Functional impairment of p16INK4A due to CDKN2A p.Gly23Asp missense mutation
Autor: | Paula Lobao Antunes de Siqueira Torres, Mauro Alaibac, Daniela Zullato, Elisabetta Rossi, Vanna Chiarion-Sileni, Graham J. Mann, Cinzia Casella, Antonella Vecchiato, Marco Montagna, Monia Callegaro, Sandro Malacrida, Monica Quaggio, Simona Agata, Maria Chiara Scaini, Chiara Menin, Emma D'Andrea |
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Rok vydání: | 2009 |
Předmět: |
Cell cycle checkpoint
Health Toxicology and Mutagenesis Protein domain Cell Mutation Missense Biology Germline mutation Mutant protein CDKN2A Genetics medicine Humans Missense mutation Phosphorylation Melanoma neoplasms Molecular Biology Cyclin-Dependent Kinase Inhibitor p16 Polymorphism Genetic Genes p16 Cell Cycle Molecular biology Salivary Proline-Rich Proteins medicine.anatomical_structure Cancer research G1 phase |
Zdroj: | Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis. 671:26-32 |
ISSN: | 0027-5107 |
Popis: | The CDKN2A locus encodes for two distinct tumor suppressor proteins, p16 INK4A and p14 ARF , involved in cell cycle regulation. CDKN2A germline mutations have been associated with familial predisposition to melanoma and other tumor types. Besides bona-fide pathogenic mutations, many sequence variants have been identified, but their effect is not well known. We detected the p.Gly23Asp missense mutation in one of the two tested melanoma patients of a family with three melanoma cases. Even though the mutated amino acid is located in a conserved domain that specifically binds to and blocks the function of CDK4/6, its lack of segregation with disease suggested a series of functional assays to discriminate between a pathogenic variant and a neutral polymorphism. The effect of this mutation has been investigated exploiting four p16 INK4A properties: its ability (i) to bind CDK4, (ii) to inhibit pRb phosphorylation, (iii) to evenly localize in the cell, and (iv) to cause cell cycle arrest. The mutant protein properties were evaluated transfecting three different cell lines (U2-OS and NM-39, both p16-null, and SaOS 2, p53 and pRb-null) with plasmids expressing either p16 wt , p16 23Asp , or the p16 32Pro pathogenic variant. We found that p16 23Asp was less efficient than p16 wt in CDK4 binding, in inhibiting pRb phosphorylation, in inducing G1 cell cycle arrest; moreover, its pattern of distribution throughout the cell was suggestive of protein aggregation, thus assessing a pathogenic role for p16 23Asp in familial melanoma. |
Databáze: | OpenAIRE |
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