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How does caspase help apoptosis?

How does caspase help apoptosis?

Caspases are a large family of evolutionarily conserved, aspartate-specific cysteine proteases that are essential for the initiation and execution of apoptosis1-3. Initiator caspases initiate the apoptosis signal while the executioner caspases carry out the mass proteolysis that leads to apoptosis.

Which caspases are involved in apoptosis?

Caspases involved in apoptosis are classified into two groups, the initiator caspases, such as caspase-9 in mammals or its functional ortholog Dronc in Drosophila, and the effector caspases, such as caspases-3 and -7 in mammals and their homolog DrICE in Drosophila (Fig. 1 ▶).

Is apoptosis a good thing?

Apoptosis removes cells during development. It also eliminates pre-cancerous and virus-infected cells, although “successful” cancer cells manage to escape apoptosis so they can continue dividing. Apoptosis maintains the balance of cells in the human body and is particularly important in the immune system.

What is the role of caspase-3 in apoptosis?

Caspase-3 is known as an executioner caspase in apoptosis because of its role in coordinating the destruction of cellular structures such as DNA fragmentation or degradation of cytoskeletal proteins (1). The activity of caspase-3 is tightly regulated and it is produced as zymogen in an inactive pro-form (1).

What is Blebbing in apoptosis?

Blebbing is one of the defined features of apoptosis. During apoptosis (programmed cell death), the cell’s cytoskeleton breaks up and causes the membrane to bulge outward. These bulges may separate from the cell, taking a portion of cytoplasm with them, to become known as apoptotic blebs.

What can trigger apoptosis?

Apoptosis can also be triggered in otherwise normal cells by external stimuli, including nutrient removal, toxins, hormones, heat, and radiation. It is estimated that a mass of cells equal to body weight is removed by apoptosis each year.

What triggers apoptosis?

Apoptosis can be activated by stimuli coming within the cell, including cell stressors, such as hypoxia or lack of nutrients, and agents that cause damage of DNA or other cell structures. A third pathway leading to apoptosis is specific of cytotoxic T lymphocytes (CTL) and natural killer cells (NK) (Chapter 30).