TY  - JOUR
A1  - Butt, Elke
A1  - Stempfle, Katrin
A1  - Lister, Lorenz
A1  - Wolf, Felix
A1  - Kraft, Marcella
A1  - Herrmann, Andreas B.
A1  - Viciano, Cristina Perpina
A1  - Weber, Christian
A1  - Hochhaus, Andreas
A1  - Ernst, Thomas
A1  - Hoffmann, Carsten
A1  - Zernecke, Alma
A1  - Frietsch, Jochen J.
T1  - Phosphorylation-dependent differences in CXCR4-LASP1-AKT1 interaction between breast cancer and chronic myeloid leukemia
JF  - Cells
N2  - The serine/threonine protein kinase AKT1 is a downstream target of the chemokine receptor 4 (CXCR4), and both proteins play a central role in the modulation of diverse cellular processes, including proliferation and cell survival. While in chronic myeloid leukemia (CML) the CXCR4 is downregulated, thereby promoting the mobilization of progenitor cells into blood, the receptor is highly expressed in breast cancer cells, favoring the migratory capacity of these cells. Recently, the LIM and SH3 domain protein 1 (LASP1) has been described as a novel CXCR4 binding partner and as a promoter of the PI3K/AKT pathway. In this study, we uncovered a direct binding of LASP1, phosphorylated at S146, to both CXCR4 and AKT1, as shown by immunoprecipitation assays, pull-down experiments, and immunohistochemistry data. In contrast, phosphorylation of LASP1 at Y171 abrogated these interactions, suggesting that both LASP1 phospho-forms interact. Finally, findings demonstrating different phosphorylation patterns of LASP1 in breast cancer and chronic myeloid leukemia may have implications for CXCR4 function and tyrosine kinase inhibitor treatment.
KW  - LASP1
KW  - CXCR4
KW  - AKT1
KW  - CML
KW  - breast cancer
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-200638
SN  - 2073-4409
VL  - 9
IS  - 2
ER  - 
TY  - JOUR
A1  - Volpato, Daniela
A1  - Kauk, Michael
A1  - Messerer, Regina
A1  - Bermudez, Marcel
A1  - Wolber, Gerhard
A1  - Bock, Andreas
A1  - Hoffmann, Carsten
A1  - Holzgrabe, Ulrike
T1  - The Role of Orthosteric Building Blocks of Bitopic Ligands for Muscarinic M1 Receptors
JF  - ACS Omega
N2  - The muscarinic M\(_1\) acetylcholine receptor is an important drug target for the treatment of various neurological disorders. Designing M\(_1\) receptor-selective drugs has proven challenging, mainly due to the high conservation of the acetylcholine binding site among muscarinic receptor subtypes. Therefore, less conserved and topographically distinct allosteric binding sites have been explored to increase M\(_1\) receptor selectivity. In this line, bitopic ligands, which target orthosteric and allosteric binding sites simultaneously, may provide a promising strategy. Here, we explore the allosteric, M1-selective BQCAd scaffold derived from BQCA as a starting point for the design, synthesis, and pharmacological evaluation of a series of novel bitopic ligands in which the orthosteric moieties and linker lengths are systematically varied. Since β-arrestin recruitment seems to be favorable to therapeutic implication, all the compounds were investigated by G protein and β-arrestin assays. Some bitopic ligands are partial to full agonists for G protein activation, some activate β-arrestin recruitment, and the degree of β-arrestin recruitment varies according to the respective modification. The allosteric BQCAd scaffold controls the positioning of the orthosteric ammonium group of all ligands, suggesting that this interaction is essential for stimulating G protein activation. However, β-arrestin recruitment is not affected. The novel set of bitopic ligands may constitute a toolbox to study the requirements of β-arrestin recruitment during ligand design for therapeutic usage.
KW  - muscarinic M1 receptor
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-230548
VL  - 5
IS  - 49
ER  -