Now, it turns out that precursor nerve cells contain that same repressive protein after all. In fact, the protein directs the complex network of genes that transforms an embryonic stem cell into a mature nerve cell, say Howard Hughes Medical Institute (HHMI) researchers.
This new study, published in the May 20, 2005, issue of the journal Cell, may be among the first to track a set of genes from stem cell to differentiated neuron. It also reveals fundamental details of how stem cells retain developmental plasticity.
"A single protein does it all," said Gail Mandel, HHMI investigator at the State University of New York at Stony Brook. "It keeps the genes totally off in non-neuronal tissues, such as skin, where you don't dare express a neuronal gene. But it also allows the full elaboration of the neuronal phenotype from the precursor cell."
Led by HHMI associate Nurit Ballas, a postdoctoral fellow in Mandel's lab, the study may advance stem cell research aimed at understanding repairing spinal cord injuries or replacing malfunctioning brain cells in neurodegenerative diseases. It may also provide insights into other diseases, such as small cell lung cancer, which mistakenly make neuronal proteins, or neurological syndromes, where neuronal proteins produced by cancers may trigger the immune cells to attack the nervous system.
The study focuses on a protein called REST, which is short for RE1-silencing transcription factor. It was independently discovered 10 years ago by Mandel's group and a second team led by HHMI investigator David J. Anderson at Caltech.
Source:Howard Hughes Medical Institute