Kinesin

Is a group of kinesin motor proteins in eukaryotic cells. In cooperation with other motor proteins such as myosin and dynein they are significantly involved in the intracellular transport of biological loads such as biological macromolecules, vesicles and organelles. Kinesin comes along with dynein to microtubule ( constituents of the cytoskeleton ) as a transport of vesicles and other molecules before.

Design and function

The Kinesinkomplex consists of two heavy protein chains and two light protein chains. The kinesin protein itself consists of a head region, which can bind to microtubules and contains the catalytic domain, a neck, a long stem, and a tail that can interact with other proteins through a variety of related proteins. The energy for transport is derived from the cleavage of adenosine triphosphate ( ATP), the catalytic center of the head region, won. By ATP hydrolysis to the active site, the conformation of the head and neck changed, a 8 nm long step with a Tubulinheterodimer, the structural unit of a microtubule follows. Kinesinkomplexe bind to a transporting molecule per se and ' run ' then along a microtubule. They move processively, ie very stably bound to microtubules, as always one of the two heads is bound to microtubules. Transport shall be directed, most kinesins walk along the microtubule toward the growing microtubule end ( so-called plus - end ). Since microtubules normally grow from the cell interior to the exterior, these kinesins transport their cargo from the cell interior to the cell periphery ( anterograde transport). There are also other kinesins (eg, kinesin -like proteins ), transport the cargo toward the minus end. The directed by the minus - end transport on the microtubule is also achieved by dynein.