A newly discovered “Ras” protein, which is related to a group known to be a factor in nearly 30 percent of all human tumors, has been identified by a Yale professor.
“There are three known Ras proteins,” said Sankar Ghosh, associate professor in the Departments of Immunobiology, Molecular Biophysics and Biochemistry, and Molecular, Cellular & Developmental Biology. “They are associated with about 30 percent of all human tumors and therefore are one of the most intensely studied proteins in biology. What we found is basically a new subclass of Ras proteins.”
The Ras proteins have been found to be mutated in 50 percent of colon tumors and 90 percent of a class of pancreatic tumors.
What is most noteworthy about this particular Ras protein is that, in its natural form, it resembles the other Ras proteins in their mutated form, said Ghosh, who also is an associate investigator for the Howard Hughes Medical Institute. His findings were published in the current issue of the journal, Science.
Ghosh and his collaborator, Jae Woon Lee of Chonnam National University in Korea, believe this new class of Ras protein helps regulate the activity of a transcription factor known as NFkB. Transcription is the process by which messenger RNA is synthesized from a DNA template, resulting in the transfer of genetic information from the DNA molecule to messenger RNA.
Among the questions the investigators plan to pursue in the future is whether this new protein is also associated with cancer. In order for Ras proteins to cause cancer they have to localize in the membrane, but this protein does not have the sequences that allow it to go to the membrane, Ghosh said.
“However, it is possible that in certain cancers this protein could be mutated so that it could be localized to the membrane,” he said.
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