Genetic evidence against involvement of TRPC proteins in SOCE, ROCE, and CRAC channel function
Using genetically engineered mice and cell lines derived from genetically engineered mice we show that depletion of ER delimited Ca<sup>2+</sup> stores activates heteromeric Ca<sup>2+</sup> entry (SOCE) channels formed obligatorily, but not exclusively by Orai1 molecules. Comparison of Orai-dependent Ca<sup>2+</sup> entries revealed Orai1 to be dominant when compared to Orai2 and Orai3. Unexpectedly, we found that store-depletion-activated Ca<sup>2+</sup> entry does not depend obligatorily on functionally intact TRPC molecules, as SOCE monitored with the Fura2 Ca<sup>2+</sup> reporter dye is unaffected in cells in which all seven TRPC coding genes have been structurally and functionally inactivated. Unexpectedly as well, we found that TRPC-independent Gq-coupled receptor-operated Ca<sup>2+</sup> entry (ROCE) also depends on Orai1. Biophysical measurements of Ca<sup>2+</sup> release activated Ca<sup>2+</sup> currents (Icrac) are likewise unaffected by ablation of all seven TRPC genes. We refer to mice and cells carrying the seven-fold disruption of TRPC genes as TRPC heptaKO mice and cells. TRPC heptaKO mice are fertile allowing the creation of a new homozygous inbred strain.
Authors
- Lutz Birnbaumer (ORCID: https://orcid.org/0000-0002-0775-8661)
- Nicholas W. Plummer
- Yanhong Liao (ORCID: https://orcid.org/0000-0001-6308-3120)
- Erika Hayes (ORCID: https://orcid.org/0000-0002-2363-7253)
- Sebastián Susperreguy (ORCID: https://orcid.org/0000-0001-7532-4825)
- Lauranell H. Burch
- Karina Formoso (ORCID: https://orcid.org/0000-0003-4890-8547)
- Mitzie Walker
- Brandon E. Johnson
- Lori Hazlehurst (ORCID: https://orcid.org/0000-0001-7040-4084)
- Chan-Il Choi
- Veit Flockerzi (ORCID: https://orcid.org/0000-0001-6002-6294)
- Murali Prakriya (ORCID: https://orcid.org/0000-0003-0781-4480)
- Reinhold Penner (ORCID: https://orcid.org/0000-0002-5366-1537)
- Megumi Yamashita (ORCID: https://orcid.org/0000-0003-0196-0428)
- Dagoberto Grenet
- Marc Freichel (ORCID: https://orcid.org/0000-0003-1387-2636)
- Yingpei Zhang
- Joel Abramowitz
- Andrea Fleig
- T. Śliwa (ORCID: https://orcid.org/0000-0002-4967-0641)
- Jean Pierre Kinet (ORCID: https://orcid.org/0000-0003-1475-3364)
- Tom Blankenship
Institutions
- Northwestern University (US)
- University of Hawaiʻi at Mānoa (US)
- West Virginia University (US)
- Beth Israel Deaconess Medical Center (US)
- University of Hawaii System (US)
- Harvard University (US)
- Heidelberg University (DE)
- Pontificia Universidad Católica Argentina (AR)
- National Institute of Environmental Health Sciences (US)
- Queen's Medical Center (US)
- University of Hawaii Cancer Center
- Huazhong University of Science and Technology (CN)
- Saarland University (DE)
Publication Details
- Journal
- Proceedings of the National Academy of Sciences
- Published
- 2024-11-27
- DOI
- https://doi.org/10.1073/pnas.2411389121
- Citations
- 4
- Primary Topic
- Ion Channels and Receptors
- Type
- article
- Field-Weighted Citation Impact
- 1.44
Funders
- National Institutes of Health