The menin tumor suppressor protein is phosphorylated in response to DNA damage

• Published in: PloS one 2011-01, Vol.6 (1), p.e16119-e16119
• Main Authors: Francis, Joshua, Lin, Wenchu, Rozenblatt-Rosen, Orit, Meyerson, Matthew
• Format: Article
• Language: English
• Subjects: Addition polymerization; Apoptosis; Biology; Cancer; Cell cycle; Cell Line; Chromatin; Cyclin-dependent kinases; Damage; Deficient mutant; Deoxyribonucleic acid; DNA; DNA damage; DNA Damage - genetics; DNA methylation; DNA repair; DNA-directed RNA polymerase; Elongation; Gadd45A protein; Gene regulation; Genes; Genetic aspects; Histone methyltransferase; Histones; Humans; Kinases; Medical schools; Medicine; Methylation; Methyltransferases; Multiple endocrine neoplasia; Mutants; Mutation; Neuroendocrine tumors; Oncology; Pancreas; Parathyroid; Pathology; Phosphorylation; Phosphorylation - physiology; Pituitary; Protein Binding; Proteins; Proto-Oncogene Proteins - metabolism; Ribonucleic acid; RNA; RNA polymerase; RNA polymerase II; RNA Polymerase II - metabolism; Serine - metabolism; Studies; Transcription; Transcription (Genetics); Transcription factors; Transcription, Genetic; Transgenic animals; Tumor suppressor genes; Tumor suppressor proteins; Tumor Suppressor Proteins - metabolism; Tumors
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0016119

Multiple endocrine neoplasia type 1 (MEN1) is a heritable cancer syndrome characterized by tumors of the pituitary, pancreas and parathyroid. Menin, the product of the MEN1 gene, is a tumor suppressor protein that functions in part through the regulation of transcription mediated by interactions with chromatin modifying enzymes. Here we show menin association with the 5' regions of DNA damage response genes increases after DNA damage and is correlated with RNA polymerase II association but not with changes in histone methylation. Furthermore, we were able to detect significant levels of menin at the 3' regions of CDKN1A and GADD45A under conditions of enhanced transcription following DNA damage. We also demonstrate that menin is specifically phosphorylated at Ser394 in response to several forms of DNA damage, Ser487 is dynamically phosphorylated and Ser543 is constitutively phosphorylated. Phosphorylation at these sites however does not influence the ability to interact with histone methyltransferase activity. In contrast, the interaction between menin and RNA polymerase II is influenced by phosphorylation, whereby a phospho-deficient mutant had a higher affinity for the elongating form of RNA polymerase compared to wild type. Additionally, a subset of MEN1-associated missense point mutants, fail to undergo DNA damage dependent phosphorylation. Together, our findings suggest that the menin tumor suppressor protein undergoes DNA damage induced phosphorylation and participates in the DNA damage transcriptional response.