Alessia Schirripa Alessia Schirripa Helge Schöppe Helge Schöppe Sofie Nebenfuehr Sofie Nebenfuehr Markus Zojer Markus Zojer Thorsten Klampfl Thorsten Klampfl Valentina Kugler Valentina Kugler Belinda S. Maw Belinda S. Maw Huriye Ceylan Huriye Ceylan Iris Z. Uras Iris Z. Uras Lisa Scheiblecker Lisa Scheiblecker Elisabeth Gamper Elisabeth Gamper Ulrich Stelzl Ulrich Stelzl Eduard Stefan Eduard Stefan Teresa Kaserer Teresa Kaserer Veronika Sexl Veronika Sexl Karoline Kollmann Karoline Kollmann MDPI 2025 The vital cell cycle machinery is tightly regulated and alterations of its central signaling hubs are a hallmark of cancer. The activity of CDK6 is controlled by interaction with several partners including cyclins and INK4 proteins, which have been shown to mainly bind to the amino-terminal lobe. We analyzed the impact of CDK6's C-terminus on its functions in a leukemia model, revealing a central role in promoting proliferation. C-terminally truncated Cdk6 (Cdk6 D C) shows reduced nuclear translocation and therefore chromatin interaction and fails to enhance proliferation and disease progression. The combination of proteomic analysis and protein modeling highlights that Cdk6's C-terminus is essential for protein flexibility and for its binding potential to cyclin D, p27 Kip1 and INK4 proteins but not cyclin B. We demonstrate that the C-terminus is a unique and essential part of the CDK6 protein, regulating interaction partner binding and therefore CDK6's functionality. PDFDocument eng 2025-03-06T10:03:39.805508Z 2025 Cyclin-Dependent Kinase Cell-Cycle Structural Basis Crystal-Structure Intrinsic Disorder Protein-Structure Inhibitor Prediction Complex Links 6360680 b application/pdf http://creativecommons.org/licenses/by/4.0/