Green Fluorescent Protein - A Jennifer Lippincott-Schwartz Videocast

In the past 15 years, the two biggest technical advances that have helped us Cell Biologists are RNAi and green fluorescent protein, aka GFP.

You see before the advent of GFP, researchers could only analyze the distribution of proteins in a living cell by first fixing and thus killing the sample. No information could be collected from a protein within it's natural envioronment, that of active cytoplasm. We could figure out where proteins were at a certain point in time, but not how they behaved over time. You see we were missing the temporal dimension. Sure there were exceptions, Yuli Wang had microinjected rhrodamine conjugated actin into tissue culture cells and Tim Mitchison did the same with tubulin, but outside the cytoskeletal field little was know about the dynamics of proteins in living cells.

Then came green fluorescent protein from the jellyfish Aequorea victoria. Douglas Prasher first isolated and sequenced the gene but lost his funding before he could do any work on the protein (and then left academic science!) Martin Chalfie heard about GFP (at a talk?) got the DNA from Prasher as his lab was closing. Then the Chalfie lab published the first paper where GFP was expressed in a single cell type in C. elegans.

Then Jennifer Lippincott-Schwartz got a hand on GFP.

There are so many cool imaging techniques that were developed in her lab, it is truly breathtaking. She developed a photo-activatable GFP, the FRAP (Fluorescence recovery after photobleaching), and FLIP (Fluorescence loss in photobleaching) techniques that allow the microscopoist to measure the mobility of molecules inside the cell. Recent she helped develop photoactivated localization microscopy. Here's the abstract from a paper that appeared last year in Science:

We introduce a method for optically imaging intracellular proteins at nanometer spatial resolution. Numerous sparse subsets of photoactivatable fluorescent protein molecules were activated, localized (to approximately 2 to 25 nanometers), and then bleached. The aggregate position information from all subsets was then assembled into a superresolution image. We used this method--termed photoactivated localization microscopy--to image specific target proteins in thin sections of lysosomes and mitochondria; in fixed whole cells, we imaged vinculin at focal adhesions, actin within a lamellipodium, and the distribution of the retroviral protein Gag at the plasma membrane.

Along the way her studies have revealed much of how organelles are made, destroyed. In fact last year's breakthrough studies on the transient nature of the Golgi validated much of her early work.

Then a couple of days ago we stumbled onto this conference she gave at the NIH (where she works). So if you are interested in microscopy, the development of GFP or organellar biology, I strongly recommend that you follow this link and watch her seminar.