In vivo expression and analysis of a novel protein, NIAM, in Drosophila melanogaster

The Arf-Mdm2-p53 is a critical tumor suppressor pathway that is lost in many cancers. A novel protein known as NIAM (Nuclear Interactor of Arf and Mdm2) has functions both dependent and independent of the Arf-Mdm2-p53 pathway. NIAM functions to inhibit chromosomal instability and cell proliferation, both common characteristics of cancers, perhaps indicating a role as a novel tumor suppressor. NIAM contains FYRN/FYRC domains found in many chromatin-associated proteins. The corresponding protein found in Drosophila, dNIAM, also retains FYRN/FYRC domains, which we predict associate with chromatin similarly to the mammalian form. Objectives were to investigate whether NIAM is a chromatin associated protein in flies and determine the biological role of dNIAM in Drosophila melanogaster. When expressed in flies, dNIAM localized to chromosomes at decondensed regions, consistent with a role in chromatin regulation. Understanding the functions and mechanisms involving the protein, NIAM, may provide future avenues for cancer research and treatment.