chemokine activity

Definition

Target type: molecularfunction

The function of a family of small chemotactic cytokines; their name is derived from their ability to induce directed chemotaxis in nearby responsive cells. All chemokines possess a number of conserved cysteine residues involved in intramolecular disulfide bond formation. Some chemokines are considered pro-inflammatory and can be induced during an immune response to recruit cells of the immune system to a site of infection, while others are considered homeostatic and are involved in controlling the migration of cells during normal processes of tissue maintenance or development. Chemokines are found in all vertebrates, some viruses and some bacteria. [GOC:BHF, GOC:rl, PMID:12183377, Wikipedia:Chemokine]

Chemokine activity refers to the ability of a protein, known as a chemokine, to bind to specific receptors on the surface of cells, triggering a cascade of intracellular signaling events that ultimately lead to cell migration, chemotaxis. Chemokines are small, secreted proteins that are crucial for immune cell trafficking, inflammation, and tissue development. They are highly diverse and can be classified into four main families based on their cysteine residue patterns: CXC, CC, CX3C, and XC.

The process of chemokine signaling begins with the binding of a chemokine to its cognate G protein-coupled receptor (GPCR) on the target cell. This interaction activates the GPCR, leading to the dissociation of the G protein subunits. The activated G protein subunits then trigger a series of downstream signaling pathways, including the activation of phospholipase C (PLC), which hydrolyzes phosphatidylinositol 4,5-bisphosphate (PIP2) into diacylglycerol (DAG) and inositol trisphosphate (IP3). IP3 mobilizes intracellular calcium stores, while DAG activates protein kinase C (PKC), a key enzyme involved in numerous cellular processes.

The chemokine-induced signaling cascade ultimately leads to the activation of various cytoskeletal proteins, such as actin and microtubules, which are essential for cell movement. These rearrangements in the cytoskeleton enable the cell to migrate towards the source of the chemokine, a process known as chemotaxis.

Chemokines play diverse roles in immune responses. They are critical for attracting immune cells, such as neutrophils, monocytes, and lymphocytes, to sites of inflammation or infection. Chemokines also contribute to the development and organization of lymphoid tissues, such as lymph nodes and the spleen.

In addition to their role in immune regulation, chemokines have been implicated in various pathological processes, including cancer metastasis, atherosclerosis, and neurodegenerative diseases. Their involvement in these diseases stems from their ability to influence cell migration, inflammation, and angiogenesis.

In summary, chemokine activity encompasses the binding of chemokines to their receptors, triggering a cascade of intracellular signaling events that culminate in cell migration, chemotaxis. This fundamental process plays crucial roles in immune cell trafficking, inflammation, tissue development, and a variety of pathological conditions.'
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Proteins (4)

Compounds (18)