PSKH1 kinase activity is differentially modulated via allosteric binding of Ca <sup>2+</sup> sensor proteins
Protein Serine Kinase H1 (PSKH1) was recently identified as a crucial factor in kidney development and is overexpressed in prostate, lung, and kidney cancers. However, little is known about PSKH1 regulatory mechanisms, leading to its classification as a "dark" kinase. Here, we used biochemistry and mass spectrometry to define PSKH1's consensus substrate motif, protein interactors, and how interactors, including Ca<sup>2+</sup> sensor proteins, promote or suppress activity. Intriguingly, despite the absence of a canonical Calmodulin binding motif, Ca<sup>2+</sup>-Calmodulin activated PSKH1 while, in contrast, the ER-resident Ca<sup>2+</sup> sensor of the Cab45, Reticulocalbin, Erc55, Calumenin (CREC) family, Reticulocalbin-3, suppressed PSKH1 catalytic activity. In addition to antagonistic regulation of the PSKH1 kinase domain by Ca<sup>2+</sup> sensing proteins, we identified UNC119B as a protein interactor that activates PSKH1 via direct engagement of the kinase domain. Our findings identify complementary allosteric mechanisms by which regulatory proteins tune PSKH1's catalytic activity and raise the possibility that different Ca<sup>2+</sup> sensors may act more broadly to tune kinase activities by detecting and decoding extremes of intracellular Ca<sup>2+</sup> concentrations.
Authors
- Patrick A. Eyers (ORCID: https://orcid.org/0000-0002-9220-2966)
- Emily M. Huntsman (ORCID: https://orcid.org/0000-0002-8541-4944)
- Mark A. Febbraio (ORCID: https://orcid.org/0000-0002-9296-4418)
- Claire E. Eyers (ORCID: https://orcid.org/0000-0002-3223-5926)
- Laura F. Dagley (ORCID: https://orcid.org/0000-0003-4171-3712)
- Christopher R. Horne (ORCID: https://orcid.org/0000-0003-1318-514X)
- James M. Murphy (ORCID: https://orcid.org/0000-0003-0195-3949)
- Leonard A. Daly (ORCID: https://orcid.org/0000-0001-9712-9676)
- Dominic P. Byrne (ORCID: https://orcid.org/0000-0001-5197-345X)
- Samuel N. Young (ORCID: https://orcid.org/0009-0001-6543-1851)
- Toby A. Dite (ORCID: https://orcid.org/0000-0001-8001-3634)
- David R. Croucher (ORCID: https://orcid.org/0000-0003-4965-8674)
- Maria C. Tanzer (ORCID: https://orcid.org/0000-0002-4657-9869)
- Jared L. Johnson (ORCID: https://orcid.org/0000-0003-1802-6527)
- Lewis C. Cantley (ORCID: https://orcid.org/0000-0002-1298-7653)
- John W. Scott (ORCID: https://orcid.org/0000-0002-1896-9798)
- Boaz H. Ng (ORCID: https://orcid.org/0000-0002-2244-4636)
- Tomer M. Yaron (ORCID: https://orcid.org/0000-0001-6574-7314)
- Antonia L. Cadell (ORCID: https://orcid.org/0000-0002-3560-4125)
- Jumana M. Yousef (ORCID: https://orcid.org/0000-0002-2364-6299)
- Gerard Manning (ORCID: https://orcid.org/0000-0002-5087-9151)
- Luke M. McAloon (ORCID: https://orcid.org/0000-0002-9646-5544)
- Dylan H. Multari (ORCID: https://orcid.org/0000-0001-6932-9881)
- Lianju Shen
- Anthony R. Means (ORCID: https://orcid.org/0000-0002-9207-6752)
- Lucy J. Mather
Institutions
- Harvard University (US)
- Garvan Institute of Medical Research (AU)
- University of Liverpool (GB)
- The University of Melbourne (AU)
- Baylor College of Medicine (US)
- Walter and Eliza Hall Institute of Medical Research (AU)
- Cornell University (US)
- Florey Institute of Neuroscience and Mental Health (AU)
- Lander Institute (IL)
- UNSW Sydney (AU)
- Dana-Farber Cancer Institute (US)
- Systems Biology Institute (JP)
- Meyer (China) (CN)
- Columbia College (CA)
- Royal College of Physicians (GB)
- Weill Cornell Medicine (US)
- Monash University (AU)
- St Vincents Institute of Medical Research (AU)
- Columbia University (US)
- Australian Catholic University (AU)
Publication Details
- Journal
- Proceedings of the National Academy of Sciences
- Published
- 2025-02-18
- DOI
- https://doi.org/10.1073/pnas.2420961122
- Citations
- 3
- Primary Topic
- Protein Kinase Regulation and GTPase Signaling
- Type
- article
- Field-Weighted Citation Impact
- 2.42
Funders
- National Health and Medical Research Council