In many cells actin filaments identical in structure and com

In many cells, actin filaments identical in structure and composition can be involved in different functions within the same cell cytoplasm. How is this accomplished?

Solution

Actin filaments structurally represent linear polymers of globular proteins. Owing to their structure, actin filaments comprise of many unique functions which can be discussed as below:

1. Cell division: Owing to their ability to grow/replicate and divide with the cytoplasm of the cell, the actin filaments are integrally associated with cellular division. During this process, multiple cellular structures becomes immotile and aggregate inside the cell due to dis-integration of actin thus help in cell division.

2. Cell motility: Actin filaments have very unique property of accomplishing cellular division. Actin filaments accomplish cellular motility by providing structural strength to the cytoplasmic extension and formation of pseudopodia, by formation of cellular appendages etc. Further, actins are also integrally associated with muscular contraction and relaxation through dynamic movement of actin and myosin fibres in the muscles.

3. Cellular reproduction: Actin filament constitutes the important structural part of the sperm head by modification of its structure by its own. Formation of coiled actin structures at the sperm head makes the sperm highly motile and helps in constant contraction-relaxation thus accomplishing swimming.

Thus, these examples help in understanding that although the actin remains in the cytoplasm with similar structure in many cell types, it accomplishes variety of functions by the virtue of its structural and functional properties.