LincRNAs serve as genetic air-traffic c...( BOSTON Earlier this year a scientif...)

BOSTON Earlier this year, a scientific team from Beth Israel Deaconess Medical Center (BIDMC) and the Broad Institute identified a class of RNA genes known as large intervening non-coding RNAs or "lincRNAs," a discovery that has pushed the field forward in understanding the roles of these molecules in many biological processes, including stem cell pluripotency, cell cycle regulation, and the innate immune response.

But even as one question was being answered, another was close on its heels: What, exactly, were these mysterious molecules doing?

They now appear to have found an important clue. Described in the July 14 issue of the Proceedings of the National Academy of Sciences (PNAS) the scientific team from BIDMC and the Broad Institute shows that lincRNAs once dismissed as "genomic junk" have a global role in genome regulation, ferrying proteins to assist their regulation at specific regions of the genome.

"I like to think of them as genetic air traffic controllers," explains co-senior author John Rinn, PhD, a Harvard Medical School Assistant Professor of Pathology at BIDMC and Associate Member of the Broad Institute. "It has long been a mystery as to how widely expressed proteins shape the fate of cells. How does the same protein know to regulate one genomic location in a brain cell and regulate a different genomic region in a liver cell? Our study suggests that in the same way that air traffic controllers organize planes in the air, lincRNAs may be organizing key chromatin complexes in the cell."

Inspired by a lincRNA called HOTAIR -- which is known to bind key chromatin modifier proteins and to assist in getting these proteins to the proper location in the genome the researchers hypothesized that other lincRNA molecules might be playing similar roles.

"DNA wraps around partner proteins to form a structure called chromatin, which affects which genes are 'turned on' and which are 'turned off'," expla
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