Abstract: A soluble N-methyl-D-aspartate receptor (NMDAR) protein construct includes one or more NMDAR autoantibody epitopes. The construct includes an extracellular domain (ECD) of the NMDAR subunit GluN1 or a fragment of the subunit and an ECD of at least one of the NMDAR subunits GluN2A, GluN2B, GluN2C or GluN2D, or fragment of these subunits. An in vitro method for the detection of NMDAR autoantibodies in a sample includes providing a sample suspected of including NMDAR autoantibodies, providing the NMDAR protein construct as a capture molecule, contacting the sample with the NMDAR protein construct, thereby binding NMDAR autoantibodies from the sample to the NMDAR protein construct, and determining the presence and optionally the amount of bound NMDAR autoantibodies. The method is applied for the diagnosis, prognosis, disease monitoring, patient stratification and/or therapy monitoring of a medical condition associated with autoantibodies against the NMDAR, preferably anti-NMDAR encephalitis.

Abstract: The present invention relates to nucleic acid sequences and isolated proteins which are novel interaction partners for inwardly rectifying potassium channels (Kirs), in particular G protein-coupled inwardly rectifying potassium channels (GIRKs). These interaction partners form protein complexes together with Kirs and GIRKs. The invention further relates to a charged domain of the novel interaction partners which binds to the complex intracellular region of Kirs and influences the activity of Kirs in general or of GIRKS in particular. The invention additionally relates to protein complexes composed of interaction partners and inwardly rectifying potassium channels, nucleic acid sequences or recombinant nucleic acid constructs which code for such proteins or domains, and the uses thereof. The invention additionally relates to protein complexes composed of the novel proteins with other proteins.