The inner vision of a cell

Created by BioVision from Harvard



First came cross this fantastic animation from Jean's blog. The high quality flash version can be found at Studio Daily, and at, whoelse, YouTube. Unfortunately that I can't seem to find the web site in Harvard.

Detailed explaination see Andrew Sobala's blog:
"You are in a blood vessel, then zoom in to a cell rolling along the endothelium wall (basically looking for injuries or cells that are generally "upset"). The closeup of the long spindly proteins are, I believe, contact proteins between the two cells. You then see a cell membrane - not the GCSE model, but what it actually looks like - including a lipid raft surfing containing a group of localised proteins. You then zoom out and see some of the general cytoskeletal structure under the cell membrane (if anyone can identify specifics, please let me know).

You see an actin filament being manufactured from its constituent monomers; these fibres are instrumental in pulling subcellular structures around the cell and also for providing a framework for materials to be transported around the cell on. A protein comes in and chop the actin fibre - the manufacture and dissociation of both actin and microtubules is a regulated, dynamic process. Similarly you see microtubule formation and a microtubule catastrophe - when microtubules dissociate, it's very fast. Then the coolest bit of the video - a microtubule motor protein pulls a vesicle to its destination in the cell. The cellular motor proteins really do look like this - their mechanism of action is basically a walk forwards.

The aniation fades to the nuclear surface, and some mRNA pops out of the nuclear pores - these molecules are derived from DNA and contain the code to make a single protein. They form loops and a ribosome comes in and scans for the start of the protein coding sequence. It moves along the mRNA and a protein comes out of the end. An orange and blue thing floats across the screen for no apparent reason. Then you see another ribosome land on the ER translocon and repeat the protein synthesis process - it injects the protein straight into the ER, which is the beginning of the pathway for proteins that are required on the cell membrane or outside the cell (there are other reasons for sending a protein down the ER pathway). You see the walker again, then a shot of some vesicles fusing with the Golgi body - a series of membrane stacks that forms a protein modification machine.

The animation then cuts to outside the cell again, and you see some proteins being thrown out by exocytosis - in the process, some integrins are placed on the cell surface. The cell they are on decides it wants to form an adhesive interaction with the basal lamina, because after about 10 seconds the integrin molecules all "stand up" - they move into their active, adhesive form. Then you see the blood vessel again, and the cell that was rolling along the wall enters into a cellular junction and disappears."