integrin alphaL-beta2 complex
Definition
Target type: cellularcomponent
An integrin complex that comprises one alphaL subunit and one beta2 subunit. [PMID:12297042]
The integrin alphaL-beta2 complex, also known as LFA-1 (lymphocyte function-associated antigen 1) or CD11a/CD18, is a heterodimeric transmembrane receptor that plays a crucial role in leukocyte adhesion, migration, and signaling. It is expressed on the surface of various immune cells, including lymphocytes, neutrophils, monocytes, and macrophages. The alphaL (CD11a) and beta2 (CD18) subunits are both type I transmembrane proteins, each containing an extracellular domain, a transmembrane domain, and a cytoplasmic domain.
The extracellular domain of alphaL-beta2 is responsible for ligand binding. It consists of a large, globular head domain that is formed by the association of the alphaL and beta2 subunits. This head domain contains several domains, including the I-domain, a metal-ion-dependent adhesion site (MIDAS), and the ligand-binding site. The I-domain is a unique structure that is found in a subset of integrins, including alphaL-beta2. It contains a metal ion (typically Mg2+) that is essential for ligand binding. The MIDAS is located within the I-domain and is responsible for coordinating the interaction with the ligand. The ligand-binding site is located at the interface between the alphaL and beta2 subunits and is responsible for recognizing and binding to specific ligands.
The transmembrane domain of alphaL-beta2 anchors the complex to the cell membrane. The cytoplasmic domain of alphaL-beta2 is responsible for mediating intracellular signaling events. It contains binding sites for various cytoplasmic proteins, including talin, kindlin, and filamin. These proteins are involved in regulating the activation, clustering, and signaling of alphaL-beta2.
In terms of cellular component, alphaL-beta2 is primarily located on the plasma membrane of immune cells. It is often found clustered in lipid rafts, which are specialized microdomains within the plasma membrane that are enriched in cholesterol and sphingolipids. These clusters of alphaL-beta2 can interact with other receptors, signaling molecules, and cytoskeletal components, facilitating the assembly of adhesion complexes and the initiation of intracellular signaling cascades.
Overall, the cellular component of alphaL-beta2 complex can be summarized as the plasma membrane of immune cells, specifically within lipid rafts where it forms clusters and interacts with other components involved in adhesion and signaling.'
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Proteins (2)
| Protein | Definition | Taxonomy |
|---|---|---|
| Integrin alpha-L | An integrin alpha-L that is encoded in the genome of human. [PRO:CNA, UniProtKB:P20701] | Homo sapiens (human) |
| Integrin beta-2 | An integrin beta-2 that is encoded in the genome of human. [PRO:WCB, UniProtKB:P05107] | Homo sapiens (human) |
Compounds (15)
| Compound | Definition | Classes | Roles |
|---|---|---|---|
| indole | indole; polycyclic heteroarene | Escherichia coli metabolite | |
| 1,4-benzodioxan | 1,4-benzodioxan: structure in first source | ||
| 1-methylindole | 1-methylindole: SKATOLE refers to 3-methylindole; RN given refers to parent cpd; structure methylindole : Any member of the class of indoles carrying one or more methyl substituents. | ||
| lovastatin | lovastatin : A fatty acid ester that is mevastatin carrying an additional methyl group on the carbobicyclic skeleton. It is used in as an anticholesteremic drug and has been found in fungal species such as Aspergillus terreus and Pleurotus ostreatus (oyster mushroom). Lovastatin: A fungal metabolite isolated from cultures of Aspergillus terreus. The compound is a potent anticholesteremic agent. It inhibits 3-hydroxy-3-methylglutaryl coenzyme A reductase (HYDROXYMETHYLGLUTARYL COA REDUCTASES), which is the rate-limiting enzyme in cholesterol biosynthesis. It also stimulates the production of low-density lipoprotein receptors in the liver. | delta-lactone; fatty acid ester; hexahydronaphthalenes; polyketide; statin (naturally occurring) | anticholesteremic drug; antineoplastic agent; Aspergillus metabolite; prodrug |
| chlorfenethazine | chlorfenethazine: RN given refers to parent cpd; synonym elroquil refers to HCl; structure | phenothiazines | |
| 2-bromohippuric acid | |||
| cucurbitacin r | 23,24-dihydrocucurbitacin D : A 23,24-dihydrocucurbitacin in which a lanostane skeleton is multi-substituted with hydroxy, methyl and oxo substituents, with unsaturation at position 5. cucurbitacin R: from Cayaponia tayuya roots; structure in first source | 23,24-dihydrocucurbitacin; secondary alpha-hydroxy ketone; tertiary alpha-hydroxy ketone | |
| benzotript | benzotript: anti-gastrinic; active group is amide; structure | ||
| cucurbitacin d | cucurbitacin D : A cucurbitacin in which a lanostane skeleton is multi-substituted with hydroxy, methyl and oxo substituents, with unsaturation at positions 5 and 23. cucurbitacin D: toxic constituent in edible gourd; see also records for cucurbitacins & specific cucurbitacins | cucurbitacin; secondary alpha-hydroxy ketone; tertiary alpha-hydroxy ketone | |
| nsc 106399 | cucurbitacin E : A cucurbitacin in which a lanostane skeleton is multi-substituted with hydroxy, methyl and oxo substituents, with unsaturation at positions 1, 5 and 23. cucurbitacin E: RN refers to (9beta,10alpha,16alpha,23E)-isomer; structure given in first source | cucurbitacin; tertiary alpha-hydroxy ketone | |
| cucurbitacin i | cucurbitacin I : A cucurbitacin that is 9,10,14-trimethyl-4,9-cyclo-9,10-secocholesta-2,5,23-triene substituted by hydroxy groups at positions 2, 16, 20 and 25 and oxo groups at positions 1, 11 and 22. cucurbitacin I: toxic constituent in edible gourd; see also records for cucurbitacins & specific cucurbitacins | cucurbitacin; tertiary alpha-hydroxy ketone | antineoplastic agent; plant metabolite |
| birt 377 | |||
| a 286982 | A 286982: inhibits the interaction between leukocyte function-associated antigen-1 and intracellular adhesion molecule-1; structure in first source | ||
| bio 1211 | BIO 1211: integrin alpha4beta1 inhibitor; structure in first source | ||
| sar 1118 | lifitegrast : An N-acyl-L-alpha-amino acid obtained by formal condensation of the carboxy group of N-[2-(1-benzofuran-6-carbonyl)]-5,7-dichloro-1,2,3,4-tetrahydroisoquinoline-6-carboxylic acid with the amino group of 3-(methanesulfonyl)-L-phenylalanine. Used for treatment of keratoconjunctivitis sicca (dry eye syndrome). lifitegrast: An LFA-1 (LYMPHOCYTE FUNCTION-ASSOCIATED ANTIGEN-1) antagonist that is used in the treatment of DRY EYE SYNDROMES. | 1-benzofurans; isoquinolines; L-phenylalanine derivative; N-acyl-L-alpha-amino acid; sulfone | anti-inflammatory drug; lymphocyte function-associated antigen-1 antagonist |