a type 1 transmembrane protein of the integrin beta chain family. Heterodimerizes with multiple different alpha chains to form receptors for collagen, CSPG4, cytotactin, epiligrin, fibrinogen, fibronectin, fractalkine, IL1B, laminin, osteopontin, PLA2G2A, thrombospondin, VCAM1, and vitronectin. Essential for IL1B signaling. Recognizes the sequence R-G-D in a wide array of ligands. Involved in promoting endothelial cell motility and angiogenesis; osteoblast compaction; and up-regulation of the activity of kinases such as PKC via binding to KRT1. Together with KRT1 and RACK1, serves as a platform for SRC activation or inactivation. Plays a mechanistic adhesive role during telophase, required for the successful completion of cytokinesis. May participate in the adhesion, formation of invadopodia, matrix degradation processes, and promoting cell invasion. ITGA6:ITGB1 is present in oocytes and is involved in sperm-egg fusion. Acts as a coreceptor for human echoviruses 1 and 8, Cytomegalovirus, Epstein-Barr virus, human parvovirus B19, human rotavirus, and mammalian reovirus. In case of HIV-1 infection, integrin ITGA5:ITGB1 binding to extracellular viral Tat protein, seeming to enhance angiogenesis in Kaposi's sarcoma lesions. Belongs to the integrin beta chain family. 5 alternatively spliced human isoforms have been reported. Isoform 1 is widely expressed, other isoforms are generally coexpressed with a more restricted distribution. Isoform 2 is expressed in skin, liver, skeletal muscle, cardiac muscle, placenta, umbilical vein endothelial cells, neuroblastoma cells, lymphoma cells, hepatoma cells and astrocytoma cells. Isoform 3 and isoform 4 are expressed in muscle, kidney, liver, placenta, cervical epithelium, umbilical vein endothelial cells, fibroblast cells, embryonal kidney cells, platelets and several blood cell lines. Isoform 4, rather than isoform 3, is selectively expressed in peripheral T-cells. Isoform 3 is expressed in non-proliferating and differentiated prostate gland epithelial cells and in platelets, on the surface of erythroleukemia cells and in various hematopoietic cell lines. Isoform 5 is expressed specifically in striated muscle (skeletal and cardiac muscle). Note: This description may include information from UniProtKB.