Difference Between Dynein and Kinesin

The key difference between dynein and kinesin is that dynein is a cytoskeleton motor protein that moves towards the minus-end of microtubules while kinesin is another cytoskeleton motor protein that moves towards the plus end of microtubules.

The cytoskeleton consists of different kinds of filaments. Microtubules are one type among them. They guide the material movement within the cell. They are also important in maintaining the shape of the cell. Apart from that, microtubules are vital in separating chromosomes in mitosis and meiosis. Furthermore, microtubules are key components of cilia and flagella of some eukaryotic cells. Structurally, microtubules are polar structures. They have a plus end and minus end. Generally, minus end extends towards the center of the cell while the plus end extends towards the cell surface. During the intracellular transport of vesicles and organelles, two types of cytoskeleton motor proteins help microtubules. They are dyneins and kinesins. Dyneins move towards the minus end of the microtubules while carrying materials to the center of the cell. In contrast, kinesins travel towards the cell surface carrying materials to the periphery of the cell.

CONTENTS

1. Overview and Key Difference
2. What is Dynein 
3. What is Kinesin
4. Similarities Between Dynein and Kinesin
5. Side by Side Comparison – Dynein vs Kinesin in Tabular Form
6. Summary

What is Dynein?

Dynein is a motor protein present in the cytoskeleton of the cells. They are capable of moving along microtubules and aiding the intracellular transport of vesicles and organelles. Dynein travels towards the minus end of the microtubules. While traveling, they carry materials towards the center of the cell since the minus end is towards the center of the cell.

In simple words, dyneins are the cytoskeleton motor proteins that transport cargo (organelles and vesicles) from the periphery of the cell towards the center (retrograde transport). Not only that, dynein is a key component of cilia and flagella that is important in sliding microtubules relative to one another. Hence, they are important in the beating of the cilia and flagella located on the surface of some eukaryotic cells.

What is Kinesin?

Kinesin is another type of cytoskeleton motor protein that is capable of moving along the microtubules filaments. Moreover, kinesins are ATPases. Their movements are energy consuming. Most kinesins travel towards the plus end of the microtubules that are present towards the periphery of the cell (towards the cell surface). While traveling, kinesins carry cargo (organelles and vesicles) from the center of the cell to the periphery of the cell (anterograde transport).

Mutations of kinesin proteins can lead to nervous system disorders. One such common disease is peripheral neuropathy.

What are the Similarities Between Dynein and Kinesin?

• Dynein and kinesin are two motor proteins.
• They are important molecules of the cytoskeleton.
• Both dynein and kinesin move along the microtubules.
• Moreover, they aid in material transport within the cell.
• Also, both proteins are important in cell division.
• Structurally, both these proteins are ATP hydrolases.

What is the Difference Between Dynein and Kinesin?

The key difference between dynein and kinesin is the direction of their movement along the microtubules. Dynein moves towards the minus end of the microtubule while kinesin moves towards the plus end of the microtubule. Moreover, dynein transports cargo from the periphery to the center of the cell while kinesin transports cargo from the center to the periphery of the cell. Thus, this is an important functional difference between dynein and kinesin. Structurally, dynein protein consists of one to three heavy chains complex to intermediate, light-intermediate and light chains. On the other hand, kinesin protein consists of two heavy chains and two light chains. Therefore, this is another difference between dynein and kinesin.

Summary – Dynein vs Kinesin

Dynein and kinesin are two important motor proteins present in the cytoskeleton. They move along the microtubules and facilitate the intracellular transport of vesicles and organelles. The key difference between dynein and kinesin is the direction of the movement. Dynein moves towards the minus end of the microtubule while kinesin moves towards the plus end of the microtubule. Furthermore, dynein transports cargo to the center of the cell while kinesin transports cargo to the periphery of the cell. Both these proteins are ATP hydrolases. Moreover, both these proteins are important for cell division. Other than that, dyneins are important in the beating of cilia and flagella of some eukaryotic cells. Thus, this summarizes the difference between dynein and kinesin.

Reference:

1. Berg, Jeremy M. “Kinesin and Dynein Move Along Microtubules.” Biochemistry. 5th Edition., U.S. National Library of Medicine, 1 Jan. 1970, Available here.
2. Endow, Sharyn A., et al. “Kinesins at a Glance.” Journal of Cell Science, The Company of Biologists Ltd, 15 Oct. 2010, Available here.

Image Courtesy:

1. “DyneinHeavyChainOnMT” By TheTrappist – Own work (CC BY-SA 3.0) via Commons Wikimedia
2. “Kinesin cartoon” (CC BY-SA 3.0) via Commons Wikimedia