domain:The tail domain binds to the cytoplasmic domain of both integrin beta-1a and beta-1d isoforms. The presence of Ca(2+) ions does not prevent binding of a fragment consisting of the second cysteine rich repeat and the tail domain but prevents the binding of the full-length protein.,function:May play a role during maturation and/or organization of muscles cells.,similarity:Contains 1 CS domain.,similarity:Contains 2 CHORD domains.,subunit:Interacts with beta-1 integrin subunit. This interaction is regulated by divalent cations, and it occurs only in absence of calcium.,tissue specificity:Expressed in skeletal and cardiac muscles but not in other tissues.,