'''Integrin alpha M''' (ITGAM) is one protein subunit that forms the [[heterodimer]]ic [[integrin]] alpha-M beta-2 (α<sub>M</sub>β<sub>2</sub>) molecule, also known as ''[[macrophage-1 antigen]]'' (Mac-1) or ''[[complement receptor]] 3'' (CR3).<ref name = solov>{{cite journal | vauthors = Solovjov DA, Pluskota E, Plow EF | title = Distinct roles for the alpha and beta subunits in the functions of integrin alphaMbeta2 | journal = The Journal of Biological Chemistry | volume = 280 | issue = 2 | pages = 1336–45 | date = January 2005 | pmid = 15485828 | doi = 10.1074/jbc.M406968200 }}</ref> ITGAM is also known as CR3A, and [[cluster of differentiation]] molecule 11B (CD11B). The second chain of α<sub>M</sub>β<sub>2</sub> is the common integrin β<sub>2</sub> subunit known as [[CD18]], and integrin α<sub>M</sub>β<sub>2</sub> thus belongs to the β<sub>2</sub> subfamily (or leukocyte) integrins.<ref>{{cite journal | vauthors = Larson RS, Springer TA | title = Structure and function of leukocyte integrins | journal = Immunological Reviews | volume = 114 | issue = | pages = 181–217 | date = April 1990 | pmid = 2196220 | doi = 10.1111/j.1600-065X.1990.tb00565.x }}</ref>
'''Integrin alpha M''' (ITGAM) is one protein subunit that forms [[heterodimer]]ic [[integrin]] alpha-M beta-2 (α<sub>M</sub>β<sub>2</sub>) molecule, also known as ''[[macrophage-1 antigen]]'' (Mac-1) or ''[[complement receptor]] 3'' (CR3).<ref name = solov>{{cite journal | vauthors = Solovjov DA, Pluskota E, Plow EF | title = Distinct roles for the alpha and beta subunits in the functions of integrin alphaMbeta2 | journal = The Journal of Biological Chemistry | volume = 280 | issue = 2 | pages = 1336–45 | date = January 2005 | pmid = 15485828 | doi = 10.1074/jbc.M406968200 }}</ref> ITGAM is also known as CR3A, and [[cluster of differentiation]] molecule 11B (CD11B). The second chain of α<sub>M</sub>β<sub>2</sub> is the common integrin β<sub>2</sub> subunit known as [[CD18]], and integrin α<sub>M</sub>β<sub>2</sub> thus belongs to the β<sub>2</sub> subfamily (or leukocyte) integrins.<ref>{{cite journal | vauthors = Larson RS, Springer TA | title = Structure and function of leukocyte integrins | journal = Immunological Reviews | volume = 114 | issue = | pages = 181–217 | date = April 1990 | pmid = 2196220 | doi = 10.1111/j.1600-065X.1990.tb00565.x }}</ref>
α<sub>M</sub>β<sub>2</sub> is expressed on the surface of many [[leukocyte]]s involved in the [[innate immune system]], including [[monocyte]]s, [[granulocyte]]s, [[macrophage]]s, and [[natural killer cell]]s.<ref name = solov/> It mediates inflammation by regulating leukocyte [[cell adhesion|adhesion]] and migration and has been implicated in several immune processes such as [[phagocytosis]], cell-mediated cytotoxicity, [[chemotaxis]] and cellular activation.<ref name = solov/> It is involved in the [[complement system]] due to its capacity to bind inactivated [[complement component 3b]] (iC3b).<ref>{{cite journal | vauthors = Arnaout MA, Todd RF, Dana N, Melamed J, Schlossman SF, Colten HR | title = Inhibition of phagocytosis of complement C3- or immunoglobulin G-coated particles and of C3bi binding by monoclonal antibodies to a monocyte-granulocyte membrane glycoprotein (Mol) | journal = The Journal of Clinical Investigation | volume = 72 | issue = 1 | pages = 171–9 | date = July 1983 | pmid = 6874946 | pmc = 1129172 | doi = 10.1172/JCI110955 }}</ref> The ITGAM (alpha) subunit of integrin α<sub>M</sub>β<sub>2</sub> is directly involved in causing the adhesion and spreading of cells but cannot mediate cellular migration without the presence of the β2 (CD18) subunit.<ref name = solov/>
