This gene encodes a protein that is a member of the integrin superfamily. Integrins are transmembrane receptors involved cell adhesion and signaling, and they are subdivided based on the heterodimer formation of alpha and beta chains. This protein has been shown to heterodimerize with beta 4 to bind laminin and to form the main component of hemidesmosomes, which mediate attachment of epithelia to basement membranes. In mouse, deficiency of this gene is associated with absence of hemidesmosomes, severe skin blistering, and early post-natal death. In humans mutations of this gene are associated with epidermolysis bullosa. Alternative splicing results in multiple transcript variants that encode different protein isoforms. [provided by RefSeq, May 2013]