Chemokine receptor: Difference between revisions

Latest revision as of 11:06, 15 February 2025

Chemokine receptor[edit]

Chemokine receptors are a type of G protein-coupled receptor (GPCR) found on the surface of certain cells. They play a crucial role in the immune system by directing the movement of leukocytes (white blood cells) to sites of inflammation, infection, and injury. These receptors are activated by chemokines, which are small signaling proteins secreted by cells in response to various stimuli.

Structure[edit]

Chemokine receptors are characterized by their seven transmembrane domains, a hallmark of GPCRs. The extracellular N-terminus and three extracellular loops are involved in ligand binding, while the intracellular C-terminus and three intracellular loops interact with G proteins to transduce signals inside the cell.

Function[edit]

The primary function of chemokine receptors is to mediate the effects of chemokines. Upon binding to their specific chemokines, these receptors activate intracellular signaling pathways that lead to various cellular responses, including:

Chemotaxis: The directed movement of cells towards higher concentrations of chemokines.
Cell adhesion: Enhancing the ability of leukocytes to adhere to the endothelium and migrate into tissues.
Cell activation: Triggering the activation of leukocytes, which can lead to the release of cytokines and other inflammatory mediators.

Types of Chemokine Receptors[edit]

Chemokine receptors are classified into four main families based on the structure of their ligands:

CXC receptors (CXCR): These receptors bind to CXC chemokines, which have a single amino acid separating the first two cysteines.
CC receptors (CCR): These receptors bind to CC chemokines, which have adjacent cysteines.
CX3C receptors (CX3CR): These receptors bind to CX3C chemokines, which have three amino acids between the first two cysteines.
XC receptors (XCR): These receptors bind to XC chemokines, which lack the first and third cysteines.

Clinical Significance[edit]

Chemokine receptors are involved in a variety of physiological and pathological processes. They are critical in the development and function of the immune system, but they also play roles in:

Cancer: Some chemokine receptors are involved in tumor growth and metastasis.
HIV infection: Certain chemokine receptors, such as CCR5 and CXCR4, serve as co-receptors for HIV entry into cells.
Autoimmune diseases: Aberrant chemokine receptor signaling can contribute to the pathogenesis of diseases like rheumatoid arthritis and multiple sclerosis.

Related pages[edit]

@@ Line 1: / Line 1: @@
-'''Chemokine Receptor'''
+{{DISPLAYTITLE:Chemokine receptor}}
-A '''chemokine receptor''' is a type of [[protein]] that spans the [[cell membrane]] and interacts with [[chemokines]] to elicit cellular responses. These receptors belong to the larger family of [[G protein-coupled receptors]] (GPCRs), which are integral membrane proteins involved in various physiological processes.
+== Chemokine receptor ==
-==Structure==
+[[File:Chemrec_white.jpg|thumb|right|Diagram of a chemokine receptor]]
-Chemokine receptors are composed of seven transmembrane domains connected by three extracellular and three intracellular loops. The N-terminus is located outside the cell, while the C-terminus is inside. The specific structure of each receptor is determined by the chemokine it binds to.
+Chemokine receptors are a type of [[G protein-coupled receptor]] (GPCR) found on the surface of certain cells. They play a crucial role in the [[immune system]] by directing the movement of [[leukocytes]] (white blood cells) to sites of inflammation, infection, and injury. These receptors are activated by [[chemokines]], which are small signaling proteins secreted by cells in response to various stimuli.
-==Function==
+== Structure ==
-Chemokine receptors play a crucial role in the [[immune system]]. They are responsible for the directed migration of [[leukocytes]] (white blood cells) to sites of inflammation or injury. This process, known as [[chemotaxis]], is a key aspect of the immune response.
+Chemokine receptors are characterized by their seven transmembrane domains, a hallmark of GPCRs. The extracellular N-terminus and three extracellular loops are involved in ligand binding, while the intracellular C-terminus and three intracellular loops interact with G proteins to transduce signals inside the cell.
-In addition to their role in the immune system, chemokine receptors are involved in [[HIV]] infection. The virus uses these receptors, particularly CCR5 and CXCR4, to enter and infect cells.
+== Function ==
-==Types==
+The primary function of chemokine receptors is to mediate the effects of chemokines. Upon binding to their specific chemokines, these receptors activate intracellular signaling pathways that lead to various cellular responses, including:
-There are approximately 20 known types of chemokine receptors, which are classified based on the chemokines they bind to. The main types include CCR (C-C chemokine receptor), CXCR (C-X-C chemokine receptor), CX3CR (C-X3-C chemokine receptor), and XCR (X-C chemokine receptor).
+* [[Chemotaxis]]: The directed movement of cells towards higher concentrations of chemokines.
+* [[Cell adhesion]]: Enhancing the ability of leukocytes to adhere to the [[endothelium]] and migrate into tissues.
+* [[Cell activation]]: Triggering the activation of leukocytes, which can lead to the release of [[cytokines]] and other inflammatory mediators.
-==Clinical Significance==
+== Types of Chemokine Receptors ==
-Given their role in immune response and HIV infection, chemokine receptors are potential targets for therapeutic intervention. Drugs that block these receptors could potentially be used to treat inflammatory diseases and prevent HIV infection.
+Chemokine receptors are classified into four main families based on the structure of their ligands:
+* '''CXC receptors (CXCR)''': These receptors bind to CXC chemokines, which have a single amino acid separating the first two cysteines.
+* '''CC receptors (CCR)''': These receptors bind to CC chemokines, which have adjacent cysteines.
+* '''CX3C receptors (CX3CR)''': These receptors bind to CX3C chemokines, which have three amino acids between the first two cysteines.
+* '''XC receptors (XCR)''': These receptors bind to XC chemokines, which lack the first and third cysteines.
+== Clinical Significance ==
+Chemokine receptors are involved in a variety of physiological and pathological processes. They are critical in the development and function of the immune system, but they also play roles in:
+* '''[[Cancer]]''': Some chemokine receptors are involved in tumor growth and metastasis.
+* '''[[HIV]] infection''': Certain chemokine receptors, such as [[CCR5]] and [[CXCR4]], serve as co-receptors for HIV entry into cells.
+* '''[[Autoimmune diseases]]''': Aberrant chemokine receptor signaling can contribute to the pathogenesis of diseases like [[rheumatoid arthritis]] and [[multiple sclerosis]].
+== Related pages ==
+* [[G protein-coupled receptor]]
+* [[Chemokine]]
+* [[Immune system]]
+* [[Leukocyte]]
+* [[Cytokine]]
-[[Category:Cell biology]]
 [[Category:Immunology]]
-[[Category:Proteins]]
+[[Category:Cell signaling]]
-{{cell-biology-stub}}
-{{immunology-stub}}
-{{protein-stub}}