{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,14]],"date-time":"2026-10-14T13:49:15Z","timestamp":1791985755566,"version":"4.4.0"},"reference-count":0,"publisher":"The Company of Biologists","license":[{"start":{"date-parts":[[2026,10,14]],"date-time":"2026-10-14T00:00:00Z","timestamp":1791936000000},"content-version":"am","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"abstract":"<jats:p>The cell cycle is controlled in G1-phase by activities of three cyclin-dependent kinases (CDKs), CDK4\/6 and CDK2, and their regulatory partners, cyclin D and cyclin E, respectively. p21 (CDKN1A), a member of the KIP\/CIP family, is involved in regulation of CDK\/cyclin complexes. In the present study, we analysed the impact of p21 on CDK\/cyclin complex formation in living cells by fluorescence lifetime imaging microscopy (FLIM)-based F\u00f6rster resonance energy transfer (FRET) measurements. Depending on the additional expression of p21, both CDK4\/cyclin D3 and CDK2\/cyclin E1 interactions have been favoured reflected by increased FRET efficiencies (E). Furthermore, post-translational modifications (PTM) as well as the redox status of p21 can regulate the impact on CDK\/cyclin complexes. We show that phosphorylation-mimicking mutants of p21 seem to be able to affect the CDK\/cyclin protein-protein interactions (PPIs), and that the reduced p21C41S variant decreased binding between CDK4 and cyclin D3. In contrast, p21C41S increased the CDK2\/cyclin E1 interaction such as wild-type p21. Hence, wild-type p21 and its specific variants have an impact on the formation of distinct CDK\/cyclin complexes under physiological conditions.<\/jats:p>","DOI":"10.1242\/jcs.265097","type":"journal-article","created":{"date-parts":[[2026,10,14]],"date-time":"2026-10-14T13:14:46Z","timestamp":1791983686000},"source":"Crossref","is-referenced-by-count":0,"title":["Visualisation of the regulation of CDK\/cyclin complexes by p21 (CDKN1A) in living cells using FLIM-FRET"],"prefix":"10.1242","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-1870-9419","authenticated-orcid":false,"given":"Christian","family":"Melle","sequence":"first","affiliation":[{"name":"Biomolecular Photonics Group, CeTraMed\/ThIMEDOP, Jena University Hospital, Friedrich Schiller University Jena, 07740 Jena, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0007-7964-6400","authenticated-orcid":false,"given":"Birgit","family":"Hoffmann","sequence":"additional","affiliation":[{"name":"Biomolecular Photonics Group, CeTraMed\/ThIMEDOP, Jena University Hospital, Friedrich Schiller University Jena, 07740 Jena, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Annett","family":"Wiesenburg","sequence":"additional","affiliation":[{"name":"Biomolecular Photonics Group, CeTraMed\/ThIMEDOP, Jena University Hospital, Friedrich Schiller University Jena, 07740 Jena, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0000-7245-6603","authenticated-orcid":false,"given":"Christoph","family":"Biskup","sequence":"additional","affiliation":[{"name":"Biomolecular Photonics Group, CeTraMed\/ThIMEDOP, Jena University Hospital, Friedrich Schiller University Jena, 07740 Jena, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"237","published-online":{"date-parts":[[2026,10,14]]},"container-title":["Journal of Cell Science"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.biologists.com\/jcs\/article-pdf\/doi\/10.1242\/jcs.265097\/3721394\/jcs265097.pdf","content-type":"application\/pdf","content-version":"am","intended-application":"syndication"},{"URL":"https:\/\/journals.biologists.com\/jcs\/article-pdf\/doi\/10.1242\/jcs.265097\/3721394\/jcs265097.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,10,14]],"date-time":"2026-10-14T13:14:46Z","timestamp":1791983686000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.biologists.com\/jcs\/article\/doi\/10.1242\/jcs.265097\/373140\/Visualisation-of-the-regulation-of-CDK-cyclin"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,10,14]]},"references-count":0,"URL":"https:\/\/doi.org\/10.1242\/jcs.265097","relation":{},"ISSN":["0021-9533","1477-9137"],"issn-type":[{"value":"0021-9533","type":"print"},{"value":"1477-9137","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,10,14]]},"article-number":"jcs.265097"}}