Biochemical characterization of the feedforward loop between CDK1 and FOXM1 in epidermal stem cells

• Published in: Biology direct Vol. 19; no. 1; pp. 91 - 14
• Main Authors: Polito, Maria Pia, Romaldini, Alessio, Tagliazucchi, Lorenzo, Marini, Grazia, Radice, Federica, Gozza, Gaia Andrea, Bergamini, Giulia, Costi, Maria Paola, Enzo, Elena
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 13.10.2024; BioMed Central; BMC
• Subjects: Analysis; Biopsy; Care and treatment; CDC2 Protein Kinase - genetics; CDC2 Protein Kinase - metabolism; CDK1; Cell culture; Cell cycle; Cell Differentiation; Cell self-renewal; Cells, Cultured; Cloning; Cyclin-dependent kinases; Diagnosis; Epidermal Cells - metabolism; Epidermal stem cell; Epidermis - metabolism; Ethylenediaminetetraacetic acid; Forkhead Box Protein M1 - genetics; Forkhead Box Protein M1 - metabolism; FOXM1; Gene expression; Gene therapy; Genetic aspects; Health aspects; Humans; International economic relations; Keratinocytes; Keratinocytes - cytology; Keratinocytes - metabolism; Kinases; Localization; Mass spectrometry; Mass spectroscopy; Patient outcomes; Penicillin; Peptides; Phosphorylation; Proteins; Proteomics; Scientific equipment and supplies industry; Skin; Skin diseases; Stem cells; Stem Cells - cytology; Stem Cells - metabolism; Tissues; Transcription factors; Upstream; Italy; United States; United States > US; CDK1; Phosphorylation; Epidermal stem cell; FOXM1
• ISSN: 1745-6150; 1745-6150
• DOI: 10.1186/s13062-024-00540-8

The complex network governing self-renewal in epidermal stem cells (EPSCs) is only partially defined. FOXM1 is one of the main players in this network, but the upstream signals regulating its activity remain to be elucidated. In this study, we identify cyclin-dependent kinase 1 (CDK1) as the principal kinase controlling FOXM1 activity in human primary keratinocytes. Mass spectrometry identified CDK1 as a key hub in a stem cell-associated protein network, showing its upregulation and interaction with essential self renewal-related markers. CDK1 phosphorylates FOXM1 at specific residues, stabilizing the protein and enhancing its nuclear localization and transcriptional activity, promoting self-renewal. Additionally, FOXM1 binds to the CDK1 promoter, inducing its expression.We identify the CDK1-FOXM1 feedforward loop as a critical axis sustaining EPSCs during in vitro cultivation. Understanding the upstream regulators of FOXM1 activity offers new insights into the biochemical mechanisms underlying self-renewal and differentiation in human primary keratinocytes.