Biologists have discovered a new super-family of developmental proteins that are critical for cell growth and differentiation and whose further study is expected to benefit research on cancer and the nerve-cell repair. The protein super-family, which existed before the emergence of animals about 850 million years ago, is of major importance for understanding how life evolved in primordial times. The discovery will be described in the 14 February 2007 issue of the journal PLoS ONE.
"This super-family is highly divergent, even in animals with an ancient lineage such as the sea anemone. This super-family also evolves rapidly, so its proteins may provide a model system for investigating how rapidly mutating genes contribute to, and are likely necessary for, the diversity and adaptability of animal life," explains Penn State Assistant Professor Randen Patterson, the senior author of the study. The new protein superfamily is named "DANGER," an acronym for "Differentiation and Neuronal Growth Evolve Rapidly."
The discovery was led by Patterson and Damian van Rossum, a postdoctoral scholar at Penn State in University Park, Pennsylvania, and collaborators at Johns Hopkins University in Baltimore, Maryland. "Most DANGER proteins have not been researched, but from what little we do know these proteins, they are critical for cell growth and differentiation," van Rossum says.
Because so many genomes for diverse organisms have been sequenced and annotated, the discovery of a new and deeply rooted protein family is quite rare. The relationship of the six family members comprising the DANGER super-family escaped detection due to the high rates of mutations between family members, although a few family members had been detected previously and had been shown to control the differentiation of cells into organs in worms, fish, and mice. Deletion of these their DANGER genes led to gross structural changes and prenatal death.