α<sub>M</sub>β<sub>2</sub> is expressed on the surface of many [[leukocyte]]s involved in the [[innate immune system]], including [[monocyte]]s, [[granulocyte]]s, [[macrophage]]s, and [[natural killer cell]]s.<ref name = solov/> It mediates inflammation by regulating leukocyte [[cell adhesion|adhesion]] and migration and has been implicated in several immune processes such as [[phagocytosis]], cell-mediated cytotoxicity, [[chemotaxis]] and cellular activation.<ref name = solov/> It is involved in the [[complement system]] due to its capacity to bind inactivated [[complement component 3b]] (iC3b).<ref>{{cite journal | vauthors = Arnaout MA, Todd RF, Dana N, Melamed J, Schlossman SF, Colten HR | title = Inhibition of phagocytosis of complement C3- or immunoglobulin G-coated particles and of C3bi binding by monoclonal antibodies to a monocyte-granulocyte membrane glycoprotein (Mol) | journal = The Journal of Clinical Investigation | volume = 72 | issue = 1 | pages = 171–9 | date = July 1983 | pmid = 6874946 | pmc = 1129172 | doi = 10.1172/JCI110955 }}</ref> The ITGAM (alpha) subunit of integrin α<sub>M</sub>β<sub>2</sub> is directly involved in causing the adhesion and spreading of cells but cannot mediate cellular migration without the presence of the β2 (CD18) subunit.<ref name = solov/>
Integrin alpha M (ITGAM) is one protein subunit that forms heterodimericintegrin alpha-M beta-2 (αMβ2) molecule, also known as macrophage-1 antigen (Mac-1) or complement receptor 3 (CR3).[1] ITGAM is also known as CR3A, and cluster of differentiation molecule 11B (CD11B). The second chain of αMβ2 is the common integrin β2 subunit known as CD18, and integrin αMβ2 thus belongs to the β2 subfamily (or leukocyte) integrins.[2]
αMβ2 is expressed on the surface of many leukocytes involved in the innate immune system, including monocytes, granulocytes, macrophages, and natural killer cells.[1] It mediates inflammation by regulating leukocyte adhesion and migration and has been implicated in several immune processes such as phagocytosis, cell-mediated cytotoxicity, chemotaxis and cellular activation.[1] It is involved in the complement system due to its capacity to bind inactivated complement component 3b (iC3b).[3] The ITGAM (alpha) subunit of integrin αMβ2 is directly involved in causing the adhesion and spreading of cells but cannot mediate cellular migration without the presence of the β2 (CD18) subunit.[1]
In genomewide association studies, single nucleotide polymorphisms in ITGAM had the strongest association with systemic lupus erythematosus, with an odds ratio of 1.65 for the T allele of rs9888739 and lupus.[4][5]
↑ 1.01.11.21.3Solovjov DA, Pluskota E, Plow EF (January 2005). "Distinct roles for the alpha and beta subunits in the functions of integrin alphaMbeta2". The Journal of Biological Chemistry. 280 (2): 1336–45. doi:10.1074/jbc.M406968200. PMID15485828.
↑Crow MK (February 2008). "Collaboration, genetic associations, and lupus erythematosus". The New England Journal of Medicine. 358 (9): 956–61. doi:10.1056/NEJMe0800096. PMID18204099.
↑Hom G, Graham RR, Modrek B, Taylor KE, Ortmann W, Garnier S, Lee AT, Chung SA, Ferreira RC, Pant PV, Ballinger DG, Kosoy R, Demirci FY, Kamboh MI, Kao AH, Tian C, Gunnarsson I, Bengtsson AA, Rantapää-Dahlqvist S, Petri M, Manzi S, Seldin MF, Rönnblom L, Syvänen AC, Criswell LA, Gregersen PK, Behrens TW (February 2008). "Association of systemic lupus erythematosus with C8orf13-BLK and ITGAM-ITGAX". The New England Journal of Medicine. 358 (9): 900–9. doi:10.1056/NEJMoa0707865. PMID18204098.
Todd RF, Petty HR (May 1997). "Beta 2 (CD11/CD18) integrins can serve as signaling partners for other leukocyte receptors". The Journal of Laboratory and Clinical Medicine. 129 (5): 492–8. doi:10.1016/S0022-2143(97)90003-2. PMID9142045.
Schymeinsky J, Mócsai A, Walzog B (August 2007). "Neutrophil activation via beta2 integrins (CD11/CD18): molecular mechanisms and clinical implications". Thrombosis and Haemostasis. 98 (2): 262–73. doi:10.1160/th07-02-0156. PMID17721605.
