Cathepsin G

Cathepsin G is a protein that in humans is encoded by the CTSG gene. It is a member of the peptidase S1 family, also known as the serine protease family. Cathepsin G is primarily found in neutrophil granulocytes, a type of white blood cell that plays a crucial role in the immune system.

Structure

The CTSG gene is located on the chromosome 14 (14q11.2). It spans approximately 6.3 kilobases and contains five exons. The protein encoded by this gene is a serine protease composed of a signal peptide, a propeptide, and a mature chain. The mature chain consists of a light and a heavy chain, which are linked by a disulfide bond.

Function

Cathepsin G is stored in the azurophil granules of neutrophil granulocytes and is released upon cell activation. It is involved in the killing of ingested microorganisms and shows bactericidal activity. The protein can degrade collagen, elastin, and coagulation factors, and it can activate or inactivate specific chemokines, suggesting a role in inflammatory processes.

Clinical significance

Alterations in the activity of cathepsin G can lead to various diseases. For example, it has been implicated in the pathogenesis of chronic obstructive pulmonary disease (COPD) and rheumatoid arthritis. In addition, cathepsin G is a potential therapeutic target for the treatment of cystic fibrosis and cancer.

See also

• Cathepsin
• Serine protease
• Neutrophil granulocytes
• Immune system

References

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