Kinesin

Kinesin is a type of protein that moves along microtubule filaments in cells. It is a motor protein that converts chemical energy stored in adenosine triphosphate (ATP) into mechanical work. Kinesins have a wide range of roles in cells, including transporting vesicles, organelles, and chromosomes, and helping to form the mitotic spindle during cell division.

Structure

Kinesins are composed of two heavy chains and two light chains. The heavy chains form a coiled-coil structure and contain a globular head at one end, which is the motor domain. This domain binds to microtubules and hydrolyzes ATP to generate movement. The light chains bind to the cargo that the kinesin transports.

Function

Kinesins move along microtubules in a processive manner, meaning they can take many steps along the filament before detaching. They generally move towards the plus end of the microtubule, which is usually oriented towards the cell periphery. This is known as anterograde transport and is important for moving materials from the center of the cell to the periphery.

Kinesins are involved in many cellular processes. They transport vesicles and organelles, including mitochondria, lysosomes, and endoplasmic reticulum. They also play a key role in cell division, where they help to form the mitotic spindle and separate chromosomes.

Types of Kinesins

There are many different types of kinesins, which are classified into 14 families. These include Kinesin-1, the conventional kinesin that is best understood and was the first to be identified, and Kinesin-2, which is involved in the transport of organelles and vesicles. Other kinesins have more specialized roles, such as Kinesin-13, which depolymerizes microtubules, and Kinesin-14, which moves towards the minus end of the microtubule.

See Also

• Motor protein
• Dynein
• Myosin