Ptprk, Protein Tyrosine Phosphatase Receptor Type K, is a receptor tyrosine phosphatase. It is involved in regulating growth factor signalling, cell-cell adhesion, and is often associated with tumour suppression. Ptprk functions in multiple signalling pathways such as EGFR, Wnt, and those related to cell adhesion. Its regulation impacts various biological processes like cell proliferation, migration, and metabolism [2,3,4,5]. Genetically modified mouse models have been crucial in understanding its functions.

In obesity-related studies, high-fat-fed PTPRK knockout male and female mice had lower weight gain and reduced hepatic fat accumulation. PTPRK was found to regulate glycolysis and de novo lipogenesis in hepatocytes, promoting metabolic reprogramming [1]. In colorectal cancer, PTPRK knockout mouse models and xenografts confirmed its role as a tumour suppressor, regulating cell adhesion signalling, suppressing invasion, and promoting collective, directed migration [2].

In summary, Ptprk plays essential roles in metabolism, cell-cell adhesion, and tumour suppression. Gene knockout mouse models have been instrumental in revealing its functions in obesity-related metabolic disorders and cancer, providing insights into potential therapeutic targets for these diseases.

References:

1. Gilglioni, Eduardo H, Li, Ao, St-Pierre-Wijckmans, Wadsen, Wu, Wei, Gurzov, Esteban N. 2024. PTPRK regulates glycolysis and de novo lipogenesis to promote hepatocyte metabolic reprogramming in obesity. In Nature communications, 15, 9522. doi:10.1038/s41467-024-53733-0. https://pubmed.ncbi.nlm.nih.gov/39496584/

2. Young, Katherine A, Wojdyla, Katarzyna, Lai, Tiffany, Fearnley, Gareth W, Sharpe, Hayley J. 2024. The receptor protein tyrosine phosphatase PTPRK promotes intestinal repair and catalysis-independent tumour suppression. In Journal of cell science, 137, . doi:10.1242/jcs.261914. https://pubmed.ncbi.nlm.nih.gov/38904097/

3. Kim, Minseong, Reinhard, Carmen, Niehrs, Christof. 2021. A MET-PTPRK kinase-phosphatase rheostat controls ZNRF3 and Wnt signaling. In eLife, 10, . doi:10.7554/eLife.70885. https://pubmed.ncbi.nlm.nih.gov/34590584/

4. Chang, Ling-Shih, Kim, Minseong, Glinka, Andrey, Reinhard, Carmen, Niehrs, Christof. 2020. The tumor suppressor PTPRK promotes ZNRF3 internalization and is required for Wnt inhibition in the Spemann organizer. In eLife, 9, . doi:10.7554/eLife.51248. https://pubmed.ncbi.nlm.nih.gov/31934854/

5. Fearnley, Gareth W, Young, Katherine A, Edgar, James R, Deane, Janet E, Sharpe, Hayley J. 2019. The homophilic receptor PTPRK selectively dephosphorylates multiple junctional regulators to promote cell-cell adhesion. In eLife, 8, . doi:10.7554/eLife.44597. https://pubmed.ncbi.nlm.nih.gov/30924770/