Ploessl, Karolina and Straub, Kristina and Schmid, Verena and Strunz, Franziska and Wild, Jens and Merkl, Rainer and Weber, Bernhard H. F. and Friedrich, Ulrike (2019) Identification of the retinoschisin-binding site on the retinal Na/K-ATPase. PLOS ONE, 14 (5): e0216320. ISSN 1932-6203,
Full text not available from this repository. (Request a copy)Abstract
X-linked juvenile retinoschisis (XLRS) is a hereditary retinal dystrophy, caused by mutations in the RS1 gene which encodes the secreted protein retinoschisin. In recent years, several molecules have been proposed to interact with retinoschisin, including the retinal Na/K-ATPase, L-voltage gated Ca2+ channels, and specific sugars. We recently showed that the retinal Na/K-ATPase consisting of subunits ATP1A3 and ATP1B2 is essential for anchoring retinoschisin to plasma membranes and identified the glycosylated ATP1B2 subunit as the direct interaction partner for retinoschisin. We now aimed to precisely map the retinoschisin binding domain(s) in ATP1B2. In general, retinoschisin binding was not affected after selective elimination of individual glycosylation sites via site-directed mutagenesis as well as after full enzymatic deglycosylation of ATP1B2. Applying the interface prediction tool PresCont, two putative protein-protein interaction patches ("patch I" and "patch II") consisting each of four hydrophobic amino acid stretches on the ATP1B2 surface were identified. These were consecutively altered by site-directed mutagenesis. Functional assays with the ATP1B2 patch mutants identified patch II and, specifically, the associated amino acid at position 240 (harboring a threonine in ATP1B2) as crucial for retinoschisin binding to ATP1B2. These and previous results led us to suggest an induced-fit binding mechanism for the interaction between retinoschisin and the Na/K-ATPase, which is dependent on threonine 240 in ATP1B2 allowing the accommodation of hyperflexible retinoschisin spikes by the associated protein-protein interaction patch on ATP1B2.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | X-LINKED RETINOSCHISIS; HOT-SPOTS; PROTEIN RETINOSCHISIN; GENE; RS1; PHOTORECEPTOR; RECEPTORS; RESIDUES; SURFACE; |
| Subjects: | 500 Science > 570 Life sciences 600 Technology > 610 Medical sciences Medicine |
| Divisions: | Medicine > Lehrstuhl für Humangenetik Medicine > Lehrstuhl für Medizinische Mikrobiologie und Hygiene Biology, Preclinical Medicine > Institut für Biophysik und physikalische Biochemie Biology, Preclinical Medicine > Institut für Biophysik und physikalische Biochemie > Prof. Dr. Rainer Merkl Biology, Preclinical Medicine > Institut für Biochemie, Genetik und Mikrobiologie |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 08 Apr 2020 12:20 |
| Last Modified: | 08 Apr 2020 12:20 |
| URI: | https://pred.uni-regensburg.de/id/eprint/27033 |
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