ABSTRACT
The myc proteins are short-lived phosphoproteins which localize to the nucleus, and possess a strong nonspecific affinity for DNA. The precise nuclear location of c-myc protein and the genetic mechanism by which myc proteins regulate gene expression are still unclear. myc family gene products exist in multiple forms. The c-myc gene encodes two major phosphoproteins, measuring 67 and 64 kDa. In the human gene, Eisenman and colleagues have demonstrated that the two c-myc proteins are derived from alternative translation initiation codons in the same open reading frame (ORF). The identification of signal transduction processes which influence nuclear proto-oncogene activity is fundamental to our understanding of how growth factors induce changes in gene expression and effect pleiotropic cellular responses. A common and rapid link between receptor-transducer proteins and nuclear substrates is the network of cytoplasmic protein kinases.
