of serum albumin as an effective and highly specific CXCR4 antagonist. The endogenous peptide, termed EPI-X4, is evolutionarily conserved and generated from the highly abundant albumin precursor by pH-regulated proteases. EPI-X4 forms an unusual lasso-like structure and antagonizes CXCL12-induced tumor cell migration, mobilizes stem cells, and suppresses inflammatory responses in mice. Furthermore, the peptide is abundant in the urine of patients with inflammatory kidney diseases and may serve as a biomarker. Our results identify EPI-X4 as a key regulator of CXCR4 signaling and introduce proteolysis of an abundant precursor protein as an alternative concept for chemokine receptor regulation.
Y1  - 2015
U6  - https://doi.org/10.1016/j.celrep.2015.03.061
SN  - 2211-1247
VL  - 11
IS  - 5
SP  - 737
EP  - 747
PB  - Cell Press
CY  - Cambridge
ER  -