How a Key Development Regulator Is Regulated (IMAGE)
Caption
Using x-ray crystallography, Joshua-Tor's team has captured the equivalent of freeze-frames of enzymes called TUTases in two different modes. In one mode (LEFT), the TUTase enzyme (consisting of pink and blue/green subunits surrounded by a dotted line) adds a single uridine ("U") nucleotide to a precursor of the micro RNA let-7 (purple and orange helix). The addition of a single "U" leads to the production of a mature let-7 micro RNA, in turn supporting the process in which a stem cell differentiates into a specialized cell. In its other mode (RIGHT) a TUTase enzyme associates with a protein called Lin28, leading to the addition of 30 "U"s to a let-7 precursor. This targets it for destruction - essential for stem cells to retain their ability to proliferate indefinitely. The TUTases are potential targets in cancer cells, which seem to acquire the stem-like ability to proliferate.
Credit
Joshua-Tor lab, CSHL
Usage Restrictions
None
License
Licensed content