Actin

Sometime during our studies we come across many terms and words we do not remember or we don't have an idea about. In that case we have to consult a dictionary or have to google the word.So here I am to give general overview of terms related to microbiology as much as possible.
In coming days I will write detailed work and new research findings about the topic.

So today the word is actin.  

 Definition

A cellular protein that give important contribution in muscle and cell contraction in connection with myosin protein is called actin.

Properties

Actin protein is a monomeric subunit of microfilament which is one of the major component of cytoskeleton and it is also a part of contractile apparatus of muscle cell.

Mass: 47 kDa

Diameter: 4-7nm

Forms

G-actin:-It is a monomeric globular protein.

F-actin: - It is a polymeric fibrous actin.

Presence

Most abundant protein in eukaryotic cells.

Actin present in cytoplasm of cells with myosin protein.

Actin is highly conserved protein in cells because it is encoded by a large, highly conserved gene family.

Importance

1.    Maintenance of cell shape.

2.    Helps in muscular contraction.

3.    Actin participate in cell signalling.

4.    In non-muscular cells web of actin filament provide different cell movements (cytokinesis).

5.    Vesicle and cell organelle movement inside the cell.

6.    Establishment of cell junction.

Role in Cell Biology

When muscle cells get the signal to contract, actin and myosin protein become active. Myosin release energy by hydrolysing ATP (adenosine tri phosphate phosphate) and moves along actin filament causing two filaments to slide past each other. Myosin and actin filament made a structure called sarcomere which shrinks as filaments slide one over another. This mechanism helps entire muscle to contract. Muscle cells are made up of bundles of sarcomere.

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