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Tim HuttonTim Hutton - 2012-01-08 22:15:03+0000 - Updated: 2012-01-08 22:15:03+0000
Originally shared by Rajini RaoWalking Heads: Kinesin or The Little Engine That Could :)
Have you wondered how things (like vesicles and mitochondria) move about inside a cell? They don’t just drift aimlessly through the thick cytoplasmic soup-rather they are ferried by kinesin, a hard working molecular motor.

To watch mitochondria motor down an invisible highway inside a nerve cell see: Mitochondrial Moving in an Axon.mov

The kinesin highway is made of microtubules : a bundle of 13 filaments that have distinct ends (known as + and – ends). Kinesins move cargo towards the + end (from the center of the cell to the periphery) and dyneins move them in the opposite direction. Watch what happens when fluorescent microtubules are placed on a slide coated with kinesin! Kinesin-1 gliding motility assay, whole casein passivation.avi

Cargo is tethered to kinesin by a long coil. The two heads of the motor walk along the microtubule in a hand-over-hand mechanism using ATP hydrolysis as a power source. Each ATP moves the motor one 8 nanometer step. Notice that kinesin is a processive motor: once it is attached to the microtubule it takes (on average)100 steps, before it lets go.

For a narrated 2 min mechanism see:Kinesin Walking Narrated Version for Garland

Many, many thanks to +Kevin Staff for being such a sport and converting the kinesin video into an animated gif! Special shout out to +Andreas Schou who requested some ‘kinesin love’ and to +Henry K.O. Norman who is working on an animated production on cellular mechanisms.

For #ScienceSunday curated by +Allison Sekuler and +Robby Bowles .Kinesin Walking (animated by Kevin Staff from http://www.youtube.com/watch?v=4AnPVuzF7CA)

Kinesin Walking (animated by Kevin Staff from http://www.youtube.com/watch?v=4AnPVuzF7CA)

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+1'd by: Nick Porcino

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