The myc family of nuclear oncoproteins: Structure, biochemistry, and activities

The myc proteins are short-lived phosphoproteinsl-6 which localize to the nucleus, 7-13 and possess a strong nonspecific affinity for DNA.9,14,15 The precise nuclear location of cmyc protein and the genetic mechanism by which myc proteins regulate gene expression are still unclear. To date, c-myc proteins have been found to be associated with nuclear matrix componentsl6 or soluble proteins, 17 depending on the procedure employed. Intriguingly, the subnuclear distribution patterns of c-myc proteins have been shown to be identical to the distribution of small nuclear ribonucleoprotein particles (snRNP), and thus raise the possibility that myc may function at the level of RNA splicing. 13 In summary, elucidation of the precise subnuclear location and nucleic acid interactions of myc oncoproteins will require additional study.