This gene encodes an alphaintegrin. Integrins are heterodimeric integral membrane glycoproteins composed of an alpha chain and a beta chain that mediate cell-cell and cell-matrix adhesion. The protein encoded by this gene, when bound to the beta 1 chain, forms an integrin that is a receptor for tenascin-C, VCAM1 and osteopontin. Expression of this gene has been found to be upregulated in small cell lung cancers.[7]
The α9 subunit forms a heterodimeric complex with a β1 subunit to form the α9β1 integrin. This integrin participates in cell adhesion with various ligands in the extracellular matrix (ECM), including extra domain A (EDA)fibronectin,tenascin-C,ADAMs, EMELIN1,osteopontin, andVEGF.[9] α9β1 binding is independent of the RGD peptide sequence.
^Hibi K, Yamakawa K, Ueda R, Horio Y, Murata Y, Tamari M, Uchida K, Takahashi T, Nakamura Y, Takahashi T (Feb 1994). "Aberrant upregulation of a novel integrin alpha subunit gene at 3p21.3 in small cell lung cancer".Oncogene.9 (2):611–9.PMID8290272.
^Sulimova G, Kutsenko A, Rakhmanaliev E, Udina I, Kompaniytsev A, Protopopov A, Moisjak E, Klimov E, Muravenko O, Zelenin A, Braga E, Kashuba V, Zabarovsky E, Kisselev L (2002). "Human chromosome 3: integration of 60NotI clones into a physical and gene map".Cytogenetic and Genome Research.98 (2–3):177–183.doi:10.1159/000069814.PMID12698000.S2CID41010053.
^Høye AM, Couchman JR, Wewer UM, Fukami K, Yoneda A (May 2012). "The newcomer in the integrin family: integrin α9 in biology and cancer".Advances in Biological Regulation.52 (2):326–39.doi:10.1016/j.jbior.2012.03.004.PMID22781746.
Evans JP (2001). "Fertilin beta and other ADAMs as integrin ligands: insights into cell adhesion and fertilization".BioEssays.23 (7):628–39.doi:10.1002/bies.1088.PMID11462216.S2CID23712246.
Yamakawa K, Takahashi T, Horio Y, Murata Y, Takahashi E, Hibi K, Yokoyama S, Ueda R, Takahashi T, Nakamura Y (1993). "Frequent homozygous deletions in lung cancer cell lines detected by a DNA marker located at 3p21.3-p22".Oncogene.8 (2):327–30.PMID8381220.
Yokosaki Y, Tanaka K, Higashikawa F, Yamashita K, Eboshida A (2005). "Distinct structural requirements for binding of the integrins alphavbeta6, alphavbeta3, alphavbeta5, alpha5beta1 and alpha9beta1 to osteopontin".Matrix Biol.24 (6):418–27.doi:10.1016/j.matbio.2005.05.005.PMID16005200.
Gulubova M, Vlaykova T (2006). "Immunohistochemical assessment of fibronectin and tenascin and their integrin receptors alpha5beta1 and alpha9beta1 in gastric and colorectal cancers with lymph node and liver metastases".Acta Histochem.108 (1):25–35.doi:10.1016/j.acthis.2005.12.001.PMID16430945.
